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WW2 British Prototypes

A.11.E.1 Infantry Tank Matilda Prototype

British Empire (1934)
Infantry Tank – 1 Prototype Built

Of all the tanks in WW2 which may be derided or even mocked for being ‘ugly’ or useless, one which invariably makes the list is the British A.11 Matilda. This is partially the result of the overall poor showing of the British Expeditionary Force (B.E.F.) in France in 1940 and partially because of the strictures placed upon the design of the vehicle in the first place. It is also because the vehicle is generally not well understood and its combat record unappreciated.

The only people who really appreciated that latter element were the Germans in 1940, for whom the A.11 and its big brother, the A.12, came as a well-armored and unpleasant shock.

Whilst the A.11 was only in service with the British Army for a few years, it left a mark in the form of one of the most successful tanks of the whole war – the A.12 Matilda.

Misunderstood and underappreciated, the A.11 started as a scribble and resulted in a small, heavily armored tank which proved to be a shock to the Germans at the Battle of Arras in France in 1940. There, in conjunction with infantry and its replacement – the A.12 Matilda, the British succeeded in blunting the nose of the German advance. The A.11 Matilda seen in that battle, however, started with a special and slightly different prototype – the A.11.E.1 (A.11, Experimental model 1), with a history all of its own.

Origins

The A.11 ‘Matilda’ has its origins in the late interwar period, as the British Army was undergoing some head-scratching over not only the shape and dynamics of a future war but also how it would organize itself and what it needed to fight it. The British were generally cautious with new developments in tanks, due in no small part to the trauma of WW1, with the huge losses of men and equipment, and also to the significant limitations on expenditures as the British Empire sought to reconcile the cost of defending Europe from Germany.

Any new development, therefore, had to meet both a developmental limit, the new needs of the Army, and the strict budgetary constraints in force. Luckily for the British, these highly conservative restrictions matched with the equally austere Sir Hugh Ellis, Master General of Ordnance (M.G.O.) and Major-General A. E. Davidson as Director or Mechanisation (D.o.M.). Both men were skilled and competent in their field, with Davidson also a respected engineer, but both still saw future war along the lines of the last one.

In debating the primary role of a new tank for 1934, it was thought that it had to support infantry (an ‘I’ or ‘Infantry’ tank) in the attack against enemy infantry and positions. Enemy tanks could be dealt with by artillery, so a new tank really just needed heavy protection from enemy infantry and anti-tank guns as well as the means to deliver machine-gun fire. As it had to support infantry at their pace, the speed was almost irrelevant. As these two men debated their plans for what a new tank needed to be and how it should work tactically, they consulted with Major-General Percy Hobart, who was Inspector of the Royal Tank Corps (R.T.C.) at the time and proposed two solutions:

  1. A small tank with a crew of two men armed with machine guns built in large numbers to swarm the enemy.
  2. A heavy tank with a cannon.

The solution selected was the first one and, in October 1935, the legend of vehicle design, Sir John Carden, was approached to develop this idea. A skilled engineer and talented vehicle designer, he was also the head of tank design at Messrs. Vickers Armstrong Ltd., meaning whatever he designed, he could get into production quickly.

Sir John Carden, the brains behind the A.11 (Centre) seen on 3rd October 1935 at Heston Airport.
Source: Flight Magazine.

His rather crude initial sketch, finished on 3rd October 1935, was for this two-man small tank with a single turret and a single machine gun. A week later, this sketch was taken by Sir John Carden to Colonel M. A. Strudd, the Assistant Director of Mechanisation (A.D.o.M.). Being a technically simple vehicle and with no concerns over getting it into production in the time scale the Army was planning, just 6 months, it was approved as a project under A-vehicle number A.11. One thing not mentioned in most histories of the A.11 is revealed in that original sketch – the crossing of trenches by the vehicle was an important point, which perhaps hints at the sort of warfare terms about which the Army was still thinking. This new tank would manage to cross an impressive 8’ (2.4 m), more than adequate to cross any standard infantry trench.

Sir John Carden’s original sketch of the A.11 shows a low and long vehicle with a small cylindrical turret and, clearly noted in the corner, a protection level of 60 mm. Note the trench crossing width is clearly shown as 8’ (2.4 m).
Source: Fletcher

It is commonly repeated online and even in some books that the ‘Matilda’ name was selected after the prototype was seen ‘waddling’ like a duck. The connection between Matilda and Duck is unclear in itself in this false history especially, as that particular Disney character with that name only appeared after the war. The name could, of course, not have been penned after seeing it move, as it is first written down on 10th October 1935, when the tank was not much more than a doodle. In fact, ‘Matilda’ was just a company name for the project – a code word to disguise what the vehicle was, although officially it remained just ‘A.11’.

The price of the project, at a time of small defence budgets, however, was somewhat extraordinary, some £15,000 for all of the development and draughting costs. In 2020 values, this is over £1m and each tank was projected to run at £5,000 (£364,000 in 2020 values). For a tank armed only with a small machine gun, this was still very expensive. This is a vehicle often referred to as cheap being built to a budget. For sure, it had a budget to be built to, but it was by no means a miserly one. For reference, a small light, machine gun (or even cannon-armed) tank from the same firm, like the Vickers Light Patrol tank, was on sale in 1933 for just £700 (around £51,000 in 2020 values). It is hard, therefore, to square quite why this Infantry tank might justify costing more than 7 times what that tank would.

Vickers Light Patrol Tank seen in 1932. The same prospective armament at 14% of the cost of an A.11.
Source: Beamish Collection
Vickers 6-ton Mark A tank. The general lines and shape of this tank show a clear line of thought carried across to the A.11.
Source: The Tank Museum, Bovington

Armor

Armor for this new type of tank was going to need to be heavy – very heavy for the era which given that even 20 – 30 mm or so was considered good protection for many tanks is saying quite a bit. A standard thickness of 60 mm was proposed for the tank, with the plate made from Vibrac 45 armor steel produced by the (Vickers) English Steel Corporation. The roof and floor plates were eventually to be just 10 mm thick and made from Homogenous Hard tank armor and proof against .303 rifle fire. Originally, however, for the prototype, the hull was not going to be made from armor plating, but mild steel ‘soft plate’ instead. On A.11.E.1, the rear and hull roof were made using thinner plates than that used on the eventual production models, just 7 mm thick for the floor and roof and 8 mm thick at the rear – albeit heavily sloped.

This is common enough in a prototype tank, as it makes manufacturing easier and cheaper and permits modifications to be done quickly prior to production. Of note too is that this prototype was only made in plate 60 mm thick, as this thickness was considered sufficient protection against the primary prospective enemy anti-tank weapon of the time – the excellent German 37 mm gun (3.7 cm Pak 36).

Factory fresh German 37 mm anti-tank guns. Source: Rheinmetall

Despite having the appearance of a tank riveted to a frame, like many other tanks constructed in this period, the structure was physically strong and stiff enough that it was, in fact, simply riveted together without a frame.

Prototype – A.11.E.1

Despite being a technically simple vehicle, this first vehicle, A.11.E.1, now with an official War Department index number of T.1724, was not finished until September 1936, when it was handed over to the Mechanisation Experimental Establishment (M.E.E.).

A.11.E.1 seen shortly after delivery in September 1936. Of note are the lack of exterior fittings on the hull, such as lights and stowage boxes, with the exception of a cranked tubular tool mounted on the front half of the left side, parallel with the track. This photo shows to a good level of details of the original rubber-tyred return rollers and the toothed idler wheel at the front.
Source: Beamish Collection

Firstly, on 9th December 1936, splash tests were conducted at Farnborough and the turret, in particular, was found to be a problem. Here, under concentrated machine-gun fire using standard ball ammunition, it was found that the mantlet could actually break up under the stress of multiple impact and allow splash to enter the vehicle, to the detriment of the crew. As a result of this, Messrs Vickers-Armstrong replaced the mantlet with a cast steel mantlet which would chip away under the repeated stresses of concentrated fire, but would neither jam nor break up.

Some three months later, on 16th March 1937, armor plating 60 mm thick of the type intended for the primary armor was tested at Shoeburyness. Here, it was found that, whilst 60 mm rolled plate and 60 mm castings were sufficient to stop armor-piercing shots from the British two-pounder, there was not sufficient additional protection to allow for a sufficient margin of safety. As a result, the armor was recommended to be upgraded to a new requirement 65 mm thick with a tensile strength of 75 tons (76.2 tonnes) for production vehicles.

Further splash trials were carried out in November 1938 and, once more, there were problems. Specifically, splash could enter through the large driver’s hatch as well as through the engine louvers. On top of this problem, the bullet-proof glass selected by Vickers had the unpleasant characteristic of splintering when shot and had to be replaced. Quite why this testing process had to be dragged out over a nearly two-year period when the whole tank was needed ‘within 6 months’ is somewhat unfathomable. Nonetheless, the lessons from the trials meant that modifications to both thickness and splash protection were made between A.11.E.1 and production A.11 models.

Most noticeable are the changes around the driver’s area. On the prototype vehicle, the sidewalls of the hull are straight and cut flush with the surface. This created a sharp edge and provided no angling to reduce splash from small arms, which could go towards the driver’s hatch. These top edges of the side were therefore chamfered at roughly a 45-degree angle. Likewise, the tendency for splash to penetrate the leading lip of the large hatch was rectified with a protective strip riveted to the top edge of the driver’s panel. An additional change was the addition of a pair of horizontal raised strips across the full width of the glacis. These ribs would stop rounds that struck the glacis from ricochetting up into the direction of the driver’s visor or hatch edge. One splash guard which was later to be modified from the A.11.E.1 design, however, was the one that ran across the width of the hull roof in front of the turret. By the time the vehicle entered production, this was not as high and just covered the bottom edge of the turret.

Comparing the hull front around the driver’s area from A.11.E.1 (left) to a production A.11 (right) highlights the findings from the splash trials. The chamfering of the vertical side armor is obvious, as is the splash guard on the driver’s plate. Noteworthy too are the horizontal splash guards across the glacis plate to further reduce the problem.
Source: IWM

Layout

The vehicle itself was very simple in arrangement. With just two crew, the driver sat centrally in the front, operating the steering and propulsion via levers and pedals. Behind him, and manning the gun as well as commanding the tank, was the second crew member, the commander. Both these men occupied the small yet adequate fighting compartment and were separated from the engine by an internal bulkhead. The driver sat forward in the hull and was provided with a single, full hull width rectangular hatch above him. This large hatch was supported by two hydraulic cylinders due to its weight. No episcope was originally fitted to A.11.E1., but this was added during testing. Without it, the driver was limited to just a narrow view directly ahead when the hatch was closed – with it, he could provide additional situational awareness to the sides.

The rear of the vehicle sloped sharply downwards over the engine bay. Perhaps the most distinctive feature of the A.11 was the lack of mudguards over the top of the track run. This is surprising given how simple such a guard would be, whether in metal or even canvas (like the Medium Mark A ‘Whippet’ from WW1). The lack of a mudguard meant dirt and branches could be caught up in the tracks and dragged along the side of the tank or thrown up onto the engine deck, none of which would improve either the mechanical or combat efficiency of the tank. The only effort to prevent such a situation were rather small and sturdy guards fitted only over the rear-drive sprocket, which was a feature of the production vehicle – another lesson from A.11.E.1.

Left side view of A.11.E.1 providing an excellent study of the suspension bogies, with the two pairs of wheels on spring leaves connected to a central support with a return roller above and integral to them. Note the toothed front idler has already been replaced and the low position of the front stowage box ahead of the leading bogie. Note that the addition of the stowage boxes has moved the tubular tool to the rear half of the hull. The flattened end of the tool is visible next to the rear sprocket.
Source: IWM

Size

Overall dimensions for A.11.E.1 were very much those of a small tank. Just 15’ 11” (4.85 m) long and 7’ 6” (2.29 m) wide from the outer track edges, with the track centres 6’ (1.83 m) apart. Overall, the top of the turret was barely 6’ (1.83 m) from the ground – an ideal size to cover a man advancing behind the tank. By the time the trials had ended, this increased to 6’ 1.5” (1.87 m) to the top of the episcope on the turret roof. Ground clearance was also very reasonable, measuring some 9.5” (240 mm) from the ground. For the sake of reference, this meant that the A.11 was shorter in length and height, and only slightly wider than the already small Renault FT of WW1.

Oddly, the trench crossing idea of managing to bridge an 8’ (2.4 m) wide trench from the original plan had been abandoned. The final design would manage just 6’ 6” (1.98 m), still enough to cross a normal infantry trench or a small ditch, whilst also keeping the overall length (and thereby, weight) of the machine down. Climbing performance was also acceptable, as those exposed tracks projecting from the front of the tank could easily grip onto a surface to help it climb a parapet or low wall, as long as it was no higher than 2’ 6” (0.76 m) high.

One other consideration in obstacle crossing for the design was the main armament, which, because it did not project, added zero risk of it becoming lodged in the bank of a ditch the tank was entering, as would be an issue with a long-barrelled weapon. That is not to say that the weapon in its armored cowl did not cause obstructions, because it did. It fouled on the driver’s hatch to the extent that, with the gun forward, the driver was not able to have his hatch fully open. No official fording capacity was noted in official data for the A.11.

Fittings

Every tank has to provide some external fittings and items for practical purposes, like lamps, so the vehicle could operate at night, or stowage for crew items externally, in order to free up internal space. The A.11.E.1 was absolutely no different but was supplied bare. No lamps, no boxes, almost no tools and this would indicate that the intention was to find a location during the trials.

Soon after trials started, these fittings started to appear, with a pair of odd-looking boxed-in headlamps fitted on stubby arms which projected from the sides of the hull, just level with the front of the turret.

The almost bare A.11.E.1 during trials, showing that the turret roof arrangement had yet to be decided, as it was completely absent, and that no episcope had yet been fitted to the driver’s hatch. The first of many modifications can, however, be determined, with a wing mirror fitted to the front right hand side to assist the driver in seeing behind him and with the pair of boxed-in headlamps on either side.
Source: The Tank Museum, Bovington

With the first essential fittings added – those necessary to drive the vehicle safely, then followed the turret roof, with a boxy style of episcope and a rotatable episcope fitted into a hole cut in the front angle of the driver’s hatch. These two additions provided much-needed situational awareness for the crew. As the first suspension changes took place, so too did the stowage on the tank, going from none to two large boxes placed low (so as to not block the driver’s view slit) on either side of the driver’s compartment. The final change or addition during testing was the result of the lack of mudguards. For whatever reason these were left as just small and somewhat flimsy sheet metal covers which only went over the sprockets and no further. By the time the tank would enter production, some additional modifications took place with those lessons learned from A.11.E.1, like changes to the stowage and headlamps, plus additional features, like smoke grenade launchers on the turret, fire extinguisher mountings, and tow cables, but the essentials of the tank were sound.

The boxed-in headlamps in their protective casing would be changed too – standard car-type headlamps could be used instead. They would be easily damaged by enemy fire or even passage through heavy scrub but they were also cheap, simple, plentiful, and easy to fix.

One non-essential item which was added as almost an afterthought was a mine plough designed by the firm of Fowler. The Fowler coulter plough (coulter is not a company, but a vertical blade in front of the ploughshare itself), as it was called, was a somewhat ungainly device consisting of a pair of long arms formed from steel girders, with one on each side of the tank. Operated up and down from travel position to a deployed position via a drum-driven chain from a power take-off on the back of the transmission, the plough could be lowered so that the wheels on the ends of the arms ran along the ground surface.

A tubular framework projected ahead of the main frame, which ensured the plough followed the terrain ahead and kept scrub from clogging the front of the device. Behind this was a set of coulters on each side, which would cut the ground and ploughshare the dirt and any mines concealed within it to the left and right of the tank’s route. This was first tried on A.11.E.1 in 1937 and was found to be highly successful, to the extent that the necessary fittings for such a plough were then added to the first production A.11 tank, although, by then, the need to get tanks off the production line was more important than a rather complex device which had never been part of its original purpose.

A.11.E.1 showing the original Fowler mine-plough in use. Note the absence of the tubular framework on the front. Source: The Tank Museum
The modified Fowler mine plough, as fitted to the first production A.11. but first trialled on A.11.E1. Source: IWM
A.11.E.1 during trials. It can be seen that the episcopes still have not been added to the driver’s hatch or turret roof, but that the toothed front idler has already been removed. Of note is the unusual shelf stowage concept on the upper right of the hull for what appear to be metal ammunition boxes. This does not appear later and appears to have been a failed modification which had been trialled.
Source: IWM

Suspension and Tracks

The original sketch from Sir John Carden showed suspension substantially different from the ones which the vehicle was subsequently built with as a prototype. In the provisional sketch, there are clearly 4 distinct and separate bogies, each with a pair of road wheels and with a spring connected to the hull and the rear of each pair. Above each bogie was a track return roller. The system drawn closely matched that of the Dragon Mark IV Artillery Tractor produced by Vickers-Armstrong. It was almost certainly meant to be based upon that system. Just like that system, the tracks used were a medium pitch design made from cast manganese steel and connected together via a single steel pin. Each link also featured no rubber pads for use on roads, but a pronounced spud to gain better traction on soft ground.

However, when the vehicle was produced, it would not use this Dragon or Dragon-like Horstman suspension, but a different Vickers product derived from the suspension of their 6-ton tank.

As a matter of some confusion in the tale of the suspension for these vehicles, there are multiple marks of vehicles and there are several distinct suspension variations worked through on Vickers products at the time.

In essence, however, this proposed suspension consisted of a pair of bogies with a flat arrangement of 4 pairs of road wheels, each mounted in pairs. Each of those pairs was connected to one end of the spring leaves, providing a degree of movement, as the entire bogie could also rotate around a central pivot point. The design was complex. Using small wheels, whilst allowing them to be placed closer together, also resulted in a small external unit that was easily clogged with mud. This style of suspension had already been rejected by the M.E.E. as a problem, so it can only be surmised that it was added as a cost-saving measure, as it was already in production.

A.11.E.1 seen after modification from its first trials.
Source: IWM
Rear three-quarter view of A.11.E1. bearing the vehicle registration mark (VRM) CMM 880. The heavily sloped rear deck is readily apparent. The arrangement of the back was modified to provide additional protection from small arms fire on the production vehicles.
Source: IWM
Production A.11 Matilda showing the change in the shape of the armor plating over the rear deck. The relocation of the exhaust from the centre of the rear to the right side is also shown. Photo Credit: Craig Moore

If there is criticism of the A.11, it has to focus mostly on this decision of choosing a system based on an idea from 1929 which the Army already disliked and had proven to be disappointing during testing. This was not a decision likely to find supporters, yet the solution was available and in production and it did work to the extent required. Pragmatism meant the suspension, as fitted, would be kept and that tweaks would have to be made just to make it work.

As it underwent testing at M.E.E., various problems were quickly identified and one of the first was that the toothed front idler was unnecessary. Further, the track was found to be collecting stones and these could become jammed in the rear sprocket. The solution to the former problem was simple – just replace the toothed idler sprocket with a non-toothed one. The latter was resolved in April 1937 and consisted of raising the rear sprocket by 5 inches (127 mm). This would not be the final change to the suspension of the A.11 during its service, but the A.11.E.1 had set the shape and suspension type which remained with the A.11 throughout its military career.

The hull production had changed too. The original sides of the A.11, as seen on A.11.E1, were a simple two-piece fabrication with an offset vertical line of rivets about halfway down the length. On the production vehicles, this seam was retained, but the rearmost panel was now two panels which also had to be riveted together. This added a little weight to the vehicle, but also simplified production by reducing the amount of cutting of the thick armor plating which was required. Rivet-counters will also note that the front of the tank shows a different layout of rivets as well. On A.11.E1, the nose of the tank was a separate panel and bolted onto the tank with a column of four bolts on each side. The glacis plate was likewise bolted onto the tank and the nose plate was changed for production. In production, the flat edges of the glacis plate were chamfered and riveted to the structure of the tank. The nose plate was now integral with the extensions either side of the front idlers and all riveted in one piece to the front of the tank.

Radio

No radio was fitted to A.11.E.1, presumably as a cost and complexity saving measure. Right from the outset, in 1935, no wireless set had been planned for A.11. This would be rectified by the time the tank entered production, as the Wireless Set No.11 was available by 1938 and would eventually be fitted as standard on all production tanks, although this would obviously add weight and take up valuable space inside.

Trials

Other than the already known problems with the suspension system chosen, the A.11 had a remarkably easy birth when it came to testing. The exhaust pipe being moved was just one of those small changes identified during testing to avoid problems in production vehicles. Indeed, that was the entire purpose of testing and the A.11 can be considered to have tested out very well.

Stowage

The two large stowage bins fitted to A.11.E.1 were varied for production models but remained essentially the same – two large boxes, either side of the hull. On the A.12 vehicle, which followed the A.11, these stowage bins were moved forwards and downwards to flank the nose of the tank. Behind the curved front armor of the A.12, those front bins actually provide a misleading shape on the front of the A.12, giving it a full-width flush appearance when it is, in fact, a narrow nose-shape just like the A.11. Moving those boxes forwards in that manner and making them integral with the vehicle also provided the advantage of some additional protection for the A.12.

Engine

Power for the A.11.E.1 was provided by a 3.62 litre Ford V8 petrol engine delivering 70 hp connected to a Fordson four-speed crash (manual clutch) gearbox. Drive for the 11.5” (292.1 mm) wide manganese steel tracks was delivered from this gearbox via final drives at the rear, connected to the sprockets. Steering was provided through a system of clutch and brake steering (i.e. brake the right track to turn right and vice versa), which was taken directly from the Vickers light tank and controlled by the driver in the same manner – a pair of steering levers. One problem identified during testing was that the exhaust pipe from the engine was prone to cause the engine oil to heat up, so it had to be rerouted, but this was a simple affair and certainly not a failure – just a tweak to avoid a problem. It meant a very minor external change of the exhaust from the rear deck at the bottom in the middle to the right-hand side of the back instead.

