Failed Tanks WW2 British Prototypes

Valiant, Infantry Tank, A38

United Kingdom (1943)
Infantry Tank – 1 Prototype

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

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

‘An Urgent Project’

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

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

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

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

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

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

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

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

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

The final turret design. Photo: Author’s own

A38 Valiant specifications

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


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

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

‘Heavy Valiant’

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

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

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

The Suspension Trial

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

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

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

Conclusion: A Stinker or A Tragedy

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

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

Failed Tanks WW2 US Prototypes

E9-9 Mechanized Flame Thrower

U.S.A. (1943)
Flamethrower Tank – 1 Prototype

In 1943, the Standard Oil Company, based in Indiana, was one of the main companies charged with designing tank-based, or ‘Mechanized’ flamethrowers. Earlier in the year, in January, they had successfully tested their E7-7 model. This was a modified Light Tank M5A1 with the 37mm gun exchanged for a flame projector.

In April, Standard Oil was contracted to develop another tank based flamethrower. This time it would take the ‘Auxiliary’ form. Simply, this means that the flamethrower is secondary to the main gun, and does not replace it. This is unlike the ‘Main Armament’ flamethrowers, such as the M3A1 Satan or E7-7’s, which replaced the main gun.

This new flame thrower would be designated the E9-9 (this was the combination of the E9 Fuel system and E9 flame gun). The vehicle would follow the same designation, being called the E9-9 Mechanized Flame Thrower. It is sometimes known as the ‘Indiana-Merz E9’, though what ‘Merz’ relates to is unknown.

The E9-9 Mechanized Flame Thrower. Photo: Presidio Press

The M5A1

The M5 was the last in the lineage of light tanks which had followed the same design since the Combat Car M1 which entered service in 1935. Entering service in 1942, the M5 was designed to replace the now aging M3. It was originally going to be designated the M4, but to avoid confusion with the Medium Tank it was changed to M5.

Overall the design was similar. It shared the same vertical volute spring suspension (VVSS) and 37mm gun main armament. The real differences lay with the hull design and engine. The hull was a completely different design but followed elements used on the M3A3. Gone was the stepped armor layout at the front of the tank. It was replaced by a large sloped plate, granting more effective protection.

The original twin Cadillac Series 42 engine was replaced by another Cadillac model. This time twin V-8 automobile engines were used. The M5 gradually replaced the M3 in active service. After the fruitless M7 project, the M5 was replaced with the M24 Chaffee, a completely new design.

A Stuart Crocodile?

The aim of the E9 program was to produce a tank-based flame thrower with a large fuel capacity, a projection range of 200 yards (183 metres) and that would not reduce the M5A1’s original firepower. To achieve this, all the flame thrower equipment, such as the fuel tanks and propellent gas bottles, were placed in a trailer that was towed by the tank. The only part of the system installed on the tank itself was the flame projector, mounted on the front of the tank. This configuration is similar to the famous Churchill Crocodile and lesser-known Sherman Crocodile. Both of these flame throwing tanks kept all of their fuel and gas load in a towed, wheeled trailer.

By comparison with the trailers of its Crocodilian cousins, the E9’s was extremely large. It was approximately the same height and width as the tank itself. In this 12 ton trailer, there was a 1200 US gallon (5455 litre) armored steel tank. This would be filled with 800 US gallons (3637 litres) of flame fuel. The 400 US gallon (1818 litre) void that was left was employed as an air cushion. There were two air-compressors in the trailer which provided 800 psi from a bottle above the fuel tank.

The trailer was attached to the rear of the M5 via a 10-inch (254mm) diameter ball-and-socket joint. The joint granted the trailer the ability to turn 105-degrees left or right from the center line. The fuel line which fed the projector passed through this ball joint. In an emergency, the trailer could be jettisoned. Valves in the piping would close upon this action to prevent fuel from the tank spilling.

Another view of the E9 with 2 two crew members, showing the size of its large trailer. Photo: Osprey Publishing

The E9 Flame Gun

The flame projector was mounted in between the drive sprockets at the front of the tank. It was operated by the bow machine gunner/assistant driver through a series of pulleys and cables. The flame gun could traverse 60-degrees left and right, and elevate +30 to -15 degrees.

The E9 was a duplex flame gun, meaning it had two nozzles side by side. One nozzle was ¼ inch (6.35 mm) in diameter, the other was ¾ inches (19.05mm) in diameter. The thinner nozzle was tighter, this granted a higher pressure thus providing greater range. The wider nozzle did the opposite and provided a wider field of fire at closer ranges.

A diagram of the flame gun and puly system. Photo: Presidio Press.

Catastrophic Tests

The E9-9 project would come to a deadly end, meaning tests would never be completed. During a live fire trial on the 29th of May 1944, 500 US gallons (2273 liters) of Napalm thickened gasoline was provided and prepared in the trailer’s fuel tank. The tank was pressurized to 500 psi. During a fire test, one of the air compressors failed. Shortly after this, the main fuel tank exploded ripping the trailer apart and engulfing the M5 in flames. The incident was fatal, resulting in the death of all four tank crew. This catastrophe brought about an abrupt end to the E9-9 project, with all work halting. As a result, none of the E9 equipment survives today.

Illustration of the E9-9 without fuel trailer by Tank Encyclopedia’s own David Bocquelet

M3 Stuart specifications

Dimensions 4.62 x 2.39 x 2.33 m (15’2″ x 7’10” x 7’8″)
Total weight, battle ready 16.5 tons (tank) + 12 ton trailer (28.5 tons)
Crew 4
Propulsion Twin Cadillac V8, 296 hp (220 kW), air cooled gasoline
Speed 58 km/h (36 mph) road
29 km/h (18 mph) off-road
Range 120 km at medium speed (74.5 mi)
Armament E9 Flame thrower gun
37mm Tank Gun M6
1x Browning .30 Cal. (7.62 mm) M1919 machine gun
Armor From 13 to 51 mm (0.52-2 in)


Presidio Press, Stuart – A History of the American Light Tank Vol. 1, R.P. Hunnicutt
Osprey Publishing, New Vanguard #186: US Marine Corps Tanks of World War II
Osprey Publishing, New Vanguard #206: US Flamethrower Tanks of World War II
Fort Leonard Wood, U.S. Army Flame Thrower Vehicles, Part 1, Captain John Ringquist

Cold War US MBT Prototypes Failed Tanks

90mm Gun Tank T42

Failed tank

U.S.A. (1948-54)
Medium Tank Prototype – 6 built

In the early 1950s, the United States Military began a design program to develop tanks that would replace those currently in service. The faithful M4 Sherman had begun to show its age and was in the process of being replaced by the M26 Pershing and the upgraded M46 Patton.
At their core, however, these tanks were still very much vehicles of World War II era and did not make use of newer technologies that had begun to appear. One of the tanks to spring from the design program was the Medium Tank T42. Other tanks to spring from this program included the Light Tank T41 and Heavy Tank T43. These would become the 76mm Gun Tank M41 Walker Bulldog and the 120mm Gun Tank M103 respectively.

