76mm Gun Motor Carriage T86, T86E1, and T87 (Amphibious)

T86 GMC (Amphibious) showing new flotation hull on M18 chassis.

T87 GMC (Amphibious) with 105mm howitzer and modified hull.

Combat experience in the Pacific led to several experiments and projects to give amphibious capability to US AFVs.

As a result of meetings held on the Ritchie Project in December 1943 and January 1944, the National Defense Research Council undertook to develop an amphibious gun motor carriage created from the M18. This involved removal of the M18 hull plate down to the sponson line and substituting a larger amphibious hull of lighter construction. The reduction gear final drive gear ratio was lowered and suspension changes were made to accommodate an M24 Light Tank type 21 inch track This vehicle was called the T86 Amphibious Gun Motor Carriage

The original T86 continued the 14-inch track of the M18 because the new tracks were not ready in time Marmon-Herrington was given the contract in January 1944 to build three pilots. The T86 was track propelled the T86E1 had twin 26-inch screws driven from a rear transfer case. The screws were in tunnels with twin cable-controlled rudders behind them. The best of these two propulsion methods was to be used in the T87. This proved to be the track type, and an improved track was incorporated in the T87 along with detail changes to the hull.

The T86 (sometimes called the Esch Device) was designed to provide a vehicle with high firepower and good performance on both land and water. Land performance turned out to be practically the same as that of the M18. It floated with about 15 inches freeboard and it had a speed of 4-6 m.ph in water using the standard M18 track. The vehicle later was modified to add a third steering position just forward of the turret and cutting off the forward corners of the deck, adding vision blocks in both corners and additional periscopes for the driver. The T86E1 began undergoing tests late in April 1944 It weighed 23 tons and developed a speed in water of 6.2 m.p.h. with no appreciable reduction in land speed The T86E1 later was modified by removing one screw.

The third pilot was to incorporate the best features of both but the armament was to be a 105-mm howitzer.

This was the T87.

The T87 with the 105-mm. howitzer weighed 1,000 pounds less than the T86E1 and was 2ft 3in shorter.

The T87 appeared in December 1944 and was still undergoing trials at the cessation of hostilities, after which it was cancelled. The T87 had the same 105mm howitzer as the T88 while the T86/T86E1 had the 76mm gun of the M18. The T87 had a slightly shorter hull. All these prototypes proved satisfactory on test with a good performance in surf. However, forward vision was generally poor due to the hull shape. In addition it was found necessary to add cable-controlled rudders at the hull rear to assist steering.

It was track propelled Marmon-Herrington also modified for the Navy Bureau of Ships an M18 into what was called the LVT 76-mm Amphibious Gun Carrier. Curiously, electrolytic action between dissimilar metals caused a fabrication problem so this vehicle was only some 30 per cent completed. It was to have had a Ford 500 h. p. V-8 engine and a Jered No 900 transmission, but these were never installed.

Variation/prototype on T87 with wadding trunk and detachable pontoon. One of the attempts to adapt the M18 for amphibious operations was the development of the Ritchie T7 swimming device, a set of pontoons and associated trunks. This shows the cumbersome affair attached to one of the T88 pilots. A total of 250 sets of this kit were manufactured, but they were never used in combat.

Variation/prototype on T86 with overhead turret protection.

Rocket Launcher Mounts on M4 Series Vehicles

Firing 4.5 inch rockets from M4-Sherman “Calliope” multiple rocket launcher, mounted on M-4, No. A-3 tank. 14th Armored, France.

T40/M17 mounted on M4 Sherman

While numerous rocket launcher mounts were developed for fitting to M4 series vehicles, very few saw operational use or reached production status.

Rocket Launcher T34 (Calliope): This consisted of 60 4·6in rocket tubes mounted in a frame above the turret. The two bottom sets of 12 tubes each could be jettisoned if necessary on all variants except the M4A1. The mount was traversed with the tank turret and elevated by a rod linked to the gun barrel. The Calliope was a “limited procurement” weapon, developed in 1943 and first used by 2nd Armored Division in France in August 1944. This weapon saw limited combat use until the end of the war.

The T34 Calliope Rocket Launcher was developed in 1943 and consisted of an array of sixty rocket tubes on a frame mounted above the turret of a Sherman tank. The tubes traversed with the turret and could be raised or lowered via a connecting rod to the gun barrel. The name came from its resemblance to the musical steam organ which has similar pipes. The T34 saw action with the US Army in 1944-45, firing 4.6-inch or 114-mm rockets, while the T34E2 saw this calibre increased to 7.2-inch or 183 mm.

Rocket Launcher T34E1: As T34 but with 14 tubes in two bottom projector units.

