Sir William Tritton had designed the original ‘Chaser’ tank; the Medium Mark A popularly known as the Whippet. Tritton had personally visited the Western Front in 1917 to speak with crew of his tanks and get their reflection and suggestions. He also got a first-hand chance to see the terrain over which his tanks were being used and this left a deep impression on his mind.
The original Whippet, the Medium Mark A, even before production was complete was being seen as needing replacement. A follow-on design to incorporate the feedback from the troops and the requirements of the War Office. The two prospective replacements for the Whippet were semi-rival designs in this regard and were the Medium Mark B which was the design on Major Walter Wilson and the Medium Mark C designed by the designer of the Medium Mark A, Sir William Tritton.
Wilson had already started on his ‘B’ design and as a result, Tritton from the firm of William Foster and Co. with his chief engineer, William Rigby started to put together the ‘C’ design following a request by Admiral Moore on 3rd January 1918. Drawings were ready by 14th February and these were accepted as a design by the War Office on 19th April 1918. Construction then began on a prototype which was ready in the August of that year. Despite having started design and construction after Wilson, Tritton’s machine was ready one month prior to Wilson’s and was nicknamed ‘HORNET’ at some point. Quite why the military authorised two replacement designs to go ahead is unclear as is the switch from a fast hunting dog to a stinging insect for the name inspiration although a large aggressive insect with a very unpleasant sting certainly fits the bill for the role. It is possible the intention was to produce both in order to compare them for performance and order the better of the two or it could just be indecision or desperation to make sure they got one functional design.
The Medium Mark C was a large tank, completely unlike the Whippet it was to replace, she was actually larger and taller than the Mk.V and 2 tons heavier than the Medium Mark B of Major Wilson. Centennial WW1 POSTER
The distinguishing features of the Medium Mark C are the very large box structure at the front which housed the commander and two machine gunners and the driver. Despite the lack of a turret the commander was equipped with a fully rotating cupola for improvised vision and a map table to assist in navigation. No radio was fitted but semaphore was provided for and the crew could communicate by means of speaking tubes. Previous tank designs suffered from terrible ventilation in particular of engine fumes and carbon monoxide from guns. The Medium Mark C separated the crew from the engine fumes with the bulkhead and large fans were also fitted to provide fresh air for the crew compartment although in event of a gas attack etc. the crew would have to resort to gas masks. Other innovations for the Mark C included the ability to add sulphonic acid to the exhaust to create a smokescreen just like the Medium Mark B. For The driver though was located centrally and was provided with a large flap which could be raised for better visibility when driving in a non combat area or road march while the rest of the crew used any of the 11 view ports provided around the tank. In keeping with the design of the Medium Mark A the Mark C used 7 Timken bearings on the main roller bearings which took the greatest load and non-timken bearing rollers fore and aft of these. Medium Mark C Hornet during trials probably on the William Foster test field in Lincoln. Little Willie can be seen in the background of one of the shots
Consideration was given to creating both a Male and a Female version of the Medium Mark C just like there had been for the Medium Mark B. The Medium Mark C Male planned to have a single 6 pounder L/40 gun facing forwards and the female just machine guns with provisional plans for the production of 4000 female and 200 male tanks in case the war had continued into 1919. The new tanks required by the War Office were to be medium tanks though which meant machine guns only. So, in the end, no ‘male’ or ‘female’ versions were made and the Hornet was just armed with 4 Hotchkiss machine guns. Rear view of a Medium Mark C rear door which is open and the rear machine gun position (to the left of the exhaust pipe)
Unlike the Medium Mark B of Major Wilson which was suffered from production delays the Medium C ‘Hornet’ prototype had been completed on schedule and subsequently received a production order for 200 machines (later increased to 600). By the time of the Armistice in November 1918 though no vehicles had actually been completed. 36 machines which were in various stages of construction though were finished and delivered to the 2nd Battalion, Tank Corps. A further 14 vehicles were constructed from the spare parts and materials which had been assembled for production. The remaining balance on the order was cancelled and no more Mark C’s were to be made. Layout of the Medium Mark C Hornet
Very clean Medium Mark C, [this photo shows signs of a contemporary ‘touch up’ removing the background] Photo: Beamish Archive
Hornet on trial in test ground of William Foster and Co. Ltd. The state of the ground is obvious from the amount of mud all over the hull. More vehicles can be seen in the sheds in the background. Photo: IWM
Medium Mark C, standard livery 1919.
The new engine
Early in 1917 following problems with engine deliveries Colonel Albert Stern had engaged Harry Ricardo to develop a tank engine capable of 150hp, using no scarce metals like aluminium (which was prioritised at the time for aircraft production) and could run at sharp angles of tilt (35 degrees) for up to 100 hours on low grade petrol. The engine had to be compact but the design of the tank allowed for a wider and much taller engine than before. This allowed Ricardo to develop a rather tall 6 cylinder engine with long stroke pistons. Once completed this engine could actually produce 165hp at maximum speed (1200rpm) which allowed for a 10% overload on the engine for short periods without damage.
Stern ordered 700 of these engines from 5 separate engine makers immediately for the tanks like the Hornet which weren’t even in the design stage at the time. Stern felt that this step in ordering engines for tanks as soon as possible would remove the problems of supply which were holding back tank production. The British War Office however, was decidedly unimpressed with such foresight, production management and strategic thinking, and ordered Stern’s bosses at the Ministry of Munitions to cancel this ‘wasteful’ order forthwith. Stern therefore doubled the order to 1400 engines. This was the character of that man. The engine bay in the Mark C was large, large enough to fit this engine and like Major Wilson’s tank had also learned the lesson of isolating the crew from the engine by means of a firewall.
The Oldbury trials of March 1917 had showed the value of the epicyclic gearbox which further developed by Major Wilson would find much tank use in later years. These engines and gearboxes were to find their way into the Mark V in July 1917 and prospectively for the VI heavy tank but no orders for the Mark V were placed until November that year. When the engine was finally made though more aluminium was allowed to be used in the manufacture permitting the engine to be lighter than originally thought.
End game
The Medium Mark C Hornet, was a better tank overall than the Medium Mark B, but unlike the Mark B she was neither sold nor deployed outside of Great Britain. Medium Mark C’s during the 1919 Victory Parade, London
The Medium Mark C’s made an appearance at the Victory parade in London in July 1919 and a single vehicle was modified with wire handrails to form an unforgettable and rather hazardous amusement ride for visitors at Bovington Camp in July 1921.
Medium Mark C amusement ride, Bovington July 1921 Medium Mark C’s deployed to the streets of Liverpool in August 1919
Medium Mark C’s deployed the Glasgow in 1919 and stationed in the Salt Market (the city’s cattle market)
The only action the Medium C ever saw was a brief deployment of approximately 6 tanks of which at least 3 were Medium Mark C’s to Glasgow in January to March 1919 after a period of civil unrest but were withdrawn without a shot fired. Likewise to quell a public disorder at least 4 tanks were deployed to the streets of Liverpool in August 1919 but again left within firing a shot. One vehicle was put on outdoor display at the Imperial War Museum at the Crystal Palace, London between 1920 and 1924 before she was towed to Cricklewood for breaking. Imperial War Museum Crystal Palace, London 1920-1924 Medium Mark C being towed to Cricklewood. Photo IWM
The Medium Mark C instead formed the backbone of the Royal Tank Corps from 1924 to 1925 until it was replaced by Vickers tanks. As the Medium Mark C’s were phased out they went to stores or training. In 1930 six vehicle were sent to the Mechanical Warfare Experimental Establishment (M.W.E.E.) for development work on an armoured recovery vehicle. Two examples were sent to Bovington camp for storage but like the Medium B were not saved but cut up for scrap before WW2. There are no surviving examples.
Medium Mark C Bovington ~1920 showing its ease of crushing barbed wire entanglements. Photo: Tank Museum
Medium Mark C Hornet serial number H2272 stuck in a roadside ditch in the 1920’s providing an interesting view of the top of the vehicle
The Medium Mark C smoke generating tank
The World War One tank killer was artillery and later in the war direct fire from German field Guns. The Allies found out that a defence to this menace was the deployment of a smoke screen by artillery bombardment using white phosphorus shells or to start the battle early under the cover of mist or fog. If the advancing tanks could not be seen by the enemy’s artillery spotter, then their artillery and anti-tank fire was not accurate. Unlike tanks in World War Two the metal monsters of the Great War were not fitted with smoke grenade launchers.
In 1925 British scientists at the War Office Technical Chemical Department at the Experimental Station based in Porton Down, Wiltshire, started work on developing a system that could be fitted to a bullet proof tank that could advance toward the enemy and generate a thick and expansive smoke screen that could not only hide the attacking tanks moving across no-man’s-land towards enemy trenches but also the infantry, making it harder for the enemy to find a target they could shoot at accurately.
The Medium Mark C smoke generating tank had a large 360-gallon oil emulsion container fitted on its rear roof.
Before the use of white phosphorus to deploy smoke screens became the norm, other methods were first tried. A British War Office report WO 189/3600 details how a special oil emulsion was experimented with. The principle of ‘oil smoke’ is the vaporisation of oil by heat. This was done by spraying an oil emulsion into the hot exhaust manifold of a tank’s engine. By this method, no back pressure or negative effect is produced that will harm the engine.
A British Medium C tank was used for the experiment. A large rectangular welded sheet iron container that was 5ft 6in long, 2ft wide and 2ft tall was fitted to the rear section of the tank roof. It could hold 136 gallons of oil emulsion and is marked ‘A’ on the photograph of the tank. The oil pump could force through one gallon of liquid per minute at a pressure of 100 lbs per square inch through the brass spray nozzle. It was mounted and coupled up to the engine fan in front of the exhaust manifold and is marked ‘C’ on the photograph.
The 360-gallon oil emulsion container is on the left of this photograph and the liquid was pumped into the Exhaust manifold to produce a thick cloud of smoke.
A pipe led to a pressure gauge placed by the driver’s seat that allowed him to see at a glance whether the pump was working properly or not. An opening and closing stop cock lever was fitted externally to the pump. The smoke was started or stopped by the driver operating a handle placed by the driver’s seat next to the engine controls. It actuated a rod which moved up or down thus shutting or opening the stop cock lever on the top of the tank.
The device was tried out in a field and a good thick dense oil smoke cloud was obtained. The generated smoke was deemed to be harmless to both personnel and machinery. The amount of oil emulsion carried in the container was found to be sufficient for a two-hour continuous run.
Sources
Royal Tank Corps Journal, November 1926
Medium Mark C, Charlie Clelland
Glasgow Digital Library
David Fletcher “British Tanks 1915-19”, Crowood, 2001
Peter Chamberlain and Chris Ellis “(AFV Weapons Profiles No.7) Medium Tanks Marks A-D”, Profile Publications, 1970
www.landships.info
Medium Mark A Whippet, David Fletcher, 2014
Medium Marks A to D by Christopher Ellis and Peter Chamberlain
Medium Mark B Tank, David Fletcher, Wheel and Track 42 – 1993
Medium Mark C Tank, David Fletcher, Wheel and Track 43 – 1993
Landships, David Fletcher, 1984
WO 194/3600 National Archives at Kew
Medium Mark C ‘Hornet’ specifications
Dimensions
26’ long, 9′ 6” high, 8’ 4” wide (7.92m x 2.9m x 2.54m)
Total weight, battle ready
20 tons (19,182kg)
Crew
4 (commander, driver, 2 x machine gunners
Propulsion
6 cylinder Ricardo producing 150hp at 1200rpm
Suspension
track and bearings only
Speed (road)
8 mph
Range
140 miles (230km)
Armament
4 x Hotchkiss machine guns with 7200 round, service rifles and cup grenade launchers. (Lewis guns could also be used)
Armor
6-14mm max.
Total production
50 (200 ordered 1918, 36 in service, 14 assembled from parts)
For information about abbreviations check the Lexical Index
Republic of Poland (1940-1943)
Tank/Armored Personnel Carrier – None Built
The Enigmatic Colonel Chrobok
Of the many Polish tank designs prior to 1945, those from the pen of Pawel Chrobok are perhaps some of the most unusual. Very little is known of Chrobok, save for a few patents submitted in his name while living in exile in Great Britain during WW2. In 1940 and 1941, Colonel Chrobok of the Polish Free Army, Rothsay, Scotland submitted two designs for a tank/APC hybrid vehicle.
The First Design
Col. Chrobok’s first design was submitted in December 1940 while residing at the Polish Army camp in Rothesay, and titled ‘Improvements Relating to Automobile Gun-Carriages.’ The object of the design was to provide heavy and light ordnance in the tank along with a contingent of foot troops and other portable equipment such as light field guns all in one package.
The front of this first design would concentrate its armament with a wide array of guns consisting of heavy armour-piercing guns, heavy machine guns, flame throwing devices and anti-aircraft guns as thought fit. The entire vehicle was to be armor plated, with special care being given to the crew cabin. The rear troop area of the vehicle was specified to have armored sides and, depending on the requirement, would have either a waterproof fabric cover or an armored roof.
Inside the rear troop compartment were a series of stepped bench-seats arranged longitudinally for troops with a storage area underneath for equipment. The whole area was accessed through a large rear hatch which could hinge either downwards or outwards. The side walls were also intended to open in order to facilitate loading or offloading as the vehicle was also intended to move supplies and the wounded on stretchers. The complete specification for this patent application was complete by 27th December 1941 and it was accepted on 6th July 1942 under Patent number GB 546,287(A).
Colonel Chrobok’s original 1940 design for his ‘Automobile Gun Carriage’
Improvements
In January 1941, Colonel Chrobok submitted a second and improved variation of his first design, this time titled ‘An Improved Armoured Gun Carriage.’ The most substantial change brought by this improved design was the addition of a small round turret at the rear of the machine, which was to serve as an anti-aircraft gun. A less obvious difference was the addition of two parallel longitudinal firing ports on each side of the troop compartment, permitting the troops to fire from within.
Colonel Chrobok’s ‘Improved Armoured Gun Carriage’ of 1941
A Third and Larger Idea
Colonel Chrobok’s fortunes did not favor his designs and at some point, he left the Polish Army camp by February 1943 and was giving his home address as Du Cane Court, Baltham, London. From here, Colonel Chrobok’s inventiveness continued with a design for fire fighting apparatus in October 1942 and an even more impressive and substantial ‘tank’ in February 1943. This new tank design was intended to fulfil offensive and defensive roles and equipped with, according to Chrobok, “very powerful offensive armament.” With a similar frontal aspect to the previous designs, this design specified that the cylindrical gun turrets (one or more) would be sunk into the body and have a diameter of approximately ⅓ of the overall vehicle width. Specifically, there would be an overlap on the side walls in order to provide buoyancy and the large amphibious design would be propelled in the water by its tracks.