The wooden mockup of the proposed T42. Photo: Presidio Press

Design and Development

At a meeting at Detroit Arsenal on the 28th of September 1948, specifications outlined by the United States military for a new Medium Tank were put forward. On the 2nd of December, the designation of Medium Tank T42 was secured.
The Military’s Specifications were thus:

  • A weight of approximately 36 tons
  • Better armor protection than the M46 but equivalent armament
  • Main armament stabilization in elevation and azimuth
  • An automatic loading system
  • A concentric recoil system (Hollow tube around the barrel. A space-saving alternative to traditional recoil cylinders)
  • Blister mounted  .30 Cal (7.62mm) machine gun on each side of the turret
  • Coaxial .50 Cal (12.7mm) and .30 Cal machine guns.

A number of these initial features were based on the Prototype Light Tank T37. This included the blister mounted machine guns. Other features included a similar chassis length with five road wheels, powerplant and transmission, mudguards/sand shields over the tracks, and a turret ring diameter of 69 inches. This was the same diameter that was introduced in 1941 with the M4.
Construction of a mock-up was approved in March 1949 and reviews of this model were held in October and December, with a number of suggestions put forward to improve the design. The similarities to the T37 began to disappear. Ground contact length was increased from 122 to 127 inches (3.09 to 3.22 meters), the turret ring was widened to 73 inches and finally, the turret mounted blister machines guns were deleted.


The hull of the T42 was a combination of two parts. The forward bow portion was a single homogeneous steel casting, while the rear was a welded assembly of steel armor plates. The two halves were welded together in the middle of the tank. The casting of the upper glacis plate was 4.0 inches (101.6 mm) thick, sloped at 60 degrees.
The T42 eliminated the archaic feature of a bow machine gun and accompanying crew member. As such, the driver was alone in the hull. Room left over by the absent crew member was taken up by a 36-round ammunition rack.

One of the first T42 Prototypes. Photo: US Archives


The T42 did retain the engine and transmission of the T37. This consisted of the Continental AOS-895 gasoline engine (AOS: Air-cooled, Opposed, Supercharged) rated at 500 horsepower, and the General Motors CD-500 cross-drive transmission. This gave the tank a top speed of 41 mph (66 km/h). The driver operated the vehicle with the Manual Control joystick, often known as the ‘Wobble Stick’.
The tank was considered underpowered, however. Tests were mounted by placing the powerplant in the hull of an unused Medium Tank T40 chassis and running it against a late model M4A3. These tests took place at the Aberdeen Proving Ground on the 7th of November 1950. The T42 proved to be only marginally more mobile than the M4, reinforcing the opinion that the tank was underpowered.
The tank ran on a five road-wheels with the drive sprocket at the rear. There were three return rollers unevenly placed along the return of the track. The wheels were attached to torsion bar suspension.


The turret was a completely new design, but not too dissimilar to that of the T41 (M41 Walker Bulldog) in length and shape. It was completely cast in construction. The lengthy turret bustle was used to store the radio set and also housing for the ventilator fan. The turret was manned by 3 crew members; Commander, Gunner, and Loader.
The outside of the turret was dominated most noticeably by the armored housings of the stereoscopic rangefinder lenses. Also known as ‘Frog’s Eyes’, this type of gun system continued to see use after the T42 on vehicles such as the M48 Patton III and M103. Atop the turret, on the right, was the commander’s vision cupola with an AA mount for a .50 cal. machine gun. The loader’s hatch was to the right of this.


It was suggested by a British liaison officer that the Ordnance QF 20-Pounder was far superior to the 90mm Tank Gun M3A1 used on the M46 Patton. Despite its use on Britain’s own Centurion and, being a more powerful weapon, the 20-Pounder was deemed unsuitable for use on a Medium Tank by the US.
The US instead opted for a newly developed 90mm gun, the T119. This gun was a vast improvement over the M3A1. Firing it’s APDS (Armor-Piercing Discarding-Sabot) round, it could punch through 11.1 inches (282mm) of homogenous steel armor, angled at 30 degrees, at a distance of 1000 yards (914.4 meters).
The main armament was complimented by the coaxially mounted Browning M1919A4 .30 cal. (7.62mm) Machine Gun and Browning M2HB .50 cal. (12.7mm) Heavy Machine Gun.

Nomenclature Change

On the 7th of November 1950, the United States Ordnance Committee instigated a change in nomenclature for tanks in the US Military. It was decided that weight designations (Light, Medium, Heavy) were no longer suitable due to changes in the way tanks were developed and employed on the battlefield, and the varying calibers now available. The caliber of the gun replaced the weight designation. For example, the T42 changed its designation from ‘Medium Tank T42′ to ’90mm Gun Tank T42’.

The Korean Tank Panic

Six prototypes were constructed and finally delivered to the Aberdeen Proving Grounds for testing on 30th December 1950. However, by this time, the Korean War had been raging for a full six months. To put it mildly, this caused a bit of a panic among the hierarchy of the US Military, and a crash program was launched to find a suitable tank to field in the conflict. The death warrant for the T42 was signed when the US Army Field Forces (AFF) declared the tank unfit for production. This did not stop the Ordnance Department though, who continued to work on the tank in the hopes that it could yet become the US Army’s next Medium Tank. Prior to this, in November, work had begun on the T42’s replacement, designated as the 90mm Gun Tank M47. Characteristics of the vehicle were outlined in January 1951.
The immediate answer to the panic was found by returning to the current tank in service, the M46 Patton. It was found that most of the T42’s issues were with its hull and the turret was found to be perfectly serviceable. As such, a program began to mount the T42 turret on the hull of the M46.
The M46 was slightly modified to accept the new turret. This modification took the form of expanding the hulls turret ring to match the turrets at 73 inches. This combination was tested with the use of an M46 hull. This vehicle was designated the M46E1. Only one was produced for tests purposes.
To bring the M46 hull up to the requirements for the M47, the angle of the 4-inch (101.6mm) upper plate was increased to 60 Degrees from the vertical. The air filter in the upper hull front was also removed, giving a better contour to the armor profile. This configuration was accepted and serialized as the Medium Tank M47 Patton II. However, it arrived too late to serve in the Korean War. The tank was declared obsolete in 1957 in the US Military but went on to see service in the arsenal of other countries military’s. In the US, the M47 was replaced in service by the 90mm Gun Tank M48 Patton III.

An early production M47. Photo: Presidio Press

The 90mm Gun Tank T42.