Cramped is one word – an efficient use of space however, might be another explanation for the very tight fit of the 3.62 litre Ford V8 70 hp engine in the bay. The incredible thickness of the armor can be seen on the left on the top of the exposed side plate. Note that the cable seen at the top is a hatch release for the engine deck connected to the catch at the top left of the photo – it could only be released from inside the tank. Source: Fletcher

The engine was small and the result was a relatively slow vehicle. However, this did not matter. Indeed the A.11.E.1 proved to be faster than expected and perfectly satisfactory for speed. From the notes of Col. Strudd at that 10th October 1935 meeting with Sir John Carden when the tank concept was presented, it is clear that the Army was perfectly satisfied with a top speed of just 5 mph (8.0 km/h) although 8 mph (12.9 km/h) would be better. The A.11.E1., could, in fact, achieve a top speed of 10.9 mph (17.5 km/h) on a road and 5.8 mph (9.3 km/h) off-road, but this was not a problem at all for the design, as it only had to keep pace with infantry on foot. The average speed the tank could sustain on a road was 8.17 mph (13.1 km/h) and 5.6 mph (9.0 km/h) off-road.

The internal fuel tanks held 43 Imperial gallons (195.5 liters) of petrol for an official maximum operational range of 80 miles (129 km). With 43 litres of petrol and a known fuel consumption rate during the trials of 2 gallons (9.1 litres) per hour on-road and 1.8 gallons (8.2 litres) per hour off-road, that also meant up to 21.5 hours of road use and 23.8 hours off-road.

Turret

Made in a single piece, the turret was a substantial casting with armor 60 mm thick all round. Provision was made for a single armament – either a Vickers .303 caliber machine gun or the somewhat beefier .50 Vickers instead.

Almost cylindrical in shape, the basic elements of the A.11 turret were the same as drawn originally by Sir John Carden. The cylinder was angled at the back, providing a little more space, and the front carried forwards the trunnions for the main gun, all within this one-piece casting.

Atop the turret was a simple circular hatch which opened in 2 pieces – two quarter circles at the rear half, forming a semicircle, opened out and the whole front half of the turret roof formed the other semi-circle. On the left side of this front half-circular hatch was the single episcope for the commander.

Turret roof of T.3347 showing the unusual split hatch. Source: Chris Stillito, Armour in Focus

The original turret casting for A.11.E.1 was a little more complex than on the production model. The outer edge on the front half of the turret at the top is the reference point for spotting the difference. On the prototype, there is a pronounced half-rim running around the front of the turret and projecting from the sides. This is not easily visible on the production turret, which replaced this hard rim with a more rounded and less pronounced outswell, although the purpose was the same – to reduce the chances of ricochets up the sides of the turret hitting an exposed commander. The turret was also asymmetrical, with that rear swell offset to the right at the back and the front casting for the armament offset to the right as well at the front. This meant that the trunnion mount can be seen on the right-hand side of the turret but not on the left and the reason for this offset is obvious – it allows the commander to share space with the gun. With the primary (and only) weapon on the A.11 being the single machine gun, it was belt-fed from the left, so setting the gun off slightly to the right allowed the commander to operate the gun and reload it much more easily.

The rear of the turret would noticeably change from A.11.E.1 too, from a rounded back on the prototype to the production turret which angled-off the swell at the back of the turret and created a short ‘step’ underneath – a very modest change to create a little extra space inside.

The rear of the A.11.E.1 turret (above) differs noticeably in shape from the rear of the production turret (below)

Two more small features of note on the turret which would change from A.11.E.1 would be the addition of a small triangular bracket for mounting a radio antenna base on the rear right-hand side for the No. 11 Wireless Set inside, and the addition of a pair of mounts for the smoke grenade launchers, one on each side of the turret and operated by cable from inside. Both the addition of a radio and smoke grenades would be substantial improvements from the very basic tank which was A.11.E.1.

Armament

A.11.E.1 was intended to support infantry by providing not just a mobile protective shield in front of them, but also to suppress enemy positions with machine-gun fire. The machine gun, not the cannon, was the primary choice for killing enemy troops and destroying machine-gun positions, which were a major threat to the infantry. For A.11.E.1, the original weapon chosen was simply the standard water-cooled .303 calibre Vickers machine gun albeit, with a short note which followed saying “we can try our idea of M/C gun but this is not so urgent”.

‘M/C’ in this context may be taken to mean ‘Machine Cannon’ i.e. a heavy machine gun with added anti-armor capability over the standard .303 machine gun or another compact gun capable of firing a small high explosive charges as well. The details were clearly not finished, as the priority was to get the tank into development as soon as possible. The small turret would make the fitting of a larger gun harder but not impossible. For the development of the A.11, just two guns were selected, either a .303 calibre Vickers machine gun or its heavier brother, the 0.5 calibre Vickers machine gun. Whatever ‘machine cannon’ Sir John Carden and Colonel Strudd were discussing in October 1935 is not known.

Vickers .303 calibre Mark IVA machine gun.
Source: The Vickers Machine Gun
Vickers 0.50 calibre Mark V heavy machine gun
Source: The Vickers Machine Gun
Armament Options for A.11
Gun Vickers Mark IVA Vickers Mark V
Caliber .303 0.50*
Muzzle Velocity 744 m/s 760 m/s
Weight (vehicle mounted) 65 ½ lbs. (29.7 kg) 71 ¾ lbs. (32.5 kg)
Rate of fire 500 650-700
Belt size 250 rounds 100 rounds
Note * 12.7 x 81 mm (.5 Vickers also known as the ‘.5V/580’) rather than the 12.7 x 120mm (0.5 Vickers High Velocity also known as the ‘.5 V/690’). The number after the ‘V’ in both cases referred to the weight of the bullet in grains rather than a velocity

Both types of machine gun were available with a variety of ammunition, from a lead core ‘normal’ bullet suitable for general use to an armor-piercing round. When it comes to the common complaint about the A.11, that it was under-armed, the existence of armor-piercing ammunition for both guns has to be taken into consideration.

For the .303 caliber gun, armor-piercing rounds had been available since WW1, as had incendiary rounds. The Mark.VII.W.z Armour Piercing round of 1917 (known later as the W Mk.Iz from 1927) was a 174 grain (11.28 gram) cupro-nickel jacketed bullet with a 93 grain (6.02 gram) steel tip. Traveling at 762 m/s, the bullet was designed to meet a requirement that 70% of rounds could penetrate a 10 mm thick armor plate at 100 yards (91.4 m). An effective anti-armor range of 100 m does not sound like much, but was perfectly adequate to deal with close-by enemy positions and also for suppressing protected targets further away.

For the 0.5 calibre gun, the armor-piercing round was known as the ‘Armour Piercing W. Mark 1z’ and also featured a hardened steel core. The penetrative requirements for this round were that 7 times out of 10, it would be able to penetrate 18 mm of armor plate at 0 degrees and 15 mm at 20 degrees vertical, all at 100 yards (91.4 m). A tracer version of this round, known as the SAP Tracer FG, came in various marks and there was even an incendiary version of it, known as the ‘Incendiary B Mark I.z’.

Whilst the .303 was an ideal weapon for suppressing enemy positions, mowing down enemy troops and dealing with soft-skinned vehicles, it was not suitable for picking off enemy forces behind a shield, like a gun crew. It was also not suitable for dealing with light enemy armor. The option of mounting the .50 calibre version removed that problem at short ranges. Both guns were perfectly adequate for general work, with acceptable accuracy on target out to at least 1,500 m. Both versions were virtually indistinguishable from each other when fitted into the turret and concealed within the large cast armor housing over the water-cooling jacket, although only troop leader’s tanks were fitted with the 0.50 calibre.

Some 3,000 rounds (12 belts) of .303 caliber ammunition were eventually to be carried as standard, which would be sufficient for just 6 minutes of continuous automatic fire. In the trial photos, there is one which appears to show half a dozen ammunition cans on a shelf on the right hand side. Assuming this was an attempt to carry more ammunition, then that would be several more belts for perhaps as much as 5,000 rounds carried. Boxes for the .50 Vickers ammunition held just a single 100 round belt, such was the greater size of the round. Assuming the ammunition stowage for both guns was to be proportional, this would mean 1,200 .50 Vickers rounds, enough for just 2 minutes of continuous fire.

Production

A contract for the production of 60 tanks was signed at the end of April 1938 and, ten days later, another order for the same amount came, meaning a total of 120 tanks. This would be enough to provide tanks for 2 whole battalions.

Conclusion

The A.11.E.1 was a successful prototype. It arrived late and perhaps this was partially the result of the untimely death of its creator, Sir John Carden, in December 1935 in an air crash. Certainly, there was nothing particularly novel about the tank or some new technology that had to be invented for it to exist.

The A.11.E.1 occupies an unusual space within British tank design too, as it languished in that period in the 1930’s where a new weapon was needed, but not one was entirely sure on what they were really going to need. Nonetheless, the design was still capable of being modified from its original form into something a little more than that and of being a capable platform for a device like the Fowler mine plough. The reality for it was that, by the time it was in production and being delivered, there was already a replacement in the pipeline in the form of the A.12 Matilda. That particular vehicle had a much more difficult birth and yet it could not have existed in its final form without the A.11 beforehand. The heavily armored infantry tank which started with A.11 and its prototype A.11.E.1, became the foundation of the heavily armored A.12 and its most dominant feature. The A.11.E.1 should, therefore, not be seen as some retrograde step for the Army to some attempt to rerun the First World War, but an attempt to learn from that war and produce a tank sufficiently protected for the next one.

The first production A.11 off the production line. In this head on view, the offset of the machine gun to one side is evident, as is the very narrow profile the tank presents front-on to an enemy. Source: Fletcher
Matilda A.11.E.1. Illustration by Stoneheartisk.
Top view of the Matilda A.11.E.1. Illustration by Stoneheartisk.
Rear view of the Matilda A.11.E.1. Illustration by Stoneheartisk.
Right side view of the Matilda A.11.E.1. Illustration by Stoneheartisk.
Front view of the Matilda A.11.E.1. Illustration by Stoneheartisk.

 

Specifications A.11.E.1

Dimensions (L-H-W) 15’11” (4.85 m) Long, 7’ 6” (2.29 m) wide, 6’ 1.5” (1.87 m) high
Engine 3.63 litre Ford V8 petrol producing 70 hp
Speed top speed 10.9 mph (17.5 km/h) on road and 5.8 mph (9.3 km/h) off road, cruising speed 8.17 mph (13.1 km/h) and 5.6 mph (9.0 km/h) off road.
Armament .303 or 0.5 Vickers machine gun
Crew 2 (Driver, Commander/Gunner)

Sources

Fletcher, D. (1991). Mechanised Force. HMSO, UK
Fletcher, D. (2017). British Battle Tanks. Osprey Publishing, UK
Foss, C., & McKenzie, P. (1988). The Vickers Tanks. Haynes Publishing, UK
Forty, G., & Forty, A. (1988). Bovington Tanks. DPC, UK
Brown, P. (2014). 1 ATB in France 1939-40. Military Modelling Vol.44 No.4. 2014
Brown, P. (2014). 1 ATB in France 1939-40. Military Modelling Vol.44 No.5. 2014
Solarz, J. (2008). Matilda 1939-1945. Tank Power vol. LXI. Warsaw, Poland
Obituary, Sir John Carden. Flight Magazine, 19th December 1935
Tank Training Vol. II Part III Pamphlet No.2 .303-IN., Vickers Machine Guns Marks VI, IVA, IBV and I. (1936). HMSO, UK
Tank Training Vol. II Part III Pamphlet No.5 .5-IN., Vickers Machine Guns Mark V. (1937). HMSO, UK
War Office File 194/44 Matilda Infantry Tank, September 1936
War Office File 291-1439 British Tank Data
Williams, A. (2012). The .5” Vickers Guns and Ammunition. https://quarryhs.co.uk/Vickers.html

Categories
WW2 British Prototypes

TOG Citadel

United Kingdom (1939)
Heavy Tank – Concept Only

Background

The battlefields of the Western Front during WW1 were characterized by thick belts of barbed wire covered by machine-gun fire often from concrete bunkers, creating an area which was all but impassable to infantry. The ground, shattered by years of war and millions of rounds of artillery fire, was often a quagmire of mud into which men, beasts, and machines would drown. Even if they managed to cross all of that, they would be faced with having to cross enemy trenches, anti-tank ditches, minefields, and other obstacles.

The British tanks of WW1 were specifically designed to overcome much of these problems, adopting a characteristic quasi-rhomboidal shape in which the tracks would run over the top of the hull, producing a high leading point for the track and carefully shaped to maximize the ability to both climb a step and cross ditches.

The early designs were relatively crude affairs, with inadequate armor, quickly falling prey to German anti-tank rifles and slow enough to be hit by enemy artillery. As the war progressed, the British progressively improved the armor and layout to the pinnacle of the whole design evolution, in the form of the Anglo-American Mk. VIII heavy tank. It had improved armor, improved mobility, in a larger tank with more firepower, and still retained the ability to extract itself from the terrible ground conditions. However, that tank did not get the opportunity to show its true power during the war and the mass production of it, which was being put in place, was canceled with the end of the war. Nonetheless, the principles had been established and if only thinking in WW1 terms, then this layout of the tank was clearly going to be ideal.

In 1939, many people could see the clouds of war gathering over Europe as an expansionist Nazi Germany under Adolf Hitler became more and more assertive, dominant, and militaristic. With the 1938 invasion of Czechoslovakia by Germany, any doubts about the future aspirations of Hitler to become the preeminent military power in Europe were over. Despite the appeasement of men such as the British Prime Minister, Neville Chamberlain, Germany was not going to cease in its growth and there was little time to prepare for a new major land war.

Thus, on the eve of war, and apparently with little comprehension that the nature of this forthcoming conflict was going to be different from those conditions experienced 20 years prior, the Army was in a rush to find a heavy tank. They simply resorted to exactly what they knew had worked before, a Mk. VIII shaped vehicle, albeit with more armor and firepower than before and the additional task of smashing reinforced bunkers.

It is not without a substantial degree of irony that the man substantially responsible for the Mk. VIII design, Sir Albert Stern, had, unlike the Army, moved on in thought. Along with his colleagues on the not yet named design committee, he was proposing a much more modern design in the form of the 300G. That tank featured a high leading track to help climb, a longer hull to help cross obstacles, and firepower concentrated in the turret to better deliver its firepower.

The Anglo-American Mk.VIII tank. Source: Beamish Collection

Origins

Lt. Col. Sir Albert Stern, a man who was very much ‘made’ by his experiences in helping to shape armored warfare in WW1, was in a powerful position, with a title, wealth, experience, and contacts in government. He also foresaw what he thought was to come and, in June 1939, was asked to visit the Minister of Supply, Mr. Leslie Burgin, to discuss the issue of heavy tanks.

The outlook was dire. British tank development had, since the end of WW1, stood almost stationary. There were few tanks, and what there was a mixed bag of various types and quality, with the best armored of the bunch being the A.11 and A.12 Matildas. Both carried substantial armor for the time, 60 mm or more, enough to protect from most infantry weapons available short of artillery, yet both were under-armed and not long enough to perform the sort of assault role envisaged by some British military planners.

Despite the protestations of men such as General Sir Maurice Taylor, Senior Military Advisor to the Ministry of Supply, who was dead-set against heavy tanks, Stern had gathered supporters in the form of men such as Sir Maurice Grove Taylor and Major General Alexander Elliot Davidson, Director of Mechanisation at the Ministry of Supply, to his side.

If there was to be a new and heavy tank, these men decided it should be along the lines of what was already proven and with which they were familiar. Given the parlous state of interwar British tank design and the utter lack of a viable alternative, the outcome was as obvious as it was inevitable, the new heavy tank should be along the lines of the Mk.VIII tank of WW1. Whilst Stern and his team gathered together their expertise and came up with their idea in the form of 300G, the Army would busy itself with its own ideas and generate a list of specifications identified as RBM-17. Then, they made their own outline of a tank to meet their own specifications – the Citadel.

RBM-17

With the 300G in hand, Sir Albert Stern had an outline for what he and the members of his as yet unofficial committee felt would meet the sort of need they saw coming. This was not a full-scale reversion to the conditions of WW1, but an improved vehicle with more trench and obstacle crossing ability than existed before.

The philosophy of a new special tank was therefore already tacitly in place and set roughly even before war was declared on 3rd September. At that point, Britain was suddenly at war with a major and aggressive European power and had no heavy tanks at all. Although this initial idea that a new tank was needed was already in place, it is inextricable that it still took until 29th September for the results to travel all the way from the General Staff to the Adelphi Hotel, where rooms had been prepared for Stern and his team to work.

On 28th September 1939, however, when the Army brought with them their list of requirements for a new tank, it immediately meant that the 300G design, on which the team had been working, was redundant. The Army was absolutely insistent that the vehicle had to have certain features, including the firepower concentrated in sponsons and a large gun in the front to smash bunkers, two features impossible to accommodate into 300G. Further, they wanted a fundamental shift in design from a turreted machine back to an ‘all-round’ track machine, as this would facilitate heavy unditching equipment.

Copy of R.B.M.-17, the original specifications for what the Army demanded from the nascent S.V.D.C.
Source: Author’s collection.

The specifications themselves clearly show exactly what the Army felt it needed in terms of a short-range special-purpose tank, but they also show the naivety on engineering matters and of tank design in general, especially as at one point, some felt this could be achieved for a vehicle under 40 tonnes in weight.

Criteria Set

Design

The tank to meet the requirements of RBM-17 was going to have to meet a set of criteria like no other tank had ever been asked to fulfill. This set, in September 1939, may well have seemed impossible to achieve to the General Staff. If one were to assume that they had deliberately set Sir Albert an impossible task to keep him busy and quiet, they were to find that even these extreme criteria were met and exceeded.

Requirement one, and the most important, was that it had to be able to cross a 16’ (4.9 m) wide trench and climb a parapet or other obstacle 7’ (2.1 m high). This was basically the widest anti-tank ditch and a high wall. Both of these obstacles were uncrossable by any British tank then in existence and the RBM-17 was to cross these without the aid of a fascine (a large bundle of sticks to fill in a ditch) or bridge.

Length Requirements

This first criterion, right from the start, guaranteed more than any other that the final size of the machine would have to be at least twice the length of the trench simply to avoid falling into it. A 16’ (4.9 m) wide trench, therefore, meant a tank 32’ (9.8 m) or so long. To climb a 7’ (2.1 m) step meant a very high track at the front in order to get purchase (grip) high on the wall or parapet. It is no surprise that these match the general ‘all-over’ track shape of the Mk. VIII tank.

Shape Requirements

The other reasons the RBM-17 was to follow the Mk.VIII’s shape were equally practical. The tank needed the maximum bearing surface on the ground, meaning the widest track possible, so it would not get stuck in soft ground. It also had to carry heavy unditching gear. In other words, it had to be able to get itself out of a hole or soft ground using a method like that used in WW1, a large spar of timber carried over the top of the tank, on which the tracks could get purchase to pull itself out. This ‘log extraction’ is still in use today and the carriage of an unditching beam or log is now most famously associated with Russian/Soviet tanks, which are often still seen with a log on the back. The method of use is identical in principle except that, in the RBM-17’s case, no crew would need to get out. In order for that spar to be carried over the tank by the tracks and underneath, it also determined that an ‘all-round’ track machine and one without a turret, which would get in the way of the spar, was needed.

Armor Requirements

The tank would have to be immune to both 37 mm and 47 mm anti-tank fire at 100 yards (91 m) and against the impact of a German 105 mm howitzer shell at normal impact. Given that the ‘rival’ A.20 was being considered around a 60 mm basis at this time due to a similar need to be immune to the 37 mm gun and yet could not meet the demand, the RBM-17 would have had to have not less than this thickness of armor at any point. More armor, of course, meant more weight.

The preeminent 37 mm anti-tank gun of the era was the German Pak 36, which could achieve around 64 mm of anti-armor performance at 100 m. For a 47 mm gun, weapons such as the French 47 mm SA 37 could deliver an anti-armor performance up to around 90 mm at just over 500 m and around 100 mm at 100 m.

A 105 mm shell, such as that from the German 10.5 cm leFH 18, was nearly 15 kg in weight with nearly 2 kg of explosives inside. Bearing in mind the often wafer-thin armor on the roof of tanks, being hit directly by such a shell would be devastating. Even a close ‘hit’ landing and bursting nearby was perfectly capable of crippling a vehicle, stripping off wheels or tracks or topping it over.

The Army was demanding immunity at 100 yards (just under 100 m), so clearly anything less than 80 mm of armor was going to be unacceptable, although the attention to protection from artillery would wane a little in emphasis as time went on.

Firepower Requirements

The gun was still not yet decided but had to be in the front and capable of defeating the heavy German bunkers (7’/2.1 m thick concrete) which were so worrisome to the General Staff. As such a gun would, by its very nature, be restricted to only a limited range of fire to the front, the tank would also need side armament to rake German positions as it passed them. Here, the General Staff wanted something simple, just a 2 pdr. and Besa machine gun combination in a sponson on each side. On top of this was to be a separate Besa pointing forwards and another to the rear. Eight smoke dischargers completed the required armament, as these would provide cover for the tank and infantry to follow.

All of this equipment and armament meant a crew complement of 7 to 8 men. The tank was to be powered by a diesel engine to reduce fire risk, fitted with a No.9 radio to speak with other tanks and troops, had to be able to go 50 miles (161 km) on its own and, on top of this, be able to be transportable by rail with little or no disassembly.

It must also be considered that Sir Albert and the soon-to-be-named ‘Old Gang’ clearly thought little of the ‘no turret’ and all-over track idea. Their first design was, in fact, far more similar in shape to the A.12 and A.20 than the Mk.VIII. When the requirements for the length of trench to be crossed were decided, the design grew longer, and when the turret was abandoned and all-round track selected by the General Staff, the Mk.VIII shape was inevitable. Those other TOG designs are known only by drawing number 300G in both a long and ‘compact’ form. Both were shelved in favor of the Mk.VIII approach, although the longer version would later be resurrected when a modicum of sanity returned to the General Staff.