Front view of Colonel Chrobok’s 1943 ‘Improved Armoured Gun Carriage’
Side and top view of Colonel Chrobok’s 1943 ‘Improved Armoured Gun Carriage’ The turrets were arranged so that the hull was stepped, allowing each of the three steps to fire over the other. Each turret was to be equipped with a pair of guns mounted in fixed cradles and elevated or depressed by means of an electric motor. Other armament was to consist of heavy and light machine guns with six of the heavy machine guns located in the angled side walls of each ‘step’ and two light machine guns mounted in the rear of the machine. All machine guns to be held in ball joints for “universal movement.” The “very powerful offensive armament” called for 3.5m long 40-60 mm caliber autoloading guns in the front and central turrets and a 4.5m long 40-60 mm caliber autoloading gun in the rear turret. There was also to be auxiliary armament of hydrogen gas powered flamethrowers mounted in the side walls and a “mine-thrower” in the floor. Each turret was to be equipped with a crew of two and an observer on each deck, one of whom doubled as the tank commander. They were also to be fitted with an electrically operated fan for ventilation. Cross section of one of the turrets outlining the method for turret rotation and gun elevation/depressionSteering was to be by selective track drive with each track speed being varied independently and allowing the tank to turn. Fuel would be carried underneath the fighting compartment along the bottom of the tank under the engine compartment which was to house more than one engine.
Proposed automotive layout of engines driving the tracks from a twin-engine design.
The armor of the vehicle was to be welded and make use of the angular layout to deflect enemy fire and in keeping with the earlier designs, space was allocated for troops, 75mm field guns and stores as required.
Sectional views of Colonel Chrobok’s 1943 ‘Improved Armoured Gun Carriage’
This final design by Colonel Chrobok didn’t progress past this stage but was approved on 10th December 1943, but subsequently went nowhere. These designs were uncovered by the author as patent archives, previously lost and forgotten. Despite the obvious limitations of the designs they are of historic value as these three vehicle designs were submitted at a time when Poland was being occupied by German forces. Little is known of Colonel Chrobok himself although there is a Wikipedia page for someone likely to be Chrobok but has not been verified.
Review
Colonel Chrobok’s designs were certainly interesting, combining many different ideas but were unworkable. Too large, too many guns and turrets, a nightmare to command and like many projects which try to do everything perfectly, they manage to do no one thing well. They were very complicated ideas at a time when Poland was in German hands and British industry was struggling to produce its own designs. These ideas were complicated, and the financial and human-time costs of developing these into working vehicles was simply not available. It is not known if he ever submitted these designs for official consideration but if he did they did not get very far in the evaluation process. None-the-less his motives were noble, his country was occupied and the need for effective tanks was great. Whoever Colonel Pawel Chrobok was, his designs were both interesting and odd in equal measure and help fill in a black hole in Polish tank history even if now over 70 years later they appear to be outdated and unworkable concepts.
Twin 40-60mm auto-loading 3.5m long guns in each of front and central turrets
Twin 40-60mm auto-loading 4.5m long guns in the rear turret
8 machine guns (2 in front hull, 2 in each step of vehicle and 2 facing over the rear)
Hydrogen gas powered flamethrowers
Floor mounted mine thrower
Total production
Zero
For information about abbreviations check the Lexical Index
Pawel Chrobok’s original 1940 ‘Automobile Gun Carriage’ design – Illustrated by Jaycee Davis (Amazing Ace)
Pawel Chrobok’s 1941 ‘Improved Armoured Gun Carriage’ design – Illustrated by Jaycee Davis (Amazing Ace)
Tracked Hussars Shirt
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The Medium Mark A Whippet was still in production when serious thought was being given regarding a new improved machine. The British War Office desired a new machine for service in summer 1918, to embody the role of the Medium Mark A but with specific improvements. The role was to be that of exploiting breaches in the enemy lines to disrupt and destroy behind the front line. In order to achieve this, trench crossing, which was limited in the Mark A, was to be increased but the overall length minimized partially to aid transportation of the machines by rail. The initial requirement for the new tank was for 380 machines with 40 intended for training purposes. Production was supposed to reach 650 machines to fill the perceived need for ‘medium’ tanks.
Wilson’s New Whippet
Major Walter Wilson (credited post war as the co-inventor of the tank with Sir William Tritton) started his own work on a replacement for the Mark A in July 1917 and focused on the needs of the British War Office for improved crew comfort, cross country mobility, and improved fighting ability. To improve mobility, Wilson intended to use a new 4 cylinder in-line version of the equally new Ricardo 6 cylinder 150hp engine. The 4 cylinder version was only rated at 100hp but was shorter in length than the 6 cylinder version. Orders for the 4 cylinder engine were placed with the firm of Messrs. Mirlees, Bickerton, and Day Ltd. in August 1917, but at just 100hp this new machine could barely manage just over 6 miles per hour (~10 km/h) which made it slower than the Mark A. This new machine received the designation of Medium Mark B.
Tritton’s New Whippet
The Mark A tank from Sir William Tritton (credited post war as the other co-inventor of the tank) of William Foster and Co. Ltd. in Lincoln was a novel design but it also had some significant shortcomings. Tritton, like Wilson, had been tasked by the War Office to prepare an improved tank to replace the Whippet. As it turned out, both designers’ vehicles ended up looking nothing like the preceding Mark A. Tritton countered with his own design. By all accounts, the rivalry between the two was fairly good natured but that would not mean that the design work would not be taken seriously. The new vehicle from Tritton was designated the Medium Mark C Tank. The two designs ‘B’ and ‘C’ are sometimes confused but the C can be readily differentiated from the B by the much taller superstructure cab and the raised upper hull running along the back between the tracks.
Production delays
Production of Medium Mark B tanks was slowed, however, by production capacity for the new Ricardo 150hp engines (6 cylinder) which were taking priority over the 4 cylinder version. Those engines were destined for the existing Mk.IV tanks. The Wilson epicyclic transmission was also intended to be utilized in the Mk.IVA variant. These transmissions though were also needed for the Medium B. Very few Mk.IV’s were upgraded to the MK.IVA but despite this, the program caused significant delays to Medium Mark B production. Worth noting is that the Mark B utilized a single engine compared to the Medium Mark A’s two engines.
Males and Females
The original idea for the Medium Mark B called for ‘Male’ and ‘Female’ versions of the machine, the females being armed with machine guns and the male version with an unspecified type of 2 pounder guns. The Male version was canceled in March 1918 and without a male counterpart, the Medium Mark Bs were not referred to as ‘Female’ machines.
Layout of the Medium Mark B
Suitable for an acrobatic midget
The original British War Office plan called for the engine as far back as possible, moving the center of gravity to the rear and improving trench crossing capabilities. However, in order to ensure a sloping rear deck, the engine ended up further forward than intended and created a very cramped space for the crew.
Additional work was needed with the engine and transmission as the combination of the Ricardo 100hp engine and the Wilson 4 speed epicyclic transmission was reportedly very unreliable. The engine was divided from the crew compartment by a steel bulkhead, protecting the crew from much of the heat and fumes and from potential engine fires. The bulkhead was fitted with two small doors which led into the cramped space to work on the motor.
This was the most significant thing about the machine. Despite the advantage of having a steel bulkhead separating the engine area from the crew space, access through the small sliding doors was extremely tight. So cramped and difficult in fact that, according to General Duncan, the work of servicing this engine was “only suited to an acrobatic midget.” When it could be done, the actual servicing reportedly took three times longer than other vehicles as well.
The prototype Medium Mark B was completed by the Metropolitan Carriage Wagon and Finance Company of Birmingham, England in September 1918, beaten by Tritton’s Mark C machine by a month. Subsequently, Wilson’s B machine was sent on trials.
Medium Mark B ‘Whippet’ during trials at the Metropolitan Carriage Wagon and Finance Co. test ground in Birmingham, England. The superstructure is remarkably clean considering how dirty the rest of the vehicle is from mud. Major Wilson is in the center with the cane and to his right with a pipe and hands in his pockets is the famous engine designer Harry Ricardo. Photo credit: IWM
The General Staff had waited to examine the Medium Mark A’s performance in combat before placing orders for production of the Medium Mark B and the trials of the Mark B showed that despite its ungainly appearance, it was a capable machine and worth ordering into production. Some 450 machines were on order by the middle of 1918, presumably also conditional on a suitable performance at the trials.
Orders were placed with three manufacturers, Metropolitan Carriage Wagon and Finance Company (M.C.W. & F. Co.) of Birmingham which was contracted for 100 machines, and the North British Locomotive Co. (N.B.L. Co.) in Glasgow and Coventry Ordnance Works in Coventry (C.O.W.) were both contracted for approximately 100 machines each. A fourth firm, Patent Shaft and Axletree (P.S. & A.) of Wednesbury also received a production contract but this was canceled before any were produced. Coventry Ordnance Works was the first company to finish a machine, and between these three firms some 102 vehicles were produced.
By the time of the armistice in November 1918, only 45 tanks had actually been completed and the outstanding tanks on order were canceled. Other sources state that the ‘45’ was the in-service number and that actually 102 had been finished with the other 57 awaiting acceptance by the Army. Another source states that just 23 vehicles were completed, delivered and tested by the time of the Armistice and 79 more finished afterward, of which 22 were accepted for service (making the total 45) and the remainder (57) being scrapped. Either way, the production and acceptance into Army service number is still 102 machines.
The remaining production vehicles that had been finished but not delivered were scrapped and some of the finished vehicles were sent to Bovington Camp for training, where they remained from 1919 to 1921. Six machines were sent to Russia in May 1919 to assist in the fight against the Bolsheviks and a small number were sent to Ireland in late 1919 as replacements for the obsolete Mk.IVs.
Early Mark B on trials on the testing ground at Dollis Hill, London. Of note in the background is a gun carrier hull, floating experimental tank (possibly Mark IX) and a crane vehicle. Photo credit: IWM
Early Coventry Ordnance Works built Medium B – note the lack of the curved rail above the sponson, and the machine gun ball in the side sponson, a feature omitted on later Medium Mark Bs
It is surprising that, despite the obvious shortcomings, any of the Medium Mark Bs were ordered at all. Tritton’s Medium Mark C was finished sooner and was more capable than the Mark B machine. Additionally, the Mark B was underpowered for a medium tank, being 2 miles per hour slower than the medium tank it was meant to replace. The commander had very poor visibility, no cupola, no turret and had to rely on a series of vision slits to see.
On the positive side, the Mark B was significantly easier to steer than the Mark A machine and the driver, instead of being in a tight position with a long engine in front of him, had a better high central front position, making it much easier to see. It was also significantly easier to drive, unlike the Mark A which had two engines requiring continuous driving adjustment to stay in a straight line. The original design with seven machine gun positions was overkill, considering a turret with twin machine guns could likely have done the job just as efficiently.
Machine guns
The Medium Mark B had a large fighting box equipped with 5 Hotchkiss ball mounted machine guns, 2 forward, 1 left, 1 right, 1 rear, plus a roof hatch which could be fitted with another machine gun. Yet another machine gun was located on each side in small sponsons which doubled as the access doors to the fighting box. Those sponson mounted machine guns were abandoned later on when it was realized that mud falling from the tracks would render them useless. No radio was fitted in the Mark B but they were fitted with a semaphore system for communication.
Brand new Medium Mark B finished at the works in the North British Locomotive Company, Springburn, Glasgow. (1600 series)
Medium B built by Metropolitan Carriage Wagon and Finance Company (MCW & F Co.) The sponson machine gun is omitted in this later variant and it has an additional large curved steel section above the sponson door to prevent a fully depressed machine gun from being hit by the tracks. All the 1200 series serial numbered tanks were built by MCW & F
One of the advantages of the rhomboid shape design of early British tanks was that they could mount an unditching beam (a large baulk of timber) on a chain. In the event of becoming mired in the mud, it could be fastened to the tracks and would drag under the tank providing sufficient traction for the vehicle to extricate itself. To surmount the small cab at the front, vehicles used rails over which this beam could travel so it would be able to clear the cab. No such rails were provided for on the Medium B which had a very pronounced cabin. This cabin, therefore, negated the benefits of the rhomboid shape and having the tracks running over the top of the machine, but with none of the benefits of a turret.
Two views demonstrating the unditching beam which was slung over the back of some tanks and the rails over which it would be dragged to get the front of the tank. This unditching system was not possible on the Medium Mark B design due to the cabin.
The problem of unditching the tank remained unsolved but, like other vehicles, it could have spuds attached to the 22.5” wide, 6mm thick steel track plates to improve passage in heavy mud. It is worth noting that this same problem over an obstructed track run over the top of the machine was encountered 20 years later, during the initial design of what became the Churchill tank.
Very clean Medium Mark Bs serial numbers 1607 and 1212 respectively undergoing trials, showing the differences made to the area around the sponsons and the semaphore device – Photo of #1212: Beamish archives
The Medium Mark B was considered a superior tank to its Mark A forebear, but still significantly limited in terms of mobility and armament. By the time the vehicles were built and available for use, the war against Germany was over and the need for them had waned. Britain had a surplus of tanks, huge war debts and other matters to attend to. Of the 102 vehicles built, just 45 (see earlier comments regarding confusion over actual numbers) were accepted for service and the remainder were scrapped.
A row of Medium Mark Bs in storage post war.
C.O.W. built Medium Mark B in service with the Royal Engineers (hence the ‘R.E’ crossing a pontoon bridge)
Combat and Post WW1
Remarkably, despite its many failures, some machines did see combat. Some were sent to Dublin, Ireland to assist in maintaining order during the Civil War. They arrived with C Company, 17th Battalion Tank Corps where no doubt the name ‘Whippet’ has helped confound many people subsequently looking for the Medium Mark A ‘Whippet’. If they left the barracks though it was infrequent.
Early Mark B
Mark B in the standard green livery
Russian Mark B in winter paint
Medium Mark B ‘Whippets’ ‘Latgalietis’ and ‘Vidzemnieks’ in service with the Latvian Army. Photo: virtualriga.com and Latvian War Museum Collection
Medium Mark B ‘Latgalietis’ during training in Latvia. Photo: Latvian war museum collection
Medium Mark B ‘Latgalietis’ in Latvia in storage. Photo: Latvian war museum collection
Three vehicles were issued to the North Russia Tank Detachment (which comprised of six tanks) and sent to Russia in August 1919 to assist in the fight against the Russian Bolshevik forces. One served with the White Russian forces but was later abandoned and dumped in the River Divna along with a Mk.V, and both were hauled out by Bolshevik forces. The remaining two were handed to the Latvian Army in October 1919 who retained one vehicle as late as 1926. One of those vehicles was recaptured by Russian Bolshevik forces and ended up in Red Army service. It is unclear whether it was that Mark B or the one fished out of the Divna River which ended up in the inventory of the Red Army in 1925. That vehicle was unarmed but in running condition presumably for training purposes, and later scrapped.
Medium Mark B in Red Army service. Photo: landships.com
Despite the Medium Mark B being canceled and replaced by the more successful Medium Mark C, one remained in British Army service as late as January 1941 at the Royal Engineers Experimental Bridging Establishment at Christchurch, Dorset. A Medium Mark B had been there since late 1918, which is caught on film.
Medium Mark B in use at Christchurch as part of the load testing of a Mark III Inglis tubular bridge. The engine and much of the top deck and at least one of the machine gun ball-mounts appears to have been removed. Photo: IWM
The size and weight of the vehicle were used to test bridge loading and presumably this tank was scrapped during the war. No examples of the Medium Mark B are believed to survive. One, which had been destined to be preserved at Bovington, was scrapped instead.