The 90mm Gun Tank M47 Patton II, the combination of the T42’s turret and the hull of the M46 Patton.

The Medium Tank T69 with an Oscillating Turret mounted on the Hull of T42 Prototype vehicle no. 3.
All three illustrations are by Tank Encyclopedia’s own David Bocquelet

Further Developments

The Aberdeen trials began with automotive tests. In an effort to improve the T42’s mobility problems, the prototype vehicles sent to Aberdeen were fitted with the upgraded AOS-895-3 engine and CD-500-3 transmission. Thanks to the substitution of some steel parts with aluminum, this incarnation was 500 pounds (227 kg) lighter than its predecessor. The overall performance was improved, finally meeting the original specifications and surpassing the results of the previous test using the T40 hull. The Army Field Forces were still not impressed enough. Considering the T42 still much too underpowered, they continued to refuse its adoption. By this time, their attention had shifted to the M47 and T48 (later M48) development program.
The trials did not start well for the T42. Pilot vehicle number 1 was completely destroyed by a catastrophic fire caused by a loose pin in the final drive which tore a hole in the fuel tank. This resulted in fuel spraying over hot components of the engine. The tank was a fireball in seconds. Pilot vehicle number 2 arrived at Aberdeen in April 1951 to continue the now delayed automotive tests. This vehicle was later modified to allow the installation of a new transmission, the XT-500. This necessitated a modification the rear hull. This took the form of replacing the sloping rear hull plate with a vertical one. The XT was more efficient and had a lower production cost of the CD model, with just 60 percent of the overall part-count.

The T42 with CD Transmission on the left, and XT Transmission on the right. Note the changes to the rear of the tank. Photos: Presidio Press
Despite the deletion of the blister machine guns on the turret, developers were keen to employ extra machine guns somewhere on the vehicle to compensate for the lack of a bow mounted weapon. One solution was the mounting of machine guns on the mudguards just above the idler wheels. This took the form of an armored box. The box would contain one Browning M1919A4 machine gun, 680 rounds of .30 caliber (7.62mm) ammunition, a pneumatic charger, firing solenoid and a compressed air bottle. The system would be operated by controls in the driver’s position. The guns were fixed in traverse and elevation. Though not practical to aim, it was found that the weapons provided a good suppressing fire over an area. Further development was suggested, mostly to add a degree of traverse in the guns, but it went no further. The whole concept was later completely dropped.
During the spring of 1953, in an effort to keep the T42 project alive, a plan was formed to turn it into an option for a lighter more economical tank. Modifications planned were a steel elliptical hull and flat track suspension (track return supported by road wheels, as used on tanks such as the Soviet T-54). Had these plans materialized, the vehicle would have received the designation of 90mm Gun Tank T87, or Medium Tank T87. May 1953 marked the end of this project and the whole T42 program in general. The project was officially ended in Autumn 1954.

One of the later T42 Prototypes. Photo: Presidio Press

T69, the Only Variant

One of the original specifications for the T42 was not researched until almost a year after the tank was declared unfit for service. This specification was that an autoloader would be added when such a device was available. It was found that trying to add an autoloader in a conventional turret was impractical as the breach of the gun would have to return to a 0-degree elevation angle for it to line up after every shot. For this reason, it was decided that an oscillating turret would be the best option. Oscillating turrets are divided into two parts. A lower collar attached to the turret ring, and an upper portion with the gun fixed in place. The upper portion pivots on trunnions under hydraulic power providing the gun elevation and depression. With the gun fixed in place, the autoloader has a straight path to ram in the shells.
The new turret was mounted on the hull of T42 prototype number 3 which was modified with the XT-500 transmission. The tank received the designation of 90mm Gun Tank T69, also known as Medium Tank T69. The tank took part in a number of trials but, like the T42, it was not accepted for service. It was found that the vehicle bore no advantage over conventional designs.

The T69 at aberdeen proving grounds for evaluation. Photo: Presidio Press


No whole T42 survives today. The only way the vehicle does survive is through the uses of its parts. A single hull survives as the T69, which currently resides in storage at National Armor and Cavalry Museum, Georgia, USA. The turret can, of course, be found all over the world where there is an M47 on display.

An article by Mark Nash

T42 Specifications

Dimensions (L-W-H) 26’9″ x 11’7″ x 9’4″ (8.1m x 3.5m x 2.8m)
Total weight, battle ready 38 tons
Crew 4 (commander, driver, loader, gunner)
Propulsion Continental AOS-895 gasoline engine, (air-cooled six-cylinder supercharged 8.2-liter engine), 500 horsepower
Transmission General Motors CD-500
Maximum speed 41 mph (66 km/h)
Suspensions Torsion bars suspensions, shock absorbers
Armament 90mm Tank Gun T119
Sec: 2 x Browning M2HB .50 Cal. (12.7 mm) Heavy Machine Guns
+ 1 Browning M1919 .30 Cal. (7.62 mm) Machine Gun
Armor 4 in (101.6 mm)
Total production 6
For information about abbreviations check the Lexical Index

Links, Resources & Further Reading

Presidio Press, Patton: A History of the American Main Battle Tank, Volume 1, R. P. Hunnicutt
US National Archives

Cold War US MBTs Failed Tanks

152mm Gun/Launcher M60A2 ‘Starship’

Failed tank

152mm Gun/Launcher M60A2 ‘Starship’ (1975)
Medium Tank – 526 built

In the middle of the Cold War, there was some debate regarding the main tank weapon of the future, largely focused on conventional kinetic energy rounds (cannon shell) versus missiles. In 1966, in an effort to utilize both capabilities, General Dynamics Land Systems designed a new low profile turret, equipped with a 152mm Gun/Missile Launch system that could fire conventional HEAT (High-Explosive Anti-Tank) and HE (High-Explosive) rounds, or launch ATGMs (Anti-Tank Guided-Missiles).
The new turret was mated to a Medium Tank M60 Patton hull, creating the M60A2, unofficially nicknamed the “Starship”. Though the vehicle was one the most technologically complex of its era, this also contributed to its failure, largely due to difficulties with maintenance, training, and complicated operation.


The M60A2 was designed as a stop-gap vehicle until the joint US-German MBT-70 project was ready for service. This project was intended to provide both the United States and German militaries with one Main Battle Tank. It would use the same Gun/Launcher weapon as the A2 and later in the M551 Sheridan.
The United States ordered the M60A2 in 1971, however, production did not start until 1973, and continued through 1975, at the Chrysler Tank Plant in Warren, Michigan. Initial plans called to replace the turret of every M60 with the new A2 turret, but only 526 vehicles were produced (according to official US Army documentation).
Aside from the turret and weaponry changes, the tank was nearly identical to the regular M60. It featured the same 4.29 in (109 mm) glacis armor, torsion bar suspension, and the 750hp Continental AVDS-1790-2 V12, air-cooled twin-turbo diesel engine which would propel the vehicle to approximately 30 mph (48 km/h).