In these early days, the selection of armament was a key consideration and a variety of armament and mounting options were considered across Sir Albert’s work and the A.20, including a 2 pdr./Besa 7.92 mm machine gun combination, as found in the turret of the A.12 Matilda, a 3” howitzer, a 3.7” howitzer, naval 6 pounder, and the French 75 mm gun, as used on the Char B1.

The 2 pdr./Besa option would only work if a turret was going to be selected for the tank, which meant a hull-mounted gun. With the 3” and 3.7” guns being low-velocity weapons, they were abandoned. This was because the work of Sir Albert had been given a very strict and very specific set of requirements, one of which would require a particularly powerful gun firing a high-velocity shell capable of breaching 7’ (2.1 m) of reinforced (ferro) concrete.

The requirements were specifically listed under the heading “Super-Heavy Tank (Land Battleship)” under the code ‘RBM-17’. The exact meaning of those code letters has never been adequately explained but, given that Sir Albert’s committee was already being labeled in a sort of British public-school humor kind of way as ‘The Old Gang’, it could be speculated that such a boyish kind of name was being thought of here for this ‘Really Big Machine’. The committee designing this vehicle would later (October 1939) receive a formal acknowledgment as the Special Vehicle Development Committee (S.V.D.C.), but they were equally happy using the ‘TOG’ term themselves as a badge of honor rather than as a mark of scorn, as has been happily assumed by some authors in the decades since the war.

The Citadel Design

Brigadier Kenchington from the War Office and Colonel Watson were the men who brought the RBM-17 specification ‘wish-list’ to the meeting with Sir Albert Stern. With them too was an interpretation of what this would look like for the committee to work on. It is not clear if the vehicle outline that they brought with them as a ‘Citadel’ tank was directly from these individual officers themselves or from the War Office or General Staff or a mix of the bunch, but the design was clear in realizing the needs of RBM-17.

The outline for the Citadel, labeled as ‘TOG-1’, dating somewhere between September and probably November 1939.
Source: The Tank Museum, Bovington

Layout

The presented vehicle was a long, low, lozenge-shaped tank, roughly along the lines of the Mk. VIII, but with a large field gun mounted in the front of the hull with heavy unditching gear. It was drawn showing large round, presumably cast sponsons for the 2 pdr. / coaxial machine gun combination. One important note on this design is the issue of crew access. No doors are shown and, in correspondence over the next month or so, the only comment on this topic was on the removal of side doors behind the sponsons. This too was presumably similar in intent to the Mk. VIII, although the shape or style of such a door is unlikely to have been the same given the heavy armor requirement.

Side access doors for the WW1 era Mk. VIII were thick enough to protect against small arms and even anti-tank rifle fire, but were nowhere near the armor required by RBM-17. Likewise, the idea of a door-mounted machine gun was never contemplated, as the side machine gun was to be coaxial with the sponson-mounted 2 pdr. Note the small rails for the unditching beam on the back do not extend forwards to the casemate.
Source: US National Archives

On top of the tank and projecting above the level of the tracks was a raised superstructure with a small cupola. This lookout allowed the commander to see where he was going and communicate to the driver in the front left. Whilst it may or may not have been rotatable, it was not an armed turret. The more notable issue on this raised section in the fighting chamber was that, just like the Mk. VIII, it would prevent the whole unditching beam over the top of the tank idea as well. Here, then, there seems to have been a disconnect in the minds of the military planners for the General Staff, who seemed to be confusing the earlier marks of British tanks, which used rails over a small raised structure for an unditching beam to travel over, with the rear-mounted beam on the Mk. VIII. Photographs of the Mk. VIII clearly show that the rails on its roof only extended over the rear section of the tail and thus that the beam would then not be able to be carried forward to help unditch the vehicle. The Mk. VIII therefore would only be able to deploy this beam backward to reverse out of a particularly boggy hole, whereas the early tanks, such as the Mk. IV, could deploy the beam forwards to get out of a hole forwards or in reverse.

Shown post-war on display, this vehicle clearly shows the issue of the top rails, whereby a beam or other equipment, such as a fascine could be dragged over the top without fouling on the casemate.
Source: Pinterest

Armor

No details on the armor for the Citadel idea were noted, other than the immunity requirement. Given that 37 mm and 47 mm anti-tank guns could respectively perforate between around 60 and 80 mm of armor at 100 yards (91 m), the requirements guaranteed armor not less than that already in use of the A.12 Matilda, with 3” (76 mm) of armor. Importantly, the immunity requirement did not specify that the armor had to be that thick per se, just that it needed to provide that level of protection. Whilst the vertical sides would need to be at least that thick, the front may not have needed to be, given the slope, but even so it would seem unlikely that the front, even sloped, would be thinner. The same is true of the sponsons, with their distinctive curved shape, projecting from the sides. Given the size of them, each would likely weigh roughly the same as the turret of the A.12 as well. It is not hard, therefore, to see why the desire to replace two of them with just one turret would finally win out later.

Armament

RBM-17 made it clear that the Army wanted a field gun in the front which could breach enemy heavy bunkers up to 7’ (2.1 m) thick and various options would be discussed with the S.V.D.C. as they tried to meet this demand. Of the options considered, there was little to choose from.

The biggest gun which could potentially be made to fit in the front was the venerable 60 pounder. The B.L. 60 pounder was over 30 years old and had seen extensive service in WW1, firing a 60 lb. (27 kg) shell containing 8 lbs. (3.6 kg) of high explosive at 650 m/s out to a range of 9 km. The gun itself was massive, employing a wheeled carriage and usually serviced by a crew of 10 men when used as a field gun. Even so, it produced a rate of fire of just 2 rounds per minute. The gun was also very long, with the barrel alone measuring nearly 5 m from breech to muzzle. This produced a problem for the front of the vehicle, as the barrel would potentially impale itself into an obstacle, such as the opposite face of a ditch when the vehicle was crossing it. Thus, the option of shortening the barrel was considered, even though this would reduce the muzzle velocity of the gun. However, as the long version firing HE could not defeat the 7’ (2.1 m) of concrete, the Army demanded that the gun would not be shortened.

Little discussion seems to have focussed on the two other huge problems of using such a gun in the front. Firstly, the fact that just one man was supposed to operate it and, no matter how much bully beef he might get, this would be an enormous task for one man who was also at some point supposed to use the front machine gun too. The second issue was how to mount such a heavy gun in the hull. Perhaps thankfully, this gun was discounted as a realistic option before any precious design resources were expended on trying to create a mounting that could take both the weight and the recoil.

British B.L. 60 pounder Mk. II in service in the 1930s with the British Army. A crew of 5 men can be seen operating this gun, with other men off-camera.
Source: wiki

The reality was that, in September 1939, there was no gun that could be mounted in the front which could achieve that 7’ (2.1 m) requirement. Whilst the demand for concrete destruction would be kept, it would end up as an ‘as much as possible’ requirement going forward through the end of 1939, rather than an absolute figure to be achieved.

Speed

The tank did not need to be fast in any way. There was simply no need. This vehicle would primarily be used for smashing enemy positions. Further, a slower vehicle emphasizing protection would resist the deleterious effect of enemy fire which it would attract, provide a more stable firing platform for firing back, and also clear a path for further tanks and troops to follow.

The low speed was also a reflection of reality. Whilst 5 mph (8 km/h) is certainly not by any means fast, it is surprisingly quick across the sort of terrible terrain which might be encountered in a Flanders-type shattered battlefield, with heavy mud and waterlogged ground. In fact, this speed would not only be faster than its forebears a generation earlier over such ground but also faster than any other tank in such conditions as well.

Crew

RBM-17 called for a commander, a driver, and a separate radio operator. Separating the radio operator from the commander, which was usually his dual job in a British tank, would at least take away one burden from him, but the job of commanding the vehicle was not going to be simplified much, as he would have to now control the crew operating the gun in the front hull and both sponsons. Two men, one for the 2 pdr. and one for the machine gun, would crew the sponsons on each side and just one man was supposed to operate the front hull gun on his own.

This herculean task for the front hull gunner/loader would certainly have been more than a little burdensome if a gun like the 60-pounder was adopted, having to haul the shells on his own, load them, aim the gun and fire, and then repeat. This would have been exhausting and slow work in the confines of the tank with all of the other activities going on, especially if it was moving at the time.

Power

The powerplant for this machine was not mentioned, described, or suggested. The fuel type was clearly spelled out as ‘diesel’. Although high speeds were not called for in the design brief, there was still going to be an issue over the availability of high-power diesel engines and how to transmit that power from the engine/s to the tracks. An eventual solution would be found to meet the need for power from a diesel thanks to Harry Ricardo, the engine designer on the S.V.D.C.

However, in September 1939, it was not that clear cut and engine options were severely limited by not only the power output needed, but also by the fuel type, as few diesel engines were available which could deliver the power of more than 500 hp which would be required and options to be considered included more than one engine, various domestic and foreign engines, and different types of transmissions to maintain efficiency.

An approximation of the Citadel tank of September 1939 modeled from the eventual hull of TOG-1 with the rounded sponsons and shown here with the long-barrelled 60-pdr. gun projecting from the front.
Source: Author
An approximation of the Citadel tank of September 1939 modeled from the eventual hull of TOG-1 with the rounded sponsons and shown here with the shortened 60-pdr. gun projecting from the front.
Source: Author

Conclusion

The Army’s design for the Citadel was odd, harkening back to the worst days of the slaughter of WW1 and no doubt that conflict served up generous helpings of concerns of a repeat of it. Seemingly in haste, the Army had leapt on Stern’s idea that, quite rightly, the Army needed a new special tank to prevent that type of warfare from taking place. Equally, the high command appeared to be panicking. This rush to get ‘something’ is seemingly made clear by the disconnect over the general outline of a tank. The Army were insistent on a turretless tank, so as not to interfere with heavy unditching gear, yet this very requirement was gone even by the end of WW1 with the change from all-over rails to just rails at the back for the unditching beam. Indeed, it is unclear how the High Command seemingly lacked knowledge on the topic, as even in WW1, vehicles had gone away from this type of complete top rail, as seen on the Mk. VIII, Medium Mk. B Whippet, and Medium Mk. C Hornet. Why the Army seemed so insistent on no turret because it would interfere with this equipment makes no sense when a turret would make no more interference than the raised casemate. This, perhaps more than anything else, shows that the Army was rushing to get ‘something’ to fill a need rather than relying on experts like Stern’s committee to develop a new vehicle.

The proposed design had too many crewmen and was too hard to control. Reducing the crew meant fewer men would be needed, more space in the fighting chamber for air to circulate, more space to move around, and more space for storage of ammunition, etcetera. Fewer men could be achieved by the adoption of a turret which would concentrate the firepower equivalent to both sponsons in one place as, afterall, both sponsons could not fire on the same target at the same time in anything other than the very limited circumstances of the target being directly ahead of the tank a distance away.

Removing sponsons would not only eliminate the need for so many crew and improve the interior volume, but would also remove two other significant burdens. One was the problem of transshipment, as no sponsons, or just small machine gun sponsons were far easier to move, fold in, or remove than these huge sponsons demanded. Secondly, their removal would save a lot of unnecessary weight from men, armor, and guns.

Adopting a turret would become the logical conclusion as the S.V.D.C. got to work on the Army’s idea, as saving crew and weight, and improving the distribution of firepower issues altered the general shape of the eventual vehicle into the ‘TOG-1’. Even with a turret, it was not the vehicle that the S.V.D.C. would design to meet the needs of RMB-17. That vehicle would have to wait, as the committee formed under Stern got to work in October 1939.

The size of the machine was inevitably going to be big given the size of the trench that needed to be crossed and the same is true of the front contact, with a 7’ step requiring a high front end. The Army’s demand for an all-road track likewise demanded a machine shaped like the Mk. VIII.

What the struggle to find a suitable powerplant would show was just how unrealistic RBM-17 was as a demand. At one point, the Army’s goal was to make this monster of a tank under 40 tonnes, a completely ludicrous idea that any engineer or designer would have laughed at when the Army was literally demanding a gallon in a pint pot.

In the end, the Army would not be able to get what they wanted. The requirements, although they could be met, could also be improved upon. The S.V.D.C. under Sir Albert Stern would develop a vehicle along the lines wanted by the Army and eventually persuade them of the value of a turret over large sponsons, and that vehicle would be TOG-1. The performance of TOG-1 would also exceed the Army’s requirements for mobility and obstacle crossing and, in fact, exceed their extreme requirements for a vehicle for all but the ability to smash a 7’ thick reinforced concrete structure. That requirement would be practically impossible at the time anyway, regardless of what design they might have come up with, and would remain out of reach for a couple of years until the advent of the 17 pdr.

The Citadel, however, was a starting point for the SVDC, as limited and relatively crude as it was. With a team of experts and mandate for work, the restrictions of RBM-17 would fade a little as the war developed, but the special tank concept would continue and the Citadel became just a footnote in the history of the committee.

Side view of the TOG Citadel with the shortened 60 pounder gun. Illustration by Ed Jackson, the winner of our illustration competition.

Specifications TOG Citadel

Dimensions >32’ (9.75 m) long
Weight >40 tons
Crew 7 – 8 (commander, driver, wireless operator, 4 – 5 gunners)
Speed (road) 5 mph required (min. off road of very bad ground)
Range 50 miles (80 km)
Fuel Diesel
Primary Armament heavy field gun such as 60 pdr. or shortened 60 pdr.
Sponson Armament 2 pounder gun and 7.92 mm BESA MG on each side
Other Armament front and rear 7.92 mm BESA MGs
Armor Sufficient to protect against 37 and 47 mm anti-tank guns and 105 mm howitzer
For information about abbreviations check the Lexical Index

Sources

Hills, A. (2017). The Tanks of TOG. FWD Publishing, USA.

Categories
WW2 Australian Prototypes WW2 British Prototypes

Gerrey Machine Gun Motor Vehicle

Australia/United Kingdom (1939)
AFV – None Built

Budgong Gap may not be the sort of world-famous location associated with great architecture or magnificent structures of the ancient world. Nor is it a place with any association in the world of armored fighting vehicle manufacturers, yet this somewhat obscure location, lying nearly a 3-hour drive south of Sydney, New South Wales in Australia, does have one claim to armored vehicle fame – the Gerreys. World War 2 broke out for Great Britain on 3rd September 1939, when it declared war on Germany after the Wehrmacht had invaded Poland. Australia followed suit, with Prime Minister Robert Menzies announcing that Australia was also once more at war. Within a month, the Gerreys had submitted a design for their own tracked and turreted weapon of war. Looking like a tracked motor car with a turret, the Gerrey design is perhaps yet another of those well-intentioned designs submitted in wartime but is also one of, if not the first of Australia’s homegrown armored vehicle designs of the war.

The Gerreys

The Gerrey family were ranchers/farmers from a very rural part of Australia and had been established in the area from at least the turn of the century.

The two inventive members of this family were Bernard Bowland Gerrey and James Laurence Gerrey. Although it is not known what their relationship was, it is surmised that they were brothers. Both men gave their occupations in Budgong Gap in 1939 as Timber Hauliers. Bernard had previously been in the National Press in 1931, relating of a possible sighting of the wreckage of the Southern Cloud, an Avro 618 which was lost in bad weather in March that year over densely forested wilderness. There would be no fame or reward for Gerrey for that foray into the public eye and the plane was not found until 1958.

The Design

In October 1939, when the Gerreys (both Bernard and James) submitted their design, the vehicle was intended to fulfill a single simple objective – to provide a “motor propelled armoured vehicle” with a turret “in which a series of automatic machine guns are mounted in superposed groups”.

Shaped like a giant boot, the vehicle effectively had the appearance of a tracked saloon car with a giant cylinder sticking up on the back of it. Access to the vehicle was via a pair of large rectangular doors on the right-hand side of the vehicle. The left side is not shown in the drawing, but it can be assumed that these doors were duplicated on the left side as well. The first door was directly accessing the cab area of the ‘car’ part of the vehicle, roughly halfway along the side. The second door was at the back of the vehicle, below the cylindrical turret. Judging from the size of the doors, it would indicate enough space inside for perhaps as many as three men, although a crew of two is perhaps more reasonable as only one man would be needed to drive the vehicle and another to operate the weapons. One final note on access is what appears to be a series of 5 or 6 parallel steps on the right-hand side (and presumably the left as well to match). These steps were on the sides of the vehicle running vertically just behind the door to the driver’s position and running up to the roofline. There appears to be a third hatch shown on the side view just above and behind the side door as well, although it is neither mentioned in the text of the patent application nor in the plan view drawing.

Outline of the Gerrey Machine Gun Motor Vehicle, as modified from the Patent image by the author.

The other very notable feature of the design is the very elegantly sculpted cowls for the pair of headlamps on the wings of the vehicle over the tracks. Such a design feature provided zero military advantages and was clearly inspired by a civilian style of automobile instead.

A crew of two would also match the plan view of the vehicle, which shows just a single opening in the front for the driver and no such opening or weapon on the left of the cab to indicate the need for a second crewman in the ‘car’. Likewise, in the turret, the plan view clearly shows a tractor-style seat for the weapon operator to sit on, indicating just a single man in the turret. At most, therefore, a crew of three could be hypothesized with the third man presumably languishing inside the passenger side of the ‘car’, occupied perhaps with managing a radio.

Both the 1931 report of a possible aircraft sighting and their employment as Timber Hauliers in 1939, as well as the rugged terrain in which they lived, indicate that they should have had at least a working knowledge of vehicles off-road, such as log-hauling tractors. This may account for the flat style of tracks used, as they have the appearance of the type more associated with industrial plant-like crawler tractors and even tracked cranes than the sort of tracks associated with military vehicles, which usually have a well-defined and raised leading front edge for the track.

Indeed, the flat style of track selected is not usually a problem on industrial machines, as the front and back of the bodywork rarely project the way they do on this vehicle. The projection over the back of the vehicle would, for this design, severely limit the steepness of a slope that could be climbed and likewise, at the front, the projecting bodywork would foul on the ground reducing trench crossing ability. This is perhaps the most surprising weakness of the design of the machine from the Gerreys.

Automotive

The ‘car’ shape of the body of the vehicle is misleading, as the means of propulsion is decidedly not-car-like. Instead of running on rubber-tired road wheels, like a normal passenger motor car, this vehicle instead used a pair of full-length and rather narrow tracks. The Gerreys described the means of propulsion for these tracks as consisting of an “internal combustion motor of ordinary type and associated with the usual driving and change speed gear”. However, despite showing the vehicle on tracks, the Gerreys also suggested that this type of turret and armament system could be mounted upon “any kind of transport vehicle”.

The side view available from the patent indicates 20 or so large flat links per track with power delivered via a toothed sprocket located at the back. Each link is overly large for such a small vehicle with a large pitch and would indicate that the vehicle would have serious limitations on its top speed. Likewise, the positioning of the drive sprocket and idler, both in contact with the surface, would create a most uncomfortable ride even if there was any suspension shown or described, which there was not.

The engine, as shown in the plan view, lay at the front, under the bonnet, as would in the case of an ordinary passenger motor car, with the radiator in front of it. In order to protect the radiator from enemy fire, a set of hinged and moveable plates were fitted to the front, which could be opened in order to access the radiator and also allow more air in to improve cooling. Although the lines of the front of the car suggest a bonnet that could be opened in order to access the engine, there is none showed, which would mean a difficult time for anyone trying to do maintenance on the vehicle.

Armament

The primary weapons for the Gerrey design were a series of automatic machine guns. All of them were connected together in the wall of the turret and provided with a slot or other opening through which the barrels could protrude. All of the machine guns could be operated by a single crewman using a simple one-pull trigger, firing all of them at the same time. This wall of fire was no doubt an impressive thought. Assuming perhaps a rate of fire of 600 rounds per minute from each of the unspecified machine guns, it would be essential that each one was fed by a belt, or else the only job of the gunner would be changing magazines. With three rows of machine gun pairs fitted within the large cylindrical turret, a total of at least 6 machine guns (and as much as 18) are shown with their barrels projecting from small loopholes. Six machine guns firing 600 rounds per minute would be 3,600 rounds per minute fired in the general direction of an enemy through a narrow opening, allowing for very limited vertical movement of the guns.

As the vehicle, as drawn, would be using weapons compatible with British supplies, it would suggest weapons like the Browning machine gun and a bullet caliber of .303 or 7.92 mm, like that fired from the BESA machine gun. Belts for the Browning machine gun came in lengths of 500 rounds with two belts to a crate. Assuming the crates or boxes were dispensed off, the weight of the ammunition alone to serve these weapons is a significant burden the Gerreys failed to take into account, as one belt alone weighed in the region of 7 kg. One minute of sustained fire therefore would demand:

((No. of guns x rate of fire) / rounds per belt) x weight of belt

((6 x 600) / 500) x 7 kg = 50 kg of ammunition per minute

That is 50 kg of ammunition per minute, so even a modestly useful combat load of just 10 minutes-worth of fire would mean carrying half a tonne in ammunition alone. For anything other than perhaps anti-aircraft work, the six machine guns were simply adding the weight of the guns, complexity of the mechanism, and weight of the extra ammunition for no particular benefit. Given that the design of the Gerrey vehicle would preclude the anti-aircraft option due to the limited elevation of the guns, it has to be considered that a far more useful and practical arrangement of the firepower from this vehicle would have been served with just a pair of machine guns.

It was, however, these superimposed rows of automatic weapons, all operated by a single person, which was the crux of the patent invention, as they felt that this style of turret was both novel and important. Thus, the Gerreys patented something novel but inherently unusable.

Plan view taken from British Patent GB537405 showing the engine and radiator at the front and the protective covers over the front grill. Note the vehicle is right-hand drive, as would be expected from a British or Australian vehicle. The single-seat for the gunner and the array of automatic weapons in front of the seat can be seen in the turret, shown facing backward. Source: British Patent GB537405
Plan view of the layout of the Gerrey’s machine gun motor vehicle taken from the patent and cleaned by the author to remove annotations and interior. The radiator shutter has also been added. Source: British Patent GB537405 as amended by the author.

