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WW2 American Prototypes WW2 British Prototypes

The Bechhold Tank

Light tank – Single partial prototype and design. (1938-41)
United Kingdom – None built

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

Although the tank was never built as shown, there is some information available from contemporary press reports too. Also, bearing in mind that the vehicle was based on the Christie design (purchased in 1939), and that it was advertised as 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 mud guards 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. Becchold. 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
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 Prototype- 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.

Johnson’s Light Tropical Tank. Photo: SOURCE


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.

The solution to the sloping front problem. The Mk.1 Centurion also featured the more powerful 17 pounder gun.
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 1,186

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

Categories
Failed Tanks WW2 British Prototypes

Valiant, Infantry Tank, A38

United Kingdom (1943)
Infantry Tank – 1 Prototype

The A38 Infantry Tank, codenamed as ‘Valiant’. Much has been said about this widely maligned British tank design, perhaps too much when one stops to look at the vehicle and its very short lived story. Reports of unsettling injuries to crewmen, horrendous shot traps, and poor comparison to existing infantry tanks to name but a few. However, how much truth really exists behind these statements?

Tank, Infantry, A38 Valiant, a Misunderstood Failure. Photo: Osprey Publishing

‘An Urgent Project’

Development of A38 Infantry/Assault Tank started in August of 1942, when Vickers Armstrong were awarded a contract to produce three pilot models of a ‘heavy assault tank’ by the Ministry of Supply. This had followed discussions from the Tank Board of improvements and possible successors to the Valentine Infantry Tank series. This design was classed as ‘urgent’ by the Tank Board and would be focused on along with improvements to the existing Valentine series. There was also a specific emphasis placed on the implementation of side skirting plates in this design. However, the design of the Valiant had origins in an existing project by Vickers; the Vanguard.
Vanguard was an existing design that had been presented and designed earlier by Vickers as a possible replacement for early infantry tanks such as the A11 Matilda I and early models of the Valentine. The design was interesting in that it utilized a unique suspension system, sharing some commonality in smaller components with the Valentine. The system consisted of independently sprung pairs of road wheels, each supported by external wishbones. This chassis had been used in the first trials of the QF 17 pounder AT gun in what would eventually become the Archer SPG, which was a 17-pdr mounted to a rear-facing Valentine chassis. With this design already drawn up and built, Vickers simply designed the new tank on top of this existing object.
The original design for the assault tank, which continued to be referred to as ‘Vanguard’ for at least the few months of its development, was very similar to the final vehicle that was built. The weight of the vehicle was 23 tons, as required by the contract, making it a much lighter alternative to the A33 “Excelsior” and A22 Churchill tanks that were in development at the same time. This reduced weight was achieved by reducing the turret from a 3-man configuration to a 2-man configuration.

The design drawing for the A38 Valiant. Photo: The Tank Museum Archives
The design was armed with the proven 6 Pounder (57mm) gun, with a 7.92mm BESA machine gun mounted coaxially. The 6pdr was a preferred weapon to the more commonly available 2 pounder (40mm) due to its wider range of ammunition and ability to perform outside of an anti-tank role. Two 2 inch (51mm) smoke mortars were to be included, with 18 smoke bombs being provided. Frontal hull armor was listed at 4 ½ inches (114mm) thick, with the sides having 4 inches (102mm) and the rear 3 inches (76mm). This gave the vehicle very impressive protection for the time, especially in comparison with early war designs such as A.11. The design also featured a pike nose design, utilising two plates that were ‘pre-angled’ to give greater armor obliquity angles. This shows a level of forward-thinking that would not be seen on a tank until the reveal of the Soviet IS-3 heavy tank in 1945. The turret was a small design, bearing in mind that it was meant only to accommodate 2 crewmen. It bore a resemblance to the Valentine MK. X turret, however, its design had some variance in features. It featured a large single door hatch in the left side, as to allow for a quick escape in the case of the tank being knocked out, as well as allowing for easier loading of the proposed 55 rounds of 6pdr ammunition to be carried. The top of the turret featured a single split-door hatch for the commander, as well as two periscopes for vision under closed-down position and two antenna mounts.

The original wooden mock-up of the A38 Valiant. Photo: The Tank Museum Archives
Mobility was listed at 16 mph (25.75 km/h), made possible by the Rolls-Royce Meteorite; a proposed 8-cylinder engine capable of 400 horsepower. The road range, or ‘circuit of action’ as described by the design specification, was 100 miles (161km). The design was to have a 30-degree minimum climb angle, as well as the ability to clear a 3 inch (76mm) obstacle. Steering was to be conducted in the traditional ‘clutch and brake’ configuration. The design was specified with a 5-speed synchromesh gearbox. Interestingly, later in the development of Valiant, The Department of Tank Design conducted a report on the amount of effort required in gear changing with Valiant, Valentine and the M4 Sherman. It was found that little difficulty would be experienced with Valiant, except for some difficulty when changing from second to third; this was suggested to be improved by fitting a diesel or ‘oil’ engine which would enable the engine to pick up at lower speeds. The suspension was of the aforementioned ‘Vanguard’ type. This consisted of six pairs of road wheels per side. These pairs of rubber-tired road wheels are mounted onto independent transverse spring units, each supported by an internal spring and a wishbone mount. Shock absorbers in the form of 8 hydraulic double piston stations are present on wheel stations 1, 2, 5 and 6. There are 3 top rollers provided to support the upper weight and tension of the track. The track itself was specified as 20 inches (50cm) wide and of manganese construction. Featuring twin guide horns, these tracks were specified to produce 10.5lb./sq.in. (7g/sq.cm) of ground pressure.
This initial design can be compared favorably to existing tanks that were in production, considering that these were designed in the late 1930s. The armament was superior to that on previous infantry tanks such as A11 and A12, as well as early models of Valentine. This gun not only allowed it to be effective at engaging enemy armor, but also allowed it to perform its primary function of infantry support, something that existing British guns in the form of the 2 Pounder were not capable of. The armor profile was designed fairly ahead of its time with the use of slopes and pike noses, no major shot traps existed on this original vehicle.

From Vickers to Rolls-Royce, Rolls-Royce to Ruston and Hornsby

The vehicle continued to be developed at Vickers for a few months after the contract had been awarded, with amendments regarding engine power. The contract now called for six pilots, four to be designated as Mk.I using existing engines found on the Valentine series; these were the A.E.C produced A189 petrol engine and the General Motors Company produced diesel engine, producing 135 and 138 horsepower respectively. The remaining two pilots were Mk.II, equipped with the originally specified Meteorite by Rolls-Royce or an unspecified V8 petrol engine produced by Ford. Due to poor reception of the 6pdr in the Valentine IX, the Tank Board suggested in February of 1943 that a 75mm armament was worked into the design of the tank, however, this was never implemented. A 3-man turret was also specified. Shortly following these changes, Vickers decided that the project was to receive a new parent designer. The reason for this was stated as a response to increased workload and a priority shift at the Chertsey facility; the project had already been declared as of lower priority by the Tank Board, stating that the bulk of Vickers’ workload was to focus on the continuation of existing tank production, as well as building American tanks. The new parentage of the design was undecided at the time, however, it had been agreed that Rolls-Royce would be responsible for developing the engine and transmission compartment; this work would be completed at their facility at Belper (Derbyshire); the engineers here had previously worked on the A.33 Assault Tank design in 1941.
This is where the first design alterations were made from the original Vickers design. The exhaust openings were moved from facing the sides of the vehicle to the engine deck, where they now faced upwards. Along with this, the transmission housings were up-armored. This was done by welding several large plates below the transmission. These alterations were the first that began to have negative impacts upon the Valiant, as it added an imbalance of weight towards the rear suspension. The original ground clearance of the design was 16.9 inches (43cm), an average value in comparison to tanks of the time. However, 4 ½ inches of armor plate reduced this value not only with the physical thickness of the material, but also by weighing down the rear suspension and causing the whole vehicle to sink to the rear. By the time the ground clearance data had been taken in May of 1945, the suspension gave an eye-watering 10 inches (25cm) of ground clearance at the rear and 8.9 inches (27cm) from the rear suspension units. By May of 1945, the suspension had been in existence for a few years and had been the basis of the Valiant prototype since 1944, giving a year for these additions, as well as the engine to drop the ground clearance. Thus, it can be assumed that the ground clearance was perhaps greater upon the completion of the prototype than in its suspension trials.