The M60A2 featured a unique Gun/Launcher mounted in a new, low profile “space age” turret. It consisted of a large disk with a narrow channel in the center. Each crew member in the turret had their own hatch, a rare feature in tanks. As a result, each crew member was effectively isolated from one another with the gunner and loader separated by Shillelagh missiles in their storage position. The commander was isolated in the rear compartment under a large rotating machine gun equipped cupola, which somewhat negated the low profile silhouette of the turret.
There was a mounting point to the left of the gun for a Xenon White-Light or Infrared Spotlight for night time operations. A large basket for storage was added to the rear of the turret and also included banks of smoke-grenade launchers, one bank of four on each side of the turret.


The main feature of the A2 turret, is its main armament, the M162 Rifled 152 mm Gun/Launcher, a weapon similar to the M81E1 found on the M551 Sheridan Light Tank. As mentioned previously, it was capable of firing both HEAT (High-Explosive Anti-Tank) and HE (High-Explosive) rounds or launch the MGM-51 Shillelagh ATGMs (Anti-Tank Guided-Missiles). Load-out for the main armament was 33 conventional rounds and 13 missiles.
The conventional rounds had a range of 1.5km (1640 yds). The HE was a more than capable anti-infantry weapon, while the HEAT ideal for close range anti-armor engagements. For a longer range anti-armor capability, the ATGM was to be utilized.
The Shillelagh ATGM guided system. After acquiring a target a small charge would launch the missile out of the barrel. Once clear, four rear stabilizing fins would deploy followed by ignition of the engine. The missile was guided to the target via IF (Infrared) beam. As long as the gunner kept the target in his scope, the missile would strike accurately. This system, however, contributed to one of the tank’s major issues. The M162 Gun/Launcher experienced frequent faulty breeches. Often, not closing correctly, allowing the exhaust of the launching Shillelagh to vent hot noxious gasses into the crew compartment.
The Gun/Launcher was fully stabilized. This meant that while moving over rough terrain the gun would stay relatively level and the gunner able to keep a target in his sight. This did not apply to the use of the ATGM however, which could not be fired on the move.

An A2 being restocked with the MGM-51 Shillelagh
In early testing, the system was plagued with misfires and premature detonations of the conventional case ammunition, caused by unburnt propellant in the bore and breech. This was often catastrophic as it set off the projectile in the barrel as it was fired. To combat this, early versions of the gun were equipped with a traditional fume extractor on the barrel. Later versions would use the Closed Bore Scavenger system, a compressed air system that pushed the fumes and gasses out of the muzzle when the breech is opened.
Secondary armament consisted of an M85 .50 Cal. machine gun in the commander’s rotating cupola, and a coaxial M73 7.62mm machine gun. Neither weapon was especially liked by the crews and later replaced. For the commander’s cupola, the traditional .50 Cal. (12.7mm) M2HB “Ma Deuce” was installed, and the coaxial replaced by the M240, a license-built copy of the Belgian FN Mag. Loadout for the MGs was 5, 560 rounds of 7.62 mm and 1, 080 rounds of .50 Cal. (12.7mm).
One of the A2’s more hi-tech features was its laser range finder and the M60A2 was the first tank to be equipped with one. This worked well in daylight but less so in darkness, effective to 600 meters in 25% moonlight. A special filter was added to the exterior searchlight to alleviate this issue.

The crew of a late model A2 sit atop their tank. Photo: Sabot Publications

Early model M60A2, US Army 3rd Armoured Division. Note the fume extractor on the barrel.

Later model M60A2 in MERDC (Mobility Equipment Research and Development Center) camo scheme. Note the barrel is without fume extractor.
Both Illustrations are by Tank Encyclopedia’s own David Bocquelet

Service and Failure

In total, around 520 M60A2s were built, with service in the US Army and the US Marine Corps. A study by the US Army, proposed the M60A2 operate in an “overwatch” role, in support of more traditionally armed tanks, and provide long-range anti-tank support capability from the rear.
The A2 had a short service life succumbing to the same failings of Sheridan, concerning the missile system. The designers of the missile, Ford Aeronutronic, a division of the Ford Motor Company, greatly underestimated the task of producing a fully operational Anti-Tank Guided Missile as advanced as the MGM-51. Development of the Shillelagh was awash with technical and mechanical issues, including problems with the propellant, ignition of the propellant, tracking system and the infrared command link responsible for missile guidance.
Despite its many problems, the A2 did succeed in enabling “carry-over” technology for the MBT-70 project and the later M1 Abrams Main Battle Tank. The A2 was fully removed from service by 1981. Many of the A2s had their turrets removed and replaced by M60A3 turrets. In 1985 some M60A2s were converted into engineering vehicles such as the M60A1 AVLB bridge layers or the remotely controlled Panther mine clearing vehicle.


The M60A2 is frequently referred to as the “Starship”. However, there is no official use of the name in any documentation, at least dated to when the vehicle was in service. It may well be a post-service name. It is widely believed that it bears this name due to either its highly sophisticated technology (for its time) or the non-traditional appearance of its turret.

Early model A2 taking part in training. Sabot Publications

An article by Mark Nash

M60A2 Specifications

Dimensions (L-W-H) 30’9″ x 11’9″ x 10’7″
(9.43m (6.94m) x 3.63m x 3.27m)
Total weight, battle ready 52 tons (114,640 lbs)
Crew 4 (commander, driver, loader, gunner)
Propulsion Continental AVDS-1790-2 V12, AC TT diesel, 750 bhp (560 kW), 15.08 bhp/t
Transmission General Motors, CD SD 2 fw/1 rv ranges
Maximum speed 30 mph (48 km/h) on road
Suspension Torsion bars suspensions, shock absorbers
Range (fuel) 300 miles/500 km (1457 liters/385 US gal.)
Armament M81E1 Rifled 152 mm Gun/Launcher: 33 HE & HEAT, 13 MGM-51 Shillelagh ATGMs
Sec: 1 x cal .50 M85 (12.7 mm)+ 1 cal .30 (7.62 mm) Browning M73
Armor RHA max. 6.125 in (155 mm)
Total production Aprx. 520
For information about abbreviations check the Lexical Index

Links, Resources and Further Reading

R. P. Hunnicutt, Patton: A History of American Medium Tank, Presidio Publishing
Armor Magazine, January-February 1972: The Death of the Tank by Lt.Col. Warren W. Lennon.
Osprey Publishing, New Vanguard #85: M60 Main Battle Tank 1960–91
Sabot Publications, M60A2 Main Battle Tank in Detail, Volume 1
Sabot Publications, M60A2 Main Battle Tank in Detail, Volume 2
The M60A2 on Military Today

Failed Tanks WW2 British Light Tanks WW2 US Light Tanks

Light Tank (Airborne) M22 Locust

Failed tank

 Great Britain/U.S.A. (1941)
Air-Mobile Light Tank – 830 Built

The M22 Locust came about in 1941 as a request from the British War Office for a bespoke air-deployable tank. Until this point, the British had been using the Light Tank Mk. VII Tetrarch for the role. The Tetrarch did not start out as an airborne tank however, so it was believed to be inferior to a vehicle dedicatedly designed for this role.