Protection

Few specifics of the armor on the vehicle were described in the patent application, other than to say that the chassis was relatively lightly armored. From this, it can be inferred to be protection against small arms fire rather than the type of protection that would be needed against anti-tank shell fire.

The turret was sat recessed slightly into the body of the vehicle, which would reduce the chances of it being jammed by enemy fire and prevent splash from entering the vehicle through the gap.

Conclusion

The vehicle submitted by the Gerrys was a simple one, well within the technical abilities of the day to produce, but it was also redundant and somewhat naive. Even assuming the engine would have had sufficient power to propel the machine off-road, it was poorly laid out in terms of using space and was therefore going to be heavier than it needed to be. The same is true of the mechanism in the turret – heavily burdened with large gearing more akin to a heavy drive system than one for simply moving and firing machine guns.

They may be excused for some lack of knowledge when it comes to tank design, but it is hard to explain how they might see this vehicle moving across the sort of terrain they would have been familiar with. Overall, the design is crude and relatively poor, showing a great deal of naivety when it came to military vehicle design, with poor use of space and layout. The inherent problems of command and control between the driver and gunner and the excessive multitude of weapons would make any serious operation of the Gerrey vehicle problematic, to say the least, and likely one which would not be able to be operated efficiently under the stresses of combat. Indeed, only the US Army of the era might have been interested in a machine with such a preposterous number of machine guns, but regardless of the military faults, it is the tracks that are the biggest surprise.

For a pair of men who clearly have experience outdoors and almost certainly had seen or used vehicles in that terrain, it is easy to imagine the inspiration for the shape of the tracks they selected. What is less clear, however, is why the overhangs were not identified as a problem.

Nothing became of the design from the Gerreys, which is not really much of a surprise. As skilled as they may have been as timberers or as rugged outback pioneers, their ideas, whilst well-meaning, were simply too naive, too crude, and not fully thought-through – they simply were not what Australia or Britain needed in the war. This design, unofficial as it was, at least started the multitude of ideas coming from Australia for its own armored vehicle programs. Forgotten perhaps almost as soon as it was patented, the vehicle is little more than a short misstep in Australia producing what eventually became a very competent independent tank program. What became of the Gerreys is not clear, but they seem to have dropped their military ideas, submitted no more patents, and likely returned to what they knew best.

Illustration of the Gerry Machine Gun Motor Vehicle. Illustration by Yuvnashva Sharma, funded by our Patreon campaign.

Sources

British Patent GB537405, ‘Improvements in Armoured Motor Vehicles provided with Machine Guns’, filed 16th October 1939, granted 20th June 1941.
Kangaroo Valley Voice July 2008: An insight to life back then.
New South Wales Parliament, Proceedings of the Legislative council Votes and Proceedings Volume 6
The Sun (Sydney) 11th July 1931 ‘Southern Cloud Search’
Northern Times (Carnarvon) 16th July 1931 ‘Wreckage of Plane Discovered’
Sidney Morning Herald 25th October 2019 ‘From the Archives, 1958: The Southern Cloud mystery solved after 27 years

Categories
WW2 British Prototypes WW2 Polish Prototypes

Smeaton Sochaczewski Carrier

United Kingdom/Poland (1944-1945)
Armored Carrier – Design Only

Poland had been crushed in WW2. Hitler had invaded Poland from the west on 1st September 1939, followed by a Soviet invasion from the east 16 days later. Despite dogged resistance, it was all futile and the country was split between the two ideologically opposing powers. Thousands of Polish nationals and soldiers had, however, escaped the invaders and many of them fled to Great Britain, which had declared war on Nazi Germany on 3rd September, although not on the Soviet Union following their part in the invasion. With their country occupied and terrorized, many of the escaped and exiled Poles and Polish nationals living in the UK either joined up with the British to fight for a free Poland or put their skills to use in other areas, such as inventions or contributing to war production.

One Polish national, Stanisław Sochaczewski, would submit an idea for an improved armored carrier in concert with a British woman and would produce an unusual idea for a variation on the Universal Carrier.

The People

Isabel Smeaton (British) and Stanisław Sochaczewski (Polish) both provided an address of 4 Clarence House, London, for their September 1944 patent application for improvements in motor vehicles. The relationship between them is unclear, and we have no information of either of them except that Stanisław Sochaczewski could be General Stanisław Zygmunt Sochaczewski (27/8/1877 – 14/7/1953), a retired Polish Army Officer who had been living in Britain since May 1939, where he was a critic of General Władysław Sikorski. General Sikorski was the Prime Minister of the Polish Government in exile starting from September 1939 and Sochaczewski’s criticism of Sikorski even led to Sochaczewski being imprisoned in Scotland for a short period of time.

General Stanisław Sochaczewski 27/8/1877 to 14/7/1953. Source: Wikimedia Commons

This was not Sochaczewski’s first attempt at a small carrier-type vehicle. In December 1943, he had sent a somewhat self-aggrandizing letter to the War Office suggesting what he called ‘Armoured Trolleys’, roughly the size of a Universal Carrier, which could be used to rapidly assault enemy positions. Evaluated by the Canadians, that suggestion had rightly been rejected as impractical. He had, however, ended that letter with a hint of his thinking – thinking which would shape this application with Mrs. Smeaton.

“During the few weeks taken by polishing up and duplicating which has been said above [his idea for the Armoured Trolley amongst others], there has been disclosed that an armoured fighting vehicle [emphasis added by Sochaczewski] which is perfectly suitable for the purpose described is already developed and mass produced. It is the British Army’s Universal Carrier (Lloyd-Carrier) [sic: Loyd Carrier] which can very easily be accommodated for carrying in a comfortable prone laying posture not three as had been suggested, but five-men, in two layers; two Bren-gunners below and three automatic-riflemen on top of the latter, all comfortably posted, fully protected by armour, aiming through periscopes and, if there is need, fully covered from bullets or splinters coming from above (very important for the street fighting and under strafing air attacks).
When out of enemy’s fire, men are comfortably sitting and there is plenty of room for fuel, ammunition and water. No better accommodation can be found”

As it happened, Sochaczewski was to tone down the prospective crew of 5 to just 3 for his patent application, but it cannot be left unremarked that he was somehow unaware in late 1942 of the existence of the ‘Universal Carrier’.

Sochaczewski’s Armoured Trolley with an outline of a standing soldier for scale. Based on this drawing the vehicle would be a little over a meter high. Source: Canadian Archives

Design

The goal of the design was the production of an armored vehicle using tracks that could be used to haul a number of men and their equipment safe from enemy fire as well as allowing them to position their weapons to facilitate fire on the enemy.

To create this vehicle, an open-topped armored box-body was formed from two sections, allowing for men to sit or lay at different heights. In normal usage, the men inside would sit upright for comfort but for protection would be able to lie down inside and still operate the vehicle. The body was described as:

“The vehicle comprises an armored body, mounted on an undercarriage composed of a plurality of wheels and an endless track of known form, which undercarriage constitutes no part of the present invention”

What this meant was that their invention was not for a complete vehicle in its own right, but a modification to an existing vehicle and the obvious visual similarity here to the Universal Carrier-type vehicle is unmistakable although, it should be clearly noted that, with four road-wheels, the design actually most clearly matches the American-built T16 carrier rather than the 3-roadwheel carrier

T16 ‘Universal’-type carrier. Source: diggerhistory

The body would be new, to facilitate the new and improved layout and protection, but the running gear, suspension, and tracks would be the same.

The seating in the back of the vehicle was to go on top of the sponsons, forming two rows of bench seating behind the driver’s space in the front. Using removable covers for those benches and rolled matting meant that, if the vehicle went into combat, then the benching could be quickly folded up, the matting unrolled and the men lay down in relative comfort. The compartment was also arranged with a type of false floor forming a shelf. This allowed for one soldier to lie at the lower tier of the vehicle, with another on the shelf above him, meaning more men would be able to face forwards to fire.

Front view of the carrier showing the three firing positions. Source: UK Patent 568636

The driver, however, was different. In normal driving, he would be sat up like the others, but in combat, his seat would recline backward so as to position him in a semi-lying position. This, therefore, is one of, if not the first use of a reclined driver’s station for an armored fighting vehicle. This is something considered a significantly valuable feature of the Chieftain main battle tank and still in use as a concept today.

At the back left-hand side of the vehicle, there was a protected space, under the stowed sections of roof armor for the stowage of stores, and ammunition.

Side view of the carrier with the crew in ‘normal’ positions (top) and combat positions (bottom). Source: UK Patent 568636

Automotive

No specific engine was detailed in the design, but it was positioned in the rear center of the vehicle, with fuel tanks on the right side of the rear section, with a reserve oil tank on the right side above the sponson. Although no claim over the suspension system is made, the notable exception to anything being mentioned is the transmission. On the Universal Carrier, the rear-mounted engine was connected by a drive shaft to a transmission mounted across the front and, although there would still be room on this design for the transmission in the front, it would have been a tight fit against the face of the lower man. The other option perhaps was to put the transmission in the rear, but none of that was mentioned by the designers, who were preoccupied with layout and fightability.

Armor

No thicknesses of armor were specified in the patent and the vehicle was nominally open-topped in much the same style as the ‘Bren’ or ‘Universal’ Carrier. During normal operations, the men sat upright but, for combat, the men could lie down inside. The armor at the front was shaped in such a way as to provide a convenient aperture for the rifles, providing a rest for them. Although there is no thickness, the designers wanted the frontal armor to consist of two main plates, with the upper of the two fitted with two gun apertures and the lower plate with just one. The low-tier man would be able to fire from the lower aperture and the two upper-tier men from the upper two apertures. To allow for better traverse of fire, each aperture was also provided with a second plate to overlap the edges of the armor around each aperture to ensure that no gap was permitted.

Adding to the overall protection was the provision of moveable roof armor stowed at the back of the vehicle, which would be brought forward covering the roof of the vehicle when the men were lying down. No hatches were provided, so, to get out, the men would simply have to move up or back the armored roof plate. If this vehicle was to roughly match the Universal-type carrier’s armor would be bulletproof, up to 10 mm thick or so.

Top-down view of the Smeaton/Sochaczewski carrier showing the position of the two men on the top tier and below them just visible the front of the man on the lower tier. Source: UK Patent 568636

Armament

No specific armament other than rifles is mentioned in the patent. Four men, with one driving, meant potentially three weapons facing forwards at the same time and, although the British .303 SMLE was a famously quick-firing bolt action rifle, three such rifles was not a tremendous amount of firepower, especially considering the ‘Universal’ or ‘Bren’-type carrier was usually seen carrying a Bren .303 light machine gun (LMG).

British .303 caliber Bren light machine gun. Source: Wikimedia Commons

The side view of the combat positions, however, clearly shows that the lower position was drawn with a weapon using a curved magazine coming out of the top and a distinctive flared muzzle – features matching the Bren LMG. If this was the case, then the armament would be limited to just a pair of rifles in the top tier and a light machine gun below them.

Other work

Isabel Smeaton is hard to track down but, as of September 1944, was likely still living at 4 Clarence House, as there is a recorded death of a John Stuart Smeaton (presumably her husband or father) on 7th July 1944. His occupation was given as a ‘sanitary engineer’. It was with John Smeaton that both Isabel and Stanislaw had submitted a patent application back in January 1942 for a small mirror system for shooting from behind cover and reference was specifically drawn in the carrier-patent to that design. Other inventions of war time relevance involved training devices for the army but, as far as can be ascertained, none of them were successful.

Design for a small mirrored device to allow a rifle user to shoot from behind cover. Source: UK Patent 555356

Conclusion

The work of Smeaton and Sochaczewski on this carrier had taken a lot of thought to try and consider the problems of improving protection and fightability. Creating a roof, adding firepower and useability were all good and noble ideas. Several key factors of note within the design were particularly credible such as:

  • Removable flooring rolled up when not in use
  • Removable benches
  • Interior divided longitudinally into compartments
  • Driver’s seat able to adjust from sitting up to a reclined position
  • Armored movable roof plates to protect the men from above
  • Additional apertures for rifles and/or other weaponry in the front

The problems with the design are readily apparent, however. The vehicle was never going to be of significant combat potential and all that work to create an extra tier of firepower when a simple Vickers machine gun on top would more than quadruple the firepower of the existing vehicle without having to completely retool a manufacturing line for the tens of thousands of carriers produced. None of these Smeaton Sochaczewski carriers were ever made, as the design simply offered far too little to warrant replacing a mass produced vehicle already in widespread use.

Illustration of the Smeaton Sochaczewski Carrier by Yuvnashva Sharma, funded by our Patreon campaign.

Smeaton Sochaczewski Carrier specifications

Crew 1 (driver) – up to three more fighting men
Propulsion unknown
Speed unknown
Armament 2 x .303 rifles and 1 x .303 light machine gun
Armor ~bulletproof

Sources

Universal Carriers https://www.canadiansoldiers.com/vehicles/universalcarriers/universalcarriers.htm
UK Patent 568636 ‘Improvements in or relating to Armoured Vehicles, filed 6th September 1944, granted 13th April 1945
UK Patent 645416 ‘ Improvements in automatic small arms’, filed 11th December 1947, granted 1st November 1950
UK Patent 627207 ‘ Improvements in or relating to Recoil Operated Small Arms’, filed 21st August 1946, granted 3rd August 1949
UK Patent 555356 ‘ Improvements in or relating to Rifles and Like Guns’, filed 18th February 1942, granted 19th August 1943
UK Patent 567121 ‘Improved Wheeled Carrier for Bandoliers or Belts Packed with Ammunition’, filed 14th July 1944, granted 29th January 1945
UK Patent 540079 ‘Improvements in or relating to Appliances for Musketry and the like Training’ filed 27th March 1939, granted 3rd October 1941 (address formerly Mokotowska No.3, Warsaw, Poland – now at 20 Chesney Court, Shirland Road, London W9)
Biography of Stanisław Zygmunt Sochaczewski at iPSB https://www.ipsb.nina.gov.pl/a/biografia/stanislaw-zygmunt-sochaczewski
Sochaczewski, S. (1943). New Fighting Equipment – Modified Infantry Tactics. London 1943. Canadia Archives Reference C-5829: 55/6276/1
The London Gazette, 22nd September 1944, page 4419

Categories
WW2 British Prototypes

TOG Amphibian

United Kingdom (1940)
Amphibious Tank – Design Only

The Old Gang (TOG) was an informal and perhaps derogatory name applied to the men who had been primarily responsible for delivering British tank designs in WW1. With a new war started in 1939, these men, under the leadership of Sir Albert Stern, were formed into the Special Vehicle Development Committee (S.V.D.C.), although they soon adopted the TOG moniker as a badge of honor. More commonly known for work on the large heavy tank projects TOG-1 and TOG-2, the SVDC were actually a body utilised for their expertise for a number of projects and one of those, in the Summer of 1940, was the need for an amphibious tank.

With a flair for design and the ability to work unencumbered by the normal military and political bureaucracy, the SVDC delivered one of the most unusual ideas for an assault tank of the war – one which approached the enemy from under water.

Sir Albert Stern photographed in 1945. Source: National Portrait Gallery

Background

On 30th July 1940, Mr. Burton, the Director General of Tank Technology (D.G.T.T.), approached Sir Albert Stern to request S.V.D.C. assistance in solving two tank design questions: a tank suitable for an airborne invasion, and a tank for a seaborne invasion.

General Pope, the Director of Armoured Fighting Vehicles (D.A.F.V.) had actually issued the original requirements for an amphibious tank back in March and clearly, the task was so difficult that the S.V.D.C.’s help was now being sought. This difficulty is hardly a surprise given the almost utter absence of any work on amphibious or wading of tanks in the preceding decades, asides from some like the Mk. V and VI Light Tanks, and of course the minuscule Vickers Carden-Loyd Amphibian (A.4.E12). All of these were vehicles which were barely bulletproof and utterly useless for any invasion of the French mainland with an opposed amphibious landing against a prepared enemy.

Vickers Carden Loyd Amphibious Tank (A.4.E.12). Source: Wikimedia Commons

This need for an amphibious tank was less obvious in March 1940, when it was ‘something we might want’, as opposed to a post-Dunkirk point when the British had been pushed off continental Europe. Any new attempt to bring a land war against Germany in France would guarantee the need for an amphibious landing and this would have to be led by tanks. The small problem was that virtually no work had been done on the subject and there was no suitable vehicle available.

“the War Office considers it very important that an amphibian tank should be developed to meet modern requirements… It seems to me that this is a problem that might well be studied by your Committee, and the scheme developed possibly up to the stage of making pilot models… the development of an amphibian tank of real use is a matter of great importance.”

Letter from Sir Albert Stern to Mr. Burton, dated 9th August 1940

On 9th August 1940, Stern wrote back to Mr. Burton agreeing that the S.V.D.C. would assist in the design of an amphibious tank and that they would need £100,000 for the production of a pilot model.

Sir Albert Stern Stern invited Mr. Burton and General Pope to meet directly with the SV.D.C. on 12th August to discuss the exact requirements for this amphibious tank. General Pope, however, was unable to attend but forwarded to them the requirements as document ‘Specification 1.A Amphibious Tank Operations’ with the clear goal “to land tanks on an open beach in the face of enemy resistance and to gain a bridgehead 3 to 5 miles [4.8 – 8.0 km] deep to cover the landing of other troops”, certainly no small requirement.

The S.V.D.C. were to be tasked with investigation of a design which could be launched 200 yards (183 m) from the beach and navigated to shore above or below water if necessary and both of those options came with advantages and disadvantages alike. There was even the possibility of considering “fitting the necessary tracks and armour to a boat with some sea going powers but limited cross country performance” although the obvious impracticalities of such an idea were as apparent then as they are now. The S.V.D.C.-designed amphibian would have to be designed, trialled, and approved, and built in large numbers to be available by 1st April 1941 – less than a year away!

Armor was not going to be ignored as it had on the very limited attempts at amphibious tank work beforehand. This vehicle would have to be proof against all enemy small arms fire, including armor piercing bullets at normal impact at all ranges as a minimum. Further, the front of the tank should be able to resist the German 37 mm gun at normal impact at 300 yards (274 m). Armament, as dictated by General Pope’s requirements, was not the 6 pdr. Stern had been looking at the venerable 2 pounder. This was obviously going to be a disappointment in terms of not getting the bigger gun mounted but was a logical move given the incredibly tight time constraints needed. Adoption of a known and proven gun meant a lot of savings in development time. Alongside this gun was to be a 7.92 mm Besa machine gun and both weapons were to be mounted in a turret. Interestingly, there is no mention at all of a hull-mounted weapon of any kind.

Crewed by 3 men, a commander, gunner, and a driver, the tank would have to be able to manage 8 – 10 mph (13 – 16 km/h) on land cross country and negotiate water (either above or below the waves) at 4 knots (7.4 km/h).

Dimensions of the tank would be somewhat dictated by the need to cross trenches and climb steps but these requirements were far below those set for the other TOG tanks back in September 1939. This time, the need was to cross a gap 5’ 6” (1.7 m) wide and a step just 3’ (0.9 m) high. The vehicle would only need a range of operation of 50 miles (80 km) but would have to be able to climb up wet, loose, shingle beaches and be “capable of operating under tropical and European conditions”. The inclusion of a No.11 wireless set (or equivalent) as well as an inter-troop radio set completed the needs identified by the Army for the tank.

By 19th August, just 10 days after receiving the order, the SVDC had finished their design whilst still working on TOG-1, a new hydraulic system for TOG-1A, and the new primary heavy tank TOG-2, amongst other work.

The SVDC surmised the amphibious tank into 3 key considerations. Firstly, it had to be ready for action the moment it got to the beach – there would be no time to shed buoyancy packs or screens. Secondly, it would have to be immune to enemy fire, including strafing or bombing by enemy aircraft during the water phase of the assault and be as light and small as possible. Thirdly, by making the vehicle as small as physically possible, the armor requirements would likewise be kept as small as was possible whilst still meeting the requirements for protection which had been set. When Stern released the SVDC designs of the tank, it was to be 18’ 9” (5.7 m) long and just 7’ 9” (2.4 m) wide with the hull an incredibly small 3’ (0.9 m) high.

Accounting for a ground clearance of just 15” (0.38 m), this would mean that the top of the hull would be a mere 51” (1.3 m) from the ground. The driver would likely have to be lying a little supine in order to fit. What this tight design would do was to keep the weight to just 14 tons (14.2 tonnes) (plus or minus 10 %) (12.6 to 15.4 tons / 12.8 to 15.6 tonnes). The design produced was a tank which was only slightly lighter than the 16-ton (16.3 tonnes) Valentine (Infantry Mk. III) tank which also mounted a 2 pounder gun and was a little shorter than this vehicle. It proved to be unsuitable for amphibious wading.

An alternative method of unloading tanks on shore shown here with a Valentine (Infantry Mk. III) was fine on a beach like here in Sierra Leone where no enemy awaited the vehicle. This method was obviously hopeless for an opposed landing. Source: Imperial War Museum

“war should not be handled in this way.”

Report of Interview between Sir Albert Stern and Herbert Morrison, dated 3rd September 1940

Work continued through 23rd August with General Pope still adamant on the need for an amphibious tank and it was one of three topics of discussion at a meeting held on 3rd September 1940 and also to discuss the growing rift between Sir Albert Stern and Mr. Hopkins, the Director of Naval Land Equipment (N.L.E.). The N.L.E. felt out of sorts that the S.V.D.C. had been tasked with designing a tank to operate at sea, when the sea was something they felt was in their domain.

Yet, at the same time, Mr. Hopkins was perfectly happy to be carrying on a programme of development of an enormous trench digger which took engines from the S.V.D.C.’s own projects, having no qualms about his Department developing a land-based vehicle.