One of the last remaining Medium Mark Bs outside at Bovington Camp, date unknown. Photo: landships.com
Links
Medium Mark B ‘Whippet’ by Eugene Sautin and Robert Robinson
landships.info
Medium Mark A Whippet, David Fletcher, 2014
Medium Mark B Tank, David Fletcher, Wheel and Track 42 – 1993
Medium Mark C Tank, David Fletcher, Wheel and Track 43 – 1993
Medium Marks A to D by Christopher Ellis and Peter Chamberlain
One more river to cross, J.H. Joiner
Medium Mark C, Charlie Clelland
Landships.info
Kā sauca tankus un bruņumašīnas Latvijas armijā by Dr. Juris Ciganovs
National Archives of Latvia
Walter Wilson; Portrait of an Inventor, A.Gordon Wilson
Medium Mark B ‘Whippet’ specifications
Dimensions (LxWxH)
6.95 x 2.82 x 2.55 m
22ft 10in x 9ft 3in x 8ft 4in
Total weight, battle ready
18 tons
Crew
4 (commander, driver, 2x machine gunners)
Propulsion
Ricardo 4 cylinder water cooled petrol, 100hp at 1200rpm
Wilson 4 speed gearbox
Suspension
Tracks and rollers
Speed (road)
6.1 mph (~10 km/h)
Range
65 miles (105 km)
Armament
Early version: 7+1 Hotchkiss machine guns with 7500 rounds
Service rifles and cup grenade launchers
Late version: 5+1 Hotchkiss Machine Guns
service rifles and cup grenade launchers
Armor
6 – 14 mm max.
Total production
700 ordered
102 built
45 in service
57 scrapped
Latvia – 2
Russia (Bolshevik) – 1+1
Russia (White) – 1
For information about abbreviations check the Lexical Index
Kingdom of Belgium (1977-1990)
Light Tank – 1 Built
From AFV to tank
Despite the lack of successful orders for the APC/AFV version of the Cobra, the ACEC Cobra’s powertrain was successful and compact enough to warrant a further attempt to enter the armoured vehicle market, this time in the light tank category.
In order to make a tank which was still as small as possible but capable of packing a big punch ACEC redesigned the Cobra hull. This was the final version of the hull produced and involved a complete rearrangement inside although the wheels, track and suspension arrangement remained the same. The single driver was now located centrally where the engine used to be and the engine and motors were moved to the back of the vehicle in a conventional arrangement for an unconventional tank. It still retained the electrical transmission meaning it was still very light and had excellent acceleration but now came in a light tank, and a reconnaissance version.
The reconnaissance version was known as the Cobra 25, with a crew of 3 men, 2 of whom were in the turret. The weight was still under 10 tons and mounted the 25mm Oerlikon KBB cannon (25 x 181) and a secondary 7.62mm machine gun in the turret along with an OIP/SCS-5 x 8 periscope each for the commander and gunner, a x8 night sight for the gunner and a x6 night sight for the commander. The cannon was able to be elevated to 60 degrees allowing this vehicle to double up in the air defence role as well. This very adaptable design too sadly received no orders.
tACEC Cobra 25 fitted with the Cockerill C25 turret
A final turret, the 2 man (gunner on the right and commander on the left) AK90E was designed by ACEC in around 1984 and was fitted with a 90mm MECAR/KENERGA main gun, capable of firing a full range of 90mm ammunition including APFSDS type rounds, and a secondary 7.62mm machine gun. It was also capable of fitting the Cockerill Mk.7 90mm gun.
The turret was intended to be available for other vehicles as it weighed just 2,600kg but never received any orders. Made from armour steel welded all around, the front could withstand armour piercing 7.62mm ammunition at 500 metres but the sides and rear were rated only for 7.62mm ball. The main armament could be elevated from -10 to +25 and the turret could complete a full rotation in about 28 seconds.
Marketed correctly as a ‘deadly threat to battle tanks’ ACEC had produced a very light, innovative and simple package ideally suited to the export market especially as it was under 10 tons in weight. View of the ACEC Cobra 90 with rearranged hull and mounting 90mm Cockerill gun ACEC AK90E electrical turret (smoke dischargers not fitted)
There were only a couple of other modifications to the ACEC Cobra 90 hull. The original driver’s hatch featured a single large front view port on the hatch which opened in a manner similar to the Soviet T-34 of WW2. This was modified later with additional side view ports on the hatch as can be seen on the surviving vehicle. This hull also had optional side skirts which could be removed too. The turret is sometimes seen with a large spot lamp which could be mounted on either side of the gun. ACEC Cobra 90 showing early single viewport drivers hatch, the optional side skirts raised and no spot lamp on the turret.
ACEC Cobra 90, illustration by David Bocquelet
Photo credit: armyrecognition.com Surviving ACEC Cobra 90, serial number 9601135 at the Depot of the Royal Museum of the Armed Forces, Kapellen, Belgium with gun removed.
Conclusion
The ACEC Cobra was a highly innovative vehicle, it just came at the wrong time. By the time it was ready for production there were already plenty of competitor designs for an AFV/APC and even light tank. The electrical drive system was probably off-putting for many mainly traditional buyers of arms unwilling to consider that it might be better than what they may have been used to. The Cold War ended not long afterwards too meaning a huge reduction in conventional forces in Western Europe and a glut of surplus equipment on the open market killed off what was a very promising line of development as the parent firm was sold off. With it died the prospect of a full range of variants based on this design such as the Cobra Command Post, Ambulance, Cobra Engineering vehicle, and Cobra Mortar Carrier fitted with a 120mm heavy mortar.
It is perhaps ironic that many of the features of the Cobra are once more being investigated to solve the same problems of reducing size and weight from rubber tracks to electric drive. Even the choice of the RCDU was ahead of its time with remote weapons stations common now.
The Cobra 90 tank is reported to have been shown at an international arms fair in Kuala Lumpur in about 1985 giving an indication as to the potential markets being sought but despite the advantages this design offered over its contemporaries it too failed to secure any orders. The Cobra tank prototype thankfully survives at the Belgian Tank Museum, Kapellen along with the APC versions, although the 90mm gun has been removed from the tank. The ACEC Cobra, be it the APC or the tank variant, might not originate from the most well known European tank making nation but the designs were well planned, well executed and well reviewed. Sometimes it doesn’t matter if you are better and cheaper than your competitors and the Cobra today is almost forgotten.
4.77(hull), 5.30m(over gun) x 2.75m x 1.38m(hull), 1.95m(turret)
Total weight, battle ready
9,500kg
Crew
3 (driver, gunner, commander)
Propulsion
Cummins VT-190 V6 diesel 190hp
Suspension
Helical springs with hydraulic shock absorbers on wheel 1 and 5
Speed (road)
75-80 km/h (46.6 – 49.7 mph) / 5km/h (water)
Range
600 km (372.8 mi)
Armament
25mm Oerlikon KBB cannon with 250 rounds
Armor
All welded steel hull and turret providing protection 105mm HE shell bursts, small arms fire from NATO 7.62mm ball (at any angle or range) frontally proof against 7.62mm AP ammunition.
Total production
1
For information about abbreviations check the Lexical Index
Cobra 90 specifications
Dimensions
4.77(hull), 6.89m(over gun) x 2.75m x 1.38m(hull), 2.0m(turret)
Total weight, battle ready
9,500kg
Crew
3 (driver, gunner, commander)
Propulsion
Cummins VT-190 V6 diesel 190hp
Suspension
Helical springs with hydraulic shock absorbers on wheel 1 and 5
Speed (road)
75-80 km/h (46.6 – 49.7 mph) / 5km/h (water)
Range
600 km (372.8 mi)
Armament
90mm MECAR, 90mm Cockerill Mk.7 with 30 rounds
Armor
All welded steel hull and turret providing protection 105mm HE shell bursts, small arms fire from NATO 7.62mm ball (at any angle or range) frontally proof against 7.62mm AP ammunition.
Total production
1
For information about abbreviations check the Lexical Index
Kingdom of Belgium (1977-1990)
Infantry Fighting Vehicle – 4 Built
Belgium is not the first country to leap to mind for most people when they think of tanks or armored fighting vehicles, yet it has produced a few particularly interesting designs over the years. One of the these, which is virtually unknown, is the ACEC Cobra.
The Cobra is not a single vehicle but a platform, adaptable, lightweight and cost effective using diesel-electric drive to ensure the lowest possible weight and maximum space. The ACEC electric drive was one of the biggest selling points of the design allowing the Cobra into an exclusive club of diesel electric military vehicles.
The small and highly innovative Cobra was produced by the now defunct firm (acquired piece by piece by other companies until 1989) of Ateliers de Constructions Electriques de Charleroi ‘ACEC’. ACEC specialised in the manufacture of electrical motors including those for electric locomotives, and in 1970 ACEC did some work as part of the French Crotale surface to air missile program. As far back as 1967, ACEC had started work on electrical transmissions for tracked vehicles and, by 1970, had produced a version of the M24 Chaffee Light Tank fitted with an electrical transmission and an AMX 10P with one by 1978 too. Direct Current motor reduction gear and brake assembly for the ACEC Cobra
The original Cummins diesel used on the ACEC Cobra producing 112 kW at 3300 rpm. Later versions increased output to 140 kW at 3300 rpm
After several years of study, ACEC determined that, rather than try and modify an existing vehicle to take an electrical transmission, it would be better to start from scratch with a whole new vehicle. As a result, in 1977, as a private venture, ACEC started working with the Belgian Army to create an APC with an electrical transmission, which would have allowed the new vehicle to be much lighter and more spacious than its contemporaries.
By the end of 1981, three prototypes had been completed by ACEC and finished their evaluation trials with the Belgian Army. A fourth vehicle with an improved engine was allegedly delivered for testing by 1985, but may simply be confused with the Cobra 90. Other trials were conducted in the USA by TACOM and the Department for Organization and Armament in Abu Dhabi, both of which found the handling and mobility to be very good.
The power from the engine in a conventional vehicle goes through a clutch and gearbox, through various reduction gearing and to the drive sprocket. For the Cobra, by using the power to drive just a generator, power could go directly to the gear reduction drives for each wheel instead, thus avoiding a lot of complex machinery, bulk, and more importantly, weight. Other advantages an electrical system offers over the traditional mechanical system are that it makes driving much simpler (no gear changes needed for example), steering is light and easy, thus reducing driver fatigue, and the maintenance of complex gear trains is eliminated.
Being lighter and using a generator system for power, the Cobra had a 600km range of action. Finally, the Cobra’s electrical transmission allowed it to accelerate faster than a mechanical transmission. The transmission also allowed the Cobra to accelerate and drive just as fast backwards as it did forwards.This is very useful for a reconnaissance vehicle, as it allows it to get out of trouble fast.
Early ACEC Cobra prototype hull, either P1 or P2, during fabrication. The spartan but rather spacious interior has two simple metal benches running lengthwise along each side. The driver’s stations can be seen at the front and are not closed off from the troop space. From inside, both front hull machine gun mounts can be seen and the arrangement of the drivers either side of the engine is clear. Two hatches (one circular and one rectangular) can be seen for the turret and additional crew egress respectively. Two smaller rectangular hatches are above the driver’s stations.
Dimensions
Weight was very important to the Cobra’s design. At only 7.5 tons (nominal), it was light enough to appeal as an export to many third world countries which lacked heavy infrastructure, as well as to Western forces, as a C-130 Hercules could carry three complete vehicles, making it easy to deploy. By the time of the fourth prototype, the combat weight was given as 8.5 tons, which still provided it with a power to weight ratio of over 20 hp per ton. ACEC Cobra prototype number 3 during evaluation, note the full length track skirt and simple single machine gun mount on the central hatch. The tools are also stowed on a different location to later versions where they are on the sides.
Construction
The Cobra was manufactured as a welded all steel hull providing protection against all small arms fire including armor piercing ammunition.
Propulsion from the diesel engine was distributed by electrical motors to the rubber tracks driven by sprockets at the rear. The rubber belt track had steel links and rubber pads and the wheels were rubber tired meaning that the rolling noise of the Cobra was very low, due to the low engine noise, lack of transmission whine and lack of ‘squeaky’ track noise. The suspension consisted of helical springs with a hydraulic shock absorber on the first and last of the five wheel stations and four track return rollers.
The vehicle had a very large hatch in the back for the soldiers to enter/dismount with water-propulsion propellers either side of it. When entering water and engaging the propellers the front mounted trim vane automatically rose up on the front of the hull.
View of the rear of the Cobra showing rear door and the steerable propulsion propellers. Note the steering vanes not present on the earlier vehicles.
The APC version could seat up to 10 soldiers (5 each side). The crew (driver and co-driver) sat either side of the front mounted engine.
ACEC Cobra prototype number 4 with roof mounted heavy machine gun showing its trim vane in the raised position at the front and the large door and water propulsion propellers at the rear.
Engines
The first three prototypes (P1 to P3) were powered by a Cummins V-6 diesel engine producing 143 hp at 3300 rpm but P4 was fitted with a more powerful Cummins VT-190 supercharged diesel producing 190 hp at 3300 rpm. Another source states an 155 hp engine was used at one point. Water propulsion was supplied by means of two 3-blade propellers mounted at the back either side of the large rear door. Various views of ACEC Cobra early prototype P1 or P2 lacking side skirts completely, no equipment on the sides, the folding trim vane and mounting twin anti-tank rockets. Note the 2nd visible machine gun port isn’t blanked off and that the mudflaps at the front appear to be simple rubber flaps rather than the hinged metal ones later.
ACEC Cobra prototype number 3 with a single machine-gun mounted on the cupola and initial set of sideskirts. Illustration by Tank Encyclopedia’s own David Bocquelet Three surviving ACEC Cobra APC’s at the Depot of the Royal Museum of the Armed Forces, Kapellen, Belgium. Confusingly, the plain green painted vehicle appears to have another modification to the rear of the side, possibly connected to the hydrojet propulsion and removal of the propellers. The camouflage painted vehicle lacks this modification despite having a later registration number. 9601136 (plain green), 9601137 (sand), and 9601138 (camo) respectively. All vehicles display the later exhaust and muffler on the right hand side and the flat front ‘nose.’ This museum also holds serial number 9601135 which is the tank version. Photo credits:(left) armyrecognition.com, (center) Belgian Tank Museum, (right) army recognition.com. Close up view of the ACEC lightweight (300kg) electric turret as fitted to the ACEC Cobra APC and mounting an FN 12.7mm M2HB heavy machine gun. Elevation range is -10 to +50. The searchlight moves with the gun as does the M20 x6 periscope. The turret is rated completely immune to 7.62mm ammunition at any angle or range as is the 10cm thick viewport. Space is provided in the back for a radio to be fitted.
ACEC Cobra APC during trials fitted with 12.7mm FN M2HB machine gun. It was at some point painted orange in perhaps a nod to the Dutch. Note the second machine gun hull mount is covered with spare track parts and that the ‘nose’ is the same profile as the rest of the glacis.
Armament
Standard fitting on the APC version was a single 12.7mm M2HB machine gun on the roof in a small turret fitted with vision blocks and two 3-barrel smoke dischargers (operated by one of the mounted soldiers) and a 7.62mm machine gun for the right hand side crew position fixed in a ball mount in the hull front. P4 was fitted with this weapon setup. A second hull machine gun mount in front of the other drivers station was also provided and is visible in some photos.