The rear transmission armor. Note the downward drop in suspension caused by the additional plate of armor. Photo: Author’s own
Two months following the decision to transfer responsibility to Rolls-Royce, the Ministry of Supply named a new parent for the project, now known as A.38 Valiant, as Ruston and Hornsby (R&H), and terminated the existing contract with Vickers Armstrong. Ruston and Hornsby had experience in building diesel and steam locomotives, as well as producing A.12 Matilda II. However, they had no prior experience in designing armored vehicles. R&H made several amendments to the design. The front armor profile was altered, whilst the pike nose was retained, a new superstructure was added to the front, creating a large bulge which not only added weight to the design, but also created a massive weak spot in the armor. The new 3-man turret was also designed at this stage. To accommodate the larger turret, the turret ring was increased by welding two elliptical plates to either side of the hull, further increasing weight. The new turret itself was much larger than the original turret, with a central bulge that presented a severe shot trap. The turret ring itself was unarmoured, causing further vulnerability to it being damaged by enemy fire.

The altered front profile. Note the retention of the pike front underneath. Photo: Author’s own

One of the added turret ellipticals. Photo: Author’s own

The air intake vents, moved upwards by R&H. Photo: Author’s own)

The final turret design. Photo: Author’s own

A38 Valiant specifications

Dimensions 5.4 x 2.8 x 2.1 m (17 ft 8.6 in x 9 ft 2 in x 6 ft 10.7 in)
Total weight, battle ready 27 tons
Crew 4 (driver, commander, gunner, loader)
Propulsion GMC 6004 diesel 210 hp (157 kW) 7,8 hp/t
Suspension Individual coil springs, double-wishbone
Speed (road) 19 km/h (12 mph)
Range 130 km (80 miles)
Armament QF 6 pdr (57 mm) gun, coaxial Besa 7.92 mm, 2-in smoke bomb launcher
Armor 34 to 114 mm (1.3 to 4.5 in)
Total production 1 in 1944

Sources

Special thanks to Ed Francis for his personal assistance and his discovery of the information on Vanguard that assisted in this piece.
Archives of The Tank Museum, Bovington, UK.
Examination of the A38 by the author, Bovington Tank Museum


Illustration of the A38 Valiant by Tank Encyclopedia’s own David Bocquelet, with corrections from Alexe Pavel.

‘Heavy Valiant’

The ‘Heavy Valiant’ was a separate design to Valiant that appeared in February of 1944, presented to the Tank Board by Rolls-Royce. It is not a ‘Valiant Mk.III’, nor is it a development of Valiant Mk.II. It is also a completely different machine from the A.33, also known as ‘Excelsior’ or ‘Heavy Cromwell’, although it was to use several components from this vehicle. The purpose of this design was to produce an ‘assault tank with exceptional protection’, as stated by the design brochure, specifically to have 50% greater armor than on any current British or American design. The intent was to produce a vehicle that could reach these requirements by compressing internal volume and reducing the crew number to 3, which would solve the problems of increased weight and dimensions. From the design brochure, it seems that this vehicle was pitched as an improvement on the A33 Excelsior, which had been designed previously by Rolls-Royce at Belper.

The initial plan for ‘Heavy Valiant’. The HVSS suspension system from T1/A.33 is clearly visible. Photo: The Tank Museum Archives
Upon viewing the design for Heavy Valiant, many visual similarities are shared from the Valiant, albeit in its final form. Dimensions were 20 feet 10 inches (6.3m) long with the armament forward and 10 feet 4 inches (3.1m) wide, larger than Valiant Mk.I, but smaller than the A33 Excelsior, which had the problem of being unable to cross the standard Bailey Bridge used by the British Army. The pike nose was present, with a frontal thickness of 9 inches (220mm) on the frontal upper plate and 8 ½ inches (210mm) on the lower plate. Side armor was listed 5 ½ inches (140mm), along with additional skirting that covered much of the suspension. The final weight of the vehicle was 42.27 tons (38.34 tonnes), making it more than twice the weight of the original specification of what became Valiant. The thickness of the belly plate was 25mm thick, a 5mm increase from that on the A33. The turret of the Heavy Valiant was almost identical in shape and design to that on A.38 Valiant, however, the frontal thickness of the casting is a staggering 10 inches thick, with an armored recess for the turret ring to prevent it from being damaged in combat.

The armor profiling of ‘Heavy Valiant’. Note the retained pike nose of the A.38 Photo: The Tank Museum Archives
The armament on the Heavy Valiant was varied. The main armament was a selection of 3 guns; the American 75mm as used in the T1 Heavy, the 6-pdr as used in the existing Valiant design, or the 95mm howitzer, a gun most famously used on the A27L Centaur in a close support role. This armament was to be accompanied by a 7.92mm BESA machine gun in a coaxial mounting, as well as one 2 inch smoke mortar. Alternatively, .303 machine guns and even the 20mm Oerlikon cannon were suggested for ‘increased man-killing proposition’. As an infantry support vehicle, the design states reliance on special ammunition types such as sabot, hollow charge and squeeze bore to increase penetration in case the vehicle is required to destroy other armored targets, highlighting the emphasis of this vehicle not being primarily intended to engage other tanks.
The maximum speed of the vehicle was to be 13 mph (20.92 km/h), slower than originally envisioned with the Valiant’s speed of 16 mph, however, given the increase in weight the difference is quite small. The engine was to be the same Meteorite V8 engine as on the Valiant Mk.II, tuned to 330 bhp. The road range was to be 60 miles (90.56 km), provided with a full tank of 63 gallons of petrol fuel, a reduced range from Valiant. The transmission was a 5-speed Rolls-Royce synchromesh gearbox, with a 16 inch (41cm) triple plate clutch. Steering was to be conducted through an epicyclically controlled unit built by Rolls-Royce. The suspension was a Horizontal Volute Spring Suspension (HVSS), the same used on the T1 Heavy Tank design from the U.S.A; this was carried over from the A.33 also, a possible reason as to why these two designs are sometimes mistaken as the same. The suspension had 3 units per side, each carrying two pairs of rubber-tired road wheels. The track system was also carried over from the T1/A.33, this was a 25 ½ inch (65cm) wide track with rubber insert pads. Both of these units had already completed 1000 miles of testing from A.33, so they were seen to have been proven. Suitable mobility was a primary focus for this design, as it was seen as a part of the vehicle’s offensive capability. Additionally, the design utilized the same turret traverse gear as the A.33 Excelsior. The power to weight ratio of 8hp per ton was not appreciably worse than that of the A.22 Churchill, which was in service at the time.
As a design concept, the Heavy Valiant was a significant improvement over both the A38 Valiant and A33 Excelsior designs that had preceded it; understandable given the time gap between the designs. The Heavy Valiant would have been a more suitable vehicle for 1944, with its heavy armor and proven infantry support armaments. However, the design did not get past design stages, with rumors of a prototype being completed and sent for trials at Lulworth (the British Army Armoured Fighting Vehicle Gunnery School located in Dorset) being unproven at best; no reliable sources pinpoint this occurring at all. This fate was shared with many similar designs for heavier vehicles such as A43 Black Prince or the A39 Tortoise. All of these designs came at a time when the ‘Universal Tank’ concept had been introduced, a concept that eventually culminated in the Centurion.