It is hardly any wonder that efforts at a high level took place to keep Mr. Hopkins away from meetings where Sir Albert Stern was going to be present, likely to protect him from the critique of that hypocrisy which would be inevitable. The split in the relationship of the two was not helped by the decision by Mr. Burton in September to strip from the S.V.D.C. of the role (still officially unofficial) of design responsibility of the amphibious tank and hand it to Mr. Hopkins at the N.L.E. telling Stern to “give out advice” – an optimistic sentiment all things considered and a slap in the face of Stern and the S.V.D.C. who had completed their design. With the obviousness that Stern would not work like that, Mr. Burton did eventually relent and agreed that the N.L.E. and S.V.D.C. should work together on the design and produce a working model.

That issue, amongst others connected with the other TOG designs, only served to illustrate and prove Stern’s point to Mr. Morrison that there was a need for a separate body solely in charge of tank design. A point he omitted no chance to press for and would not get. S.V.D.C. work officially ceased on 10th September 1940, all work was to go to the N.L.E. instead although the N.L.E. did continue to use the expertise of Mr. Ricardo for his engine expertise for some time afterwards.

Under the Sea

Valentine Tank fitted with the Duplex Drive floatation system – a large screen to displace enough water to make it float. The vehicles using this system were vulnerable to overtopping by waves and the canvas could easily be perforated by enemy fire. The tank could not fire back with the screen deployed. Source: Divernet and BBC respectively

The biggest difference between this SVDC vehicle and preceding designs was going to be that this vehicle was not going to try and float, but drive on the sea floor instead. The logic for this decision was as simple as it may be initially counter intuitive. Whilst on the surface, on pontoons or with a screen (like a Straussler system), a tank would be visible to the enemy the entire time and unable to fire back. At the mercy of enemy gunnery, casualties could be inflicted even before they reached the beach, at which point the encumbrance of the floatation equipment would be a big problem. Indeed, in 1940 this had not yet been overcome with Straussler equipment, explosive removal of wading equipment and waterproofing compounds to seal the vehicle.

The 1940 solution for the SVDC was both unusual and innovative in that, whilst on the seafloor, the tank would be completely immune to enemy fire and be able to rise out of the water at the surf instantly ready to fire on the surprised enemy watching these poseidon-esque vehicles rising from the depths.

On the sea bed, the tracks would be able to engage with the sand and shale at a higher speed than on the surface without worrying about a rip tide or breakers. In fact, the SVDC estimated a sea floor speed of 6 knots and, at the same time, completely removed the complications of a propeller or the as-yet-to-be-designed steerable water jets from Messrs. William Foster and Co. As the vehicle was in contact with a tractable surface (sand and shale of the beach) there were no worries about the vehicle becoming trapped in the surf onshore, as could easily happen with a floating tank with little purchase on the beach at this key point. A large vulnerable floating target therefore stranded on the foreshore like a whale could be avoided by just being underwater could the equal risk of becoming damaged on the way to shore with a pontoon becoming holes and the tank capsizing or sinking.

The obvious question over an underwater vehicle is the problem of keeping water out, however this is not as big of a problem as may be imagined. With a submersion duration of just 3 minutes, a small bilge pump capable of pumping 30 gallons (136 litres) per minute against a head of 25 ft. (7.6 m) of water was more than adequate for the task. The next obvious problem is air for the crew and engine. For the engine, this was provided for with tanks of compressed air and for the crew by simply battening down the hatches to prevent air escaping. There was plenty of breathable air inside the volume of the hull and turret for the time submerged. It is not that there was no time for escape either. Designed for submarines, the Davis Escape Apparatus was already available in 1939 and, by 1944, the Tank Underwater Escape Breathing Apparatus would also be widely available. That piece of kit provided up to 7 minutes of oxygen for each crew man to get to the surface of the water in case of a problem requiring escape.

Navigation underway was to be aided by means of a spot lamp on the turret and a compass, although it was accepted that submerged rocks might be a problem for which there was no easy solution, although most of the large ones had already been well charted.

Deployment

In order to protect the vehicle during the water phase of the assault, Sir Albert Stern, a man who was himself an amateur sailor with some experience in boats, proposed the use of a large ship to deliver the tanks. That ship would have to have a draft of at least 18 to 20 feet (5.5 – 6.1 m) and launch the tanks into water about 25 feet (7.6 m) deep via a ramp. As many tanks as possible should be packed onto that ship to maximise the weight of tank-force being delivered to the shore and this, with the ship size, meant deploying up to 600 yards (549 m) from shore instead of 200 yards (183 m).

In an October 1940 report, Mr. Ricardo suggested a suitable ship as a repurposed whaling vessel about 10,000 to 20,000 tons (10,160 to 20,320 tonnes) in weight, as they had ramps capable of dealing with whales weighing 80 to 100 tons (81 to 102 tonnes) and could launch “several hundred small submersible tanks” very quickly.

Armor

The TOG amphibian had to be proof against all enemy small arms fire including armor piercing bullets at normal impact at all ranges as a minimum. In addition to this, the vehicle should ideally be able to resist the German 37 mm gun at 300 yards (274 m) at normal impact although absolute immunity was accepted as unattainable for the tank.

To meet these needs, the first step was to make the tank as small as possible so as to present the minimum possible target to the enemy.

On top of that, armor not less than 2 ½” (63.5 mm) was proposed on the front, although 2” (50.8 mm) would probably be sufficient if needs be, especially where normal impact was unlikely. Side armor was to be substantially thinner, just ⅞” (22.2 mm) thick and with floor and roof plates between 3/8” and ½” (9.5 to 12.7 mm) thick.

Automotive

The primary manufacturer for pilot models for the S.V.D.C. was Messrs. William Foster and Co. of Lincoln and they had no experience in building amphibious vehicles. They did, however, have experience building barges for the Admiralty. Those barges were specifically designed to obviate the need for propellers for propulsion, as a propeller would be damaged by hitting a beach. The same sort of thing was going to be true of this tank design and the solution offered was to be the same too. If the tank was going to float, it would use jet propulsion instead of a propeller, even though the lack of a keel made those barges hard to steer and this would be the case with a floating tank too. The solution was to create a new design of a steerable jet instead.

Ground clearance was to be 15” (0.38 m) and the tank would run on tracks 18” wide producing a ground pressure of just 6 lbs. sq. in. (41.4 kPa). This very low ground pressure would assist in the obviously saturated ground it would have to drive on under the water but the bigger problem of being underwater was buoyancy.

Buoyancy was obviously essential if you wanted to float but here the important part was to not be buoyant. Floating was to be avoided and buoyancy was a function of the mass of water displaced. This tank was to weigh 14 tons (14.2 tonnes) so, if it displaced more than 14 tons (14.2 tonnes / 14.2 m3) of water, it would float.

The S.V.D.C. calculated the actual buoyancy of the tank as just 8.5 tons (8.6 tonnes), meaning that the effective weight of the tank when submerged was just 5.5 tons (5.6 tonnes) reducing the ground pressure to an incredible 2.5 lbs.sq.in. (17.2 kPa). Bearing in mind an average human exerts a pressure of about 8 lbs.sq.in. (55.2 kPa) reducing this to just 2.5 lbs.sq.in. (17.2 kPa) was exceptional.

A lesser-appreciated problem of running a vehicle underwater is that of engine cooling. With the engine compartment having to be sealed off during transit, the radiators would be out of action and this meant that the cooling would have to be able to work with a high water temperature, something which ruled out the possibility of simply cooling the engine with sea water.

This issue was resolved by use of a heat exchanger arranged in series with the radiator so that a fresh water cooling system could be retained, which could be the primary cooling on land. When submerged, the air intake shutters could be closed to keep sea water out and have the heat exchanger dump the engine heat to the external sea water. Even less of a problem was the exhausting of gases from the engine. Even against a head of 20 ft. (6.1 m) of water, the engine exhaust could comfortably bubble out the gas, although this would cause large bubbles on the surface of the water (the bubbles will expand on their way to the surface courtesy of Boyle’s law). If complete secrecy was needed, then these bubbles bursting out on the surface of the water could be disguised by means of a simple canvas pipe from the exhaust pipe of the tank to the small float on the surface. As soon as the tank surfaced on the beach, the canvas tube would drag behind and rapidly burn off from the heat, removing the need for someone to get out to take it off.

Air for the engine was to be provided for by one of two possible solutions. The first was the use of a 3” (76.2 mm) diameter telescopic tube to the surface of the water, but this was vulnerable to damage. The alternative, and the solution which was selected, was provided for by means of compressed air. It was calculated that the effort of driving the tank in the water-medium instead of air would waste 50 hp of the engine, so that 5 knots was the realistic submerged speed. At that speed, it would take 3 minutes to reach fresh air and, with the engines consuming around 1.3 cu. ft. (3.68 x 10-3 m3) of air per hp. per minute, a 3 minute journey would require 200 cu. ft. (5.66 m3) of air. In order to allow a margin of safety, two 400 cu.ft (11.3 m3) cylinders would be fitted, providing a 4:1 safety factor. With the engine power wastage through water and at the sprocket (an additional waste of 0.5 hp per ton per mph) and with a mechanical transmission efficiency of around 80%, the minimum engine size of 70% in an ideal world would actually would have to be 87.5 hp, which led the S.V.D.C. to decide an engine of not less than 90 hp was needed.

In considering an engine, there were two options. The first was a Ford V8, and the second was an engine from Vauxhall Motors, as used in the Bedford lorry. Both could produce the 90 hp required from 67 octane petrol but would also consume more air than previously planned for, specifically around 350 cu. ft (9.9 m3) of air for that 3 minutes of submerged driving. The adoption of the two 400 cu. ft. (11.3 m3) air tanks would still be sufficient and reduced the margin of safety from 4:1 to just 2.25:1.

Of the two engines, the Ford V8 was shorter, so this was chosen as the preferred motor.

Armament

At the time of the instigation of the TOG Amphibian programme in July 1940, the primary British tank gun was still the 2 pounder. A gun of 40 mm calibre, the 2 pounder was an excellent weapon capable of knocking holes very effectively through the armor of even the heaviest German tanks of the day. It was, however, seen by General Pope as having had its day. There was another gun on the drawing board for tanks and that was a 6 pounder gun. Not the low velocity 6 pounder of WW1 era tanks, but a new gun firing an armor piercing capped (APC) round as well as a usefully large high-explosive round. The old 2 pounder did have a high-explosive shell for it but it saw little service due to the very small charge it carried.

The Army, however, at this time, had at best an ambivalence towards this new gun, due in no small part no doubt to the lack of any tank able to carry it at the time.

The only design, in fact, for which the 6 pounder had even been tried on by this time was the A.12 and that project had ended that month, leaving Sir Albert Stern and the SVDC as the only people interested in it.

Sir Albert Stern was pressing the case hard at this time for adoption of the 6 pounder, in part for TOG-2 but also because he, like General Pope, clearly saw the need for a bigger gun than the 2 pounder for tanks. When Mr. Burton approached him that month then, it would have been no surprise at all if the 6 pounder formed the basis of the armament for both the airborne and amphibian designs the S.V.D.C. considered. Other than a note of the gun for the airborne vehicle, however, it was not to be. General Pope’s requirements were clear and called for a 2 pounder gun instead, and a 2 pounder gun it would have to be.

The gun had been chosen for them but the turret and diameter had not. Stern proposed the adoption of a turret with a diameter of 4’ 6” (54” / 1,372 mm), which would be armored to match the hull, producing a turret around 3.75 tons (3.81 tonnes) in weight when fully armed. This turret ring was slightly smaller than that used on the A.12 Matilda (54.3” / 1,379 mm) and A.22 (54.25” / 1,378 mm) but was exactly the same size as the turret diameter for the Cruiser Mk. III and IV (A.13). This is suggestive that it was to be an A.13 turret which would have been used, although it would have to have been uparmored to meet the frontal armor requirement.

When the N.L.E. did finally get around to producing an amphibian tank like this AT.1*,it was more boat than tank and a gargantuan target when on land. Despite decent armor protection, like the S.V.D.C. amphibian, these vehicles were bigger and heavier. The only thing they shared with the S.V.D.C. amphibian was that these also never entered production.

Conclusion

When the N.L.E. did finally finish their own amphibian tank designs in December 1940, they were nothing like the design from the S.V.D.C. Gone was any notion of being underwater. The N.L.E. machines would float. The N.L.E. continued to use the expertise of Mr. Ricardo even after 10th September 1940 and he revealed his views of their alternatives that October. In his report, Mr. Ricardo still emphasized the importance of a secret and safe underwater approach, still pushed for the S.V.D.C. design, and bemoaned the idea of a small floating tank. If a floating assault tank was to be used it should, he argued, be substantially larger and better armed. Mr. Ricardo felt that Mr. Hopkins made far too much of the water-elements of an amphibian tank considering it was only going to be in the water for a few minutes. Further, Mr. Ricardo set-aside much of Mr. Hopkins’ objections especially when it came to the engine stalling underwater and he was on good ground to do so – Mr. Ricardo had, after all, extensive experience dealing with engines for submarines. The result was that no S.V.D.C. Amphibian tank was ever built and for that matter, the British never fielded a dedicated amphibious tank at all during the war.

David Bocquelet's possible rendition of the TOG amphibian
David Bocquelet’s possible rendition of the TOG amphibian

TOG Amphibian Specifications

Dimensions (LxWxH) 18’ 9” (5.7 m) x 7’ 9” (2.4 m) x 4’ 3” (1.3 m), ground clearance 15” (0.38 m)
Total weight, battle ready 14 tons (14.2 tonnes) (plus or minus 10 %) (12.6 to 15.4 tons / 12.8 to 15.6 tonnes)
Crew 3, commander, gunner, and driver
Propulsion Ford V8 90 hp petrol or Vauxhall 90 hp petrol
Speed 8 – 10 mph (12.9 – 16.1 km) on land cross country and negotiate water (either above or below the waves) at 4 knots (7.4 kph)
Range (road) 50 miles (80.5 km)
Trench Crossing 5’ 6” (1.7 m)
Step 3’(0.9 m)
Armament 2 pounder gun and 7.92 mm Besa in turret
Armor Proof against any small arms AP fire at any range. Proof against 37 mm AT fire at 300 yards (ideal) at 90 degrees.
Front: 2 ½” (63.5 mm) thick, if needs be down to 2” (50.8 mm) thick where normal shell impact was unlikely.
Sides: ⅞” (22.2 mm) thick
Floor and roof: 3’8” to ½” (9.5 to 12.7 mm) thick
Radio No.11 wireless set (or equivalent) as well as an inter-troop radio set

Sources

Hills, A. (2017). The Tanks of TOG: The work, design and tanks of the special Vehicle Development Committee 1939-1945. FWD Publishing, USA
Hills, A. (~2021). Striding Ashore. The History of British Tank and Armoured Fighting Vehicle Amphibious Wading Development in World War II. FWD Publishing, USA
Letter from Sir Albert Stern to Mr. Burton, dated 9th August 1940
Report of Interview between Sir Albert Stern and Herbert Morrison, dated 3rd September 1940
Notes made by Chairman; Visit to Lincoln 14th and 15th August, by Sir Albert Stern
Letter from G. D. Burton to Sir Albert Stern, dated 12th August 1940
Secret note entitled ‘Amphibious Tank Operations’ 1A, undated
Recommendation from Sir Albert Stern for an Amphibious Tank, dated 19th August 1940
Memorandum by Mr. Ricardo on the subject of the ‘Amphibious Tank,’ dated 21st October 1940
War Office Training Film: The D.D. Amphibious Tank: Sherman III D.D., Mark II

Categories
WW2 British Prototypes

Morris-Martel Tankettes

United Kingdom (1925)
Tankettes – 10 Built

Sir Giffard Le Quesne Martel was arguably one of the most important men in early British tank development. During the First World War and in the immediate aftermath, he served in the Royal Engineers. During this period, he became heavily involved in the development of tanks and bridging. As a gifted engineer, during his life, he would construct no less than three armored vehicles at home. His first design was a one-man tank.

Martel driving the second of the AFV’s he built at home. Here, he is in his four track tank, which he built while serving in India. Source: Locomotion Horsenomes

Major Martel began work on his one-man machine in January 1925. He looked at recent developments in warfare exposed by the Great War. The basic problem was to protect the infantryman and enable him to advance while giving enough firepower that he might outfight the enemy. This had, eventually and after much technical and doctrinal evolution, led to the tank.

However, a tank grouped several soldiers into one large target. In order to counter enemy anti-tank weapons, there seemed to be two possible alternatives. The first consisted of having the speed and mobility to avoid getting hit. The other option was to dramatically increase the armor protection of the tank. Major Martel saw this latter option as feasible from an engineering point of view. However, in a cash strapped post-war British Army, Major Martel knew that financial constraints would prevent such a solution. Building a large heavily armored tank would require stronger engines, thus increasing the cost above what the Treasury was willing to fund.

Major Martel saw a third way. What if the tank concept was boiled down to its smallest, most minimalistic design possible? By making a one-man tank which is immune to enemy small arms and armed with only a light machine gun, armoured units could vastly outnumber any potential anti-tank weapons and overwhelm them. Equally, the small size would make it significantly easier and cheaper to create such a vehicle with good mobility characteristics and would also make it harder to detect and easier to conceal.

The Martel One-Man Tankette

With this in mind, Major Martel started drawing up plans for a new class of vehicle, one he named “the Tankette”. These plans were completed by February 1925, and he started construction of the tank on a rotating table in his garage.

The Martel Prototype made of wood and painted grey. The large stabilizer wheels were replaced by smaller versions with solid rubber tyres on the later models. Source: Alternative Finland

The prototype one-man tankette was powered by a Maxwell 20 hp petrol engine, mounted on the front of the vehicle, connected to an axle taken from a Ford car. The tracks and suspension were purchased from Roadless Traction Ltd, while the large spoked wheels at the back came off an old Federal lorry. The body was made of wood, but Major Martel was careful to add extra ballast to represent the weight of armor. Work was completed in August, and the first trials showed some minor problems, such as the tail stabilizer being too lightly sprung.

At the time, Major Martel lived at the Brown Cottage in Camberley. This town was home to the British Army’s Staff College. One afternoon, Captain B.H. Liddell-Hart, who worked at the college, was taking a walk through the countryside when he came across Major Martel, who was calmly taking his home-built tank for a drive. He stood there dumbfounded and watched as Major Martel took his creation through its paces over the surrounding countryside. He went away and wrote an article for the Daily Telegraph, drawing upon Arthur Conan Doyle’s Ivanhoe for mental imagery. This piece published on 28th August 1925 brought the idea to the attention of the larger world.

‘Surprise changed to awe when this twentieth century man-at-arms, mounted on his mechanical charger, climbed out of the road up an almost perpendicular bank at least four feet high, raced across a stretch of rough gorse country at a speed no runner could have approached and no horseman would have cared to attempt across such ground, turning abruptly in such a narrow circle that would have been the envy of a London taxi-driver. Next it headed for a small but steep hill, climbed it unfalteringly at a speed of 6-7mph, then threaded its way through a tree plantation which a horse or pack-mule could barely have traversed.’
Captain B.H. Liddell-Hart, Daily Telegraph, 28th August 1925

Nearly all British service tanks prior to this time had been large and relatively slow machines. Here, in front of Captain Liddell-Hart, was a tank that he described as about the size of a horse, with mobility that exceeded the cavalryman’s. There was a loophole that a small arm, likely a light machine gun, could be fired from. Captain Liddell-Hart saw this machine as a cavalryman who was immune to small arms. A series of demonstrations of the machine followed, many of which were held at the Staff College.

One becomes Two

The result of these demonstrations was that the War Office commissioned two vehicles to be built. Major Martel suggested Morris Commercial Motors Ltd. as the manufacturer. This involved changing the engine to a Morris 16 hp petrol one. Of the two tankettes to be manufactured, one would have a one-man body, while the other would have a two-man body. The bodies of each vehicle could be changed at will. The armored hulls for these were mostly identical, apart from the fighting compartment, which was wider on the two-man version. Morris designed the chassis to be identical in both cases. For example, the steering wheel, and gear levers, were in the center of the compartment, while the pedals were set to the left-hand side. This meant that, while the driver of the two-man machine would have access to all the controls, the gunner would be limited to the steering wheel only.

This interchangeability was because Morris’ designers were thinking ahead. They thought that, if the War Office was to pay for the tankettes to be produced, then the chassis without an armored body could be sold separately as a tractor. Thus, the company could use the government to pay for all the expensive items such as developing, fault correcting, and setting up the production facilities. Then, when the chassis rolled off the production line, either a one-man or two-man armored body could be bolted onto it, or a soft skin tractor body could be installed. Such a scheme could, theoretically, create significant profits.

The Morris-Martel one- (top) and two- (bottom) man machines, handily demonstrating the minor differences, and the wider crew compartment. Source: Live Journal

As it would turn out, the chassis was wholly unsuited for use as a tractor, so this plan came to naught. Although unrecorded as to why the venture failed, it is likely down to the differing needs of tractors and tanks. A tractor would need the ability to pull objects such as plows and trailers, while the tankette would need speed and mobility. Thus, a tractor’s gearbox has to operate under a different load profile than a tankette’s.

The Morris-Martel tractor. This was a tractor body (consisting of little more than a bonnet) fitted over the same basic chassis that was supplied for both of the tankette versions. Source: Live Journal
Two pictures of the naked Morris-Martel chassis showing off the steering arrangements and mechanical layout, as well as the basic controls.
Source: IWM, Martel Papers

In late 1925, Major Martel completed his detailed drawings liaising with Morris Ltd., and construction began. The first vehicle, a one-man machine, was completed in February 1926, its body was made from 8 mm mild steel. When weighed, it came in at 1 tonne over its projected weight of 2 tonnes. To reduce this 3-tonne weight, a redesigned chassis was developed with all spare weight savings that could be engineered incorporated, along with a reduction of the armor to 6 mm, which would not have been bulletproof. Trials at an abandoned mine showed that the 3-tonne weight was not that great a problem, so the armor was increased back to 8 mm, which was the same armor value as the standard British tank of the time, the Vickers Medium.