The RCDU ‘Remote Control Defence Unit’ was developed by Fabrique Nationale Herstal SA (FN) firm of Belgium and tested on one of the Cobra prototypes. It consisted of twin FN MAG 58 7.62mm machine guns (1500 rounds) weighing 258 kg or a single 12.7mm FN M2HB machine gun (600 rounds) weighing 300 kg in a remote station mounted on the roof capable of being operated by the crew who controlled it from below by means of a TV monitor. The RCDU could also be fitted with infra-red cameras and an additional compartment for more ammunition if required.
ACEC Cobra showing the twin 7.62mm RCDU in place and the second machine gun hull mounting position blanked off.
Other options for arming the Cobra APC was the use of the Oerlikon-Contraves GAD-AOA turret with model 204GK 20mm cannon, as well as the option for the Euromissile MILAN compact turret. ACEC Cobra prototype hull with GAD-AOA turret and model 204GK 20mm cannon. Worthwhile noting here is the visible 2nd machine gun mounted in the hull front, the folding trim vane (as opposed to the automatic trim vane) and the raised ‘nose’ between the two drivers’ positions. For these reasons it is believed that this is one of the first prototype vehicles used as a demonstrator and these features are repeated on the vehicle used for the experimental RCDU and LAU-97.
A fire support version of the Cobra called LAU97 was tested in 1985 and was fitted with the FZ70 70mm rocket launcher with 40 rockets on a fully traversable mount on the roof of the vehicle. The FZ70 rocket was a product of Forges de Zeebrugge (FZ) now part of the Thales group and was an unguided rocket weighing approximately 4.3 kg and carrying 1 kg on high explosive intended for use against unarmored targets. The launcher however could also take a full range of 70mm rockets including anti-personnel, anti-tank, smoke, incendiary, illuminating, and flechette. It was able to fire them out to 8 km and designed for saturation of an area 200 x 300m. Cobra LAU97 fitted with FZ 70 mm multiple rocket launcher, 1985. Note the precarious decision to have the rear hull top rectangular hatch open which, while ideal for reloading the launcher, would be suicidal to have open during launch.
Conclusion
The ACEC Cobra APC/IFV was small, maneuverable, and well designed. Cheap and simple to operate and train crews on it offered a capable platform for a wide variety of roles. For a relative newcomer to the military vehicle industry ACEC produced a remarkable vehicle which sadly did not receive any orders. With the end of the Cold War there was no market for a new vehicle, especially one challenges some of the preconceptions of the diesel-electric drive used and this the remaining vehicles. It wasn’t the end of the Cobra story, there was one final version of the vehicle, a light tank based on a redesigned hull.
Helical springs with hydraulic shock absorbers on wheel 1 and 5
Speed (road)
75-80 km/h (46.6 – 49.7 mph) / 5km/h (water)
Range
600 km (372.8 mi)
Armament
Single or double front hull 7.62mm FN MAG with;
7.62mm FN MAG on hatch ring / twin 7.62mm RCDU / single 12.7mm RCDU / 12.7mm ACEC turret / 20mm GAD-AOA turret / Euromissile MILAN compact turret (MCT) / FZ70 rocket launcher / 12.7mm with twin AT rocket launcher
Armor
All welded steel hull and turret providing protection 105mm HE shell bursts, small arms fire from NATO 7.62mm ball (at any angle or range) frontally proof against 7.62mm AP ammunition.
Total production
4
For information about abbreviations check the Lexical Index
Kingdom of Italy (1935)
Mobile Shield – 2 Prototypes Built
MIAS and MORAS.
Background
The Motomitragliatrice blindata d’assaulto ‘MIAS’ was a vehicle borne out the Italian slaughter in WWI. Instead of the infantry facing withering machine gun fire unprotected, the MIAS would provide them with a mobile shield to cover them from fire. This is what the MIAS really was; a self-propelled mobile armored shield. It was certainly not a tank in the conventional sense despite having some of the same features. It was armored, powered and fully tracked but that was as far as the similarities went. After-all, it only had a single crew member and he didn’t even get a seat.
Technical details
The MIAS was launched by the Ansaldo company in 1935 and came in two possible versions; the MIAS and the MORAS, which differed only in armament. Both vehicles were propelled by a single 250cc Frera petrol engine producing 5 horsepower at 3000 rpm with Magento Marelli ignition. They were capable of up to 5 km/h forwards and 2.2 km/h in reverse. Frera was a brand of Italian racing motorcycle but, by the mid 1930’s, was in serious financial difficulties and eventually went bankrupt.
The armor for the vehicle provided protection against the Mauser service rifle firing SMK (7.92mm Spitzergeschoss mit kern – a steel cored armor piercing round) type ammunition at 90 degree impact at a range of 50 metres. The Mauser SMK round was capable of perforating up to 14 mm (0.55 in) of armor plate and saw extensive use in the First World War for use against tanks. The sides, being slightly thinner, were only rated against the Italian Model 1891 service rifle firing the 6.5mm 160 grain ball round from the sides at 90 degrees at 50 metres, which was still fairly respectable. The roof of the machine was hinged as well and could be elevated in order to provide additional cover for the soldier behind. MIAS showing its diminutive size and tool arrangement consisting of a pick-axe, spade and a large billhook type cutting tool for clearing obstacles – Source: MIAS Manual, Ansaldo
An illustration of the MIAS mobile shield. Not to scale. Illustrator: David Bocquelet
The MIAS version was fitted with a single weapon mounting high and slightly off center in the front. It was fitted with two Isotta-Fraschini (‘Scotti’) 6.5 mm (0.25 in) calibre machine guns with 14 degrees of elevation, 10 degrees of depression and 1000 rounds of ammunition. The MORAS version (Moto-mortaio blindato d’assaulto) had the machine-guns replaced with the 45 mm (1.77 in) Brixia mortar. The mortar in its mounting could depress to -10 degrees and elevate to an impressive 72 degrees. The vehicle carried up to fifty 0.5 kg grenades. MORAS version showing the extremely high elevation which could be reached with the 45 mm Brixia mortar – Source: MIAS Manual, Ansaldo
The 45 mm Brixia mortar was designed by the Tempini company in 1932. It was a strange and complex weapon for such a small vehicle. The mortar was unusual in that in used a magazine of blank rounds to launch an individually loaded 45mm bomb. An earlier design even had a magazine for 5 bombs reloaded by means of a hand crank.
1924 Patent by Tempini for a hand cranked cartridge launched small mortar – Source: Patent GB405159
Brixia mortar as manufactured and mounted on the infantry mount Breda made model M.1935 high explosive mortar shell for the 45mm Brixia mortar – Source: War Office Pamphlet No.4 Handbook of Enemy Ammunition 1940 and an unnamed possibly US Military Manual
The 45mm M.35 HE shell was launched at just 83 m/s at a maximum rate of fire of 1 round every 2 seconds. However, this rate of fire that does not include the time taken to replace the shell magazine. The M.35 shell remained in use through 1940 and a second shell, the M.39 version using an aluminum body instead of a brass one was available.
Work on an armor-piercing shell for the mortar was abandoned in September 1941, meaning the Brixia was only ever fielded with a rather small high explosive shell. The shell was rather useless at range but in the MORAS, it would have allowed the vehicle to very usefully suppress or destroy enemy machine gun positions.
Brixia mortar video
Conclusions
The MIAS and MORAS were interesting designs but totally unsuitable for modern warfare. A mobile shield, no matter how well armed with machine guns or small mortars, was not going to fill the gap which Italy had in the tank department.
Neither vehicle went past the prototype stage and no orders for them are known to have been placed. The machine guns and Brixia mortar saw extensive use in WW2. These powered one-man shields remain an odd quirk, a relic of a bygone type of war.
Links
Italian Racing Motorcycles, Mick Walker
MIAS Manual, Ansaldo
New Giant Tanks, Nov 1935. By Johnson T.M.
Artillery in the Desert 25th November 1942 – US Military Intelligence Service War Department – Appendix D – Italian Artillery – Table of Characteristics
Standard Italian Weapons Tactical and Technical Trends, No. 11, Nov. 5, 1942.
Twentieth Century Artillery, Ian Hogg
War Office Pamphlet No.4 Handbook of Enemy Ammunition 1940
UK Patent GB405159 filed 24th May 1924 by Metallurgica Bresciana Gia Tempini
ManxNorton.com
United Kingdom (1917-1918)
Medium Tank – 200 Built
From idea to production
The Whippet tank is what its name implies; a Whippet, a breed of fast hunting dogs used for chasing prey down and catching it. ‘Fast’ here being comparative. Compared to the much larger and heavier British tanks of WW1, the famous ‘rhomboid’ shaped machines, these really were Whippets.
Designed to effectively emulate the role of scout and cavalry, push ahead, harass the enemy and to use machine guns to sow confusion, the Whippet was intended to work with those heavier tanks and not to replace them.
The Order
The tests at Oldbury of the new Whippet design had met with approval. Some 200 Whippets were soon placed on order with this new polygonal style upper body. The goal was to have them delivered to France by the end of July 1917 and a further order of 200 was placed that summer which was canceled about 4 months later. Of these first 200 machines, only 166 had been completed by the summer of 1918 and it was into the autumn before the remaining 34 arrived. All 200 vehicles were assembled at the Wellington Foundry works of William Foster and Co. Ltd. The name ‘Tritton Chaser’ was gone. This was now ‘The Whippet’ or officially the ‘Medium Mark A’. They were to face the trials of combat very soon after they arrived in France.
Whippet A301 on show to the crowds at the Lord Mayor’s Parade pictured outside the High courts of Justice, London probably 1919. Photo: BNF
The Tritton Chaser had morphed into a similarly looking but larger ‘Whippet’ tank. This production vehicle was noticeably different to the rebuilt Chaser. The basic shape was the same but that curved exposed front fuel tank now had an angled armored cover. The distinctive open mud chutes on the side were slightly redesigned and there were now four roughly rectangular shaped openings. A fifth small circular one at the rear behind the fourth mudchute was for accessing the drive chain and the covering plate is sometimes missing in photographs. Another change was that those 16 Skefco roller bearings were now reduced to just 6 on each side. They bore of the most of the weight from the tank.
Factory fresh Whippet tank with just 2 of the four machine guns fitted. Photographs nicely show the changes made to the suspension arrangement and mud chuting. The small ‘arm’ seen projecting from the front is a steel arm used for attaching the canvas mud guard. Later Whippets would also have a small section of angle steel attached to the area around the front mudchute. This vehicle is actually the very last prototype prior to authorized production. Photo: IWM
Whippets under construction at the Wellington Foundry works of William Foster and Co. Ltd, Lincoln. Photo: IWM
Early design of production model Whippet tank, still with a horizontal exhaust outlet. This is curved upwards on production vehicles. Photo: IWM
One of the first production models, serial number A202, which was built in mild steel ‘soft plate’ (see door). Pictured here near to Albert, France in April 1918. Why this unarmored and unarmed early production Whippet is there can only be speculated on. Photo: IWM
Additional front metal bracket added to some Whippets the purpose of which is unclear.
These 200 vehicles were each assigned a serial number from A200 up to A399. The first Whippets to arrive in France were delivered in December 1917 and were involved in combat from then on. In April 1918, Tritton visited the front once more and discussed the Whippet and possible improvement which may have been mainly connected to the conditions inside the vehicle which were unpleasant. The heat and fumes from the engine, the fumes from the machine guns all meant that the vehicle could become stiflingly hot and tiring for the crews to operate. On top of this, the exhaust was vented on the side of the vehicle ahead of the crew space meaning, as it traveled forwards, exhaust gas could both obscure the view of the crew and re-enter the vehicle making the conditions inside even worse. The only relief from these conditions would be to open the small roof hatch which was intended for the commander to use when guiding the vehicle or the large rear door. Obviously keeping those open in combat was extremely hazardous.
Asymmetric layout of the Whippet tank. Note how the polygonal cab structure protrudes over the track run on the left hand side of the machine
The 7.72 liter 45hp Tylor engine as fitted to the Whippet tank. This side valve water cooled unit was manufactured by the Tylor Company of London and was also used (singly) on the War Department AEC Y Type 3 ton truck
In service, some Whippets were fitted with large wooden stowage boxes on the back supported by an angled steel strap fastened to the cab of the tank. These boxes would provide some much needed stowage for the crew and may also have helped in carrying additional cans of petrol. Many vehicles in service are festooned with petrol cans to extend the operational range of the vehicle.
Whippet tank next to a row of sponsons, Tank Corps Central Workshops, Teneur, France, Spring 1918. The photo provides a nice view of the engine access panels as well as the wooden stowage boxes. Photo: IWM
Two views of Sir Edward Patrick Morris, the Prime Minister of Newfoundland (Canada), on his visit to the Tank Corps Gunnery School at Merlimont, France on the 2nd July 1918 examining A326 showing the wooden stowage box and steel spud strap clearly. A326 was later stripped for spares and all but scrapped by August 1918 but was later one of the Whippets sent to Russia in 1919. Photo: IWM
A220 carrying piles of kit on the back, several petrol cans suspended from the top of the mud chutes and items strewn over the front too. The 3 rectangular items on the right of the cab next to the exhaust are wooden track spuds although these are more commonly seen carried at the back. A lot of vehicles can be noted to have a steel strap riveted hanging around the sides of the cab on which to hang items. A220 was later captured by the Germans and subjected to various trials sporting a large black cross on the sides. Photo: IWM
Nice study of the rear of Whippet A267 ‘Cork II’ pictured April 1918 near Albert, France showing the usual method of hanging the wooden track spuds and a typical assortment of kits stowed wherever the crew can put it. The vehicle on the left has a towing cable around the nose. Photo: IWM
A290 (probably) heavily festooned with an array of kit and clad in petrol cans. (A290 was known as ‘Cherubim II’) Close examination shows the use of small black stripes near to the vision slots which were added with the intention of making the targeting of the vision slots harder for enemy snipers. Photo: IWM
Black false vision slits (which have faded – look bottom left and top right of the ‘9’) as shown on A259 Caeser II at Bovington. Note the rudimentary additional vision/pistol port provided in the superstructure. Photo: tank-hunter.com
A233 ‘Crossmichael’ pictured at Biefvillers, near Bapaume, France on the 24th of August 1918 is relatively uncluttered but with a towing cable fastened the tight right hand side. Photo: NAM and IWM
Whippet in service at Demiun near Amiens, France showing stowage boxes at the back, the canvas mud guards in pace and multiple cans of petrol strapped to the nose of the tank. A single track spud is hanging from the cab on which two of the three crew are riding to avoid the unpleasant conditions inside. There was no such relief for the driver. Photo: IWM
Tales of daring do
The Medium Mark A Whippet was to see its first combat on the 26th March 1918 at Mailly-Maillet, north of Albert, France. It had been considered to send Whippets to the Army in Palestine too but that didn’t happen. The Whippet tank was to enjoy some notable combat actions most famously the actions of Musical Box (A344), and Caeser II (A259).
On the 8th August 1918, near to the town of Villers-Brettoneux, France, Whippet A344 known as Musical Box was about to become a legend. In command of the tank was Lieutenant C.B. Arnold. It began an attack with 7 other vehicles, which for one reason or another being stuck or suffering mechanical failure. This left Musical Box on her own to support some Australian Infantry and Mk.V tanks attacking the German lines. Musical Box attacked a battery of German field guns, which was somewhat suicidal at best but scattered the Germans with its machine guns allowing the Australian infantry to advance into the German position.