The Suspension Trial

The suspension trials for Valiant have probably become the most well-known stage of the vehicles development cycle, with good reason. These trials are well known for the sheer amount of problems that were encountered by the testing team. However, it is important to be aware of the fact that these trials were for the suspension only; the trials took place in May of 1945, after the end of the war in Europe. Due to the Tank Board’s decisions to press on with continued production and development of existing vehicles such as the A22 Churchill, as well as contemporary designs such as A43 Black Prince that mounted more capable armaments, the Valiant became an extremely low priority, with only a single prototype of a Mk.I having been completed by R&H in early 1944, by which time it was essentially obsolete. On these grounds, serial production of the Valiant had not been entertained since the first half of 1943. However, the Vanguard suspension system was seen to be ‘novel’ on a heavy vehicle and thus worthy of further trials; the previous trials had only occurred on lighter SPG mounts for the 17-pdr.

A view of the Vanguard suspension system. Photo: Author’s own
The Valiant was delivered to the Fighting Vehicle Proving Establishment at Chertsey, Surrey, on 7th May 1945; this was the primary facility for the proving and trials of armoured fighting vehicles at the time. The vehicle was the sole produced prototype; the proposed 3 vehicles were never built and never equipped as Mk.II tanks with Ford or Meteorite engines. The prototype was weighed at 27 tons (24 tonnes); the additions made by R&H, as well as Rolls-Royce at Belper had added 4 tons (3.6 tonnes) to the specified weight of the design.
The first action conducted by the test team was a measurement of the vehicle’s unladen weight; without crew or ammunition loaded, but filled with fuel, water and oil. The result of this was 26 tons and 13 hundredweights (27.1 tonnes). The next stage was the measurement of ground clearances. This was the first major fault that the test team recorded; the ground clearance was found to be unacceptably low. With the ground clearance at the rear at 9.6 inches (24cm) and rear suspension clearance at 8.9 inches (22cm), the vehicle would have had great difficulty on uneven terrain, with a high possibility of suffering suspension bolt shearing and being susceptible to high centers. The results, however, also record the hull ground clearances at 17.45 inches (44cm) for the front and 14.1 inches (36cm) for the rear. This would indicate the sinking of the vehicle suspension to the rear, where Belper and R&H made alterations to the transmission armor. This is also a feature that can be seen to those who visit Valiant in the Tank Museum today.
The next part of the trials involved a road test on cross-country terrain, conducted to establish the general quality of the ride, as well as the suitability of the suspension system for cross-country operation. Pitch tests were to be conducted as a part of the run, however, these trials were not conducted as the vehicle was unable to reach the cross-country trail. The vehicle was run on road conditions for approximately 13 miles (21km), during which several observations were made. Firstly, the engine oil tank had been overfilled, which was causing the oil breather to spit oil and thus cause the test team to suspect an oil leak. The reason for the overfilling was determined due to the lack of a measuring stick with the vehicle. The steering tillers of the vehicle were found to be excessively heavy; the driver was unable to continue due to fatigue. After the trials, the vehicle was placed in the workshops to determine whether this was a fault of the design or due to improper adjustment of the tillers; the heaviness of the clutches used for the steering was found to be responsible.
The footbrake also required assistance from the steering tillers, as to disengage the steering clutches before braking could occur. Furthermore, the footbrake placement in the hull necessitated the use of the heel to use it. During operation, it was speculated that there was a risk for the driver of having his heel trapped between the footbrake and the floorplate, causing ‘serious injury’. Contrary to a commonly held belief, there is no mention of a foot amputation risk on this vehicle, at least not on the official trial report. It was found that there was so little space between the gear lever in the 5th position and the right steering level, there was a risk of the driver’s wrist being broken by the violent action of moving the gear lever. The 1st gear position was located behind the battery boxes of the vehicle, where it was found to be extremely difficult to engage and physically impossible to disengage without the use of a lever or crowbar to assist. The driver’s position was also subject to criticism. It was noted that the driver had to occupy a crouched position, which presented to him a risk of serious injury from the hatch doors. The trial also pointed out the underpowered nature of the GMC engine that the tank was equipped with, noting that the vehicle encountered powertrain difficulties when dealing with even slight inclines. The suspension system, the main purpose of the trials, was found to have exposed lubrication points; the grease nipples. These grease nipples were quite fragile and would have been liable to destruction by cross-country terrain.
There were also some major letdowns in terms of maintenance. The vehicle did not include a level plug for the right-hand final drive, making any final drive servicing impossible. The final observation made by the team was the process for checking the gearbox levels and adjusting the steering brakes. Both of these necessitated the removal of the rear access louvers; these are extremely heavy on this vehicle. The procedure would require three men and a considerable amount of time to complete. At 13 miles (21km), the team decided that the vehicle was unsafe for continued operation and thus had the vehicle recovered and towed back 13 miles (21km) to the FVPE. After this, the vehicle underwent some extensive mechanical investigations in the workshops on the site, as to determine the causes of some of the technical faults found earlier.

A closer view of the exposed lubrication lines. Photo: Gabe Farrell
The trial report made several conclusions. Firstly, it was noted that the basic design of the vehicle was at fault in so many respects that there would be no useful purpose in its continued development or trials. A major concern made in the report was also that the vehicle was entirely unsafe to be put on the road and would present a danger to other road users. These limitations, as well as the technical limitations of the suspension, were seen to render any favourable points of the wishbone suspension system as “utterly valueless”. Due to the vehicle being undrivable beyond 13 miles (21km), the team stated that it would be unfair to expect anyone to risk the injuries that are presented to the driver. A final conclusion was that the design would require sufficient modifications to be introduced to make the design driveable and reasonably safe, with no mention of the further modifications that would be required to produce a serviceable vehicle.
With these conclusions, the FVPE recommended that the vehicle be immediately withdrawn from the suspension trials and returned to its makers at R&H. The report also suggested that the entire project be cancelled; a recommendation that was followed ultimately.

Conclusion: A Stinker or A Tragedy

At face value, this tank may indeed seem to be deserving of its moniker as the worst tank design in the history of AFVs, especially given the more dubious claims of the suspension trial regarding the risk of the driver losing his foot. Indeed, the final prototype suffered horrendous design traits and was outclassed in the time of 1943-1945. However, it must be remembered that the design was early war in nature; the suspension system was a pre-existing design and even the original Vanguard design was pre-1942. In this respect, the original design was actually very favourable and was an improvement on the infantry tanks that came before it, such as Valentine and A.11 Matilda, with innovative armour angling and an improved armament. Additionally, the original specification for a Meteorite engine would have made the vehicle far more reliable in terms of mobility. It is only after the vehicle is evaluated after the design alterations that it becomes more difficult to find praise. The additions made by Belper and R&H were responsible for increasing the weight of the vehicle, which had negative effects on the suspension system and overall mobility, as well as failing to implement the improved engine of the Mk.II. The wishbone system had proved itself as notable of further development from its performance on lighter SPG trials, the problem was its use on a vehicle that was 19 tons heavier than on these trials.
After the trials had seen the prototype be rejected, it was decided that it would be retained by the School of Tank Technology for educational purposes. While at the school, students were often invited to point out as many flaws as they could with the design; even as a failure, the design seems to have served some purpose in this regard. During the 1950’s, the vehicle was withdrawn by the Ministry of Supply and added to the collection books of the RAC Tank Museum in Bovington. Whilst here, it spent time indoors, as well as outside in the car park, before finally being kept inside the World War Two hall, where it can be observed today, alongside other British design oddities.

The A38 Valiant as it sits today in the Bovington Tank Museum. Photo: Author’s own.

Categories
WW2 British Prototypes WW2 Polish Prototypes

Kahn’s Obstacle Ball / Rolling Fortress ‘Tank’

UK/Poland/Mandatory Palestine
1941 – Sketches Only

Kahn’s Obstacle Ball or Rolling Fortress tank, a giant concrete ball-shaped tank, comes from the unlikely source of Mandatory Palestine. Mandatory Palestine is, perhaps, not the first place which comes to mind when considering military inventions, but what it did have was a large number of immigrants, especially Jewish immigrants from Europe, settling there. Seeing his home country of Poland overrun and under occupation, Mr. L. Kahn, a Polish-born engineer living in Palestine in June 1941, decided to send his inventions into the Ministry of Works in Mandatory Palestine for potential use in the war. No doubt he could see in the newsreels or read in the papers the ravages of this new World War and decided to turn his skills to the creation of weapons. His letter, written in June 1941, did not go very far though; his ideas were mostly poorly conceived or impractical and lay forgotten for decades. Of his ideas, it is perhaps his ‘tank’ which by virtue of its novelty is most worthy of remembrance.
Kahn, an engineer working for Technotrade Engineering and Technical Supply, Herzl Street, Tel Aviv, sent his suggestions in on the 16th June 1941 along with sketches and some explanation of the ideas.
Kahn’s is not the only ‘ball tank’. In fact, there were far earlier designs, such as the “Tumbleweed tank”, designed by the Texan inventor A.J. Richardson in 1936. There was also a mysterious German attempt known as the ‘Kugelpanzer’.