After testing during 1926, the War Office finally settled on the two-man design. This selection was down to the number of crew. The two-man design was seen as a better choice due to the extra crewman. In December, eight two-man machines were ordered. These, along with eight competing Carden-Loyd Mk.IV machines were used by the Experimental Mechanised Force in August and September 1927. Despite the small numbers involved, the Experimental Mechanised Force which ran the testing immediately demanded more machines for use during the 1928 maneuvers.

Morris-Martel two-man on maneuvers with the Experimental Mechanised Force
Source: IWM, Martel Papers

Due to the failure of the Morris plan to modify the chassis into tractors for the civilian market, Morris did not want to spend any more effort on developing the Morris-Martel. This quickly led to the death of the series and of the type.

In comparison, Carden-Loyd was happy to undertake the development of their machine in-house, freeing the War Office of the financial burden. This in-house development led very shortly to the successful Carden-Loyd Mk.VI, and in turn through to the Universal Carrier. From there, it is possible to trace a line of development that ran all the way up to the FV432 in the mid-1960s.

Publicity shot with a Carden Lloyd Mk.VI loaded with Vickers Machine gun, three archers and a halberdier. This picture seems to be trying to link with battles such as Agincourt and Crecy. Source: War Thunder

Description of the two-man version

The Morris Martel Two-Man tankette had its engine at the front of the vehicle, with the fighting compartment behind the engine. A radiator was at the front, under the bonnet. The bonnet nose was angled, with louvers in it. The transmission was behind the engine, running under the fighting compartment, being connected to the two drive sprockets. The exhaust ran on the left side of the fighting compartment, outside the armor. On either side of the engine were the tracks of the vehicle. The drive sprocket at the rear and the idler wheel at the front were both large and made contact with the ground. Two small double rubber-rimmed road-wheels completed the running gear. It is unclear how or even if any of the wheels had a suspension attached to them. A mud chute was present above the two road-wheels, meant to prevent mud from falling from the track onto the road-wheels.

The fighting compartment had the gunner on the right, manning a .303 Lewis gun with limited traverse and elevation. It is unknown how much ammunition could be stored onboard. The driver was on the left. The seats for both men could be raised and lowered to allow them to drive head-out or behind the armor. The driver had a vision slit to see when he was driving behind armor. It is unclear if this was in any way protected by a blind or by a bulletproof vision block.

At the rear of the tank were the stabilizer wheels. These had multiple purposes. They were meant to prevent the tank from tipping backward when running up slopes or hard terrain. These wheels also acted as a complementary means of steering the vehicle. Steering in other tanks at the time was done by braking one of the tracks and keeping power to the other, somewhat similar to how a small boat is steered using paddles. However, this means that the vehicle slows down because one of the tracks is stopped, that half of the power of the engine was wasted (differentials and Cletrac systems were not yet invented or in common use), and that significant wear and tear was applied to the brakes, clutches, and tracks.

On the Moris-Martel, the rear wheels worked as a very useful alternative when going on roads or hard terrain and doing relatively shallow turns. The vehicle could then turn using the wheels only, functioning like when a car is driven in reverse (wheels turn to the left when the vehicle turns to the right). This could be done without applying the brakes, without wasting engine power, and reducing wear on components.

When harder turns were required or when running on soft ground or gravel, the tracks could steer as usual. While this dual system did have its advantages, it was largely abandoned due to the added complexity and weight implied in having a secondary steering system.

Two headlights were placed in front of the fighting compartment, on either side. Two mudguards were placed at the rear of the vehicle, running from the fighting compartment to the rear wheels.

Conclusion

While the Morris-Martel would never go beyond the handful of chassis used for experimentation, it would give birth to the idea of the tankette, a class of vehicle that would become one of the oddities of the interwar period found in many countries’ arsenals. These descendants would take part in the wars leading up to, and the first stages of the Second World War.

In the United Kingdom, the concept of the tankette would go through several permutations such as the Crossley-Martel and Carden Loyd One-man machines. Martel would return to the concept that gave birth to the Moris-Martel one-man tank in the mid-1930s with the Mechanical Coffin. In the end, all these ideas would die out. However, the two-man machine would lead into the most produced armored vehicle in history, and one of its most successful, the Universal Carrier.

Morris-Martel Tankette Prototype
Morris-Martel One Man Tankette
Morris-Martel Two Man Tankette

Illustrations by Mr. C. Ryan, funded through our Patreon campaign.

Morris-Martel Tankettes specifications

Total Weight, Battle Ready 3 tons
Crew One or two depending on the body.
Propulsion Morris 16 hp petrol
Armament 1x .303 Light machine gun, or personal weapons
Armor 8 mm
Total Production 10

Sources

Martel Papers, IWM.
Private correspondence with Oliver Boyle

Additional images:
These images all come from the IWM, Martel papers.
Commercial Motor Magazine article on the Morris-Martel tractor

Categories
WW2 British Prototypes WW2 US Prototypes

Bechhold Tank

USA/United Kingdom/Belgium (1938-1941)
Light Tank – 1 Partial Prototype

Introduction

Many people interested in tanks have likely heard the name Walter Christie and are aware that he produced several prototype tanks during the period between WW1 and WW2. Whilst his vehicles had some good features, overall they were not a commercial success for Christie, who had amassed a lot of debt in developing and building them. The result was that some of his assets, his tank prototypes included, ended up being used to pay off his debts and his ‘high-speed tank’ was one of them.

Sold to pay off Christie’s debts, this vehicle ended up in the hands of a German-born American businessman, Siegfried Bechold. This new owner rebranded the tank, had some additional design changes made and then, at the start of WW2, tried to sell the ‘new’ design to both the Belgians and the British.

The Belgians needed tanks urgently but this design would come too late to help them. The British expressed interest as the light weight of the machine was suited to their need for a tank for airborne operations, and by 1940 the British Purchasing Commission was actively considering the vehicle for production. Nonetheless, the idea was over by 1941, when British attention switched to a vehicle with more armor and firepower than the ‘Bechold’ tank. Even so, this early design and the consideration of it adds to the story of how the British were trying to develop their own ideas for a new kind of mobile warfare and airborne operations.

The enigmatic Mr. Bechhold

The name Siegfried Bechhold means very little even to the most ardent tank enthusiast. However, just prior to WW2 and into its first years, Bechhold was one of the most prominent men involved in tank design and production in America, despite never having produced any tanks. This peculiar state of affairs takes some digging to get to the bottom of, as does the man himself, not helped by his name appearing variously as Bechhold, Bechold, and Buchhold.

Siegfried Bechhold appears to have been born in Bavaria, Germany in 1900, although a newspaper article from January 1941 puts his birthplace as Holland. This is likely one of those situations where people de-Germanized themselves to try and disguise their German ancestry, something which was a common occurrence at the time, especially with the switch from ‘Deutsch’ to ‘Dutch’ in terms of self-description. Another account of his early life (from April 1941) stated that he was born in Bavaria and lived in Germany until he was 11 – so maybe his family moved to Holland or maybe he was just hiding his background.

Bechhold recounted his story that, at the age of 16 (so ~1916), he was, like tens of thousands of other German boys, drafted into the German Army during World War One, although it is not known if he saw any active service or not. By 1922, with WW1 behind him but in a country ravaged by economic and social problems, he managed to make the transatlantic voyage to the United States, arriving in New York with just US$40 to his name.

His first jobs were very poorly paid but, by the late 1920’s, he was living as a tenant at 34 East 62nd Street between Madison and Park Avenues (this house was demolished in an explosion in July 2006). He had been learning English at night school and had managed to get a job as a salesman, which proved very successful for him. So successful was it, that this man, who had arrived in the USA just a few years before, could now afford to travel back and forth to Europe. He would later claim that he used these trips to pass on information about German rearmament efforts during the early 1930’s and that he believed that Germany was far ahead of other countries in weapons development, although this sounds more like his sales-speak for selling tanks than the serious recollections of an international spy.

What is known though is that during this time, he, like many others, saw the tanks of Walter Christie. These were very well covered in the newspapers and newsreels of the age with Christie’s penchant for publicity stunts. Seeing a potential business opportunity, Bechhold was interested in these tanks which were significantly faster than other tanks of the age, and in many ways the most advanced tanks in the USA at the time.

Bechhold later reported that he was encouraged in his interests by Congressman Ross Collins of Mississippi, although how these two men knew each other is unknown. It was, according to Bechhold, Collins who encouraged him to produce tanks in the United States but Bechhold was not a technical man nor an engineer despite being Vice President of the Bethlehem Engineering Export Corporation of Wall Street, New York. He was skilled in salesmanship and finance. He was, however, despite his lack of engineering skills, to be credited in the US press as coming up with the idea of putting lightweight aircraft engines into tanks in place of ordinary diesel or petrol engines, although this too sounds more like the pitch of a salesman, as Christie had already done this years beforehand.

As an aside to his tank work and to give a flavour of the way in which Bechold was trying to avoid being labelled as anything other than as a patriot, he embarked on a vigorous self-justification campaign in the media, making sure no one was in any doubt as to his loyalties. As a result, in June 1941, it was reported that Bechhold, a naturalized citizen and “intense” patriot, had refused to sell his tanks to the Russians at the time of the War against Finland. Furthermore, it was claimed that, in the new war against Hitler, he would only sell them when the Russians went to war with Hitler, even though there seems to be no evidence whatsoever for this claim.

The Tank Company

By the end of the 1930’s, Bechhold had his opportunity. Walter Christie, a man of undoubted technical gifts, was running short of investors who wanted to keep losing money on his tanks. One vehicle of his, a “high-speed tank”, had to be handed over to the partners of the Hempsted Welding Company of New York, William and Alfred Christ, as a lien against unpaid debts owed to them by Christie. Exactly which of Christie’s vehicles this was in unclear but as the M.1938 was later presented by a Mr. Bigley with some involvement from Christie suggests that Bechhold got hold of the M.1937 high speed tank from Christie as the basis of his design. However, whilst exactly which vehicle may not be known, Christie’s creditors were to be appeased with a tank available for purchase to pay his debts.

Bechhold had, through Bethlehem Engineering Co. been engaged in a commercial contract with Christie which started on 9th August 1938 whereby Bechhold and his company were granted exclusive rights to sell and manufacture the design from Christie for the princely sum of US$5,000 (just over US$91,000 in 2020 values). The idea of the partnership was simple. For this initial outlay of cash to Christie, Bethem Engineering would take the full blueprints of the design, market them globally and grant manufacturing licences for US$50,000 to each national licensee. This US$50,000 (US$915,000 in 2020 values) would be split 50:50 between Bethlehem Engineering and Christie for which the licence got not only the blueprints but also a master mechanic or draughtsman from Christie. This agreement simply fell apart not least in part to how appallingly badly written and complicated it was. In the words of the New York Second Circuit of Appeals in July 1939 ruling on whether to grant an injunction against Christie for breach of his contract:

This contract is so obscure, and, strictly taken, so incoherent, that nobody can be sure of its meaning, but so far as we can spell it out, this is what it was. The defendants made the plaintiff its exclusive agent to sell licenses to prospective manufacturers of their tank in foreign countries — perhaps also in this country as well, though apparently it was not included. The plaintiff was not free to sell such licenses generally, but only for those countries where the parties thought it “practical” to do so. The minimum license fee was to be $50,000, but the plaintiff was to try to get more, and the parties were to discuss the amount in advance: probably this implied that they should agree upon it.
105.F.2d 933 (2nd Cir. 1939)

With the case between them ending in confused acrimony, Christie and Bethlehem Engineering’s relationship was over. Christie had won that case due not least in part to how confusing the agreement was between them over rights and whilst he had retained his rights over his design he was also financially crippled.
Bechhold too had moved on and was no longer involved with the Bethlehem Engineering Expert Company and, instead, on 25th July 1939 (just 2 weeks after the ruling), formed the Armored Tank Corporation (A.T.C.), incorporated in New York. Initially, this company had just 100 shares of stock (30 Class A, and 70 Class B) at a value of US$50 each (Total nominal value US$5,000).

The purpose of the company was to acquire the Walter Christie high-speed tank from William and Alfred Christ. On 31st July 1939, this tank was purchased for an undisclosed sum along with 34 shares (Value US$1,700) in the new company (6 more were given to the attorney for their legal services). The Armored Tank Corporation (A.T.C.) of New York was now in possession of the Christie High-Speed Tank, the rights over which had fractured the relationship between Christie and Bethlehem Engineering. Bechhold now had the vehicle and also the more difficult task of making money from it.

Belgians

Within a few months of formation of the company and the purchase of this High-Speed tank, Bechhold was recruiting a draughtsman. Between December 1939 and January 1940, A.T.C.’s draughtsman prepared blueprints and drawings of this Christie tank with some modifications. During this time, a license agreement for the production of this modified Christie high-speed tank was acquired in Belgium. The Belgium firm, Ateliers de Construction de Familleureux, paid an advance royalty of US$10,000 for this license. Whatever plans there were in Belgium for this vehicle though are unknown, as the nation was overrun by the Germans in May 1940, with no Christie tanks produced.

Super Tanks

By the end of 1940, the first glimpse of what A.T.C. was working on can be seen. In November-December that year, it was advertising ‘Super-Tanks’ in the US Army Ordnance Magazine as being “built in all weights” by the Armored Tank Corporation at 30 Church Street, New York. This was formerly the location of numerous businesses such as the National Manufacturing Company, American Locomotive Sales Corporation, and the New York Railway Club (close to the site of the World Trade Center Complex today and now the location of the Century 21 Department Store). The same advert appeared that same month as being constructed by the Pressed Steel Car Co. as well.

Image of a Bechhold Tank
Image of a Bechhold Tank dated 1940, published November/December 1940. Source: Army Ordnance Magazine
Image of a Bechhold Tank
Image of a Bechhold Tank published early 1942. Source: Crismon

Although the tank was never built as shown in the 1940 image with the low cylindrical turret there was a photo of a mockup of the Bechold tank was circulated in the press by least the early part of 1942. This vehicle had the same distinctive rounded nose glacis and two hatches in the driver’s plate. Off-center to the left of the driver’s plate, next to the left hatch was a mockup of a gun of unknown type although it appears too large to be a simple machine gun. The gun is roughly in the same position as what appears to be a small machine gun on the 1940 artist’s impression. The most noticeable difference between the 1940 drawing and the mockup (other than the lack of turret on the mockup) is that 3 wheels can clearly be counted on each side along with what appears to be a pair of return rollers instead of 4 wheels with no return rollers. Also apparent is that whilst the return rollers appear to be real, the photo may have been editted to make the vehicle appear shorter than it was.

Based on the available photograph, the drawing, and information from the company’s advertising of it being “Built in all weights”, a brief analysis of the vehicle shown is possible.

Advert for Bechold’s Armored Tank Corporation of New York.
Advert for Bechold’s Armored Tank Corporation of New York. Source: Army Ordnance Magazine

In December 1940, Bechhold was reported to have been producing ‘Medium Tanks’ for the British and had also submitted a design for an airborne tank. This tank was at the time being reported in the press as weighing 10 tons (9.1 tonnes), 14 ½ feet (4.42 m) long, fitted with armor one-inch (25 mm) thick with a single 37 mm gun and a machine gun. Also noted was that it would carry two sub-machine guns, suggesting a crew of just 2 or 3. A final note is that it was designed to be carried under “a Douglas plane”.

This description is immediately reminiscent of the Christie promotional idea of an underslung high-speed tank from 1936. In that artwork, a 3-wheel Christie turretless high-speed tank was pictured being carried under an Air Corps bomber.

The idea for the rapid deployment of tanks by aircraft
The idea for the rapid deployment of tanks by aircraft appeared in Christie designs as early as 1936. Source: Popular Mechanics. May 1936.

An idea of quite how a system for carrying a tank in this manner under a plane would work can be found in a May 1941 Patent. This was filed by Alfred Anderson, assignor to the Armored Tank Corporation for a ‘Hook-on-and-Release-Mechanism for Fighting Tanks’. This invention describes an invention for attaching tanks to aircraft, specifically slung below the plane, and for dropping the tank when in flight. This is a different system to the one from Christie – that one used a pair of scissor arms to grab and retract the tank.

Instead, four upside-down triangular fittings would be attached on the underside of the fuselage of the aircraft. Each held a hydraulically controlled actuator with a large stud pushed out on a spring. When hydraulic pressure was applied, this spring would compress withdrawing the stud back inside the actuator. This would release the tank, as these four studs were attached via holes into the body of the tank. These would not be disengaged simultaneously, but in pairs. The rear pair would disengage first, allowing the bottom of the tank to hang down as the carrying plane swooped in suicidally low over the ground. At a suitable point, the front studs would also then be disengaged releasing the front of the tank. The back end of the tank was then supposed to hit the ground first from a lower height, with the front end following. This method was intended to overcome the turning effect on the vehicle. The dangers to the vehicle crew and to the aircraft performing this maneuver cannot be overstated; this was really a system designed to get the plane and its tank shot down. Even if it did work and the tank was deposited safely to the ground, one wonders how long it would take the crew to become operational after such an experience.

Hook on and Release Mechanism for a Fighting Tank.
Hook on and Release Mechanism for a Fighting Tank. US Patent US2310887 of 1941
Christie M-1950
A depiction of the gantry arrangement on top of what is supposed to be the ‘Christie M-1950’ (albeit with a different number of road wheels). The gantry could not only attach a tank, but also raise it within the fuselage of the aircraft. Source: Steel Steeds Christie

The vehicle shown in that 1936 promotion art for Christie is different from the vehicle in the 1940 ATC advert though. For sure, ATC got a Christie High-Speed Tank but its vehicle is much closer to a vehicle the size of the M3 Stuart or even the M1 Combat Car. What can be seen from the advertising image is that it was a small tank with a distinctive rounded back end to the hull running on four closely-spaced Christie type wheels (and presumably Christie spring suspension too). No track guards or mudguards at all are shown. The track itself is very similar to the flat plate track of the Christie tanks.

The nose lacks any indication of the pointedness of the earlier Christie High-Speed tanks but is uniformly rounded leading to a long glacis sloping up to a slightly inclined driver’s plate. Where the glacis meets the driver’s plate, there are two structures that appear to be mounts for fixed hull machine guns. In 1940, it should have been obvious that fixed, forward-firing machine guns were utterly useless but it was an easy way to add what was thought of as additional firepower to a design and many tanks subsequent and independent of this one retained this feature, including the M3 Grant, M4 Sherman, and Canadian Ram.

The driver’s plate featured two rectangular hatches, each with a vision slit. Out of the front of the left-hand hatch was what appears to be a heavy machine gun. From the position of the hatches and hull weapons, it would appear to have had a driver mounted on the right and hull machine gunner on the left. A third man, the commander, would most likely occupy the turret. The turret itself, as drawn, is very unusual, looking like an overturned cooking pot. On the roof was a full size (it occupies the entire roof) hatch in two parts, each opening sideways. A series of slits were placed around the exterior of the turret and at least two machine guns, one forwards and one to the left. In total, the firepower for this vehicle as drawn was 4 machine guns and one heavy machine gun.

Presumably, the part about being built in ‘all weights’ was to mean that different options in terms of fittings, armor, and weapons were potentially on offer. Certainly, the specifications and look of the vehicle were very up to date given the parlous state of US tank development at the time. The T4 medium tank, for example, from 1935/1936, was a very promising design but was 13.5 tons and capable of just 35 mph with 3 machine guns. The Bechhold tank was, at least on paper, better armed, better armored, smaller (about 50 cm shorter), and faster. No surprise then that it was an interesting prospect for investors interested in lucrative future army orders.

The 13.5 ton Medium Tank T4
The 13.5-ton Medium Tank T4 – at 13.5 tons (12.2 tonnes) this tank was armed only with machine guns and was not adopted. Source: Wiki

Investment

The potential of the A.T.C. tanks from Bechhold’s company had indeed gained attention. In June 1940, a British Purchasing Commission had arrived in the USA to look at the possibility of producing and purchasing tanks for the war effort. Great Britain had, of course, been at war since September 1939, and June 1940 was just after the evacuation of Dunkirk, a time when a lot of British armor had already been lost on the continent with the fall of France. Great Britain and its Empire now stood resolute against the Axis of Germany and Italy but it desperately needed tanks and arms to fight the war.

The same month, Bechhold managed to interest John MacEnulty, the President of the Pressed Steel Car Company, in tank production and a five-year contract (renewable for up to 2 years) was signed on 23rd July 1940. Under the terms of this contract, Pressed Steel would gain exclusive rights to the production of tanks from A.T.C. (notwithstanding that a non-exclusive Belgian production license had already been signed). Under the terms of the contract, Pressed Steel would pay A.T.C. a royalty of $750 for each vehicle of A.T.C.’s design ordered for production by the US or Foreign Governments at Pressed Steel. A.T.C. was to provide plans, drawings, technical advice and, if required, a skilled engineer to assist in production.

 John F. MacEnulty, President of Pressed Steel Car Company
John F. MacEnulty, President of Pressed Steel Car Company from 1937. Source: Railway Engineering and Maintenance Vol.34

On 25th October 1940. Pressed Steel entered into an agreement with the British Purchasing Commission for the production and delivery of 501 M3 Medium tanks. These were not tanks designed by A.T.C. but Bechhold did assist in the completion of the contract arrangement and the British sent an advance of US$500,000 to Pressed Steel. The next month, November 1940, Pressed Steel paid A.T.C. US$75,000 under the terms of the July 1940 contract with US$300,000 remaining to be paid.

It is not clear though why Pressed Steel paid this commission to A.T.C. as the vehicles being produced were Grant tanks and not the Christie-based tank design from A.T.C. Despite the huge sum paid to ATC, it was in trouble. Bechhold had finagled matters so that after October 1940, only he held all of the Class A shares in the company, and therefore had exclusive voting rights for A.T.C. He had also increased the number of shares available from 100 to 10,000 (3000 Class A and 7000 Class B) with a reduced value of just US$1 each.