Lt. Arnold pressed on regardless for several hours resulting in the dispersal of a large segment of a German infantry division, a transport column and even an observation balloon. The combat had caused the cans of petrol carried on Musical Box to be perforated leaking petrol dangerously into the tank so much so the crew were having to wear their respirators. Eventually, Muscial Box was crippled and set on fire by a direct hit from a German gun and the crew bailed out. The driver was shot but he and the machine gunner were captured. Lt. Arnold survived the war as a POW having inflicted a loss on the Germans far out of proportion to what could be expected.
Burnt out remains of A344 Musical Box pictured the day after the incredible fight with Australian soldiers of the 15th Brigade and some German prisoners.
On the 29th August 1918, Caeser II (now preserved at the Bovington Tank Museum), commanded by Lieutenant Cecil Sewell, was with the 3rd Battalion Tank Corps at Frémicourt, France. During this action, a fellow tank had slipped into a shell hole, overturned and caught fire trapping the crew inside. Sewell stopped his tank and ran out across open ground in full view of enemy fire digging out the door of the tank so the crew could escape a horrible fiery death. His own driver was wounded in this time and he went to his aid but was hit by enemy fire while doing so. Nonetheless, he got to his driver and while rendering medical aid was hit once more, this time fatally by enemy fire. For his heroism and total disregard for his own safety Lt. Sewell was awarded the Victoria Cross.
A final and more minor note of interest is that in combat in March 1918, A226 ‘China II’ resorted to borrowing a single infantry Lewis gun to replace battle damaged Hotchkiss machine guns, so, on at least one occasion, a production Whippet did use a Lewis gun.
The downside
Despite the Whippet having been designed and been up and running as a prototype in a very short time the pressures of mass production had meant that delivery of the Whippet was rather slow. The tank itself wasn’t really of any use in combat until 1918 and although the Whippet was proven to be quite useful in combat the flaws in the design were apparent. The machine guns were prone to jamming and the armor was vulnerable to anti-tank rifle fire. The steering was awkward at best and dangerous at worst.
The habitability of the vehicle was very poor and the poor driver had his work cut out steering and getting a good view of the path ahead. The Germans, though, who had captured at least two fully functional vehicles, were by all accounts impressed with the speed. Obvious parallels are drawn between the German LK II vehicle, which was still in the pre-production phase at the time of the Armistice, and the Whippet. Quite how much influence it had on the design is still debated.
Johnson’s Whippet
One particular variant of the Whippet which sadly led to nothing was a modification carried out in 1918 by Colonel Philip Johnson. The unsprung Whippet with the 6 Skefco roller bearings was modified by means of fitting leaf springs transversely beneath the hull. The twin 45hp Tylor engines were replaced with a single V12 Rolls Royce Eagle petrol aero engine and the Walter Wilson designed transmission from a Mk.V just visible in the lines of the rear of the vehicle.
The new larger engine is shown by the much larger front hull shape with the lines of the original size still visible. With this new spring suspension and much more powerful engine this vehicle was capable of 30 mph (48 km/h) and retained the same polygonal superstructure of the original. Sadly this machine was a dead end for the Whippet as it was just too expensive, Colonel Johnson though went on to other projects.
Colonel Johnson modified Whippet showing expanded engine area for the Eagle engine. It’s possible the nose says A214 which would make sense as A214 was severely damaged at Bray, France including the loss of the engine so this prototype could have been rebuilt using that wreck and other parts. Chamberlain and Ellis however state this vehicle was modified in two stages, first the spring suspension and then later the engine area which would invalidate this theory. Photos: Beamish Archive courtesy of the author and IWM
One final oddity for the Whippet in British service is this vehicle which was handed over to Commander Baynton Hippisely RN for some experiments in Bath, England.
Baynton Hippisely pictured in 1908, then an officer in the North Somerset Yeomanry. Photo: Public Domain
Bayntun Hippisley was born in July 1865 and retired from the Army in 1913. His family was well-to-do with an estate at Ston-Easton, near Bath in Somerset. At the outbreak of WW1 Hippisley, who was considered an expert and pioneer in the use of wireless telegraphy was recruited by Naval Intelligence. He was given the rank of Commander (RN) (Temporary rank listed 17/12/1915) and set to most secret and vital work intercepting wireless communications from German U-boats and Zeppelins.
During the war, he was personally issued a Whippet tank for “tests of a secret nature” on his estate. The vehicle concerned is recorded by him as being A381 which is known to have served with the 6th Battalion Tank Corps in October 1918 when it received some damage and was immobilized. The nature of the experiments Cmdr. Hippisley conducted is not clear and the vehicle had no obvious external differences to a standard Whippet save for some bullet scars. It’s possible that he was primarily occupied with wireless work with it but with the end of the war he seems to have made use of it more as a tractor on the estate maintaining the engines and hauling timber and trees or pulling them down etc.
Commander Hippisely’s Whippet A381 at his estate
The vehicle remained with him until March 1936 when he states that he received a letter from the War Office officially disposing of it and giving it to him as a free gift. He had already received for his war service an OBE (Order of the British Empire) in 1918 and in 1937 the CBE (Citizen of the British Empire). The tank appears to have been the last operational Whippet tank too when sadly in 1942 at the request of the Ministry of Work and Planning it was sent for scrap for the war effort.
Disposal and new life
Despite the success of the Whippet in combat and the potential work like that of Colonel Johnson had shown, the Whippet wasn’t going to be built anymore. Tritton already had his own improvements in mind and the Whippets left over after the shooting war on the Western front ended in November 1918 were progressively decommissioned. Many were scrapped or sold off. 17 vehicles were deployed/sold off to the white Russian anti-Bolshevik forces but to little avail with an initial 6 sent to General Deniken followed by 11 more in July 1919. Either destroyed or captured during this bitter civil war, at least one vehicle was rearmed by Bolshevik Russian forces with a 37mm gun.
Russian Whippet rearmed with a short barrelled 37mm cannon in place of the forward facing machine gun. Noteworthy is that this vehicle still retains on the nose the White-Red-White British markings. The markings were also commonly repeated on the front ‘horns’ of the vehicle on both sides and on the top of the engine to assist aircraft. On the horns, the vertical bands are 1ft (30cm) wide each.
A371 Sphinx in use by Russian forces showing the signs of wear and tear as well as the surprisingly large size of this tank
In Russian service, the last of the Whippets disappears in about 1922 presumably to scrap although in Russian service they were known as ‘Tylors’, or ‘Teiylors’ after the brand of engine.
One of the first Mark A in operations, in March 1918.
A late Whippet, A259 “Caesar II”, now in the Bovington tank museum.
The A347 “Firefly” of the sixth battalion, B company, one of the numerous “X-companies” attached to larger units made of heavy Mk.IV and V during April-May 1918. This one is now displayed at the Royal Museum of the Army in Brussels.
Whippet with rear storage
White Russian Whippet “Sphinx” with Wrangel’s 1st tank division, 2nd Det. South Russia 1920.
Captured “Red” Russian Gun Whippet rearmed with a 37mm gun, winter 1920
Beutepanzer “Whippet”
Captured use
As previously mentioned, the Bolshevik Russian forces had made use and modified their captured Whippets. The Germans who had captured at least two fully functional vehicles in 1918 put them both to use. One (A220 shown previously) was subjected to numerous trials. The other vehicle, Whippet A249, which had been captured at Bray, France (South of Albert) in March 1918, was shipped back to Germany where it ended up in the service of the Freikorps following the armistice.
A249 in Freikorps use January 1919 in Berlin. The building behind is the Eden Hotel in west Berlin. Photo: Rainer Strasheim, British Tanks in German Service Vol.2, 2011 Tankograd No.1004
Another view of Whippet A249 in Freikorps service in Berlin post war. Note that the large skull and crossbones has been painted over the large black cross on the side. A249 was eventually taken back into allied hands in 1919 and presumably scrapped.
A variety of views of Whippet A220 captured by the Germans along with A249 at Bray in March 1918. Subjected to a variety of tests this vehicle was presumably taken back by the Allies the end of 1918.
Whippet to Africa
One vehicle was purchased by the government of South Africa. A387 was intended to be a memorial and to be used for fund raising events and was named ‘HMLS Union’. HMLS Union however was to be no idle memorial. She was used as a tank during the Rand Rebellion in South Africa of 1922 where it was committed during the assault on the headquarters of the rebels. During this it became either stuck or broke down and was subsequently recovered by means of a steam truck.
HMLS Union is the focus of attention as she heads into action during the Rand Rebellion 1922 Photo:samilitaryhistory.org
Photo:samilitaryhistory.org
Following the restoration of order HMLS Union appears to have gone back into retirement until 1939 when she answered the call of empire once more in one final hurrah for King and Country. She came back to serve but was never deployed to combat, thankfully because HMLS Union is one of the very few surviving Whippet tanks and is currently on display in Pretoria.
The entirety of S.Africa’s armoured force in 1939 at the outbreak of World War 2 consisting of 2 Vickers Crossley armoured cars, 2 Medium Mk.I’s and HMLS Union. Photo:samilitaryhistory.org
Whippet of the Rising Sun
In September 1918, a further 4 Whippet tanks, A370, A386, A390, and A391 were sold to the Japanese complete with some track spuds. The only notable change made was the addition of a separate hatch for the driver allowing him a better view during a road march.
A390 during river crossing exercises. No armament appears to be fitted.
Three unidentified Whippets (the fourth is out of shot) in Japanese service on a road march. All vehicles display a small Army emblem Star on the nose and are fitted with the standard Japanese army 8mm machine guns. Note the view of the modified drivers front plate which is now a moveable hatch improving vision and no doubt ventilation too. Closer inspection shows what appear to be hoops of some description around the exhaust possibly to help keep netting off it. A tow cable is neatly fastened to the right hand side of the lead tank.
A very detailed photo of an unidentified Japanese Whippet with what appears to be an extemporized running board on the right hand side held up with straps. The metal brackets for the canvas mud guards are still fitted so this modification may be more to do with carrying troops or stores than to prevent mud being thrown up.
Colourised picture of A386 in Japanese service, presumably shortly after delivery as the British markings are still on show.
Japanese Whippet being put through its paces. Possibly at Narashino which is East of Tokyo Photo: Shimoharaguchi
Nice lineup of Whippet tanks arranged behind a row of Renaults at the Imperial Army Academy, Tokyo. Photo: Shimoharaguchi
Close up of a very clean Whippet in Japanese service showing the modification to the driver’s plate and the Japanese machine guns fitted. Photo: Shimoharaguchi
These Whippets remained in Japanese service until 1922 when they were scrapped presumably worn out despite having been provided almost new from the UK in 1919. There was no license to produce them in Japan anyway and they were large, under armed and rather clumsy.
A final operation
With the First World War effectively over the British deployed some 16 Whippet tanks to Ireland in 1919 due to ongoing troubles with rebel Irish activity. The 16 Whippets sent were part of B Company 17th Armoured Car Battalion of the Tank Corps and were stationed at Marlborough Barracks in Dublin. In celebration of the end of World War One, a parade was held in Dublin in July 1919
Dublin victory parade July 1919. Four Whippets took part; A230 GOFASTA [Go Faster] previously known as ‘Cynic II’, A378 GOLIKELL (Go Like Hell), A351 Fanny Adams, and A289 Fanny’s Sister. Noteworthy is the fact that two of the vehicles still retain the full engine deck paint White-Red-White markings for aerial observation purposes. The official guide was that a 1 foot White, 2 foot Red, 1 foot White band of color was able to be seen at 1800 feet and was to be painted on the roof of the cab. Here painted on the engine cover is clearly larger than that officially recommended.
B Company on patrol against rebel Irish activity in County Clare November 1919. These photos are sometimes noted as being 1920 but the one on the left appears in the November 26 1919 edition of the Belfast Telegraph. Photo: BNF
By May 1922 it seems all of the Whippets deployed to Ireland were withdrawn as Ireland descended into civil war.
A failed sale
The British still had some surplus Whippets available in July 1924 and had negotiated a somewhat exorbitant price of £5000 per vehicle for 3 tanks to the government of Romania. The vehicles were to be officially sold as ‘scrap’ from left over war stock but the Romanians estimated with just 2-3 months work they could be in service. The deal though never took place as the British government inexplicably never approved the sale.
The name ‘Whippet’
It is perhaps a testament to the success of the Medium Mark A that it is almost completely referred to as ‘The Whippet tank’ rather than by its official name. The first use of the name ‘Whippet’ is on the front of the Tritton Chaser itself and such a success the vehicle was that during the war even the later Renault were sometimes called a ‘Whippet’ tank too.
Contemporary postcard passed by the War Censor (Author’s collection)
In a British parliamentary debate in July 1927, Viscount Sandon asked the Secretary of State for War if he would “consider restoring the designation whippets, as used officially during the War for small tanks, in place of tankettes, unless the former term is still used to represent a particular type?” The reply from Commodore King was that “The nomenclature of the various types of tanks is under consideration.” The name Whippet though generally drops out of use by WW2 although can still be found on occasion referring to light vehicles including the occasional armored car. There was even an official British suggestion in 1940 to regroup light tanks into a ‘Dog’ class of vehicles by which time all the Whippet vehicles were officially marked as ‘obsolescent’.
British Mk.VIb on exercise recorded in the press as a ‘Whippet’. Photo: The Press, 1938
Surviving Whippets
Despite 200 being built, today there are just five surviving Whippet tanks in Belgium, the USA, Canada, South Africa and the United Kingdom.
A284 was previously at Aberdeen Proving Grounds and may currently be in storage
A387 known as HMLS Union (His Majesty’s Land Ship) is at the Army College in Pretoria, South Africa
A259 formerly of C Battalion, known as ‘Caeser II’ is presently at Bovington Tank Museum, Dorset, UK
A231 known in service as ‘Carnaby’ formerly of A Company, 3rd Battalion, is held at CFB, Borden, Canada (incorrectly showing serial number A371 which was known as ‘Sphynx’ and was captured in Russia in 1919 and still in Russian service in 1924)
A347 known as ‘FIREFLY’ is held at the Royal Museum of the Army, Brussels, Belgium
Specs
Whippet
Col. Johnson’s Whippet
Crew
3 – Driver, Commander, Machine Gunner (although a second machine gunner may have been in place on occasion)
3 – Driver, Commander, Machine Gunner (although a second machine gunner may have been in place on occasion)
Propulsion
2×7.72 litre 45hp Tylor JB4 petrol engines, 33 kW each@1200/1250rpm
V12 Rolls Royce Eagle water cooled petrol engine, over 300hp
Fuel
70 gallons (318.2 litres)
Unknown
Range
80 miles (130 km)
Unknown
Weight
14 tons (14,225kg)
14 tons (14,225kg)
Speed
8.3mph (14km/h)
30 mph (58 kph)
Ground pressure
15.8 lbs per square inch (1.11 kg/cm2)
Unknown
Trench crossing
Official 8.5 feet (2.59m), Tests 10 feet (3.05m)
Unknown
Suspension
6 Skefco roller bearings each side
Transversely mounted leaf springs
Armament
4x.303 calibre Hotchkiss Machine guns, (1 forward, 1 left, 1 right and 1 to the rear) with 5400 rounds
4x.303 calibre Hotchkiss Machine guns, (1 forward, 1 left, 1 right and 1 to the rear) with 5400 rounds
In 1916, the British Army had started using tanks in battle in an attempt to break the deadlock of trench warfare. These large lumbering Heavy Tanks were slow and unable to exploit weaknesses in enemy lines or a breakthrough. What was needed was a new ‘Medium’ Tank, and the Lincolnshire firm of William Foster and Co., the brains behind the Heavy Tanks set to work on a new Medium vehicle. By February 1917, this new vehicle, known as the Tritton Chaser or ‘Whippet’ was ready in prototype form. Two hundred of these Whippet tanks, officially known as the Medium Mark A were produced. This manual dates to the early days of the Whippet as it was being produced for the Tank Corps. A guide to the operation and maintenance of this new, smaller, and faster tank.