Plans for Kahn’s Rolling Fortress and method of towing. The area lined-off in the bottom right includes sketches of his anti-torpedo related ideas. Photo: National Archives of Israel

Spherically impractical

This design by Kahn was in an unorthodox shape for a vehicle, a sphere. Whilst there were other ideas for ‘ball-tanks’ being developed elsewhere at the same time, perhaps none of them were on this scale, which combined the ideas of the ‘ball’ with the size of the ‘big-wheel’ landships. Whereas a big wheel was needed to reduce the high ground pressure of a small wheel, in this case, a giant sphere was needed to reduce the ground pressure of a small sphere. Being big would have other advantages too for an obstacle ball.
This vehicle was to be enormous, 20 to 50 feet (6.1m to 15.2m) in diameter with walls 20 to 50 inches (0.5m to 1.3m) thick made from iron-reinforced cast concrete.
The ball was to be cast and then pressurized with high-pressure steam of 100 lb per sq. in. (6.9 x 105 Pascals) and impregnated with carbon dioxide for several hours to help cure the mix of cement, stone chippings, and sand. There was no rebar added within the mix but it was bound with circular irons to provide support for the concrete body.
Kahn is not clear in his letter as to how he expected a hollow sphere to be cast, so the assumption is that it would instead be cast in two halves and then bolted together across one of these boundary ‘irons’. On the smallest end of the scale, this design is a 6.1m diameter ball with walls just 0.5 m thick which would use approximately 49.4 m3 of concrete weighing about 123 tonnes just for the armor. On the upper end, however, the maths shows what a poor idea it really was, as with a diameter of 15.2 m and walls 1.3 m thick, this would mean over 726 cubic meters of concrete and would weigh not less than 1,800 tonnes.
The reason for the pressurization and carbon dioxide infused concrete is that, according to Kahn, this would increase not just the curing time (the time taken for the concrete to set and harden), but also significantly increase the strength by a factor of 5 to 8 times. Kahn elaborated that using this method his ‘light’ wall scheme just 20” (0.5m) thick provided the equivalent strength of a wall 6 feet (1.8m) thick. As Kahn claimed that this 6’ thick armour would be able to resist the shock from even the largest of enemy guns and howitzers, it is unclear as to why a scheme with walls 1.3m thick would ever need to have been considered.

Inside the Ball

Within the ball, things became more interesting. Behind these very thick concrete armour walls was an internal ‘car’ which, attached along an axis by hollow steel pins to the shell, rotated independently of the shell. Thus, as the ball moved, the internal car rotated inside it staying level regardless of the position of the ball.
There was not, however, a double rotation axis, meaning that this stability was not duplicated when the ball obstacle was to move along a sidegrade. There was to be sufficient space (69m3 min. to 1499m3 max.) within the ball for crew, weaponry, and stores.

Towing the Ball

To move these balls around, Kahn did not foresee an internal engine, but instead, two different methods of towing. One was to use a bespoke carriage trailer which was towed behind a standard truck and attached to the ball by the same axial rotation points. Even at 14.4 tonnes though, this ball would likely have done considerable damage to any prepared road surface and would tax the towing ability of a truck uphill as well as being dangerous on any downwards slope although Kahn did consider the need to brake the axial shaft on this carriage for presumably this exact reason. For the larger idea, no truck was capable of moving such an enormous ball and 15.2m was wider than most roads anyway.
On top of this, Kahn foresaw these balls being attached together to form trains behind a truck with between 3 and 5 hooked together meaning a weight being towed between 369 tonnes and somewhat ambitious 9,000 tonnes.


Illustration of the 23 tonne and 1,800 tonne Obstacle Ball or ‘Rolling Fortress’. Modeled by Mr. C. Ryan, funded by our Patreon campaign.

Fortress

As a defensive fortress, the idea of these giant balls perhaps had some merit to them. They could be anchored together and would be impassable to vehicles, hard to bridge over due to their shape, and hard to destroy. One advantage and clever feature of the design was the low-grade materials used. Apart from pressurizing the concrete, the castings were at least simple enough along with the irons that it could be manufactured locally in theatre rather than in a factory which would have saved time, money and engineering to focus of other things as well as remove the problems of strategic transport. It was not the only vehicle during the war to use concrete as armour. The Bison mobile pillboxes (truck-based pillboxes) were a similar idea and even some tanks used concrete too, but the scale of the concrete used as well as the shape of the vehicle is what sets it apart.
Multiple balls would be connected together through a simple double-ended bolt passed through the hollow axles, and then with nuts tightened up on the inside drawing the balls together. These balls would then be anchored together firmly whilst still able to rotate and move along a common axis, although Kahn made no mention of moving the balls whilst connected, simply drawing a train of three balls fastened together. After connection as a fortress, these balls could then be armed, therefore not just forming a physical barrier, but a fighting fortress line too, or at least, that was Mr. Kahn’s idea. Smaller balls would be fitted with machine-guns or mortars and the larger ones would be able to take cannons or even a flamethrower with the fuel tank held under the fighting platform in the bottom of the ball, although the actual positioning of the loopholes to fire from was poorly considered. The field of fire from each ball was very tightly constrained by an inability to traverse, meaning no matter how well armed a single ball was, it would be surrounded and overwhelmed. They had to, therefore, rely on flanking supporting fire, and although he foresaw these could be ‘quickly deployed to the front’, did not consider the problem for the unarmoured trucks moving these under fire. Later in his letter, Kahn describes the ‘anti-tank flamethrower’ as firing not through a loophole in the ball, but actually fixed to the axial shaft of the ball and projecting from two nozzles, with one in each direction coming from this mounting point.
Also within the area under the fighting platform was to be a tank of water for cooling the machine-guns, indicating perhaps his thoughts of Vickers water-cooled machine-guns or Maxim guns as the primary armament.
For crew access, there were to be two doors also made from concrete and the same thickness as the walls. They were set at opposite ends at the front and rear, meaning whichever angle the ball was at, one door would face down to allow the crew to escape. The other door would obviously be too heavy to open above the crew compartment and this also meant that there was a good chance that the escape door would face in the direction of enemy fire.

The Tank

Kahn was very thorough in one regard with his idea. He seems to have understood that simply towing these balls together was not possible, or at least was unfavorable, due to enemy fire against the unprotected towing vehicles, and consequently, his unpowered towed concrete ball gained an engine. Kahn did not use the term ‘tank’ to describe this adaption though, instead, he used the term ‘self-moving fortress’.
For movement, it was to use a ‘petrol motor… installed inside with both ends driving a geared cadran or V grooved cadran, with single disengaging drive”.
It is hard to envisage how in the relatively small space provided such a motor would power such a heavy ball across even hard ground, let alone on soft ground, and despite this being, in effect, a ball-shaped tank, it was supposed to drive two internally mounted, circumferential and parallel toothed gear wheels with the motor fixed to a stationary platform so as to drive the gear wheel. Kahn does, later in his letter to the Ministry, describe that the engine could also be a diesel unit. To steer the ball, the drive from the engine was switched from either driving both toothed wheels or to one, which would impart an uneven force on one side of the ball steering it in the opposite direction. Vision was provided by a periscope sticking out of each end of the axle.
The whole idea of this ball-shaped tank was poorly conceived, albeit well-intentioned. The idea was, perhaps, unsurprisingly rejected as impractical by the Mandatory’s authorities on behalf of the British Ministry of Supply.