Rocket Launcher T34E2: Similar in appearance to the T34, but longer, the T34E2 held 60 7·2in rockets and the entire mount could be jettisoned if necessary in an emergency. This mount saw limited combat use, 1945.

Rocket Launcher T39: A mount of enclosed box construction with doors over the tubes. It held 20 7·2in rockets. Experimental only.

Rocket Launcher T40(M17) (Whiz-bang): This rocket launcher held 20 7·2in rockets in a box-like frame and was elevated hydraulically from the 75mm gun controls. The entire mount could be jettisoned if required, and the rockets could be fired singly or in salvoes. This “limited procurement” weapon was classified “limited standard” and saw some combat use in 1944-45.

Rocket Launcher T40 (short version): Experimental version of the above with shorter rocket tubes and 75mm gun removed and replaced by elevation mechanism for launcher. Access door for crew added in side of vehicle which was an M4A2.

Rocket Launcher T72: Similar to T34 but with very short tubes. Not used operationally.

Rocket Launcher T73: Similar to T40 but held only 10 rockets. Not used in combat. Experimental only on M4A1.

Rocker Launcher T76: This was a M4A1 with a 7 ½ in rocket tube replacing the 75mm gun. Had an opening in turret front around the mounting to allow gases to escape on firing. Reloaded from inside turret. Experimental only, 1944. Same weapon mounted on M4A3 HVSS was designated T76E1. Rocket Launcher

T105: A single 7·2in rocket projector in box-like case mounted in M4A1 in place of 75mm gun. Developed from T76, August 1945. Did not proceed past trials stage.

Multiple Rocket Launcher T99: Two small box-like launcher mounts, each holding 22 4·5in rockets, mounted each side of turret for vehicle with 76mm gun. Few produced 1945; also fitted experimentally to M26 heavy tank.




ISU-122/152 Tank Destroyers

Developed on the basis of the IS tank. The ISU-152 was conceived as a replacement for the SU-152, which was based on the KV-1s chassis. A total of 4,635 vehicles were built from November 1943 through June 1945. The ISU-152 is well-known for its 152mm BL-10 gun. To the average observer the SU-152 and ISU- 152 were visually identical, but the ISU-152 mounted a more modern howitzer known as the ML-20S (with 20 rounds), technically a gun-howitzer and a very powerful weapon, especially at the assault ranges favoured by Red Army tactics. The weapon was protected by an armoured box made up from sloping plates of thick armour, with hand rails around the edge of the roof for use by ‘tank descent’ infantry who used the vehicles to carry them into action.

The success of the SU-152, coupled with the development of the IS (losef Stalin) heavy tank hull, led the NKTP to order design teams at Chelyabinsk, in cooperation the Mechanized Artillery Bureau (BAS) and General F. Petrov, to design two new heavy assault guns based on the IS-2 tank’s hull and chassis. The initial vehicle, designated Object 241, or ISU- 249, was similar to the SU-152, except for a higher superstructure and more rectangular with less sloped side armour.

Thicker frontal and side armour (90mm/3.54in compared to 60mm/2.36in on the SU-152) meant that the internal area of both vehicles was the same, with storage for only 20 rounds each for the 152mm (5.98in) ML-20 howitzer gun. The main difference between the SU-152 and ISU series of vehicles was a lower suspension and a new, heavy two-piece gun mantlet bolted onto the right-hand side of the hull. Re-classified as ISU-152, production began at the end of 1943.

Problems with the availability of the 152mm (5.98in) gun type because of a lack of available manufacturing capacity in Soviet artillery factories led to orders to the TsKB-2 team to explore the possibility of mounting the more abundant 122mm (4.8in) A-19 gun on the ISU hull. This proved a relatively easy task, because both calibres of gun had the same gun carriage, meaning that no radical re-design of the hull or vehicle interior was required. The new assault gun entered service in December 1943 as the ISU-122. In 1944 its firepower was improved with the introduction of the 122mm (4.8in) D-25S gun designed for the IS-2 tank. This modified design, termed ISU-122-2, also had an new gun mantlet and improved crew space. In external appearance both gun types were identical, except for the ISU-152 ‘s shorter gun barrel with a muzzle brake.

The appearance of the immensely powerful Panzerkampjwagen Vlb Royal Tiger in fighting south of Warsaw in August 1944 led to a number of plans to up-gun both types of ISU with the new 122mm (4.8in) BR-7 and 152mm (5.98in) BR-8 long-barrelled guns, but the realization that the Germans could not deploy the Royal Tiger in significant numbers caused production of these prototypes to be abandoned. Another reason was the conclusion of Soviet technicians, based on combat results, that the IS-2 tank could deal with this new threat.