The First World War’s fierce battles saw the need to develop military technology beyond anything previously imagined: as exposed infantry and cavalry were mowed down by relentless machine-gun attacks, so tanks were developed. Stunningly illustrated in full colour throughout, Tank Hunter: World War One provides historical background, facts and figures for each First World War tank as well as the locations of any surviving examples, giving you the opportunity to become a Tank Hunter yourself.
A compilation of little known military history from the 20th century. Including tales of dashing heroes, astounding feats of valour, sheer outrageous luck and the experiences of the average soldier.
Few tanks have achieved the level of notoriety and even scorn which has been cast upon the ‘Bob Semple Tank’. Few lists of ‘Worst ever tanks’ miss it out and it does seem perhaps a little ungainly at first glance. As such it is ignored for what it really was and for the genuine merits it offered. The eccentricities of the vehicle and the character of the man whose name was applied to the vehicle have become legend.
Robert ‘Bob’ Semple (21 October 1873 – 31 January 1955)
The character of the man
Robert Semple was certainly a ‘character’ and, in some ways, the vehicle even reflected him and his attitudes. He was born on 21st October 1873 at Crudine Creek, New South Wales. He started life on the rough goldfields of Australia before moving to New Zealand and at various times been a boxer in his own right as well as a miner, industrialist, union leader, and champion of the common working man. He had campaigned against involvement in World War I and was a talented orator and public character.
At one point, he had been prosecuted for refusing to disclose his son’s age to a defense officer and upon the introduction of conscription in New Zealand in 1916 had sought to use the vital position of miners to force the government to abandon compulsory service. In December that year, he was arrested again after advising miners not to be “lassoed by that Prussian octopus, conscription” and even denied a jury trial under the then newly introduced War Regulations Act. Upon his release in September 1917, Semple toured the coalfields and was very well received. After WW1, his political career waned until the Labour party returned to power in 1935 and he became a cabinet Minister for Public Works.
Robert Semple on a caterpillar tractor, between 1935-1940 – NZ National Archives Photo Ref: 1/2-041944-G
This time, when war broke out, Semple was still fighting for the common people but was much less tolerant of dissent. In 1940, Robert ‘Bob’ Semple was given the portfolio for National Service; the de facto Minister for War, where, in a remarkable U-turn, he helped implement conscription. The idealist Semple had become the hardened fighter and pragmatist Semple. A man of strong convictions, virulently anti-authoritarianist and anti-communist, Semple was now an experienced political boxer. He needed to be too, as WW2 was a different beast to WW1.
In WW1, the ideal of sending troops to fight for the mother country was contrasted to WW2 where the prospect of a Japanese invasion of the islands of New Zealand was a very real and very frightening proposition. The Japanese had rolled through the forces of the French, British, and Dutch in the Far East and were openly talking about how undefended and vulnerable New Zealand was. New Zealand was virtually defenseless with just six Bren Gun Carriers in the whole country as its armored force. With Britain fighting for its own survival, supplies of War Materials, from rifles to tanks, were not going to happen for some time. If New Zealand was to defend itself it would have to do it itself. Semple himself remarked that: “If this country is going to be invaded, we need to have equipment as good as that of the other fellow, if not better… we could not buy tanks from outside, but had to act on our own resources. Luckily we had big tractors here, and they were a godsend. They have proved one of the greatest boons the country has ever known, permitting us to build highways, aerodromes, camps, and fortifications in record time in the Dominion. They have proved invaluable for other urgent purposes outside New Zealand.”
Robert Semple (cane in hand), then Minister of Works, on a Caterpillar diesel bulldozer, 29th March 1939 – NZ National Archives Photo Ref: 1/2-105128-F
A legend is born
New Zealand was facing a potential invasion with no effective armored force, Semple found out that the NZ Defence Department had been making enquiries in the USA for supplies of armor plate. However, Semple had already seen a photograph of a Caterpillar tractor which had been converted in the United States (it is possible that this refers to the Disston tank, however, no direct proof exists) and showed it to Mr. T.G.Beck (Public Works Engineer, Christchurch) who at the time was in charge of a large irrigation scheme in the South and Mid-Canterbury region.
It was going to take some time to obtain blueprints of the American tractor tank conversion but rather than squander time, work began straight away, without the formal plans under the direction of Mr. Beck in the Public Works Department (PWD) workshops in Temuka. Mr. Beck would work with an engineer at the PWD works, Mr. A.D. Todd, and all work was overseen by Mr. A. J. Smith in the capacity as an observer.
One of the PWD Caterpillar tractors working on a project at Lake Taupo, May 1941 – Photo: Auckland Star
At Temuka, the PWD proposed to take their fleet of 81 D8 Caterpillar tractors and build armored bodies for them. The tractors could be used for their normal purpose and, if called upon for War Service, could have these armored bodies fitted. Very little modification was required of the tractors. The suspension was modified slightly and the track assembly was lengthened slightly. The existing driver’s controls were changed slightly and moved forwards. Mild steel extensions were added to which the body would be attached.
Prototype tank receiving a two-tone camouflage coat of paint – note the lack of the corrugated armor which is yet to be fitted – Photo: Classic Military Vehicle
The prototype
A prototype was ready at the Temuka PWD Depot by June 1940. The existing tractor body was removed and substituted by a 3 ply-plywood mockup of the armored cab attached to those mild steel extensions. Even at this early stage, the idea of a proper cannon for anti-tank use and infantry support was mooted. The original gearbox turned out to be insufficient and therefore an improved 2:1 ratio box was substituted. This resulted in the metal prototype having a shortened engine compartment and wider sides.
A 37 mm cannon in a revolving turret was seen as being of crucial importance, as was the provision of machine guns. It was sadly found to be impossible at the time to obtain a cannon so an additional machine gun was used instead. There are no details of what 37 mm may have been envisaged but the 40 mm 2 pounder gun which was the standard British tank gun at the time was in short supply. Having looked to the USA initially it would be likely that this 37mm gun considered was the 37mm M3 tank gun as used on the Stuart light tank.
The additional turret machine gun brought the armament to a total of six Bren .303 caliber machine guns; one on each side, one over the back, one in the turret, and two positioned forwards in the hull. One on the far right and a second one positioned centrally which would have been very awkward to operate given the position of the engine and would have to have been operated either awkwardly from the side by the driver or other gunner, or by another crew member lying on top of the cowling over the engine. The crew is often quoted as 8 based on these 6 machine gun positions, a commander and a driver but is also variously noted as 6 and as 7 crew. Clearly, the crewing would be dependent on the number of men available and the situation encountered.
Proposal of a 37mm gun turret.
This prototype was reordered in mild steel and the need was to construct an example for the Army in actual armor plate. Supplies were not available even from Australia so instead, corrugated manganese plate was used. Trials at Burnham Camp on December 1940 showed the speed had been reduced with this additional weight to only 8 to 10 km/h (5-6 mph). Additionally, the bulk of the body meant it rolled badly during off-road movement making firing on the move very difficult. The Army was still frustrated at the lack of a turret mounted cannon but with no other options available relented to have three examples constructed as they were.
Photograph of ‘Tank designed by Robert Semple between 1940 and 1941’, NZ National Archives Photo Ref: 1/2-050790-F. Note the absence of all of the corrugated armor plating which was not yet fitted and the absence also of the additional armor plates over the machine guns, turret face and drivers hatch
Robert Semple (with cane) accompanied by unidentified staff officer inspecting the very tall sides of the PWD tank. Note this photo shows the back of the vehicle and clearly shows the corrugated armor on the right-hand side extending all the way up the side.
Into construction and the public eye
This construction was carried out in the Railway Workshops in Addington, Christchurch in January 1941 with the first one ready in under a month under the direction of Mr. Hoare. The armored structure of this tank consisted of 8mm thick (0.31 inch) armor plate, fully welded, on top of which was an addition of 12.7mm thick (0.5”) manganese rich corrugated steel plate. Popular myth has it that it used corrugated roofing metal and this is probably the origin of the myth that the vehicle was badly armored. This layering system was devised by Mr. Beck and was “severely tested”. The result was that this arrangement was felt to be sufficient to stop enemy anti-tank rifle bullets up to 20 mm (0.79 in) caliber as well as being easy to fabricate. Trailers were also devised for these vehicles so that they could be towed which, according to the October 1941 assessment by Major General Puttick, “enables the machine to be moved very rapidly over long distances. Loading and off-loading is a matter of minutes only”
‘Semple’ tank loaded onto special transport trailer for rapid deployment – Photo: New Zealand Herald, 21st April 1941
By March 1941, the second tank was finished, and both took part in a parade in Christchurch on 26th April. One was then sent to Wellington and then on to Auckland to promote the war effort. It was paraded there on 10th May 1941. These public outings, as well-intentioned as they may have been to bolster flagging domestic spirit, instead promoted media ridicule. Only after these public outings did this tank become known as ‘Bob Semple’s Tank’.
Semple Tank being loaded/unloaded at a port as part of its journey to Auckland, May 1941 – Photo: Auckland Star, 6th May 1941
Two ‘Bob Semple tanks on parade in Christchurch on the 26th April 1941. The arch in the background is the Bridge of Remembrance – Photos: Christchurch Libraries and NZ Herald respectively
A Bob Semple tank in the livery suggested by contemporary photos.
Semple Tank on parade in Auckland, 10th May 1941 – Photos: NZ Herald
‘Is Mr. Semple in please?’ ‘Just a minute,-I’ll see!’ – Cartoon: New Zealand Herald, 13th May 1941
To the test
In August 1941, the vehicle’s armor was to be subjected to intensive machine gun fire and accurate close range sniping and in doing so highlighted some weakness in the design around the machine gun ports allowing for bullet splash to enter. Even so, in the absence of an alternative tank, General Puttick remarked that it was a very useful weapon for certain styles of fighting. It was powerfully armed and the speed was sufficient. The only unsatisfactory part was the height of the vehicle, in particular, the turret. The turret added more than two feet (>600 mm) to the overall height of the vehicle. Lacking a cannon in the turret, the additional machine gun provided little extra firepower to the other machine guns so General Puttick recommended the removal of the turret. Semple was to comment later that month on this creation that: “The tank was not a stroke of genius on the part of the Minister of Railways, but an honest effort on the part of the military and the Public Works Department to create something out of the materials we had. It was made by the will and consent of the military”
‘25 ton tank constructed by the Public Works Department’ – Photo: New Zealand Herald, 8th October 1941
Semple Tank undergoing trials. Note the LMG – Light Machine Gun range in the background
Major General Edward Puttick
Further tests of the ‘Semple tank’, as it was now commonly known, were carried out at Burnham camp by 8th October 1941 and witnessed by Major General Puttick (Chief of New Zealand General Staff). General Puttick was an experienced combat officer who had recently returned from the War in the Mediterranean. He noted that that at 25 tons (although the Semple tank did not weight this much) vehicles were still too heavy to cross bridges and would have to ford the streams instead but that overall: “The arrangement of the turret and of the machine guns was ingenious and efficient” and that “I was impressed with the skill and ingenuity displayed by those concerned in the tank’s design and manufacture, adapting a civilian vehicle for military purposes”
It didn’t matter though if the vehicle had merit or not. It had become tied to Semple personally so his opponents politically could attack him by way of attacking ‘his’ tank and its unconventional appearance combined to doom it to being a laughing stock. This cartoon appeared on 21st October 1941 coinciding with the arrival of the first Valentine tanks in New Zealand.
‘Don’t look now but I think there’s something following us!’ Bob Semple appears in caricature with his head out of the turret which is unusual as there was no turret hatch on at least one if not all of the vehicles. A flaw which seems to have gone unnoticed by contemporary commentators – New Zealand Herald 21st October 1941 [Note: The turret of the vehicle is actually marked ‘Semple Mk.II’]
Semple Tank undergoing testing showing the roof of the turret.
A view of the top of the ‘Semple Tank’ turret shows just a simple lifting eye and the absence of a turret roof hatch. Of all of the flaws mentioned of the Semple tank, this lack of a hatch is the most notable by its absence. This would have seriously hindered the observations from the vehicle as well as ensuring a fiery death for most of the crew. A single rear door being totally inadequate for even 6 men to exit in an emergency. Even with that flaw and its other shortcomings, Semple was rightly unrepentant saying in late October 1941: “That tank was an honest-to-God effort to do something with the material at our disposal when raider were at our back door…instead of sitting down and moaning we felt we ought to do something to manufacture weapons that would help to defend our country and our people”
At some point, these two tanks were officially handed over to the Army, reportedly having had their turrets removed. Suitable cannons had still not been obtained. General Puttick’s final recommendation was that no more of this vehicle type be made and that the three existing vehicles were deemed to be suitable for beach defence instead. Eventually, the armored bodies were stripped back off the tractors and they were returned to their civilian duties. Time had gone by and the invasion threat was over. Better, faster indigenous designs were available, Valentine tanks were being delivered, and the Bren Carrier was in production locally to boot. The Semple tanks were simply not required anymore. The third vehicle, which had remained in Auckland, was reportedly deployed into service in the Pacific theater, albeit stripped down and fitted with a dozer blade.
Semple tank without turret
End game
Despite all of the scorn and mockery, Semple was still defiant and with plenty of justification. Under Robert Semple the almost defenseless islanders of New Zealand had developed their own armored force and demonstrated the resolve to fight and to resist. Semple, in a political exchange in September 1943, said:
“When we came into office we had insufficient strength to protect a currant bun from the attack of a blowfly. But if the Japs could be killed with wheelbarrows we could have stoushed them – we had plenty of barrows…two years before the war we quietly slipped machines to Fiji and Tonga and built aerodromes there secretly… it was plain as the day that the Japs would strike south through the back door to Singapore… [island hopping] …to New Zealand..what stopped them this way?”
A retort from the floor mocked Semple saying:
“Probably your tanks, Bob”
to which he responded
“If that is a cheap sneer, you keep it. I had the vision to try and create something while a lot of others were just sniveling” [Laughter and applause to this response is recorded]
This was not the response of a man in any way ashamed or embarrassed but rather proud in what he and the PWD achieved.
Postwar commentators may also continue to sneer at this ungainly machine, but the PWD and Semple had laid down a marker, a line in the sand that New Zealand would defend itself no matter what. Semple, the fighter, the anti-authoritarian, would not give up the defence of his home to the dictatorship of Japan no matter what.