Other weapons

It is worth noting that Kahn’s other suggestions for weapons to the Mandatory’s authorities also met the same level of success as this ‘ball fortress’. Examples of these were electrified shells and electrical landmines to electrocute tanks; an electrified wire carpet to entangle and electrify tanks; concrete escort boats to protect convoys from enemy torpedoes; the fitting of propellers to the sides of ships spinning at 5,000 to 10,000 rpm to break up torpedoes before they hit; These all fell on deaf ears as ideas, as did his idea for a sound-induced death ray for destroying enemy submarines; an infrared morse code apparatus; a tethered shell for shooting down planes; and a tailless fighter aircraft. The Ministry of Supply evaluated all of these ideas as well and all were considered to add nothing new to knowledge and therefore rejected.

Specifications

Dimensions (L-w-H) Sphere 20 to 50 feet (6.1m to 15.2m) in diameter
Total weight, battle ready 123 tonnes to 1,800 tonnes
Armor Iron-reinforced cast concrete, 20 to 50 inches (0.5m to 1.3m) thick
Propulsion Petrol or Diesel
Armament Variously water-cooled machine-guns, mortars, cannon, or flamethrower

Links & Resources

Government of Palestine Archive File C/273/41 1941

Categories
WW2 British Prototypes

Vickers No. 1 & No. 2 Tanks

United Kingdom (1921)
Tank Prototypes – 2 Built

In early 1921, the British government’s Tank Board and its General staff representative Colonel John Frederick Charles Fuller were considering their next tank design. The result of their deliberations resulted in a set of very loose requirements. These requirements stated that this new tank would need to be usable in the tropics. The policy gave a list of areas that were seen as likely to be trouble spots in the future which included the Balkans, Russia, India, and South America. The latter two regions were the cause for the ‘tropics’ requirement. Furthermore, it was envisioned that the best way to combat a tank was with another tank.
Col. Fuller discovered that the Master General of Ordnance (MGO) had been working with the firm of Vickers on a new tank. He was shocked and saw it as a usurpation of his authority when in reality it was not. Col. Fuller has, in some of his works, tried to portray himself in a good light, and a British tank of this period that did not have his oversight would be rather difficult to explain, especially when he was involved with the failing Department for Tank Design and Experimentation, run by Philip Johnson.
The MGO ordered three prototypes of the new tank design to be built, these were constructed at the Vickers Erith plant near London. The first being completed in November 1921.

Vickers No. 1 Tank. Photo: SOURCE

Description

The No.1 tank was a rhomboid in shape, with a striking resemblance to a miniaturized First World War tank, although the front was more curved. On top of this sat a superstructure, with a semi-circular front. The sides of the superstructure were inside the width of the track run. On top of this superstructure was a domed turret, with a centrally placed cupola. Three barbettes were placed every 120 degrees within the turret, these held ball mounts for Hotchkiss machine guns. A fourth ball mount was placed in the turret roof for anti-aircraft work.
The driver sat at the front, in a chair that was described as ‘sumptuous’, and had ‘barber chair’ like controls to get the perfect driving position. The controls featured a large steering wheel, with two circular wheels for adjusting the transmission and which could, in theory, have a continuously variable number of gears.
These gears were provided by a Williams-Jenney hydraulic transmission, made by Variable Speed Gears Ltd. of Crayford, London. This was the same model of transmission that had been fitted to the failed Mk.VIII Tank. And which had originally been used onboard ships to power winches. Power was provided by a six-cylinder Wolseley engine, located behind a firewall at the rear of the vehicle.
The tracks were extremely basic design being nothing more than a flat plate with a pressed indentation which was filled with a wooden sole plate.

Williams-Jenney hydraulic transmission at Dollis Hill. Photo: SOURCE

Service

When the No.1 tank was completed Vickers decided it was too noisy and not reliable enough. Despite this, the tank was dispatched to the War Office tank testing section at Farnborough. There it was found that the transmission was prone to severely overheating. One of the tests the tank was subjected too was a race between the No.1 tank and the Light Infantry Tank and, according to Col. Fuller, a Medium D. The No.1 tank lost and came dead last. In 1922, the No.1 tank was returned to Vickers and fitted with better tracks and a more powerful engine. In March of the same year, she was handed back to the War Office. However, no further tests were carried out, and by March 1923 she was listed as derelict and in the tank testing sections stores.

Shot of the rear of the No.1 tank, you can see the access ports to the engine and transmission, as well as the basic track design. Photo: Aviarmor.


The Vickers No. 1 Tank armed only with machine guns.

The Vickers No. 2 Tank armed with the 3-Pounder 47mm Gun.
Both Illustrations are by William ‘Rhictor’ Byrd, funded by DeadlyDilemma through our Patreon Campaign.

The No. 2 Tank

Work started on the No.2 tank in July 1922 and would be completed in July 1923. There was one big change in this design over the No.1 tank. On the 15th March 1922, the Director General of Artillery’s (DG of A) office issued an order that all future tanks must be armed with a quick firing (QF) gun. Thus, the No.2 tank was equipped with a 3-pounder (47mm) gun. This was a higher velocity weapon than was normally fitted to tanks of the period and followed the General Staff policy about countering other tanks. This combination of policy and dedicated high-velocity armament means that the No.2 tank was likely the first ever tank to be armed to fight other tanks.
There is, at current, no details on the trials the No.2 tank was subjected too, or a list of the faults encountered in the designs, but they must have been numerous, as the design was not taken into service. The No.2 machine was scrapped in 1927.

The No.2 tank, you can see in this picture the rear access ports are wide open. This is an attempt to cool the transmission. The cooling problem was down to the oil in the hydraulic system rapidly becoming overheated. Photo: Public Domain
The third machine ordered was built as a gun carrier, with a field gun being loaded onto the bed through a ramp at the rear of the tank. Some websites claim that this prototype led to the Dragon gun tractors, although no hard evidence has been advanced for this theory.

Conclusion

Although ultimately the Vickers No.1 and No.2 failed to produce a successful design, it was likely one of the world’s first modern tanks, taking design features from the Renault FT, such as rear-mounted engine behind a firewall and a single weapon in a turret. Yet it refined these ideas, increased the crew size to something respectable, and included a gun designed for hunting and killing enemy tanks. The idea that the best counter to a tank is another tank is today widely accepted as a truism. Just a handful of years after the tank had been developed this was considered a new concept, one which ultimately proved right.
It should be mentioned here that the speculation on the role of the No.3 machine might have a part to play. There is a theory, although at the time of writing an unfounded one, that the Dragon gun tractor led to the development of the Vickers Medium Mk. I. If this is the case then the No.1 and No.2 were even more important as designs than originally thought.

Secifications (No. 1 & 2)

Total weight, battle ready 8.75 – 10 tons
Crew 5
Propulsion No. 1: Wolseley six cylinder
No. 2: 80hp Lanchester 40, Six Cylinder, Water-cooled, petrol
Speed 15 mph (24 km/h)
Range 120 mi (190 km)
Armament No. 1: 4x Hotchkiss machine guns
No. 2: 1 x QF 3-Pdr (47 mm/1.85 in) gun, 1x Hotchkiss machine gun.
Total production 2

Links & Resources

Mechanised Force: British Tanks Between the Wars, David Fletcher, ISBN 10: 0112904874 / ISBN 13: 9780112904878
tankarchives.blogspot.com
tank100.com

Forgotten Tanks and Guns of the 1920s, 1930s and 1940sForgotten Tanks and Guns of the 1920s, 1930s and 1940s

By David Lister

History forgets. Files are lost and mislaid. But this book seeks to shine a light, offering a collection of cutting edge pieces of historical research detailing some of the most fascinating arms and armament projects from the 1920s to the end of the 1940’s, nearly all of which had previously been lost to history.Included here are records from the UK’s MI10 (the forerunner of GCHQ) which tell the story of the mighty Japanese heavy tanks and their service during the Second World War.

Buy this book on Amazon!