British Interest

The desperate need for tanks meant that the British were rapidly building their own in industries repurposed from civilian work to war work, but they were also looking for American production too, as this would not be affected by the manpower shortage in Britain or by German bombing. As well as the order for the M3 tanks from Pressed Steel, various other options were being considered and the work of the Purchasing Commission continued into 1941.

One particular type of vehicle that the British were interested in was an airborne tank,namely a tank which could accompany parachute or glider-borne troops. The lightweight and compact Bechhold tank was obviously of specific interest. On 27th February 1941, on behalf of the British committee in charge of evaluating tank designs, a telegram was sent to the Consul General in New York regarding the tank situation. The British were clear on what they needed from an airborne tank:

3 man crew
37 mm gun and .30 calibre Browning in a 360 degree rotating turret (quite why a 37 mm gun was specified in preference to the 2 pounder which was already an excellent gun and fielded on the A.17 Tetrarch is unknown but it is probably to do with the 37 mm being easier to produce in the USA)
Space for a wireless
Maximum Speed 40 mph (64 km/h)
Radius of Action 200 miles (320 km)
Armor basis ‘preferably’ 40-50 mm on the front and turret. 30 mm thick sides
Weight about 9 tons (9.1 tonnes) (anything under 9 tons was felt to lack the fighting qualities required) (for reference: the A.17 Tetrarch weighed just 7.6 tonnes)
“Not very interested in dropping Tank from a height of two feet”

In other words, the idea of dropping the tank from a plane was not wanted at all. Either it had to be landed directly (some various schemes for adding wings to tanks were considered), or it had to be unloaded from an aircraft. Dropping it from underneath a plane was, quite rightly, seen as a terrible idea. These requirements exceeded those of the Bechhold tank from A.T.C. That vehicle lacked the armor and firepower required and was inferior to the available A.17 Tetrarch when what was wanted by the British was basically a better armored version of the Tetrarch. The British were also anxious to get an airborne tank as soon as possible and were hoping for interest from the USA in manufacturing the vehicle. The Bechhold tank was, therefore, not suitable for their needs as it was noted that a pilot model had not yet been built.

By the end of March 1941, British plans for “the Bechold [sic: Bechhold] Project” were over. Having analyzed the tank, the British reported that: “The tank will not have the essential fighting qualities for the operations in view” and would also divert production from heavy bombers. The matter was left in the hands of American authorities to pursue and oversee its development. In its place came consideration of a 9-ton (9.1 tonnes) tank to be carried by towed glider. A final comment on the matter, from 30th April 1941, was that it had become clear to the British that the “American War Department feel they have no capacity to devote to the development of air-borne tanks”. As the decision was that Bechhold’s tanks should be overseen in America rather than from Britain it was decided that no action be taken on the Bechhold tanks.

Sold Off

The British had not been convinced by Bechhold’s salesmanship. They had, after all, already been down the Christie suspension vehicle route with the purchase of a Christie M.1931 which became the A.13E1 in 1936/7 and they had extensive experience with light Cruiser type tanks already. They also had plenty of small light tank designs including the A.17 Tetrarch. They had been clear on what they wanted but Bechhold was either unable or unwilling to comply, or simply could not produce a prototype, which was required before a decision could be taken. With the British unconvinced and an already lucrative deal with Pressed Steel in place, Bechhold had other plans.

Shenanigans and Taxes

In February 1941, A.T.C. sold its original Christie tank for just US$3,500, (Bechhold had bought it for US$5,000 in 1939) and on 18th August that year, A.T.C. incorporated as a corporation in Delaware to avoid payment of New York franchise taxes. This was completed on 20th August and the shares changed to just 100 Class A and 9,900 Class B shares with Bechhold, of course, retaining all the Class A shares and the voting rights that went with them (he also held 6,400 of the Class B shares too). Between 2nd and 4th September 1941, A.T.C. signed over all assets and the July 1940 contract (with Pressed Steel) to a newly incorporated body in Delaware, meaning the New York ATC effectively disappeared, although it was not formally dissolved until 11th September 1941. Mr. MacEnulty of Pressed Steel wrote to Bechhold on 4th September 1941 informing him that the July 1940 contract was now canceled due to alleged misrepresentations by Bechhold and a legal fight ensued.

Bechhold was insistent that he was owed money from Pressed Steel and, despite being offered US$300,000 (the remaining balance from the British Purchasing Commission contract), Bechhold refused due to the tax liability involved. His counter-offer was US$1.5m and this was immediately rejected. Instead, Pressed Steel suggested it should buy all of the remaining shares of ATC for US$50 per share (10,000 shares at US$50 would mean a US$500,000 payday). This would mean the end of Delaware A.T.C, which would have to surrender all its designs including an “aero” (airborne) tank concept, a full size model of the hook and release mechanism for releasing a tank from an airplane, designs of various other tanks and flamethrowers, and cash. This offer was considered and changed on 3rd October 1941 with a value of US$37.50 per share (US$375,000), but this would be only the existing July 1940 contract, no other plans or designs. This was agreed to by the voting members of Delaware A.T.C., which was just Bechhold, who of course approved of this arrangement.

In order to facilitate this transaction, the Delaware incorporated A.T.C. was changed from any mention or use of Armored Tank Corporation to the ‘Illinois Tank Corporation’ (I.T.C.) on 14th October 1941. On this day, just as Armored Tank Corporation (Delaware) was bought out by Pressed Steel and changed to Illinois Tank Corporation, Bechhold started a new company in Delaware. He called this new company the ‘Armored Tank Company’ once more receiving all of the assets from the original A.T.C., other than the contract, which had now gone to I.T.C. The next day, the new A.T.C. handed over all of its shares to I.T.C. which was then distributed to the stockholders, which also included Bechhold.

From these corporate shenanigans, Bechhold netted himself a cool 100 Class A shares (100% of the voting power), and 6,400 Class B shares valued at US$243,750 in total. This 15th October 1941 payment of US$375,000 (tax year 1941-1942) was to have serious consequences for Bechhold and his creative accounting.

Following this 15th October takeover though, the original July 1940 contract was finished. Bechhold probably felt he had made enough money and the entire business of the Illinois Tank Company was wound up suggesting that what assets in terms of tank designs it might have had leftover had little to no value. I.T.C. formally dissolved on 22nd November 1941.

Certainty

The substantial pay-off which Bechhold had received was classed as personal income. He, and the other stakeholders, were found to be personally liable for taxes of this income. If there is one certainty greater than death and taxes, then it is taxation in time of war. Taken to court for non-payment of taxes, Armored Tank Corporation admitted an error in its tax liabilities and was assessed to be liable for the sum of US$390,144.91 (including US$78,028.98 in tax penalties on top of its original 80% tax liability of US$312,115.93).

This was not the end of it either, for the individual shareholders of the Armored Tank Corporation/Illinois Tank Corporation were also found personally liable for back taxes and penalties. Stockholders Philip Steckler and Hamilton Allen were found liable for US$33,750, and US$22,500 respectively, and Max and Siegfried Bechhold were found liable for US$243,750 and US$45,000 respectively. A massive combined penalty of US$735,144.91 (over US$12.8m in 2019 dollars) for not paying taxes on that US$375,000 (US$6.5m in 2019 dollars) income demonstrated the danger of trying to dodge taxes in wartime.

Accessories

A.T.C. did not just produce a tank design. One of the more unusual things it designed and produced was a trailer for vehicles. This design appears in a letter dated 19th May 1942 from the Office of the Chief of Ordnance to the Commanding General of Aberdeen Proving Grounds (A.P.G.). Confusingly though, the product in question was produced by the ‘Armored Tank Corporation’ of Jersey City, New Jersey, suggesting that Bechhold kept working on designs incorporated in a different state. It is unlikely to be a mistake as A.T.C. (NY) had ended in September 1941 and I.T.C. (DE) ended November 1941. It is undoubtedly the same firm reborn, however, as the person providing information to A.P.G. on behalf of A.T.C. (NJ) was none other than ’Mr. Bechhold’ himself.

Rota-Trailer Model 4
A.T.C.(NJ) Rota-Trailer Model 4 during testing at A.P.G., Summer 1941, hitched to the rear of a half-track. The tests did not go well. Source: The_Chieftain – WoT forum

The proposal to the military was not this time a tank, but a trailer capable of being used for hauling supplies, equipment, or fuel. According to Mr. Bechhold, the British were interested in this trailer and the report recommended that APG experiment with it over a 250 mile (402 km) course to assess its viability, showing it off to the army and British representatives respectively.

This trailer was known as the ‘ROTA-TRAILER’ and the name stenciled on the side during trials stated this was the ‘Model 4’, suggesting the other 3 models or designs were less well refined. This Model 4 trailer consisted of two large hollow wheels fitted with a 40 inch (101.6cm) rubber tire 5 inches (12.7cm) wide. The wheels were unsprung but could hold up to 60 imperial gallons (272.8 liters) of fuel, either petrol or diesel, and were covered in rubber to provide a ‘self-sealing’ effect if the wheel hub were punctured by ammunition up to .50 caliber. Between the two wheels was a large rectangular cargo compartment made from ⅛” thick (3.175 mm) thick welded steel. This large space inside could be fitted with an ammunition rack for tank or artillery shells (34 rounds of 75 mm or 108 rounds of 37 mm), small arms ammunition boxes, ration boxes, water or fuel cans, or other items that were required. A second, smaller compartment below this was specifically designed to hold four boxes of .30 ammunition.

Top-down view of the Rota-Trailer Model 4
Top-down view of the Rota-Trailer Model 4 from A.T.C. (NJ) with top cover open. It contained 3 specimen shells in a rack, two 5-US gallon (18.9 liter) ‘flimsies’ and three boxes of rations. Source: The_Chieftain – WoT forum

At the back of the trailer lay a third compartment, smaller than the first, and which contained a hand-operated fuel pump and supply hose long enough to feed the towing vehicle. Below this compartment lay a fourth compartment (just like the one at the front) which held stowage space for tools.

A.T.C.(NJ) Rota-Trailer Model 4
A.T.C.(NJ) Rota-Trailer Model 4 pictured during testing at A.P.G. Summer 1941. Source: The_Chieftain – WoT forum

Overall, the trailer was very complex containing many bespoke parts that made for complicated maintenance. The doors to access the items inside were fitted with wing nuts (butterfly nuts) but were overly laborious to unscrew to access the contents. This is something that could easily have been rectified in a production model.

Rear view of the Rota-Trailer Model 4
Rearview of the Rota-Trailer Model 4 from A.T.C. (NJ) with hand pump (top) and toolbox (bottom) open for inspection. Between the two is a towing hook for additional trailers. The narrow tires and very wide wheel hubs are apparent in this image. Source: The_Chieftain – WoT forum

The Rota-Trailer not only had these internal compartments for stowage but also the ability to have a multitude of items carried on top. A special frame was fitted which held three 5-US gallon (18.9 liter) oil cans, and various tie-downs allowed other accessories such as nets or tarpaulins or other stores to be lashed to the top of the trailer.

Testing

Despite looking good on paper, capable of extending the fighting range of a tank, the trailer had serious problems. It was tested by an M4 Sherman and two different half-tracks over a 26 mile (42 km) cross country course and 250 miles (400 km) of gravel roads and, whilst it was on a flat surface, like a road, it worked well with little bouncing. The trailer was heavy too: each wheel weighed 400 lbs (180 kg) empty and 800 lbs (360 kg) when full in addition to the weight of the other material carried. The weight of the trailer placed additional strain on the drivetrain of the towing vehicle and, during rough travel off-road, the stress and strain on the trailer risked serious damage. On top of this, the trailer reduced the maximum speed of the vehicle towing it because the instability of the load caused by the sloshing liquid in the wheels threatened to result in sideways skids at high speeds.

Even as it was, the semi-rough terrain traversed ended up with all of the cans of water inside or on top of the trailer becoming deformed and leaky but the trailer did at least provide self-floatation in mud due to the width of the fuel cells. Another downside was that the lower front compartment, just 8.75 inches (222 mm) from the ground had a tendency to become filled with mud which was forced into it.

A final problem with the trailer was that it made reversing more difficult. During testing with an M4, the trailer skewed to one side and the stress caused damage to the towing arm and the tank tracks rubbing against the trailer body.

Model 4 from A.T.C. (NJ) after testing, the twisted tow arm
View of the Rota-Trailer Model 4 from A.T.C. (NJ) after testing, the twisted tow arm and torn section of the front having been caused by contacting the tracks of the tank. Source: The_Chieftain – WoT forum

Overall, the tests of this A.T.C. product were a failure and the vehicle was not recommended for use. Its main faults were:
Difficult to reverse
Additional strain on the drivetrain of the towing vehicle
Reduces maximum possible speed of the towing vehicle
Too heavy to move easily by hand
Too little ground clearance
No suspension
Steel body is not resistant to small arms fire

None of these faults were to stop further ideas, designs, and experimentation with trailers for hauling fuel or stores by tanks, but the work from A.T.C. (NJ) on this matter was effectively dead. No more is known of A.T.C. after this time; possibly Bechhold’s resources had simply run out and this venture failed, although it is noteworthy that on 1st February 1943, despite the failings of the Rotatrailer, the British still ordered 600 of them anyway, although how many were finished or delivered is less clear.

In the Army

Siegfried Bechhold, aged 42, in October 1942 joined his second Army. His first was a German one in WW1, his second, an American one in WW2. He served as a private being sent to Camp Lee in Virginia. He is not believed to have been sent overseas.

Re-born once more?

The back end of the hull of the Bechhold Tank seen in the November/December 1940 advert is very similar to the vehicle shown to the US Army Ordnance Department in May 1942 known as the Bigley Gun Motor Carriage suggesting a possible link to that vehicle. Was, in fact, the Bigley GMC the M.1938 High-Speed tank from Christie, bought and modified by A.T.C. and then sold off, redeveloped and re-submitted by another firm? Or is it in fact the other Christie tank, the M.1937 sold off by his creditors to Mr. Bechhold. On the balance of the evidence, the former case appears to be correct.

Bigley GMC seen in May 1942
Bigley GMC seen in May 1942. Source: US Army Ordnance

By the end of WW2, Bechhold had left the field of tanks and the complications of military work. By 1948, he was living in Florida where he headed the Ribbonwriter Corporation of America, selling parts for typewriters. Siegfried Bechhold died in California in 1956.

A rendition of Bechhold’s tank, as shown in the ad published in the November/December 1940 issue of the Army Ordnance Magazine. Illustration by Adrielcz, funded by our Patreon campaign.

Sources

Army Ordnance. (November-December 1940). Super Tanks. Vol. XXI.
The Camden News. (27th June 1941). Russians now seek to buy tank designs refused them during Finnish War. Arkansas, USA
Crismon, F. (1992). US Military Tracked Vehicles. Crestline Publishing, USA
Cypher Telegram. (8th March 1941). No.1456 Supply to the Consul General in New York. For Dewar from Burton T-59.
Gray, C. (16th July 2006). A Notable Block with a Hole in its Heart. New York Times, New York, USA
Second Circuit of Appeals. (10th July 1939). Bethlehem Engineering Export Company v Christie 105.F.2d 933 (2d Cir. 1939)
Indianapolis Star. (26th January 1941). U.S. Help Brings Joy to Greeks. Indianapolis, USA
The Jewish Floridian. (24th December 1948). New Typewriter Device Produced by Dania Firm.
Keough, F. (November 1918). Contents. American Industries: The Manufacturers’ Magazine. Vol. XIX, No.4.
Nielsen, K. (2012). Pressed Steel!. Author House Publishing
Ogden Standard Examiner. (1st June 1941). Flying Tanks. Utah, USA
Pearson, D., Back, R. (9th August 1941). The Washington Merry Go-Round. Nevada State Journal.
Popular Mechanics. (May 1936). Fast-Tank and Plane Latest War Machine.
Pinedale Roundup. (29th October 1942). No Cellophane Commission. Wyoming, USA
Railway Age. (2nd December 1939). Meetings and Conventions. Railway Age, Vol.107, No.23.
Railway Engineering and Maintenance. (January 1938). Supply Trade News.
San Bernadino Sun. (13th April 1941). Breaking Nazi Morale. Volume 46, 1941.
San Francisco Examiner. (8th February 1956). Siegfried Bechhold dies in Santa Rosa Hospital. San Francisco, USA
Strausbaugh, J. (2018). Victory City: A History of New York and New Yorkers during World War II. Twelve Publishing.
United States. (1949). Reports of the Tax Court of the United States, Volume 11. US Government Printing Office
Office of the Chief of Ordnance, Bigley Tank, OCE, Washington D.C., USA
United States Tax Court. (20th October 1948). Armored Tank Corporation v. Commissioner. Docket No. 9786, 9769, 9770, 9771, 9772, 11916, 1919, 11920, 11927
US Patent US2310887(A). Hook-on-and-release mechanism for fighting tanks. Filed 6th May 1941. Granted 9th February 1943.
Weir J. D.G. Mech. E. (24th March 1941). Memo to Sir James Lithgow.
Weir J. D.G. Mech. E. (24th March 1941). Memo to Air Marshall Dawson.
Weir, J. D.G. Mech. E. (30th April 1941). Memo to A.R. 2 War Office via DAFV.
Wrynn, C. Major. (1st February 1943). Rota Trailers – Memo.. 1/Rel/ Equip Armd/1
The Chieftain’s Hatch 28th March 2014. Trailer, Ammunition and Fuel Part 1. 
Christie, J. (1985). Steel Steeds Christie. Sunflower University Press, Kansas, USA

Categories
WW2 British Prototypes

TOG 300G

United Kingdom (1939)
Heavy Tank – None Built

The precipitous plunge into a new major European land war against Germany in 1939 found the British utterly unprepared for the type of intense combat fought a generation earlier on much of the same ground in Northern France and Belgium. As Britain and France raced desperately to design and deliver a new series of heavy tanks able to break the inevitable German defensive lines to beat them on this old battlefield, the mud of Flanders loomed large in British military thought.

The French Army and the British Expeditionary Force (B.E.F.) had tanks and a lot of modern equipment of a bewildering variety and utility, from the diminutive unarmed UE tracked resupply vehicle and obsolete WW1 Renault FT light tanks, to the giant Char B1 Heavy Tank for the French, and the ‘Universal Carrier’ and Mk.IV Light tank to the A.11 and A.12 Matildas of the British. These forces were meant, as succeeded by their parents’ generation, to blunt and stall the German advance through the Low Countries (Belgium and Holland). After that, the Allies would bring over new forces and push the Germans back. A fine plan maybe in the first months, September and October 1939, with the obvious problem that the Germans did not want to play that game and instead when in May 1940 the attack came, it was launched with greater speed and focus of intensity than the British and French could cope with.

Picturing a need in the first months of the war for a new and improved heavy tank for special purposes, there was no suitable vehicle at all, as the heaviest tank available was the A.12 Matilda. A new tank was to be rapidly considered and one of the first of these came from a team led by Sir Albert Stern – a team of men largely responsible for most of the British tanks of WW1. Stern was the chairman of the Special Vehicle Development committee – more commonly known by its adopted nickname; The Old Gang (TOG) and this was to be the first TOG tank of WW2, although it never left the drawing board.

The Theory

It has to be acknowledged that, in these first few months, the requirements for a new ‘Special’ or heavy tank were fluid. Despite the issuance at the end of September 1939 by the General Staff of a set of improbable and perhaps impossibly optimistic requirements for a tank, the team led by Stern took liberties with their task. It is clear from reading the letters of the time that, right from the start, the TOG team favored only a turreted tank. Adding heavy armor and a high front track to help climb an enemy parapet or wall, the vehicle design resembled almost a hybrid between the existing A.12 Matilda and a rival vehicle of sorts being built to a different set of demands, known as the A.20.

TOG 300G redrawn from blueprints. Source: Author

When the specifications for this new tank were finally revealed at the end of September 1939, the demands were extreme. The vehicle would have to be able to cross a 16’ (4.9 m) wide trench without the use of a bridge or fascine, be heavily armored, and capable of climbing a 7’ (2.1 m) high obstacle. The 300G was simply unable to cross such a huge gap. In an effort perhaps to assuage the General Staff and have them come around to a more conventional turreted option, the vehicle was even redrawn in a longer form capable of crossing a gap 10 to 12’ (3.0 to 3.7 m) wide. Although the goal was to produce this new special tank at just 32 tons (32.5 tonnes), this longer option would obviously mean more weight, perhaps around 40 tons (40.6 tonnes), and a reduced performance (assuming the same power plant was to be used).

Based on the drawing for the outline of the tank, it would measure around 20’ to 25’ (6.10 to 7.62 m) long for the ‘compact’ and ‘lengthened’ options respectively. The width is easier to gauge, as it is shown in a railway tunnel. Railway tunnels were the size-limiter for width. The 300G vehicle completely filled the tunnel allowable width, indicating a vehicle some 10’ (3.05 m) wide.

Automotive

It is difficult to consider the automotive elements of 300G because the design simply never got that far. The requirements of TOG were to produce a diesel-engined vehicle and eventually that led to the adoption of the excellent Paxman-Ricardo series of diesel engines for the TOG 1 and TOG 2. In the early days of that part of the work of TOG, the lack of a suitable diesel motor prompted a look at various alternatives, including the use of petrol boat engines to provide sufficient power.

The designers involved in work on the S.V.D.C. project also considered alternatives to the ‘normal’ kind of mechanical transmissions, eventually considering alternatives including hydraulic and electric types. However, just like the engine, this was after the 300G idea had been replaced with work on a Mk.VIII-shaped machine for the General Staff. As a result, the engine and transmission choices or options for a TOG tank built to the outline of 300G remain unknown.

Surviving side outline of 300G in both compact and long’ forms crossing an 8’ (2.44 m) gap. The vertical obstacle shown is not given a size but is around 4’ (1.22 m) high. Source: Tanks of TOG by the author via UK National Archives.