The United States Ordnance Department received the request and began work on finding a suitable designer and builder. The famous J. Walter Christie was first on their list, who in turn produced a prototype in 1941. This prototype did not meet the size requirements, however, so the Ordnance Department looked elsewhere. The Marmon-Herrington Company then came forward with their own design. The design was approved and the Company produced a wooden prototype in August of 1941 which was designated ‘Light Tank T9’.
Christie's unused design for the project - Photo:
Christie’s unused design for the project – Photo:

Development of the T9

Marmon-Herrington was already a trusted producer of light tanks for the United States Marine Corp (USMC), so were seen as the perfect candidate to produce the United States’ first air-mobile tank. The specifications were set for a tank light in weight and able to be transported either by the US’s Douglas C-54 Skymaster transport, the specially designed Fairchild C-82 Packet or the British General Aircraft Hamilcar glider. At the time, there was no thought given to parachuting the tank in, as large and strong enough parachutes did not exist at the time. The idea was to land the tank on the ground once the first wave of paratroopers or glider infantry had secured a suitable landing area.
In April 1942, a trial vehicle was produced and sent to Fort Benning, Georgia for testing. Between the conceptualization and pilot phases, however, the tank slipped over its 7.9-ton weight limit. This led to the deletion of some of the tank’s extra features such as the power-traverse for the turret, gun stabilizer, and fixed bow machine-guns bringing the weight back down to 7.4 tons. Two prototypes of this revised designed were produced in November 1942 and designated T9E1. One of the vehicles was dispatched to Great Britain for testing along with an accompanying team of engineers. The team reported that the tank was well received and that the British were more than happy to purchase the tank.
One of the test models of the T9
One of the test models of the T9.
The British placed an order for the tanks, with production set to begin in late 1942. However, technical issues kept dogging the production of the tank, delaying it until the April of 1943. The tank didn’t officially receive it’s M22 designation until late 1944, with the British eventually nicknaming it ‘Locust.’

The Locust’s Anatomy

The M22 was one of the smallest tanks the United States had ever built, yet it still carried a crew of 3. These consisted of the commander, who also served as the loader, who, along with the gunner, was positioned in the turret, with the driver positioned on the right side of the hull. The driver had a small armored hood over his head with vision ports embedded.
Like it’s invertebrate namesake, the M22 was fast. Propelled by the 165 hp Lycoming O-435T horizontally opposed 6-cylinder gasoline engine, the tank could reach, in theory, 40 mph (64 km/h). More than fast enough for it to save itself from a sticky situation. The running gear was based on the type found on the M3/M5 Stuart Light Tanks, being slightly lower than the original. It retained the forward drive sprocket and Vertical Volute Spring Suspension (VVSS) with large trailer idler wheel at the rear.
Early model of the T9E1 during trials
Early model of the T9E1 during trials.
The M22’s speed would also serve as it’s protection. The tank was not designed to fight it out against heavy enemy armor, merely supply its accompanying airborne infantry with light armored support. As such, armor on the vehicle was only 12.5 mm (0.49 in) at its thickest.
The main armament consisted of the 37 mm (1.46 in) Tank Gun M6. This was the same gun found on the M3/M5 Stuart Light Tanks, the M3 Lee/Grant, and the M8 armored car. It could fire a range of ammunition types, including APCBC (Armor-Piercing Capped Ballistic-Capped) and HE (High Explosive). The AP ammunition could penetrate roughly 25 mm (1 in) of armor at 1,000 yards (910 m). The secondary armament consisted of a single coaxial Browning M1919 .30 cal. (7.62 mm) machine gun mounted on the right of the 37 mm gun.

Faults, Faults, and more Faults…

Until this point, the Ordnance Department had been more than happy with the developments of the T9E1 vehicle. However, Fort Knox, who had run their own tests with the tank offered a drastically different opinion in a report to Ordnance:

“Light Tank T9 is not a satisfactory combat vehicle in its present state of development due to the lack of adequate reliability and durability…and cannot be used for landing operations with any degree of success.”

Following more scathing reports such as this, the initial order of approximately 1,900 T9s was terminated with 830 tanks produced. Not exactly the swarm the tank’s name would suggest.
A British service M22 Locust emerging from a Hamilcar glider during tests
A British service M22 Locust emerging from a Hamilcar glider during tests.
Further tests by both nation’s armored boards only highlighted more the faults appearing with the M22’s design. The first issues came with the very core of the tank’s reason for being, the airmobile capability. It was found that loading the M22 onto a Douglas C-54 took a crew roughly 24 minutes, with unloading taking around 10 minutes. This was because the vehicle had to be ‘decapitated’. The turret was hoisted off and placed inside the aircraft, while the hull was driven under the belly of the C-54. It would then be suspended from the aircraft via the lifting eyes on the right and left flanks, above the suspension bogies. This method was not ideal in combat conditions. It was also apparent that deployment from a fully laden C-54 would require the capture of a suitable airfield.
In 1944, it was eventually concluded that the design of the tank was actually quite obsolete, with its armor (discussed in the above anatomy section) able to be penetrated by .50 caliber rounds.
Along the same lines, a number of complaints flowed in about the M22’s 37 mm main armament, ranging from its lack of anti-armor capabilities to the weakness of its High-Explosive rounds. The subsequent burst from the shells was too weak, making them inadequate for observation uses. Also, with the removal of the power traverse unit, the turret had to be hand cranked, meaning rotation was extremely slow.
An unreliable transmission also resulted in numerous breakdowns, meaning the tank would take up a lot of “shop time”.
Production model M22 with protective cover over the barrel - Photo: Osprey Publishing
Production model M22 with protective cover over the barrel – Photo: Osprey Publishing

Standard issue American M22, with side skirts
Standard issue American M22, with side skirts.

American M22 named Bonnie from the 28th Airborne Tank Battalion, one of the only American units to be equipped with the tank.
American M22 named “Bonnie” from the 28th Airborne Tank Battalion, one of the only American units to be equipped with the tank.

An example of the M22 Locust in British service.
An example of the M22 Locust in British service. Note the Littlejohn adaptor at the end of the Barrel and 2in Smoke-Bomb launchers on the turret.