Categories
WW2 British Prototypes

Churchill Mk.III with ‘Ardeer Aggie’ Mortar

United Kingdom (1943)
AVRE Replacement – 1 Prototype Built

In 1942, development of an armoured vehicle for use by the Royal Engineers (RE) began. This was the famous Churchill AVRE (Armoured Vehicle Royal Engineers), which was armed with a 290mm Spigot mortar. This mortar, known as the ‘Petard’ (a 16th-century word of French origin describing ‘a bomb to breach’) was capable of firing a huge, 28lb (12.7kg) projectile nicknamed the ‘Flying Dustbin’. The weapon was designed as a demolition tool that would breach defenses and crack open enemy bunkers, a role which it performed extremely well. However, there were a couple of quite dangerous problems with the operation of the Petard.

Reloading the mortar was a hazardous endeavor, as the mortar had to be reloaded externally. Not ideal in combat situations. To begin loading, the turret would be traversed so the Petard was over the bow gunner’s position. This man would then slide open his hatch (which replaced the two-part hatch on standard Churchills) and reach up to the barrel of the Petard. Like a giant shotgun, the barrel would be broken in half, and a fresh round inserted.

Range was another issue. At maximum, the Petard could only throw one of these ‘Flying Dustbins’ 100 yards (91 meters). This wasn’t ideal, as the tank would have to get extremely close to a target to fire. More often than not, AVREs would advance under the cover of regular gun-armed tanks to engage any enemy posing a threat to the AVRE.

The British Military began looking for a solution to these issues. In September 1943, interest was growing in a new mortar being designed and developed by Imperial Chemical Industries Limited at their factory at Ardeer, North Ayrshire in Scotland. This new weapon would be tested on the hull of a Mk.III Churchill, and would prove to be a powerful weapon, perhaps a little bit too powerful…

The prototype vehicle with the new giant mortar. Photo: The Tank Museum

The Churchill Mk.III

Officially designated as ‘Tank, Infantry, Mk.IV, A22’, the Churchill entered service with the British Armoured forces in 1941. It was named, contrary to popular belief, after an ancestor of the famous Winston Churchill, not the man himself. It was the last ‘Infantry Tank’ to serve in the British Military.

The specific model used in the tests was the Mk. III Churchill, which was produced from late 1942. It had armor of up to 102mm thick over the frontal arc. The turret was a welded type and mounted the tank’s usual main armament, the Ordnance Quick-Firing 6-Pounder (57mm) Gun.
Secondary armament consisted of a coaxial and a bow-mounted 7.92mm BESA machine gun. The tank was crewed by 5 men. These were the commander, gunner, loader, driver, and bow machine-gunner/wireless operator.

The Churchill was not fast. A lumbering beast at approximately 40-tons, its top speed was only 15 mph (24 km/h). It was powered by a Bedford 12-cylinder engine producing 350 hp. The tank was supported on a complicated suspension with 11 small wheels per side, each one attached to an independent coil spring. The drive wheel was at the rear with a sprocketed idler at the front. Though it was slow and heavy, the Churchill made a name for itself as being one of the best cross-country tanks ever built and could climb higher gradients or cross harder obstacles than most other tanks then in service.

The ‘Aggie’

First Prototype

The weapon that garnered so much interest was a large mortar originally designed to be placed on a towed mount. There was even a prototype of the gun tested on the mount of a towed 6-Pounder anti-tank gun. The gun was an early endeavour into the idea of ‘Recoilless’ guns. This type of gun operates on the principles of Isaac Newton’s Third Law of Motion; “For every action, there is an equal and opposite reaction”. These guns are not truly ‘Recoilless’, but they have drastically reduced recoil compared to a regular gun. When they are fired, another charge is fired backward from the rear of the gun, cancelling out the recoil effect of the projectile leaving the barrel. In the case of the Aggie, the counteraction is supplied via a counterweight being fired from rear of the gun tube simultaneously.

The first live-fire test of the prototype weapon – mounted on said 6-Pounder carriage – took place in December 1943. This mortar had a barrel with a 10½-inch (267mm) bore and fired a projectile that was both 10 inches (254smm) in diameter and length. This projectile weighed 51 pounds (23 kg) and was packed with 29 pounds (13 kg) of high-explosive (HE). The counterweight was of the same dimensions but was full of sand. The propellant charge itself weighed 2 pounds 8 ounces (969 g) and consisted of a 3/s cordite that produced a maximum pressure of 1 ton per-square-inch (15,444 kPa). At 300 yards (274 m) the weapon proved to be extremely inaccurate, while its anti-concrete performance was deemed worse than that of the Petard’s ‘Dustbin’ projectile.

The trial mortar on the towed 6-pounder mount. Photo: Ed Francis Personal Collection

Second Prototype

During the summer of 1944, the Land Assault Wing of the Assault Wing Training and Development Centre at Woolbridge in Suffolk, began experimenting with the possibility of mounting a new version of the Aggie on the hull of a Churchill Mk.III tank. In October of that year a test vehicle was sent to the Department of Tank Design (DTD) for evaluation. The specifics of the second version were as follows. The weapon had a 9 ½ inch (241 mm) bore, 1.6 inches (41mm) smaller than the Petard of the standard AVRE which had a 11.4 inch (290 mm) bore. The gun had a 10 foot (L/10, 3 meters) long barrel and fired a 54 pound (24 kg) High Explosive (HE) filled projectile, almost twice the payload of the 28lb (12.7 kg) ‘Flying Dustbin’ fired by the Petard. Range was also drastically increased from the Petard’s 100 yards (91 meters). This new mortar could lob a round to an effective range of 450 yards (410 meters). Maximum firing rate was three rounds in two minutes.

Firing the gun produced clouds of acrid smoke and fumes. This is where the “Aggie” received its name. The mortar was named after a local bus that ran people around Ayrshire (where the gun was made), which was famous for producing great clouds of smoke as it travelled. For loading, the gun broke in half with the rear portion sliding backwards (it would protrude from the rear of the tank). The projectile and gunpowder load would be placed in the fixed front half. The two haves were then reunited and locked in place prior to firing.

Turret Changes

The Churchill Mk.III’s turret was drastically modified to accept this new large gun. The standard main armament of the 6-Pounder anti-tank gun was removed, a slot carved out of the turret face along with a small section of the turret roof. Inside, the gun ran the length of the entire turret with the blast-vent protruding through the rear of the turret. This could be covered by a sliding panel. A rudimentary mantlet was welded to the turret face around the gun barrel, bent at the top to cover the part cut out of the turret roof. A small hole was made in this for the gun sight.

Side view of the modified Churchill. Photo: Scalemates

Conditions inside the turret would have been harsh, with the 9 ½ inch mortar taking up most of the room from the back to the front. It did incorporate internal loading, however, one of the issues with the AVRE that need to be changed.

Luckily for the crew in the turret, most of the smoke and fumes were ejected out of the barrel and blast-vent at the rear. The mortar, when fired, still produced horrendous recoil though, jarring the whole tank. The counterweight, placed at the opposite end of the gun, did somewhat help to reduce the recoil force, but, as one, can imagine, this was not a popular solution with the crew, as a man would have to exit the tank to replace it. This would somewhat undo the work of trying to keep everyone inside the tank when reloading.

This scale model provides us with an excellent view of the blast vent at the back of the turret. Photo: SOURCE

The turret retained the ability to rotate through a 360-Degree arc, but elevation or depression was extremely limited. Looking at photos, it is hard to say if it had any range of motion at all as it had to stay in line with the blast vent in the rear of the turret. Unfortunately, we don’t have any documents to give such detail.

Crew

The crew remained the same as regular Churchills with 5 personnel. There were three men in the turret and two in the hull. Positions were also the same with the commander at the rear right, loader on the left and gunner on the right. In the hull were the driver on the right and the bow machine gunner on the left. It is possible that the bow gunner position may have been removed to allow stowage of ammunition.