Crew

Other than a single figure on the original drawing of a somewhat awkward-looking driver, no crew is shown, so it is hard to know how many crew were planned. The ‘special’ tank discussion originated with an idea for a tank with a crew of up to 7. Examining the design, it can be assumed this would be at least 5 or maybe 6 crew members, consisting probably of a driver in the front left of the hull, a hull gunner on the front right to operate the primary armament and BESA, and three more men, commander, gunner, and loader in the turret, just as they were on the A.12.

British A.12 Matilda. Source: Wikimedia Commons

Comparison between A.12 Matilda and TOG 300G Design

A.12 Matilda TOG 300G
Weight (ton / tonne) 25 tons (25.4 tonnes) 32 tons (32.5 tonnes) to est. 40 tons (40.6 tonnes)
Length (ft / m) 18’ 5” (5.61 m) 20’ to 25’ (6.10 to 7.62 m)
Width (ft / m) 8’ 6” (2.59 m) 10’ (3.05 m)
Height (ft / m) 8’ 3” (2.51 m) est. 8’ 9” (2.75 m)
Trench ~8’ (2.44 m) ~8’ (2.44 m) to
10 – 12’ (3.05 – 3.66 m)
Hull Armament None 7.92 mm BESA plus HV gun
Turret Armament 2 pdr. / 7.92 mm BESA 2 pdr. / 7.92 mm BESA
Hull Armor 3” (76 mm) basis 3 – 4” (76 – 102 mm)
Turret Armor 3” (76 mm) basis 3” (76 mm) basis

Armament

While the tank resembled an A.12, it certainly was not one. This tank was going to have to be able to take out heavily-fortified enemy positions and, as such, a variety of guns was being considered to find whichever was best suited to the task. Amongst these were the 2” (as used on the A.12), a 3” howitzer, a 3.7” howitzer, the Naval 6 pounder, and the French 75 mm gun. These last two were certainly too large in an A.12-style turret. Both the 3” and 3.7” options were abandoned quickly due to them being low-velocity weapons. No design studies are known to have been carried out for this turret. The solution would, therefore, be to mount the ‘big’ gun in the hull, much in the manner of the French Char B, and use the otherwise perfectly adequate 2 pounder in the turret on top. The requirements for a front-mounted Besa machine gun in the driver’s plate and another in the turret were to complete the complement of weapons.

Armor

Although a thickness of armor is actually shown on the blueprint, this was not a ‘to-scale’ drawing, just an illustrative one. The armor is shown, quite rightly, as being focussed on the front with a thick and slightly angled glacis, a cut-back lower front and a vertical and slightly thicker driver’s plate. No armor is shown on the turret, which is assumed to be identical to that of the A.12, which makes it cast armor 3” (76 mm) thick all around.

If 76 mm is to be assumed as the basis, this would give the 300G a 3” thick glacis and a driver’s plate perhaps as thick as 4” (102 mm). It is certainly not possible to consider the armor to be 60 mm or so, as the ‘rival’ A.20 design was already known to be woefully under-protected with armor of that thickness, unable to keep out German 37 and 47 mm anti-tank guns even at generous combat ranges. The other reason to discount the idea that the armor was less than around 3” is that the armor designer on the TOG team was Kenneth Symes. Symes was an expert in armor protection and a strong proponent of face-hardened armor plates made in flat slabs. The slabs meant ease of production not available to castings, which needed machining, but also the ability to produce a uniform hardening on the surface. Against uncapped anti-tank shot, this face-hardened armor provided improved protection over the ‘softer’ homogenous or cast armor plate. The side armor, being vertical, would have to at least match the nearly vertical turret sides, so once more 3” (76 mm) is the most reasonable estimate for this.

If the relationships between thicknesses on the only surviving drawing (drawing 477G) are reliable, then the rear armor was about half the thickness of the front, probably around 1.5” (38 mm) thick.

A lengthened version of ‘TOG 300G’ shown crossing an 8’ (2.4 m) gap. Source: Author

Death of the Project

The death knell for what would basically have been a heavier Matilda-type tank came almost as soon as the idea was born. The General Staff were insistent that they wanted an all-round track machine with heavy unditching gear on top, which meant no turret. Lengthening the 300G would not suffice and the attention of The Old Gang would be diverted into producing a tank they very much did not want to make to meet the exacting criteria issued by the General Staff in September 1939 as ‘RMB-17’.

Conclusion

The opportunity of TOG 300G, however, was small. The Army did not need a bigger, heavier, and wider Matilda-type tank even with the benefit of a little more armor, a little more obstacle-crossing capability, and the benefit of a large front-mounted gun. They wanted something much larger, inevitably much heavier, better protected, and even more capable of crossing obstacles. That was the direction TOG was to take, against their better judgment, and it is perhaps with some irony that the 300G-style option was eventually the one adopted after years of messing around, as the A.22 Churchill. That tank was to start life as much the same layout, a small cast turret with a 2 pounder gun and a 3” howitzer in the front and got off to a rough start with serious design flaws, reliability issues, mobility problems, and inadequate armor and firepower. A similar fate might have been expected from 300G but, given that the A.22 went on to be a very successful design by the end of the war, after years of upgrades to every feature, it is hard not to project that the 300G had the same sort of potential.

Concept art of the shorter variant of the TOG 300G taken from the drawings. The hull’s similarity to that of the later Churchill is striking, while the turret is very similar to that of the Matilda 2. Illustration by Yuvnashva Sharma, funded by our Patreon campaign.

Sources

Hills, A. (2017). The Tanks of TOG. FWD Publishing, USA

TOG 300G Specifications

Dimensions (L/w/h) 6.10 to 7.62 x 3.05 x est. 2.24 (short version), 2.75 m (longer version)
20’ to 25” x 10’ x 8’ (short version), 8’ 9” (longer version)
Total weight, battle ready 32 tons (32.5 tonnes) (compact) – longer version ~40 tons (40.6 tonnes)
Crew 5 – 6
Propulsion Diesel
Range (road) 50 miles
Trench Crossing 8’ (7.3 m) to est. 10 – 12’ (3.0 -3.7 m) wide
Step Up to 7’ (2.1 m) high
Armament Naval 6 pounder or French 75 mm in the front hull
7.92 mm Besa machine gun.
2 pounder and 7.92 mm BESA MG in the turret.
Armor Turret: 3” (76 mm)
Glacis: est. 3” (76 mm)
Driver’s plate: est. 4” (102 mm)
Sides: est. 3” (76 mm)
Rear: est. 1.5” (38 mm)
Categories
WW2 British Prototypes

Johnsons Light Tropical Tank

United Kingdom (1922)
Light Tank – 1½ built

In 1919, an English man stepped off of a boat onto the soil of India. This was Colonel Philip Johnson, one of Britain’s few tank designers. Although Johnson would never design a tank that was accepted into service and had a habit of designing what he wanted, not what was required, at the time he was the Government’s only tank designer. He was in charge of the Department for Tank Design, and had been tasked with undertaking a study into the use of Tanks in the heat and rugged terrain of India, and the north-west frontier.
Johnson’s report filed in 1920 suggested that the use of tanks in those conditions was entirely possible. He went even further to suggest a family of vehicles all based upon a common chassis would be needed. The family was to consist of a tank, an amphibious vehicle, a supply carrier and gun carrier variants. As far as it is known, only the tank version, known as the Light Tropical Tank, and the Supply Carrier were built.

Design

A single photo of the Light Tropical Tank has survived. However, a good deal of information can be extracted about the design of this little-known vehicle.
The engine of the vehicle is placed at the front of the vehicle, on the left side. It was a 45hp Taylor engine. Interestingly, the vehicle has a rear transmission. This front-mounted engine rear-mounted transmission combination is quite peculiar in tank design history, although it is shared with the famous Medium Mark A Whippet and the following Medium Mark I and II. The gearbox was of the sliding bevel type, with four forward and one reverse gear. Another interesting feature, reminiscent of WWI-era armored cars, is the placement of the radiator intakes, which are situated at the front of the vehicle.

The rear of the Supply Carrier, which was based on the same chassis as the Light Tropical tank. The rear transmission is visible. Source: https://topwar.ru/121848-bronemashiny-light-infantry-tank-i-light-supply-tank-velikobritaniya.html
The suspension is almost impossible to observe due to the poor contrast of the photo and the large mud chutes which cover the outer part of the sides of the tank. It consisted of coil springs attached to small roadwheels. The vehicle has a solid front idler (although the supply carrier has a different, pressed type of idler) which can be adjusted to change the track tension. The drive sprocket is at the rear. Based on the pictures of the Supply Carrier, which is quite similar in design, five return rollers are also present. It could reach 15 mph (24 km/h) on road, with half that off road (7 mph or 11 km/h).
The superstructure of the vehicle was composed of two parts. The front part, containing the engine and the driver’s location, was quite boxy. However, its rear part was irregular in order to make room for the offset turrets. The front seems to have been slightly angled, but the rest was vertical. The rear part of the superstructure comprised the fighting compartment, being taller and irregular in shape. The right-hand side extended more to the front than the left side. Again, it comprised vertical armor plates with almost no angling. While it is hard to observe from the single available picture, it seems as though the fighting compartment also extended over the tracks, thus giving more internal space. Behind the fighting compartment was an armored cover for the transmission.
The Light Tropical tank had two turrets mounted to the rear, on top of the fighting compartment. The two turrets were offset due to the placement of the engine, and resembled those on an Austin Armoured Car, although no direct link between the two vehicles is known. No weapons were fitted but it is highly likely they would have been a pair of machine guns.
The driver was placed on the front right, having a raised compartment just in front of the right-hand side turret. This was low enough so that the weapon could traverse over it. It is unclear how the crew accessed the vehicle. The armor was flat and vertical, consisting of riveted rolled armor plates.

High-quality images of the Johnson Tropical Tank. Source: Ed Webster

 


Illustration of ‘Johnson’s Light Tropical Tank’ produced by Yuvnashva Sharma, funded by our Patreon campaign

Construction and Testing

After the design work was done, the plans were turned over to Vickers who started construction at their Erith plant. On the 7th of October, the right hand track was connected to the machinery of the tank and run for an extended period while the tank was lifted off the floor. At the time, the left hand track was still awaiting connection. Five days later, the tank was completed and run for a very short distance. Even this short run showed a number of defects which needed work. By the end of the month, more involved trials were carried out and showed some problems with the tracks, which were deemed noisy and unreliable.
Throughout November, further mechanical problems arose, including within the gearbox which had to be sent back to its makers for fixing. These mechanical problems were still plaguing the tank in June 1922, when a hopeful internal report at Vickers suggested the tank would be complete in about two months. In July, a notification was sent that a second tank had started construction. By the 10th of November 1922, the tank had been turned over to the British army and was undergoing testing at Farnborough.
During these tests, the tank had several persistent problems, such as the cables that formed the suspension stretching and fraying. The bogies were considered very weak and kept on moving out of position, causing damage to the tracks. The tracks themselves had almost constant problems with the rivets in them shearing off. Despite all this, the British army did convert the tank to use a steering wheel instead of its original levers. After 238 miles (380 km) of testing, the tank was abandoned.

The Light Supply Carrier – Source: Bovington Tank Museum on Twitter

Conclusion

In 1923, after the series of failures, Philip Johnson’s tank design department was closed down, and Johnson disappears from the records. Of the Tropical Light Tank, no further record can be found. It was likely scrapped, or used as a range target.

A Note on Dates:

There are two documents involved in creating this article. However, they contradict each other when it comes to dates. The dates used above came from “E.2011.1667 Vickers tanks notes” held at the Bovington Tank Museum. However, a second document held at Bovington, and quoted by David Fletcher in Mechanised Force, states that the Light Tropical Tank had been delivered for testing by the army in June/July 1922, a time when the previous document still had the tank at the Vickers works at Erith.

Specifications

Total weight 5 tons, 3Cwt (5.15 metric tons)
Propulsion 45hp Taylor engine
Suspension Spring cable, and Rackham steering clutches.
Transmission Sliding Bevel Gear box ( Speeds: 4 forward, 1 reverse)
Speed (road) 15 mph (24 km/h) road, 7 mph (11 km/h) Cross country
Armament Likely two machine guns in two separate turrets.
Total production 1 Completed, 1 Half-built
For information about abbreviations check the Lexical Index

Links, Resources & Further Reading

Mechanised Force (ISBN: 0112904874), Page 5, David Fletcher, HM Stationery Office Books, 1991.
Unknown document, Bovington tank museum.
E2011.1667, ‘Vickers, post war’, Bovington tank museum

Categories
WW2 British Prototypes

Comet, Cruiser Tank, A34* (Star)

United Kingdom (1945)
Cruiser Tank – 1 Built

The officially named ‘Tank, Cruiser, A34, Comet I‘, is widely regarded as the finest tank produced in Britain to see combat in the Second World War. Carrying the 77mm HV (High Velocity) main gun in, basically, an improved Cromwell (A24) chassis, the tank combined mobility with firepower.
The design though was not without its flaws. Despite early hopes, it could not mount the formidable 17 pounder gun and the armor was insufficient at the front to protect against the armor piercing (AP) shell fired from the German Panther. This vehicle was considered a significant enough threat that, whilst the next Cruiser tank was being developed, ideas were considered as to improving the Comet, in particular, the armor, to correct this weakness.
Work had begun on the Comet in 1943 but the first deliveries did not start to arrive until the end of 1944. The Department of Tank Design (DTD) was never entirely happy with the compromises made for the design, and the disappointment is reflected in the War Diary of the 29th Armoured Brigade when they received their first batch of the new A34 Comets in February 1945.

“A total of 100 fit Comets had been issued to the Bde [Brigade] by 20 Feb. Everybody was pleased to get the Comet tank, though there were criticisms. Particular disappointment was expressed at the absence of a sloping front glacis plate; however, everyone felt that this tank is a great improvement on the Sherman, and felt honoured that we were the first armoured brigade to be equipped with these new tks [tanks]”.

– 29th Armoured Brigade War diary, February 1945.

It was indeed an improvement for them over the American made M4 Sherman, as the new gun offered the firepower craved to combat German armor, but having gone from a Sherman with the large sloping glacis to the stepped-front design of the Cromwell was seen as a stepback. The armor over the glacis on the Comet was just 32mm thick, albeit steeply angled back leading up to the driver’s plate which was just 76mm thick and vertical.
The reason this driver’s plate was retained was simply that it offered a port for the driver, a mounting for a forward firing hull mounted machine-gun (although the value of such a machine-gun was already in question) and that to change it required a redesign of the hull. Redesigning the hull would have taken time and this vehicle was effectively just a stop-gap awaiting the new Cruiser, the A41 Centurion, so a redesign was out of the question. The question was, therefore, how to improve the armor to provide increased protection against the German 75mm High-Velocity AP round from the Panther tank.
A conference was held on that question and other potential modifications on 3rd February 1945 at the Headquarters of the 29th Armoured Brigade, with a follow-up meeting held at Farnborough just two weeks later on the 17th. The primary complaint was the lack of a glacis, expressed in the report as:

“Some disappointment was expressed that the hull front still had the vertical visor plate and that the sloping glacis plate of the Panther had not yet been adopted. The opinion was expressed that crew would prefer this even if it means that the driver always had to drive through his periscope and hull gun had to be abandoned. It was even suggested that the space set free by abandonment of the hull gunner should be used for the stowage of additional 77mm ammunition”

The Department of Tank Design, however, did not seem swayed by the demand for a sloping front glacis. The design of the German Panther tank had significantly affected the thoughts of men who had faced them in combat but not yet those at the DTD. Perhaps unwilling to abandon the hull machine-gun, they suggested instead a compromise of adding an additional 1″ (25.4mm) of armor plate to the 3″ (76.2mm) vertical visor plate, bringing it up to 4″ (101.6mm) across that part. The DTD were clearly unhappy with even this compromise though as they demanded further trials to see what difference this additional weight might make on the vehicle.

A24 Cromwell tank front armor. 64mm vertical plate over 25mm sloped glacis.

A34 Comet hull with new 25mm thick sloped glacis.

A34 Gets its Glacis

Adding just another inch of armor to the three the Comet had would leave it with four inches of armor on its vertical plate, which would still not provide the protection from the German gun. The following solution was simpler – do what the soldiers wanted. Remove the hull machine-gun and accept a restricted driver’s view for additional protection. The other advantages of this being the removal of the hull gunner and additional space for ammunition in the front left of the hull. The turret still retained its machinegun, so the loss of the one in the hull was of no significance compared with being able to carry a dozen or more shells for the primary armament and increased armor. The question had therefore become what thickness of a plate was needed.

A34 Comet with 25mm thick plate fastened by bolts to the front of the hull of an existing Comet. The turret is turned backward to avoid damage. Photo: PM Knight
The plan was to use a single 25mm thick plate made from I.T. 80 armor steel (the same as the tank hull’s primary armor) angled at 49 degrees from the horizontal over the front of the Comet from the nose to above the visor. The plate was fixed by means of three steel brackets welded to the old glacis to which the new glacis plate was fastened with 3 rows of 6 bolts each.


The A34* (Star) Comet. Note the added plate at the front of the tank. Illustrated by Alexe Pavel, based on an illustration by David Bocquelet.

Testing

For the purposes of the test, rather than remove the BESA machine-gun mount and plate, it was added over it, as would have to be done if the modification was adopted; the mount was simply left in situ. The test Comet was shot at using the German 7.5 cm KwK 42 L/70 gun as mounted in a captured Panther tank brought to Shoeburyness Ranges. The round fired was the Panzergranate 39/42 Armour Piercing Capped Ballistic Capped (APCBC) shell at 2578 fps (785.8 m/s). The results were perhaps predictably poor, this 25mm plate effectively made no difference. The shell pierced both it and the original visor behind it completely. A second shell penetrated both the new glacis plate and the original glacis plate behind it completely as well.
A 25mm plate angled at 70 degrees should have provided an equivalent of an additional 38mm of armor on the visor plate and an additional 13mm on the glacis and a 45mm thick (32mm + 13mm) glacis should not have been penetrated by the shell traveling below 2700 fps (823 m/s), yet both areas had been penetrated by a shell some 122 fps (37.2 m/s) slower.
The target was then moved 30 degrees to the side to test for oblique impacts. Two shots were fired at the upper part of the new glacis with the original visor behind. The first shot only penetrated the outer plate and did not penetrate the original visor, but a second shot penetrated both layers of armor even at this angle. Two more firings were carried out at the lower section of the new glacis and the results were not good. A firing limit of 2600 fps (792 m/s) equivalent to 1000 yards was established for this area of armor. The improvement of the new glacis was marginal. Head-on against this shell the plate made no difference at all and was completely penetrated at test ranges. When the vehicle was angled 30 degrees to the line of fire from the enemy vehicle this new armor added just 130 fps (40 m/s) equivalent to a range of 200 yards (183 m) to the protection of the vehicle compared to the original armor scheme
In summary, the firing trials determined that:

“Against normal attack from 7.5cm A.P.C.B.C, the additional protection plate is inferior to plates of equivalent thickness in contact with the visor and glacis, but against 30 degree attacks the protected offered to the visor is slightly higher than that given by an equivalent increase in thickness”

The protection plan was simply not as effective as it was thought it would be. The sloping glacis should either have been thicker and uniform comprising the entirety full frontal armor, or the equivalent armor 25mm simply added to a 76mm visor and 32mm glacis by welding it on as applique and retaining the stepped shape. Other than at very oblique angles this would be superior to this unusual spaced-armor glacis arrangement. It would also retain the bow machine-gun and the driver’s port.

Head On

30-Degree Oblique Impact

End

The tests were a failure. The German gun was too powerful even for this temporary fix of a temporary tank. The thinking had been good, but there was to be no substitute for a properly angled plate of the correct thickness in the first instance. For that, the British would have to wait for their A.41 afterall. A tank which became a legend in its own right, albeit, one too late to ever fight the Panther itself.

Despite the visor being substantially thicker than the glacis, the tests had shown the vulnerability of the visor plate as it was penetrated by enemy fire from that shell even out to 2650 yards (2423 m). The whole of the frontal hull armor could still be penetrated even when angled at 30 degrees, but with the glacis plate the visor and glacis were only penetrate-able at 1000 yards (914 m) instead. For the Department of Tank Design, the problems with losing a hull machine-gun and obstructing the driver’s view just outweighed any merit. The increased protection demanded could be simply provided by welding on 25mm of applique to the front anyway. The age of the stepped front tank was over.
It was felt by the Army that certain tactical roles, presumably the same sort which required the use of the 95mm howitzer like the C.S. (Close Support) role, would benefit enormously from this increased level of protection but the DTD were not to be swayed. The testing had not shown the benefits to outweigh the drawbacks and the project was nixxed and forgotten about. The A41 provided a single glacis thicker and stronger than this attempt and Comets were replaced in service as Centurion were delivered.

Note

Although the article refers to this vehicle as ‘A34*’ there is no information available as to what any official name for this vehicle would have been had she entered service although an asterix is a common British addition to a name to denote a technical modification.

Specifications

Dimensions
L x W x H
6.55 m x 3.04 m x 2.67 m
(21ft 6in x 10ft 1in x 8ft 6in)
Total weight, battle ready 33.53 tonnes (32.7 long tons)
Crew 5 (commander, driver, gunner, loader/radio op, hull machine gunner)
Propulsion Rolls Royce Meteor Mk.III V12 Petrol/gasoline engine, 600 hp (447 kW)
Suspension Christie system
Top speed 32 mph (51 km/h)
Range (road) 155 miles (250 km)
Armament 77 mm (3.03 in) High Velocity gun, 61 rounds
2x 7.92 mm (0.31 in) BESA machine guns, 5,175 rounds
Armor From 32 to 102 mm (1.26-4.02 in) + 25mm (0.9 in) glacis plate
Total production 1

Links & Resources

A.34 Comet – A Technical History, PM Knight
29th Armoured Brigade War diary
Report from a meeting at the Headquarters of the 29th Armoured Brigade, 17th February 1945