Illustrations are by Tank Encyclopedia’s own David Bocquelet


Two specially organized combat units were formed to undergo training for deployment with the M22. These were the 151st Airborne Tank Battalion activated on August 15, 1943, and the 28th Airborne Tank Battalion activated on December 6, 1943. The formation of the 151st came too late for them to see action as part of the Airborne forces involved with the commencement of D-Day in June of 1944. In the July of that year, they were relocated from their original base at Fort Knox to Camp Mackall in North Carolina. The 28th were redesignated as a standard Tank Battalion following a loss of interest by Airborne Command in October 1944.
Crew of an M22 sat aboard their tank named
Crew of an M22 sat aboard their tank named “Bonnie” from the 28th Airborne Tank Battalion – Photo: Osprey Publishing
A mere total of 25 M22s were deployed to the European theater by US forces. These were sent to the Sixth Army Group in Alsace for potential use by the venerable 1st Airborne Divison. What happened after this, however, is somewhat of a mystery as records are not currently known to exist.
Great Britain
Despite the Locust’s highlighted faults, the British War Office still wanted the tanks, believing they were more than adequate for their intended role. As such, 230 M22s were shipped to the United Kingdom under the Lend-Lease Act. The first 17 to arrive were handed to the 6th Airborne Armoured Reconnaissance Regiment (AARR) to supplement their existing arsenal of Tetrarchs.
A British Locust with the Little John adapter - Photo: Wikimedia Commons
A British Locust with the Little John adapter – Photo: Wikimedia Commons
The British made a few minor modifications to the tanks, including the addition of smoke-bomb launchers on the side of the turret, and the incorporation of the Little John adapter at the end of the muzzle. This adapter, in conjunction with special ammunition, operates under the squeeze-bore principal. The adapter is has a partially narrower aperture than the rest of the barrel, meaning the shell is under higher pressure causing it to fly faster and punch harder.
Operation Varsity
The tanks saw action with the British during Operation: Varsity, the March 1945 landings around the Rhine. Two Locust equipped units of the 6th AARR were assigned to the Operation. This operational deployment would be the Locust’s only chance to ravage the hypothetical crops of the Reich, and it bore mixed results. As designed, the tanks were brought in by Hamilcar gliders. 8 of the gliders took part in the assault. One glider was lost when the M22 it was carrying broke loose of its bindings and crashed through the tail section of the aircraft, sending both vehicles plummeting to the Rhineland. The remaining gliders touched down as planned, apart from one which hit a ditch at high speed spitting the tank causing it to tumble a number of meters with it eventually coming to rest upside down.

After this debacle of a landing, only 6 tanks remained operational. One went to support paratroopers of the US 17th Airborne Division but was knocked out by an unknown German tank destroyer. The Locust’s incessant mechanical problems once more reared their ugly heads when one tried towing a Jeep out of a downed glider. It remained in action, though, and supported elements of the 12th Parachute Battalion. Remaining Locust would continue to provide support in various infantry actions during the operation with mixed success due to the weakness of its 37 mm HE ammunition.

T18, the only Variant

The only variant built on the chassis of the Locust was the T18 Cargo Carrier (Airborne). This was a turretless M22 hull designed to operate in the same way as the M22 base vehicle. It was intended to tow supplies or air-mobile guns, such as the M2 or M3 105 mm (4.13 in) howitzer, from gliders and supply aircraft. The vehicle was not accepted for production.
The T18 tractor in testing - Photo: Osprey Publishing
The T18 tractor in testing – Photo: Osprey Publishing


The M22 was ultimately a failure and was very much a victim of its time. The technology needed to fully exploit the capabilities of an air-mobile tank was not available in time for the war. Though designed during the war especially for the M22, the Fairchild C-82 Packet was not ready until the conflict had ended. Surprisingly, long after its dismissal by both US and British Forces, the M22 saw combat again in service with the Egyptian army in the 1948 Arab-Isreali War.
Despite its many failures, however, the M22 succeeded in paving the way for future American air-mobile tank projects. These included the M56 Scorpion and M551 Sheridan.

The M22 Locust on display at The Tank Museum, Bovington – Photo: Author’s Photo
Quite a few M22 Locusts do survive to this day, in locations such as the Tank Museum in Bovington, the Rock Island Arsenal Museum in Ilinois of USA, and the Royal Dutch Army Museum at Delft in Netherlands. Others can be found the hands of private collectors world wide.

An article by Mark Nash

M22 Locust Specifications

Dimensions (L-W-H) 12’11” x 7’1” x 6’1”
(3.96 x 2.24 x 1.84 m)
Total weight 7.4 tons (74.3 tonnes)
Crew 3 (driver, gunner, commander/loader)
Propulsion Lycoming O-435T horizontally opposed 6-cylinder 4 cycle petrol/gasoline engine, 192 hp
Speed (road) 35 mph (56.3 km/h)
Operational range 110 miles (177 km)
Armament 37 mm (1.46 in) Gun M6 in mount M53 in turret
30 cal. (7.62 mm) MG M1919A4 machine gun
Armor 9.5 mm (0.37 in) to 25.4 mm (1 in)
For information about abbreviations check the Lexical Index

Links, Resources & Further Reading

Presidio Press, Stuart, A History of the American Light Tank, Volume 1, R.P. Hunicutt
Osprey Publishing, New Vanguard #153: M551 Sheridan, US Airmobile Tanks 1941-2001
M22 on The Tank Museum’s website.
The M22 on (Russian)
English translation of the above article on Tank Archives

Failed Tanks WW2 Polish Prototypes


Poland (1927)
Medium tank – 2 prototypes

The WB-10 (sometimes written W.B.10) was the first tank designed and built in Poland. It was also one of the only Polish interwar armored vehicles that was completely original. Without drawing inspiration from foreign vehicles, as was the case with the TK tankettes or 7TP. The WB-10 was planned as a successor to the French-bought Renaults FT. Unfortunately, the WB-10 was a complete failure and the whole project landed in the dustbin of history.
Very little information has remained to this day. Three photos exist which are speculated to be of the WB-10 prototypes, somewhere near Warsaw in 1939.
A supposed drawing of the vehicle is also widely circulated on the internet, but it is not compatible with the vehicles seen in the two pictures. It has become clear that the vehicle in the drawing is actually the Landsverk BT.150 II, a successor of the Swedish Landsverk L-5, in no way connected to the Polish WB-10.
It is highly important to stress that most of the information with regards to this vehicle should be treated with a healthy dose of skepticism until primary sources can be discovered and shed more light on the curious WB-10.
A Polish Renault FT. This was the only tank in Polish service when the WB-10 was designed - Source: Derela Republika
A Polish Renault FT. This was the only tank in Polish service when the WB-10 was designed – Source: Derela Republika