Numerically the ISU-122 was less important than the ISU-152, but the 122-mm version was potentially the more powerful weapon as it fired a higher-velocity projectile than the heavier 152-mm weapon, which relied more upon shell weight for its effects.

Post-war changes were made to the final production run of ISU-152Ks by using the IS-2m chassis and the IS-3 engine deck. A total of 4075 ISU-152s were produced during the war, and a further 2450 manufactured between 1945 and 1955, when production ceased. Despite a brief break in manufacture between 1945 and 1947,3130 ISU-122s were produced up to 1952. The chassis of many of these vehicles were adapted for special purposes in the 1960s. The Oka was armed with a 406mm (15.98in) gun designed to fire tactical nuclear shells to break up NATO front-line and reserve units. The ISU mounted the first FROG medium-range missiles, armed with either conventional, chemical, or nuclear warheads. Outside of these special roles in the Warsaw Pact armed forces, the ISU-152 saw service in its original role with the Egyptian Army in the 1967 and 1973 Arab-Israeli wars.

In Service

The ISU-122 and ISU-152 were used in Independent Heavy Self-Propelled Artillery Regiments, which were awarded the Guards honorific after December 1944. By the end of the war there were 56 such units. Generally attached to the tank corps, they were deployed in the second echelon of an assault, providing long-range direct, and on occasion indirect, fire support to tanks in the first echelon, targeting German strongpoints and armoured vehicles. They were also vital in providing defensive antitank and artillery support for infantry.

During 1944 and 1945 the ISU-152 and ISU-122 were in the vanguard of the Red Army advances through Germany towards Berlin. Some of the first Red Army units entering Berlin were ISU-152 units, which used their howitzers to blast away strongpoints at close ranges and clear the way to the remains of the city centre.

If the ISU weapons had a fault it was that they lacked internal ammunition stowage space. Thus they had to have a virtual constant supply of ammunition brought forward by armoured carriers, which was often a hazardous undertaking. But the massive weapon carried by the ISU vehicles was considered to be of great value in the direct support of Red Army tank and motorized infantry divisions, and both types went on to be used for some years after the war.

152 mm “beast killer”

ISU-122 [ISU = Iosef Stalin Ustanovka or Gun of Iosef Stalin]

The Army’s M1 Abrams Tank Replacement

There is no denying that in human years the M1 Abrams main battle tank (MBT) is certainly “middle-aged,” but thanks to a steady stream of updates the M1 Abrams has remained among the best tanks in the world. Since its introduction forty years ago the M1 Abrams, which was named for the late Army Chief of Staff, General Creighton W. Abrams, has proven itself on the battlefield more than any other MBT.

Several images taken at a U.S. Army workshop show a very rough idea of a possible replacement for the long-serving M1 Abrams tank. The images seem to depict at least three concept tanks, including one behemoth that dwarfs the 70-ton Abrams. The Army plans to make a decision about if and how to replace the Abrams in 2023.

However, there is still only so much that can be done with an old platform—and eventually, age just catches up with the best of anything. Replacing the M1 Abrams might not be easy, simply because the platform’s problems have been addressed already.

A lingering question is what a future tank might need or possibly might not need.

That is already being addressed by the U.S. Army Tank Automotive Research, Development and Engineering Center (TARDEC), which has begun a study under the Next Generation Combat Vehicle—Future Decisive Lethality (NGCV-FDL) program, which could determine how the next generation MBT could improve upon the current M1. Defence-Blog reported last week that the study is addressing the ways that the platform will ensure decisive superiority, be able to fight and win future wars.

The Army requires a fast combat vehicle that can exceed the performance of other MBTs and heavy combat vehicles, and the NGCV-FDL program has called for a vehicle that could be smaller and lighter than the existing Abrams or German-built Leopard. Yet the tank would still be equipped with modern active protection to address anti-tank guided missiles, RPGs, anti-tank rockets, and even tank HEAT rounds.

The American program could take a cue from the Russian military’s T-14 Armata and integrate more automation in the tank—meaning it could be able to maneuver in conjunction with other armored vehicles on the battlefield with semi-independent operations. This would be akin to driver assistance that is seen in some luxury vehicles today, but as part of a networked system could enable the tanks to respond faster than human drivers.

The next-generation MBT could also receive a very different main armament. Last month the U.S. Army announced that engineers at the Picatinny Arsenal reached a milestone in developing an advanced armament system that integrated a medium caliber weapon, ammunition, fire control and sensors to effectively engage targets at extended ranges.

The armament was developed in direct support of the Army Modernization Priorities within the development portfolio of the Next Generation Combat Vehicle Cross-Functional Team (NGCV CFT). It was designed to demonstrate the decisive lethal punch that could enable gunners to make the right firing decisions quicker and with greater accuracy at farther distances.