Major General Robert Young
The last word should go to Major-General R. Young (Dominion Commander of the Home Guard) who was touring with Bob Semple in November 1940 promoting home defence. General Young summed up the character of the man saying: “I am proud to be associated with him. He has for what I wish everyone had – a will to win the war – for when a man has got a will to win, nothing can stop him”
‘Semple Tank’ / PWD Mobile Pill Box specifications
Dimensions
13’9’’ x 10’10’’ x 12’’ ft (4.2 m x 3.30 m x 3.65 m)
Total weight, battle ready
~18tons (including 2 tons of armor plate)
Crew
6 (commander, driver, 4 x machine gunners)
(additional crew could be carried up to 8 men total)
Propulsion
6 cylinder Caterpillar diesel, 95 kW (127 hp)
Also given as 108 hp (flywheel), 96 hp (drawbar)
Climb
1 in 2 grade
Fording
4 feet (1.22 m)
Embankment
4.5 feet (1.37 m)
Other notes
Could crush saplings up to 6” diameter
Fitted with drawbar for towing of light field guns or an armored trailer
Armor
0.5″ (12.7 mm) Manganese Steel in V corrugated form backed by 0.31″ (8 mm) steel plate
90 litres of diesel held in two frontal fuel tanks
Armament
6 x .303 calibre Bren light machine guns with 25,000 rounds, (1 in turret, 1 rear, 1 left hand side, 1 right hand side, 2 forwards)
37 mm cannon (proposed but not fitted) with 5 machine guns
The tank concept itself was new to war having been unleashed on the Germans on the 15th September 1916 at Flers-Courcelette. William Tritton (knighted February 1917 for his services relating to tanks) was at the front in person less than a week after this first use of tanks. No doubt seeing first hand the appalling conditions through which his larger ‘rhomboid’ (male and female) tanks were having to proceed caused Tritton a great deal of thought.
By November 1916, less than two months after this visit, work on this light tank formally began and actual construction of a prototype was started on the 21st December 1916. This remarkably short design and development time is both a tribute to the skill of the designers; William Tritton and William Rigby, and the factory staff but was also to cause problems with the vehicle. Tank warfare was a brand new concept and the trailblazers in any field will make mistakes so some of these faults can be excused to a certain extent.
‘The Whippet’ nickname already applied to the flat front of the Tritton Chaser would later stick as an official name. The small hole below it is for the engine starting handle. Photo: IWM
Layout of the Tritton Chaser machine’s twin engines. (Source: Adapted from Logbook of a Pioneer, Stern)
The First Machine
The first machine, known by the 3rd February 1917 as the ‘Tritton Chaser’, was already able to move under its own power and for the first time featured a fully rotating turret for a single .303 calibre Lewis machine gun on a similar appearance to that of the Austin armored car of the period. It sported the name ‘The Whippet’ already and the name would stick.
This first vehicle had problems however, the front was a single vertical plate covering the engine and the driver offset to the right had a very limited field of vision. The fuel tank was at the rear and was unarmored and the machine had no exhausts on either side, meaning the crew would be directly exposed to engine exhaust gases.
This vehicle completed a running trial first of the 11th of February, and then formally on the 3rd of March at Oldbury, near Birmingham where it was demonstrated to representatives of the Ministry of Munitions. At this time the machine was ‘Tritton’s Chaser’ but was officially noted as being ‘Tritton’s Light Machine (EMB) [Experimental Machine ‘B’] and given ‘No.2’ as it was the second vehicle tested that day. During the tests, this vehicle sported a single horizontal green painted band running all around the hull just above the level of the tracks, as each vehicle tested was color coded with green being vehicle number 2 that day as this color coding would help the senior British and French officers present to tell apart which of the vehicles was being tested.
The suspension consisted of 16 sets of Skefco roller bearings on each side above which are the very distinctive holes in the side through which mud picked up across country would be discharged and which also doubled as an additional layer of armor and reduced the weight of the machine. This arrangement was patented by Tritton in a filing dated the 2nd of February 1917 clearly showing the outline of what was to become the layout of the Whippet albeit with just four mud chutes and not the 5 initially used on this first machine.
Images: Patent GB126,671 filed 2nd February 1917
Despite the flaws in the machine it managed just over 8 mph (12.9 kph) as a top speed from its twin 45hp Tylor JB4 petrol engines which was nearly double the speed of the Mark IV and V tanks. Tritton had preferred a more powerful engine to take the tank to over 10mph but the War Office (WO) had supply problems for engines so the 45hp Tylor was all there was for the tank. Sir William Tritton was later to remark that “the choice of the 45hp engines had spoiled an otherwise useful machine”. The drive system was unusual and difficult to master. Each engine drove a separate track and steering was effected by way of the driver adjusting the throttle control on each engine but it did have the advantage of only requiring one driver.
Many of the initial design features of the Chaser tank did eventually make it into the production vehicle but this initial machine was first rebuilt with the top of the machine stripped back. The turret was removed and a much large polygonal superstructure built instead. An exhaust was added to each side of the engine and but it retained the fuel tank at the rear. Machine gun ports were cut into the new polygonal superstructure and at least one ball mount fitted in the right hand side but the front of the engine bay lacked any additional vents.
Rebuilt Tritton Chaser pictured on trial on the William Foster and Co. test field. Photo: IWM
In this form, it was envisaged to now take up to four Hotchkiss .303 calibre machine guns, one in each face of the superstructure covering each side of the vehicle. The crew had increased from 2 to now as many as four (driver, commander and two machine gunners). Further work was then done to this machine with additional engine vents cut into the sides of the engine bay at the front and the moving of the fuel tank to the front under a rounded cover. It is speculated that this may have been to adjust the centre of gravity for the vehicle to improve its trench crossing ability.
The rebuilt Tritton Chaser with its trailing wheels
Close up the Hotchkiss machine gun mount as preserved on A259 Caesar II at Bovington. Photo: tank-hunter.com
Rebuilt Tritton Chaser showing the holes cut for the vents and the new forward placement of the fuel tank. In this photo the vehicle is also using prominent track spuds to obtain additional traction in soft ground. In practice these were used very rarely. Photo: IWM
Rebuilt Tritton Chaser with a rudimentary canvas track guard fitted presumably in an attempt to limit the amount of mud being thrown up onto the vehicle. Machine gun ports have been cut but no armament is fitted. Photo: IWM
Rebuilt Tritton Chaser with experimental wheels fitted (the vehicle in the foreground is a gun carrier). Photo: IWM
This prototype vehicle remained at the testing grounds of the Mechanical Warfare Supply Department at Dollis Hill, London where it was later tested with trailing wheels and even a rear tail-skid (presumably akin to that of the Renault FT) to try and improve trench crossing. No photo of this skid fitted seems to have survived and there is only one poor quality shot of the wheels fitted. It was eventually moved to the Imperial War Museum and later scrapped.The wheels were found to be more effective than the tail skid. Trench crossing trials were held in May 1918 without either wheels or a tail-skid fitted. It was found that the effective trench crossing limit of the production Whippet tank to be 10 feet (3.05m) although the official figure was 8.5 feet (2.59m). Trench crossing ability was to plague the mind of the British military in not just WW1 but well into the next war too. The Army had their lighter faster tank design ready now to go into production.
In 1916, the British Army had started using tanks in battle in an attempt to break the deadlock of trench warfare. These large lumbering Heavy Tanks were slow and unable to exploit weaknesses in enemy lines or a breakthrough. What was needed was a new ‘Medium’ Tank, and the Lincolnshire firm of William Foster and Co., the brains behind the Heavy Tanks set to work on a new Medium vehicle. By February 1917, this new vehicle, known as the Tritton Chaser or ‘Whippet’ was ready in prototype form. Two hundred of these Whippet tanks, officially known as the Medium Mark A were produced. This manual dates to the early days of the Whippet as it was being produced for the Tank Corps. A guide to the operation and maintenance of this new, smaller, and faster tank.
Of the major combatants of WW2, only Germany and Japan made any significant use of magnetic anti-tank charges. The Japanese in particular had been making good use of the Model 99 Turtle mine and had inflicted many casualties upon American and Commonwealth troops with them.
From Japan, the Model 99 Turtle mine was the shape of a large tin of shoe polish and held in place by means of four equally spaced magnets around the outside and weighed just over 1.2kg, containing 0.74kg of TNT. Placed against thin points of armor or on a hatch, this mine could penetrate 20mm of steel plate, but with one on top of another this could be increased to 30mm.
Japanese Model 99 Turtle Mine
These Japanese mines had been causing casualties for a long time and field extemporised measures, such as the use of piercing aluminium planking were fielded as early as the end of 1943. As aluminium is non-magnetic, the idea was that the mines would hopefully just fall off, and obviously holding the mine further from the vehicle would also reduce their effectiveness.
Stuart flamethrower tank in New Caledonia October 1943 with pierced aluminium matting on the glacis to protect against Japanese magnetic mines
A spiky problem
Little work though had been done on an official solution to the problem of these mines until experiments were conducted between the 2nd September 1944 and the 28th March 1945.
One method tested was the use of steel spikes welded to a 1/2 inch (12.7 mm) thick mild steel plate over horizontal surfaces on a M3A3 tank. These spikes were between 6 3/4 inches (171.45 mm) and 5 1/8 inches (130.18 mm) long in rows 4 1/2 inches (114.3 mm) apart. Another sheet of 1/4 thick (6.35 mm) steel installed around the turret and the covering for the air intake was coated with Truscon 260, a type of cement. This cement coating was found to cause the Japanese magnetic mines to slide off onto the spikes. These vertical spikes would hold the mine sufficiently off the armor that the explosion would be ineffective, and no doubt the ability to deter unwanted enemy troops climbing on the tank was not lost on the experimenters either.
The experiments were however discontinued as it was found to be impossible to protect all of the horizontal surfaces. The measures also interfered with the vision from the vehicle, and the weight of the additional protection was considered to be excessive.
M3A3 Stuart tank fitted with spiked armor on horizontal surfaces and the Trucson coating.
While this M3A3 Stuart looks menacing with its spikes, it was not a viable solution.
Australian M3 at Australian Cavalry Museum, Puckapunyal with anti-magnetic mine screen fitted over front.Even though US studies ended in March 1945, field extemporised measures had continued with the use of canvas and/or other ‘neutral materials’ being used in some manner to clad at least one US tank in the Pacific theatre by an unnamed unit where it was proven successful in preventing a magnetic mine from adhering. Other measures deployed were welded mesh gratings fitted over the hatches as a method used by both Australian and US forces. The hatches being a particularly vulnerable spot for these mines to prove effective. An August 1945 report documented the efficiency of these mines recorded that in a single engagement in Burma, six US M3A3 light tanks had been attacked with these charges with them being thrown onto the engine compartment or turret, of which five of the vehicles had caught fire.
M4 Sherman of 4th Marine Tank Battalion on Iwo Jima showing mesh grills over the hatches.
M4 Sherman on 1st Marine Tank Battalion on Okinawa 1945 showing how the aluminium matting could be used to stop magnetic mines from sticking to the hatch. This vehicles also appears to have fabric matting suspended from the sides possibly for the same purpose.
Zimmerit had been deployed ostensibly by the Germans as a counter to magnetic mines. Whether Zimmerit actually worked or not is hard to tell, as neither the US, Soviets or British made any notable use of magnetic charges. The British did have the ‘Clam’ magnetic charge from 1939 and by 1946 had supplied some 159,000 examples to the USSR, but there is no information available as to how much use these may have been put to. This rather small device contained just 8 ounces of TNT (227 grams).
The ‘Clam’ Magnetic charge. Mk.I had a metal body and the Mk.II was Bakelite but a smaller charge than this Mk.III version
The British, first encountered Zimmerit in 1944 and like the Soviets before them were intrigued by this textured coating on German tanks and in particular considered it some kind of clever camouflage. Such textured coatings had been previously encountered on items like helmets at least as far back as WW1, so the theory of camouflage by textured coatings was perfectly sound.
The British way
The British however did not have any Zimmerit material for testing at the time but even so conducted their own experiments into textured camouflage. One of these experiments in August 1944 involved the fitting of ribbed rubber material to the outside of the turrets of Cromwell tanks belonging to C Squadron, 2nd Northants. Yeomanry, 11th Armoured Division.
Cromwell tanks of C Squadron, 2nd Northants, Yeomanry, 11th Armoured Division with rubber material glued to turret
As a camouflage, Zimmerit was drawing attention from Field Marshal Montgomery who expressed the need for improved camouflage. On the 21st February 1945 he remarked that “a satisfactory camouflage is required which will eliminate all shine and reflection from the armour plate. Some form of plaster like the German ‘ZIMMERIT’ should be produced and incorporated in the manufacture of all future tanks”. Stocks of captured German Zimmerit were not available until August 1945 though, and in the meantime further experiments included test applications were carried out. These experiments used a Ram Sexton Self Propelled Gun, a Churchill tank, a Cromwell tank, and the gun shield of a 25 pdr field gun. Test results for the Ram Sexton
The Ram Sexton had a coating applied to it made from a chopped straw mix and also from a wood-wool mix to show texture differences, the exact consistency of this material is unclear but it was alcohol based, probably because it would dry and harden more rapidly as the alcohol evaporated. It was applied by means of a roller with the intent to then add ridging from either fingers drawn across the surface or with a special texturing wooden roller. If the mix was off and contained too much alcohol the surface could become shiny or simply crack and flake.
The tests of this paste were carried out in the ETO (European Theatre of Operations) in April 1945 on vehicles of the 256th Armoured Delivery Squadron. This ‘plastic’ type substance was initially applied by means of spraying (application by spraying was found to not suit the later texturing) but also by trowel and took no less than 80 man hours to apply to the Cromwell. Despite the use of alcohol, it took 2 days to dry although it is possible that the mixture was too thick or the application untried, as application on other vehicle was quicker. The most successful mixture tried involved the chopped straw and the images show an extremely well textured surface. Close-ups of different textures obtained
The Cromwell required some 5.5cwts (279kg) of this material in order to be fully coated, with care taken not to obstruct the air intakes or exhausts. The Churchill tank required some 6cwts (305kg) of material, took 2.5 days to dry and 95 man hours to apply, whereas the Ram Sexton only required 4cwts (203kg), 51.5 man hours to apply and a day and a half to dry. The 25pdr gun shield needed just 1.5 man hours to apply the 0.5cwts (25kg) required and the overall results were judged to be ‘extremely effective’.
Color photo of the Cromwell with rubber stripes on its turret.
Churchill tank demonstrating the effectiveness of a textured and painted coating as camouflage.
An additional curious side note is that, over the top of this coating, the vehicles were painted in a two-tone matt black and German yellow-green paint scheme. The Cromwell in particular was impressive, as it could “completely disappear into the background”, especially when fitted with a camouflage hessian net over the suspension units. There is no record made as to British testing this scheme against the standard German magnetic mine; the 3kg Hafthohlladung, although the British were aware of the ‘anti-magnetic charge’ purpose of the material.
The Hafthohlladung mine used three large magnetic feet to adhere to the armor of a vehicle and the shaped charge could pierce 5” inches of armor plate at a 90 degree angle. There was a smaller German magnetic version from the Luftwaffe, known as the Panzerhandmine 3 (P.H.M.3), which had the appearance of a small wine bottle with the base cut off to make room for 6 magnets.
Hafthohlladung mine showing method of use
German Panzerhandmine (P.H.M.) 3
The end of the war, the start of the tests
The British study mission into Zimmerit did not manage to confirm that the firm of C.W. Zimmer originated the Zimmerit paste, although it seems highly probable they were. Having liberated 100 tons of the stuff the British had plenty of Zimmerit to finally test out though but it had come too late.