A new Polish tank

In 1925, the only tanks available to the Polish army were the Renault FTs received in 1919. They were still usable but needed modernizations. The WWI era FT had a lousy maximal speed, a weak armament and had problems with terrain obstacles.
The Polish Army started negotiations with Great Britain over the purchase of British Medium Mark D tanks, but this endeavor failed. Finally, the Army decided that the Polish arms industry should become independent and build its own tanks. So, in 1926, the Polish press announced a contest for a project of a new tank.
The requirements for the new 12-ton design were quite strict
• All-around armor strong enough to resist the 13 mm bullets from 50 meters
• Front and sides strong enough to resist 47 mm shells from 500 meters
• One 47 mm (or higher caliber) cannon
• One 13 mm anti-aircraft machine gun
• One 7.92 mm machine gun for anti-infantry use
• Periscopes giving 360° of vision around the tank
• Engine with a warming and cooling system
• Smoke screen device
• Radio with 10 km range
• Maximal speed ≥ 25 km/h
• Operational range ≥ 200-250 km
• Possibility to ride on 35°- 40° slopes
• Possibility to cross 2.2 meters ditches, 0.8 meters walls and to ford 1 meter of water
• Average ground pressure ≤ 0,50 kg/cm2
The contest entries were underwhelming. As the tank concept was still a novelty, tracked vehicle designers and engineers were rare in Poland. Only three projects were reported – and only one project, the WB-10, designed in cooperation by two companies: S.A.B.E.M.S. and WSABP “Parowóz” (“Steam Locomotive”) received the green light.
Moreover, the two companies designed two alternative versions of the vehicle and built two models powered by small electric engines. They were designed by professor Ludwik Tadeusz Eberman of the Lviv Polytechnic, who was working for WSABP.
Until this contest, the “Parowóz” company built steam locomotives and S.A.B.E.M.S. was building engines.
Unfortunately, little to no information about the two other competitor projects are available. They were supposedly armored cars or wheel tanks, not true tanks. One of them supposedly had four axles and the second one just two.

Rise and disappointment

The new project was rather modern and complicated for the time. It was a wheel-cum-track tank, so it had the possibility to change its way of running depending on the terrain, with the wheels being preferred on roads and the tracks on rougher terrain.
Some sources claim that the WB-10 was also amphibious and could lower or raise its hull. The latter claim probably refers to how the wheel-cum-track system worked, and not that the vehicle had a sort of hydropneumatic suspension. Moreover, the chassis could be used as basis for a special tractor.
The army ordered a prototype of the new tank. The construction took a significant amount of time, but two tanks were eventually ready for testing. Regrettably, the WB-10 came to be a giant disappointment. The vehicle suffered a lot of breakdowns due to its complicated design and mistakes in the project. These caused problems with driving the vehicle and according to other versions the WB-10 was not even able to start the trials. These failures brought about the quick cancellation of the WB-10 project. The new Polish tank was rejected.
After this failure, the negotiations with Great Britain were restarted, resulting in the acquisition of the Vickers 6-ton and the eventual creation of the 7TP.
The Vickers Mark E that became the next Polish tank - Source: Derela Republika
The Vickers Mark E that became the next Polish tank – Source: Derela Republika


The fate of the WB-10 prototypes is unknown. They were probably just scrapped after the trials or sent to some army station as technical oddities. However, it is almost guaranteed that they were finally destroyed.
As the WB-10 was a total failure, it faded from memory quite rapidly. After the destruction brought about by World War II, a lot of the information about the vehicle was lost.

The design

The WB-10 was a wheel-cum-track tank. It had four wheels which could be lowered, raising the tracks of the ground. If the tank was to go cross country, the wheels would be raised and the vehicle would use its tracks.
Nothing is known about the engine. However, the designer Prof. Eberman also worked on diesel-type engines, so it is possible the vehicle had such an engine. The WB-10 was probably a massive and slow tank, typical of the period. If it indeed had any amphibious qualities, it is unknown if it had any propellers or if it used its tracks to paddle the water.
The contest requirements suggest that it was able to fit a 47 mm or higher caliber cannon. However, nothing else is known of it.
The 13 mm machine gun is also unknown. The French 13.2 mm Hotchkiss M1929 machine gun was designed years after the WB-10. The 13 mm caliber was most probably just an approximation for 12.7 mm, the typical caliber for anti-aircraft machine guns. The 7.9 mm machine gun was probably the 7.92 mm Hotchkiss wz.25. This was a widespread Polish machine gun that was an improved version of the French Mle 1914 machine gun.
The prototypes could have been painted in khaki camouflage – this color was typical for Polish prototypes (like the Renault TSF or 4TP).
The two supposed WB-10 tanks, next to a number of FIAT trucks. The soldiers unfortunately obscure a lot of details on the vehicle - Source: Odkrywca forum
The two supposed WB-10 tanks, next to a number of FIAT trucks. The soldiers, unfortunately, obscure a lot of details on the vehicle – Source: Odkrywca forum

A reconstruction of the tank claimed to be the WB-10, based on the available photographs - Illustrator: Jarosław Janas.
A reconstruction of the tank claimed to be the WB-10, based on the available photographs. Unfortunately, the illustration is no longer believed to be accurate – Illustrator: Jarosław Janas.

Another reconstruction of what the WB-10 might have looked like. Source: WoT Forums, user Tanohikari

Photos and pictures

Two photos of two unknown vehicles have appeared on the Polish website. It is claimed they were taken near Warsaw in 1939. The photos apparently come from the Patton Museum collection.
They present two groups of soldiers next to some FIAT 621 trucks and two big, mysterious tanks. These vehicles do not resemble any known tank in Polish service or anywhere else in the world. Their old-style design suggests that they may be the WB-10 prototypes, left in some army station.
The vehicle in the foreground is visible in both pictures and, although the soldiers obscure it to some degree, its design can be observed. The background tank is barely visible in one of the pictures. It seems as though it differs from the first tank.
The first tank is lacking its wheels, which were most likely removed or reused on some other vehicle. However, in one of the photos, a large bar is seen protruding from the side of the vehicle. This was most probably one of the attachment bars for the wheels. Both the vehicles are large and tall and almost certainly too heavy to be amphibious. The first vehicle has a large decagonal turret, with no hatches or other elements visible.
The other photo of the same vehicle, claimed to be the WB-10 - Source: Odkrywca forum
The other photo of the same vehicle, claimed to be the WB-10 – Source: Odkrywca forum
A third photo has emerged on the forum. It seems to show one of the same tanks, but at a later date. The general shape and details indicate that this is indeed one of the unknown tanks supposed to be the WB-10. The vehicle appears to have been partially dismantled, missing its turret and quite a few of its armor plates. However, the two supposed wheel supports are clear in this shot. Also, this is the only photograph of the front of this vehicle.
The third photo of the supposed WB-10 tank.
The third photo of the supposed WB-10 tank.
The Czech HPM magazine, in its nr 9/2001 edition, published some schematics of a tank claimed to be the WB-10. However, the drawings in the magazine are of the Landsverk BT.150 II, a successor of the Landsverk L-5, a Swedish wheel-cum-track prototype. The schematics don’t resemble in any way the two tanks in the photos.
The supposed WB-10 design, as presented in the Czech HPM magazine. It bears no relationship to the tanks in the photos and no sources are indicated
The supposed WB-10 design, as presented in the Czech HPM magazine. It bears no relationship to the tanks in the photos. It is actually a Swedish Landsverk BT.150 II – Source: SP15
Landsverk, the vehicle actually in the Czech magazine drawings The Swedish Landsverk BT.150 II, the vehicle actually in the Czech magazine drawings – Source: SP15

One of the other designs?