Fate

In the end, the project received extremely poor reviews and was rejected and deemed unsuitable for placement on the Churchill AVRE. Its rejection was mostly due to the reasons outlined in an official report on the prototype titled ‘Churchill ‘Ardeer-Aggie’ This report can be found in the Archives at The Tank Museum, Bovington.

  • The structural stability and immunity of the tank was impaired by the openings in the front and rear [of the turret].
  • If the projector was depressed from full elevation an opening occurred below the projector in the rear of the turret. This was completely unprotected and at full depression measured approx. 8 inches (20 cm) high by 15 inches (38 cm) wide. No satisfactory method of overcoming this defect could be foreseen.
  • Nearly level gun platforms would have to be selected which did not give angled of sight to targets of more than about +4 to -6 degrees.
  • The firing of a counter-projectile of sand in the neighbourhood of the engine compartment was considered undesirable even though a cover plate [could] be fitted over this compartment.
  • The absorption of the energy of discharge by the firing of a counter charge was felt to be dangerous to friendly troops whilst avoidance of this danger was considered to impose a serious limitation on the tactical employment of this weapon.
  • Stowage of counter projectiles entailed a serious reduction in the number of HE projectiles that could be carried.
  • The loading of counter projectiles aggravated considerably the arduous task of the loader.
  • The projectile had no advantage over any other alternative as regards to the time required before it could appear in service.

Other problems also included cramped conditions in the turret and the weapon being generally hazardous to operate. The turret became very cramped, not only did the mortar take up at least 50% of the space inside, but it also had to carry projectiles, charges, and the counterweights.

Even with the counterweight at the back the amount of recoil and concussive forces generated would have been extremely unpleasant for the crew. It also made a deafening sound and became very hot after firing.

As mentioned above, firing the mortar was dangerous for personnel outside the vehicle, especially if there were infantry behind the tank as the back-blast and propelled counter-weight could easily end up in fatal injuries. Attempts were made to assuage this issue by the installation of a blast shield, but this was unsuccessful.

Fate

With the rejection of the project, work on it ceased. Though too late for service in World War Two, the military would eventually find a replacement for the Petard in the Ordnance BL 6.5″ Mk. I Demolition Gun. The gun fired a 64 lb (29 kg. It also contained a 40lb charge of C-4) High Explosive Squash Head (HESH) shell at up to 2,400 m (2,600 yd). This was a vast improvement over both the Petard and the ‘Aggie’.

An article by Mark Nash, assisted by David Lister & Ed Francis



The modified Churchill Mk.III with the ‘Ardeer Aggie’ mortar. Illustration by Tank Encyclopedia’s own AmazingAce, based on work by David Bocquelet.

Specifications

Dimensions 24ft 5in x 10ft 8in x 8ft 2in
(7.44 m x 3.25 m x 2.49 m)
Total weight Aprox. 40 tonnes
Crew 5 (driver, bow-gunner, gunner, commander, loader)
Propulsion 350 hp Bedford horizontally opposed twin-six petrol engine
Speed (road) 15 mph (24 km/h)
Armament 9 ½ inch (241 mm) ‘Ardeer Aggie’ Mortar
1 x 7.92mm (0.3 in) BESA machine gun
Armor Up to 102mm
Total production 1

Sources

Haynes Owners Workshop Manuals, Churchill Tank 1941-56 (all models). An insight into the history, development, production, and role of the British Army tank of the Second World War.
Osprey Publishing, New Vanguard #7 Churchill Infantry Tank 1941-51
Article on the vehicle (Russian)
Churchill AVRE files, Archives of The Tank Museum, Bovington
Royal Engineers Museum, Kent
David Lister
Ed Francis


British Churchill Tank – Tank Encyclopedia Support Shirt

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Categories
WW2 British Prototypes

Praying Mantis

United Kingdom (1937-44)
Experimental Machine Gun Carrier – 2 Prototypes

The Praying Mantis was an experimental machine gun carrier designed by a private developer for the British Army during the Second World War. It is in competition with the Kugelpanzer as one of the strangest armored vehicle designs ever produced.
It could be said that it is ‘typically British’ in its eccentricity. The vehicle would never become as deadly a hunter as it’s invertebrate namesake, however, as it never left the prototype stage.

The First prototype of the vehicle.

Development

The Praying Mantis was a private venture by one Mr. Ernest James Tapp (often shortened to E. J. Tapp) of County Commercial Cars. The design was patented in 1937, with the construction of prototypes beginning in 1943. The vehicle was designed to shoot over walls and other obstacles while staying as concealed as possible.

Anatomy

The initial prototype of the Mantis was designed on a bespoke chassis. It had thin tracks, a rear mounted drive wheel and 4 road-wheels. The prototype was basic in its construction, intended just as a means of testing cross-country ability and the driver’s position. This prototype was displayed to the War Office shortly after the outbreak of World War II.
The second and final prototype was commissioned in 1943 and was based on the engine and running gear of the venerable Universal Carrier. The Universal Carrier was the workhorse vehicle of the British Army throughout the war and saw service with numerous countries in numerous theaters. It also spawned a number of variants and derivatives such as the Canadian Wasp flamethrower or the Australian 2-Pounder armed LP2.
With this, the Mantis retained the Carrier’s Ford V8 85bhp petrol engine and running gear that used the ‘track-bending’ steering system. This is all that the Mantis retained from the Carrier, as the rest of the tank’s chassis was rather unusual.

Chassis

The anatomy of this ‘iron invertebrate’ is unlike any other tank or armored fighting vehicle. It consists of a lower hull in which can be found the engine, a crew compartment, a pivoting ‘head’ and finally, a small machine gun armed turret, known as the ‘helmet’.

The Praying Mantis with the fighting compartment raised to full extension. Photo: The Tank Museum
The Crew compartment, known as the ‘control chamber’ took the form of a long hollow box. Inside would be the positions for the vehicles two crew members, the Driver and the Gunner, who would be effectively lying down, prone, inside the box with their heads towards the machine gun turret. At the crew’s feet was a hydraulic system that would raise the entire compartment. It would rise to about a 55-degree angle. Maximum elevation was 11f.5ft (3.48m) off the ground. In the original plans, the box had the ability to traverse left and right as well. This would bring the head, which could pivot up and down, above an obstacle allowing the gunner to engage any targets. The vehicle could move around with the crew chamber in any position. When fully lowered, the Mantis could move around behind low bushes, or even tall grass while staying concealed.
The Gunner was in charge of the vehicle’s main armament, a pair of Bren Light Machine Guns mounted side-by-side in the rotating ‘helmet’. Chambered for the standard British .303 round, the magazine fed Bren was a staple weapon of the British Army’s infantry. The gun entered service in 1938. It would serve for over 30 years, finally being withdrawn in 1991. The ‘helmet’ was also equipped with a grapple, fired by a small grappling gun.

Praying Mantis illustration
Illustration of the Praying Mantis by Tank Encyclopedia’s own David Bocquelet

Fate

The second prototype took part in a number of trials, but that’s as far as it would go. In operation, it was found that the controls were extremely hard to use. The effect on the crew was also not ideal, as many recounted the swaying of the moving vehicle gave them motion sickness. In 1944, it was officially abandoned.

Lowered fully, the Mantis could be used as cover for infantry. Photo: The Tank Museum
The first prototype was scrapped, but the second eventually found it’s way to the Bovington Tank Museum. The vehicle has been preserved there ever since, and the joints are still in operable condition. It is considered to be the strangest vehicles in their collection.
Though this vehicle was something of a flop. Mr. Tapp’s idea of a vehicle that could raise its weapons above cover without exposing itself would later be employed by various armored vehicles. The ATGM (Anti-Tank Guided Missile) launching FV1620 Humber Hornet, for example, used a similar mechanism.

The Praying Mantis as it sits today in The Tank Museum, Bovington. Author’s photo.