The War in Europe was over before any British trials involving this paste or imitation substance had any effect on the outcome, so the liberated stocks were shipped to Australia, presumably for trials against the Japanese magnetic mines. The War in the Pacific was also finishing so the Australians do not seem to have had any use for this weird substance either and there are no records of what, if anything, was done with their shipment so it seems that all of the effort that went into tracking down the source of the substance and getting hold of some was wasted.
Sherman tank painted half and half with Zimmerit paste
Overall, the British opinion was that a textured coating provided excellent camouflage and that texturing made no difference at all to the anti-magnetic mine benefit. One further thing worth noting though was that when the British tested the substance on a tank by means of a flamethrower than the uncoated vehicle got so hot inside that the ammunition could ignite however the coated vehicle remained at bearable temperatures. This lends more credibility to the Soviet report suggesting some fire or heat protection from the material although the mode of protection is more likely simply by means of insulation than anything else.
The war in Europe and in the Pacific was over before the British or allies could deploy anti-magnetic coatings for either protection from mines or for camouflage. The US were to conduct their own experiments but the only other experimental work which appears to have been done on Zimmerit is by the French who tested a very well patterned application on the hull of a M4A2.
The Soviets first encountered Zimmerit late in 1943 on Tiger tanks and Panzer IVs. Examining 5 Tiger and 15 Panzer IVs, the Soviets found that the Tigers were covered across the glacis, lower plate, hull sides, turret sides and even the track guards with this grey substance. Measuring it though they found it to be just 2-4mm thick. Of the 15 Panzer IVs captured with Zimmerit, two also had this material on the armored screens mounted on their turrets as well.
A well ‘zimmeritted’ Panzer IV on the Eastern Front, with Zimmerit on the hull and Schurzen as well as the turret screens
The Soviets were initially confused as to the purpose and make-up of the material, but quickly established that it would neither burn nor dissolve (although it would get softer in hot water). Far from thinking it to be a fire hazard, the Soviets initially suspected Zimmerit was some form of protection from incendiary bottles or camouflage, two things the British also considered later.
German records indicated that Zimmerit consisted of 40% Barium Sulphate, 25% Polyvinyl Acetate, 15% Ochre pigment, 10% Zinc Sulphide,
10% Sawdust. The Soviets examining both burned and unburned samples of Zimmerit in April 1944 (the samples provided to them from the front were rather small) found the material to have a melting point of 1100C and to consist of:
53% Barite (Barite is another name for Barium Sulphate)
16-17% Quartz
27% Organic material
~3% unidentified
The Soviet scientists did not receive very much Zimmerit to test but from what little they did have they made two assumptions. One was that the ridges may serve to concentrate the liquid and or heat from flammable liquids. This may melt the coating to extinguish the fire. The other one was that Zimmerit was some kind of winter camouflage due to the greyish color of the material.
Other vehicles found by the Soviets with it included the Panzer S35 and Panzer 38H, both of which were notable enough to be documented with at least one sent to Kubinka for trials, testing, or display.
Former German Army Panzer 38H(f) on show at the Kubinka testing ground in 1945, sporting a coat of either Zimmeritt or Cement
Former German Army Panzer S35 in Soviet hands, date unknown. Reportedly captured in Summer 1944 with a coating of either Zimmerit or Cement.
Whatever else they may have thought of it though the Soviets do not seem to have been either concerned or impressed by the material. It is possible they did some further testing with it, they probably had more pressing issues to deal with.
Panzer S35 (Captured SOMUA S35) testing Zimmerit
Panzer 38H(f) (Captured Hotchkiss H39) testing zimmerit
Germany 1945, this Panther Ausf.A has suffered a significant fire resulting from enemy fire which has scorched off the Zimmerit coating from the hull and turret side.
Was it flammable?
One note of particular interest was the unusual application of Zimmerit to a couple of T-34s. In November 1944, the Germans conducted some limited trials of Zimmerit to test the veracity of the ‘flammability’ rumors. Two captured Soviet T-34 tanks were used for the tests.
T-34 number 1 had Zimmerit applied by the manufacturer, consisting of multiple layers which were properly hardened by means of a blowtorch. T-34 number 2 has just a single layer of Zimmerit applied by range staff in a single layer and left unhardened.
Tank number 2 was then left for 4 days and was completely cold (just 5 Celsius) before the armor was heated with a blow lamp and a welding torch for a period thirty seconds, which resulted in 3-4 seconds of small flames and a slight afterglow. The flames were probably a result of burning off of some of the residue which had not evaporated due to the cold weather, as it was reported that the smell of solvent could still be felt at this time.
The vehicle was left for another 2 days, after which it was heated by means of a camp fire made inside the vehicle. This raised its temperature to about 35 Celsius, and then the vehicle was again blowtorched.This time there were about 20 seconds of small flames and a slight afterglow. It is surmised that the preheating to 35 degrees released all the remaining solvents which were the cause of the flames.
This solvent flammability was found again during testing of ‘wet’, freshly applied, undried Zimmerit. Immediately after application, it was found to burn easily across the whole tank, but was also easily extinguished with just sand. The solvent in wet Zimmerit was, of course, flammable, so this is not a surprising result. Despite these tests and the resultant burning, it was found that the intermediate layer of Zimmerit still did not burn.
After these very elementary tests were finished, some firing trials were carried out on these vehicles with a variety of shells from both the 7.5cm PaK40 and the leFH18, at a range of 250 metres:
7.5 cm Pzgr. 39, dud, no tracer (the shell is listed as being defective)
7.5 cm Pzgr. 39, unmodified
7.5 cm Pzgr. APC M61 Projectile with HE and tracer
7.5 cm Pzgr. 38 Hl/C (?)
7,5 cm PzGr 34
FH Gr. Phosphorus
At no time, from any of the impacts on either vehicle, did the Zimmerit catch fire. It was chipped off at the point of impact though and the overall conclusion of the testers was that Zimmerit was not the cause of fires in German tanks.
These German tests therefore sadly do not confirm the Soviet theory about how Zimmerit worked. The camouflaging element was essentially forgotten and the Soviets were winning anyway so wasting time on Zimmerit would have been nothing but a distraction for the Soviets. Despite the results of the tests proving Zimmerit wasn’t flammable, the Germans too dropped it.
Probably one of the more unusual elements of German tanks of WW2 is the substance known as ‘Zimmerit’. This unusual material which many tank enthusiasts and modellers have heard of but do not really know much about is as interesting as it is complicated.
The substance known as Zimmerit is referred to as a non-magnetic coating designed to prevent magnetic mines from adhering to the armor of the tank. Zimmerit first appears in 1943. The DB and Alkett factories started applying it from about November 1943 and an order from the German High Command, OKH (Oberkommando des Heeres), dated the 29th December 1943, called for Zimmerit to be applied to tanks, albeit not on the turrets or track guards. A British wartime report from 1945 later confirmed that development of Zimmerit had begun in 1943 as a counter to Russian infantry assault teams using mines held in place by magnets against German tanks.
Tiger II at Bovington showing its hull and turret Zimmerit.
Application and composition
The original order was just to cover the hull of the tank. This is logical as the hull would be the easiest part to reach for enemy infantry armed with magnetic charges. In practice however, it was often applied all over parts of the vehicle, including track guards and turrets, in a wide variety of patterns often varying on a single vehicle.
Examples of different Zimmerit patterns
Different styles of Zimmerit application on the back of the turret of a Panther. Note that neither the cupola nor the roof are coated with Zimmerit.
The actual substance was a mixture of materials almost certainly developed by the firm of C.W. Zimmer AG, Berlin (a well known manufacturer of paints) and is a mix of:
40% Barium Sulphate: BaSO4, non-flammable non-water soluble, melting point 1345 C Refractive index 1.64. Main use is in paints and dyes
25% Polyvinyl Acetate: C4H6O2, unbonded it is flammable at 104.4 C. Main use is in adhesives and paints (possible ‘Mowlith 20’ sold to the firm C.W.Zimmer in July 1943 by the firm of I.G. Farbenindustrie A.G. Hochst, Germany. Mowlith 20 was a 50% Benzene mixture)
15% Ochre pigment: such as Goethite (FeO(OH)) and Limonite (Iron 3 Oxide, Fe2O3) is basically Iron Oxide, non-flammable non-water soluble. Main use is in paints and dyes. This ingredient is responsible for the natural yellow colour of unpainted Zimmerit.
10% Zinc Sulphide: ZnS, melting (sublimation) point: 1185 C, non-flammable non-water soluble. Used extensively in infra-red optical materials
10% Sawdust: Cellulose fibers, flammable but once bonded will char creating a thermal barrier.
Unusual application of Zimmerit to side ‘Schurzen’ on these Panthers
An unusual Panzer IV with Zimmerit covering its Schurzen side plates
The paste itself had an unpleasant smell of acetone, but was easy to handle and put onto the vehicle, requiring no preparation of the bare metal surface beforehand. In practice though, a non-corrosive primer was usually applied over the metal surface before the Zimmerit.
This mixture was pasted onto the surface of the vehicle in two applications. The first layer was to be 5mm thick and left to dry for 24 hours, marked out in squares with a metal trowel. A second coat was then applied over this and marked with a metal comb, in order to create a criss-cross pattern to improve adhesion to the first layer. The entire coating was then dried and hardened with a blowtorch. It took less than an hour with a blowtorch to evaporate off the solvents used in the paste and leave it dry, but the whole application, texturing and drying process took a couple of days per vehicle. Even if it were not blowtorch dried, the paste dried out anyway and reached normal hardness within eight days.
Applied correctly, this mixture created a rough hard raised textured surface. It provided not only a poor contact surface for mines, but the texturing also gave a good camouflage finish. Even a small distance between the magnet and the vehicle body reduces the effectiveness of a magnet. This combined with the irregular surface concerned and movement over terrain, was probably quite effective as protection against magnetic weapons.
Factory application of Zimmerit on a Panther
The British investigate
In August 1945, a British team was investigating Zimmerit as a possible means of protection against the Japanese use of magnetic mines in the Pacific. Information had started to be gathered on the substance soon after it was discovered on captured and knocked out enemy vehicles, with samples scraped off and sent for analysis in 1944. Further to the intelligence work on captured samples of Zimmerit, German POW’s had also revealed some of the use of the substance, but it was not until the 14th August 1945 that the British team managed to get some substantive information on the development of Zimmerit and where it came from. That was the day that the British team finally got to the Henschel works in Kassel in Germany. Here the team interviewed the Director of Production about Zimmerit. He recounted that the paste itself was supplied to the Henschel works in drums directly from Chemische Werke Zimmer in Berlin (although other plants were also involved in the manufacture) and had the consistency of soft putty.
Detailed photo of the Saukopfblende gun mantlet from a Jagdpanzer IV showing Zimmerit
The Director of Production revealed that he had thought the order to discontinue the application of Zimmerit was due to the development by the enemy of better anti-tank weapons, rather than because of any safety, production or effectiveness concerns. The order in question had been issued by the OKH on the 9th September 1944 following rumors of Zimmerit causing fires or being flammable. Later German tests would show this to be completely false, but, in either case, there was a significant quantity of Zimmerit left at the Henschel works and the British liberated some 100 tons of it from there. Zimmerit was officially discontinued for factory application from the 9th of September 1944, however, there must have been quantities shipped out to units, as it was not ordered discontinued for field application (which would include foreign maintenance depots and even factories) until the 7th of October.
Panzer IV Ausf H of 26th Pz.Division Italy 1944 with locally applied Zimmerit coating
In use
It is possible that many vehicles got rushed through the application process. As a result some may only have received a single layer of the material due to the constraints on production, or supply. It’s also likely that many vehicles were partially through the process in the factory when the order to discontinue came in. Even at the factories, given the novelty of the material and quality control issues, it is also likely that many vehicles did not get a sufficiently thick two-layer coating. A thin single coating would dry faster so would have aided in speeding factory production. It’s also quite likely that tankers may have imitated Zimmerit on their vehicles using cement.
German soldier spray painting camouflage paint over Zimmerit
Once applied though, Zimmerit was surprisingly durable. Many vehicles have been dug up after having been buried for decades in rivers or swamps and still retain traces of it. Even battle damage didn’t blast it off the surface, as a shell would only cause localized loss of the material.
Battle damaged Tiger showing resilience of material to combat damage
Despite the stated purpose of Zimmerit for protecting against magnetic mines, it’s not clear that it actually worked. Neither the British, Russians, nor the Americans made any notable use of magnetic mines to counter German tanks. Whether or not it actually worked for the stated purpose, it was certainly effective as camouflage and this may serve to explain why so many variations of it exist on a variety of vehicles.
An article by Andrew Hills
Equipment known to have had Zimmerit applied (click link for photo)
OKH Order 29th December 1943
WW2 Infantry Anti-tank Tactics, Gordon Rottman, Osprey Elite Series No.124
21 Army Group AFV Technical Report # 26, Amended
British “Zimmerit”, by Jeffrey D. McKaughan, Museum Ordnance July 1995
Mr. Churchill’s Tank, The British Infantry Tank Mk. IV, Schiffer, 1999
ZIMMERIT; Production and Application Methods, Donald Spalding, AFV NEWS, January – April 1983 issue
Imperial War Museum IMG B9098
Bundesarchiv
‘Rubber Zimmerit?’, Bob Eburne, Military Modelling, Vol.29, No.11, October 1999
“Zimmerit” Anti-Magnetic Plaster for AFVs, British Intelligence Objectives Sub-Committee report, Major J.W. Thompson and Mr. C.E. Hollis, July 1945
‘Protection of Jap Tanks Against Sticky Grenades’, Tactical and Technical Trends, No. 25, May 20, 1943.
Zimmerit, Mike Gibb
MUN3435, Imperial War Museum, London
Stuart; A History of the US Light Tank, R.P. Hunnicutt, Presidio Press
Century Tracks No.1, Les sherman Francais de la liberation 1943-1945, Claude Gillono,
Waffen Revue Issue 27
Waffenamt Prüfwesen (WaPrüf) dated 19th November 1944 On Zimmerit, Archive Awareness, 7th August 2013
CAMD RF 38-11369-419, Field Report of substance scraped off German tanks
CAMD RF 38-11355-2219, Laboratory analysis of material submitted for testing Zimmerit, Retrieved from https://stugiii.com/zimmerit.html
Battle Experiences Against the Japanese,HQ European Theater of Operations, US Army 1st May 1945
US Military Intelligence Bulletin, 3rd May 1945, Panzerhandmine 3 Stuart Macrae’s “Toy Box”
‘Supplies to the USSR despatched between 1st October 1941 and 31st March 1946’, Russia (British Empire War Assistance) HC Deb 16 April 1946 vol 421 cc2513-9
ТРОфЕИНАЯ БРОНЕТАНКОВАЯ ТЕХНИКА ВЕРМАХТА (Captured Vehicles of the Wehrmacht) 2007
Memorandum on British Armour No.2, Camouflage, dated 21st February 1945
The US M3 Medium Series in Australia, Paul Handel, 2001 Australian Military Modelling Society, M3 Medium Tank by Al Bowie The Sherman Tank.com Gallery
Panzer IV: The Panzerkampfwagen IV Medium Tank, 1939-1945 by Kevin Hjermstad
26th Panzer Division in Italy 19433-1945, Daniele Guglielmi
Germany’s Tiger Tanks, D.W. to Tiger I, Thomas Jenzt
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