The Polish writer Janusz Magnuski mentions in his book “Wozy bojowe” (Wydawnictwo Ministerstwa Obrony Narodowej, Warsaw, 1964) that there was also third tank prototype built for the contest. It is possible it was one of the other two wheel tanks that competed against the WB-10. This third tank was designed by professor Czerwiński (no other information known about this person) and failed just like the WB-10.
Some Czech sources claim that only one WB-10 tank was built and the second prototype was another vehicle, called the WB-3. The WB-3 was apparently tested in 1927 and the WB-10 prototype was built as an alternative. According to this theory, the WB-10 tank was never completed. Also, only the WB-3 was a wheel-cum-track vehicle, while the WB-10 only had tracks. However, no Polish source mentions the WB-3 tank.


“Wozy bojowe” by Janusz Magnuski (Wydawnictwo Ministerstwa Obrony Narodowej, Warsaw, 1964)
“Czołgi Wojska Polskiego 1919-1939” by Janusz Ledwoch (Wydawnictwo Militaria, Warsaw, 2015)
On the Odkrywca forum

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Failed Tanks WW2 Soviet Prototypes

Antonov A-40

Soviet Union Soviet Union
‘Flying Tank’ (1942) – 1 prototype built

The Flying Tanks Concept

The idea of having a tank which could fly was first seen around in the early 1930s with Walter Christie’s flying M1928 tank, but other designs were made during WW2. The UK (Baynes Bat, 1943), Japan (Special Number 3 Light Tank Ku-R0 with a Kokusai Ku-8 glider, 1944), and the USSR (Antonov A-40, 1942), all attempted to make flying tanks, but none were successful. What each nation wanted was a fairly potent AFV which could fly into battle – something, even on paper, impossible. Having a large enough armament (larger than 12.7mm in caliber), and strong enough armor (at least 20mm) simply meant that the vehicle would be so heavy, that it could not possibly fly.

The Flying T-60

The Antonov A-40 (sometimes referred to as the A-40T or Krylya Tank, “tank wings”) was the Soviet attempt in 1942 to create a flying tank – only one prototype was produced. Soviet forces had originally strapped tanks and armored cars, such as the T-27, T-37A, and D-8, to the bottom of TB-3 bombers, and dropped them from a very short height; as long as the gear was in neutral, the tank would not break on impact. However, this required the crew to be dropped separately, which meant that the tank’s deployment was delayed. As a result of this, the Soviet Air Force ordered Oleg Antonov to design a glider for landing tanks…


Antonov came up with a very ingenious solution. He added a detachable cradle to a T-60 bearing large wood and fabric biplane wings and a twin tail. The wingspan is estimated to be just over 59 ft (18m) and an overall area of  923.5 ft2 (85.8m2). To put this in perspective as to how large it was, the small fighter aircraft, the Polikarpov I-16’s wingspan was 29 ft 6 in (9m), with an overall area of 156.1 ft² (14.5 m²) – the A-40’s wingspan was nearly double, and the overall area was nearly six times greater (although the A-40 cradle was dual-winged)!
The idea was for the A-40 to drop the cradle once deployed onto the battlefield – and this was necessary, for obvious reasons. No tank could possibly be deployed effectively in combat with near 60 foot wings sticking out of it. The wings would not only make the vehicle slower due to their weight, but they would create quite a lot of drag.
One T-60 placed into a glider in 1942, intended to be towed by a Petlyakov Pe-8 or a Tupolev TB-3. The tank was lightened for air use by removing its armament, ammunition and headlights, and leaving a very limited amount of fuel (and, according to some sources, its turret was also removed).

First Flight

According to the official story (which is dubious), there was a test flight on September 2, 1942. Even with the modifications, the A-40 was too heavy to be towed. A TB-3 bomber was towing it, but it had to ditch the glider to avoid crashing. The drag was simply too much, and the bomber could not handle the weight of its payload. The A-40 was piloted by the famous Soviet experimental glider pilot Sergei Anokhin, and, once ditched, it supposedly glided smoothly. The T-60 landed in a field near the airdrome it was being tested at, and after dropping the glider cradle, it was driven back to the base. There was no aircraft which could handle the weight of the vehicle, and therefore tow the A-40 at the correct speed (160km/h), and, for that reason, the project was abandoned.

Viability of the A-40

The first major problem with the Antonov A-40 is that it had huge wings. These would have to be ditched before combat, which would surely delay its combat deployment (although probably not nearly as much as dropping the crew separately). Secondly, if the vehicles were to only have limited fuel and no munitions, in order to be light enough to be dropped, then munitions and fuel would have to be dropped separately, thus meaning that the combat deployment is, yet again, delayed, because crews would have to scramble to get munitions and fuel loaded into the tank – and there is no guarantee that wind would not glide these airdrops away from their intended users.
Thirdly, the T-60 itself was not a particularly potent tank – not even in 1942. Its 20mm TNSh gun would only be viable for engaging lightly armored, or unarmored targets, and its armor, 20mm at best, could hardly withstand even the lightest of German AT guns.
Fourthly, it is unclear as to whether or not the vehicle was even successful. The official story, as recorded above, might be a gross exaggeration, or a total fantasy. The purported photo of the A-40 in flight is actually a drawing produced by the Antonov factory.

Rendition of the Antonov A-40. The colors are speculative, and it may be the case that some bare wood or tarp is showing.
antonov a 40
A drawing (or perhaps a photograph of a model), of the A-40 in flight. This image was produced by the Antonov factory and is not, as some claim, a photograph of the real prototype. The T-60 appears to be an M1942 GAZ production, as shown by the stamped wheels.
T-37 dropped
A T-37 tank being dropped by a TB-3 bomber. It is incredibly low to the ground, which would make serious combat deployment dangerous, due to enemy fire.
d-8 tb3 bomber 1932
A D-8 armored car strapped to the bottom of a TB-3 bomber during 1932 drills, Ukraine.