An article by Mark Nash

Specifications

Crew 2 (driver, machine-gunner)
Propulsion Ford T 4-cyl petrol, 40 bhp
Speed (road) 25 mph (40 km/h)
Armament 2 x .303 Bren Light Machine Guns
Armor 6 to 9 mm (0.24-0.35 in)
Total production 2 Prototypes

Links, Resources & Further Reading

Article on The Tank Museum’s Website
Patent GB577274 submitted on July 16th 1946 by Mr. E. Tapp

Categories
WW2 British Prototypes

40RBL78 MA Field Gun

United Kingdom (1940)
Self-Propelled Gun – 1 Prototype built

Why did this project exist?

In the very early stages of WW2, there were many good, and probably more not-so-good-but-well-meaning ideas to bolster the British war effort against the Nazis. The War had not gone well for Great Britain up to that point, the entire British Expeditionary Force (B.E.F.) had been forced out of continental Europe meaning that Britain had lost almost all of its best tanks. Tank production was vital and the nation was very short of tanks of such weapons. Add to this the very real fear of a pending German invasion of the British mainland from across the channel and there was a significant effort to convert peace-time industries to wartime production. Pipe makers became gun barrel makers, boilermakers and train builders started building tanks, and many firms were investigating ways of weaponizing vehicles already in production.
The county of Lincolnshire was a significant industrial hub in Great Britain and a generation beforehand had birthed the modern tank from the firm of William Foster and Co. It was a neighboring firm, however, Ruston-Bucyrus, who in this period came up with one of the more unusual ‘tank’ ideas. Ruston-Bucyrus (‘Ruston’s) had been formed in 1930 by the merger of the Lincolnshire firm of Ruston and Hornby (who had already had some experience with track laying vehicles in WW1 during the development of early British tanks) and the American firm of Bucyrus-Erie of Bucyrus, of Ohio. Ruston’s specialized in tracked earthmoving and excavation vehicles and even ‘walking machines’ moving on large feet. They, like many other firms across the country, had already received limited contracts to assist in Cruiser tank production in 1940. Obviously, with a specialization in a different type of tracked vehicles, Ruston’s sought to use their own expertise to convert their 10-RB grab cranes into military vehicles.

Ruston-Bucyrus built 10-RB with face-shovel. Photo: www.baumaschinenbilder.de

Ruston-Bucyrus 19-RB machine in British military use. Photo: pillboxesinsuffolk

The 10-RB idea

The 10-RB was a sturdy design and was actually still in production into the 1960’s and, like its slightly larger cousins, the 19-RB, 22-RB, and 37-RB, was already in limited use by the British military for earth moving duties. At least five 10-RB’s were already in use for example with No.2 Section 135th Mechanical Engineers in the construction of the GHQ Defence Line through Essex in June 1940.
The 10-RB and 19-RB, in particular, were very useful due to their small size making haulage by truck from site to site very easy although a special trailer was also available. The 22-RB and 37-RB machines were much larger and harder to transport. The 10-RB was just 9 tons (including crane boom) and was mechanically simple but was slow with a top speed of just 2.5 miles per hour (4 km/h) in top gear and 0.8 miles per hour (1.3 km/h) in low gear. This was not a hindrance on a building site but was not ideal for a military vehicle.

The special RB transport trailer in use for hauling RB cranes. Photo: pillboxesinsuffolk

1-RB0 on transport trailer

The Project

The Chief Engineer at Ruston-Bucyrus was a man named Bill Savage and he led the project to create a vehicle for military purposes, appointing their lead designer, Fred Stratton to prepare a prototype using an old rusty 1o-RB from their own yard. This vehicle was already well used as for years it had simply been used for moving scrap metal onto rail cars. The project goal was to convert this machine into a military vehicle capable of carrying a field gun. By October 1940, the outline had been drawn up for the plan for what is effectively just an armored box on the crawler body with a field gun poking out of the front.

Only known image of the 40RBL78 labeled ‘Proposed Layout of MA Field Gun’. Dated 18th October 1940


40RBL78 MA Field Gun, rendition by tank encyclopedia’s own David Bocquelet

Layout

Unlike British tanks of 1940, this design was not going to be a bolted body but instead would be fully welded. The slow speed of the 10-RB both in moving and the ‘slewing’ of the cab (the rotation speed) was significantly improved by the designers adjusting the gear ratios within the machine without changing the small electrically started 3VRON diesel engine it was using. It is not known if thought was given to substituting this small 33hp diesel unit with the larger 55hp unit from the 19-RB or not but this would have involved changing the starter from electrical to compressed air and the fitting of a small petrol donkey engine to the machine in order to fulfill that.
These mechanical adjustments to the gearing were very successful, perhaps too successful as the machine went from being capable of just 2.5 miles per hour to 15 miles per hour. Vehicles of this type have no suspension to speak of as they don’t need it for the speeds they are doing. At 15 mph though, in a vehicle with no suspension, being driven perched in a large box on top of the track which the driver would be unable to see beneath him appears to have been terrifying as an idea. This centrally-rotating cab design with the engine in the rear of the cab is a normal set-up for a machine of this type and was even known as the ‘Lincoln cab.’

Ruston-Bucyrus 3VRON 33hp 3 cylinder diesel engine. Photo: ERF on Flickr

Seen from the underside this is the chassis of the 10-RB crane on which the 40RBL78 MA was planned. 5 small rollers on each side with a chain direct driven sprocket with drive coming from the gearing system under the cab ring. The simplicity of the framework design is apparent.
It is unsurprising that this prototype machine now with its 15mph top speed was described as “virtually unsteerable” as well as being dangerous to bystanders. Fitting the weight of the armored body, crew, gun, and ammunition would not have made this machine any less dangerous to drive as it would have raised the center of gravity and made her unstable on any side slope.
The armor was not specified but the role was as an armored field gun carrying machine but bullet-proof plate would be expected in the region of 10mm thick. The field gun to be carried is also not specified but it likely would be a standard field piece. No specifications exist for the depression or elevation of the gun but the only known drawing of it clearly shows a very wide field of movement above and below the zero degree (horizontal) line.
The cab itself is a large welded box with the gun mounted forward and central. No details of crew layout are known but if it were to retain the driver control from the 10-RB, which would be probable, then the driver would sit in the front on the right with the remaining crew elsewhere. Considering the need for ammunition stowage there would likely not be room for more than 4 crew including the driver and even then would be cramped.
Unusually for a military vehicle, the ‘turret’ was not mounted in a conventional type turret ring as with conventional tanks but instead with the weight of the whole unit borne onto a series of rollers running around the turret. This system was common in cranes and was similar to the system used in some the TOG (The Old Gang) vehicles. Visibility would be poor as only 4 vision slits (2 front and one in each large side access door) are visible. No door could be provided in the back as the engine was in the rear of the cab. No self-defense weapon appears to have been provided for either.

Termination

Despite the potential to produce this vehicle cheaply compared to tank based systems this concept was one of the first British ideas for a fully enclosed self-propelled gun predating the development of the Bishop self-propelled gun. The concept was never progressed and the 10-RB prototype was returned to its former duties “to the dismay of those drivers who thereafter had to negotiate the concrete loading ramp with this errant machine.” The machine presumably lived out its usefulness there until it too was scrapped and forgotten. By the middle of 1941, the Bishop SPG project was underway and there was, therefore, a better means of moving an enclosed field gun on track.
The 40RBL78 idea should be remembered not as a dangerous or crazy idea but rather as one of the numerous, novel, and inventive ideas, from skilled engineers, determined to put their knowledge to use to defend their nation from the Nazis.

An article by Andrew Hills

40RBL78 MA Field Gun Specifications

Dimensions 8’6” (2.9 m) wide approx. 11’6” (3.5 m) high
Total weight 9 tons
Crew 2-4 (estimated)
Propulsion 33 3VRON 3 cylinder diesel engine
Speed (road) 2.5mph (original) 15mph (re-geared)
Armament Presumably a Medium caliber field gun
Armor bulletproof/10mm est. max.
Total production
For information about abbreviations check the Lexical Index

Links, Resources & Further Reading

‘Lincoln Excavators’- 1930-1945
RB-11 Instruction Manual
Pillboxes in Suffolk blogspot (LINK)
Video of 10-RB crane in use (LINK)
From Ruston to Siemens. 150 years of engineering history’ (LINK)