“The combination of enhancements not only give gunners greater versatility, but we anticipate that overall gunner operations could be as much as three times faster,” said Kevin Fitzpatrick, project officer for the new system at the Advanced Armaments Division of the Combat Capabilities Development Command Armaments Center, located at Picatinny Arsenal.

The event, a three-day workshop, was held in early October at the U.S. Army’s Ground Vehicle Systems Center at Detroit Arsenal. According to the Army, the event paired soldiers “with a team of industrial designers and Subject Matter Experts” to explore topics “from crew size to unmanned and autonomous considerations.” The team also “explored levels of desired lethality, mobility, and survivability applied to a number of concept platforms.”

The Army currently operates the M1A2 Abrams main battle tank. The service developed the Abrams in the late 1970s and began using it in the early 1980s. Although the basic design is more than 40 years old, several upgrades, including a larger main gun, depleted uranium armor, improved thermal imaging sensors, improved crew protection, and battlefield networking systems have allowed the M1 series to keep pace with armor threats.

The latest upgrade, Israel’s Trophy active protection system, uses a combination of turret-mounted radars and projectile interceptors to shoot down incoming anti-tank missiles before they hit the tank.

The Army has tried several times to replace the Abrams; at one point in the 2000s, the service spent billions without building a single vehicle. The October workshop was part of yet another effort, known as Optionally Manned Tank (OMT), to design a new main battle tank. OMT is pretty self-explanatory, but the Army is weighing exactly what it wants in a future tank—especially one that will probably serve as long as the current M1 Abrams.

One image from the workshop shows a number of scale models of contemporary tanks and fighting vehicles. The vehicles are 1/35 scale and built from commercial model kits and represent many of the most modern main battle tanks worldwide. At least three vehicles, presumably concept vehicles for the OMT, are present.

We don’t know exactly what most of the OMT concept models look like, but we can make some guesses. Assuming there are three models, they will almost certainly represent small, medium, and heavy versions of the OMT.

A smaller vehicle could retain a large gun, but carry less ammunition. It would also be lighter, allowing it to be carried by aircraft such as the C-17 Globemaster III, and substitute traditional heavy tank armor for an active protection system.

A medium-sized vehicle would be in the weight class of the M1A2 Abrams, while a large vehicle would be even bigger, retaining heavy armor to shrug off enemy anti-tank gun rounds and missiles but at the expense of strategic mobility. The medium and large tanks would be about the same width, in order to fit on railroad cars.

Each tank concept vehicle entails risk. A lighter vehicle could be deployed faster by air, but would rely heavily on the active protection system, which could be less effective against high-velocity, anti-tank rounds. A medium-sized vehicle would have to squeeze new systems, such as active protection, the ability to launch and recover drones, and perhaps even anti-drone lasers, into the tank while still supporting future growth.

A heavy tank would offer the best protection and future-proofing at the expense of strategic and tactical mobility, fitting fewer tanks in transport aircraft and leaving the tank unable to cross lighter civilian bridges.

The OMT tank will likely be equipped with a larger, more powerful gun than the M256 120-millimeter gun fitted to the M1A2 Abrams. One possibility is the new Rheinmetall 130-millimeter tank gun, which the German defense contractor says delivers 50 percent more kinetic energy (19.5 megajoules) than the M256 (approximately 13 megajoules).

Another possibility is moving up to 140 millimeters; a 140-millimeter gun designed toward the end of the Cold War delivered 20 megajoules of energy, but modern technology could probably improve on that. Other, more exotic main gun technology, including railguns and lasers, probably aren’t ready for prime time, although the tank could operate a smaller anti-drone laser.

One problem with bigger guns: the rounds themselves are too big to be manhandled into the breech. The Army prefers manually loaded tank guns due to their simplicity and higher rate of fire, but a heavier gun will force it to delete the human loader in favor of an automatic loading system. This would reduce the size of the crew from four to three, leaving fewer crewmembers available for maintenance and other tasks.

Then again, someone is going to have to remotely operate the uncrewed OMT tanks, and the Army may still include room for a fourth tanker to control the drone tanks.

Even with the progress that is being made, the Army won’t make a decision on any replacement for the Abrams until at least 2023—so it is likely that the M1 Abrams will be in service to hit the big 5-0!

1919-20 British tanks in Russia

WHIPPET TANK Seen here from the rear, the Whippet was a fast, 13-kilometre per hour (eight-mile per hour) tank armed with four Hotchkiss machine guns in its fixed turret. 17 were sent to Russia. They were used to pursue broken troops and exploit breakthroughs by other tanks. Denikin insisted that only officers could crew the tanks that had been provided. The Russian officer here is a member of the crew, seen at the rear of a Whippet.

Between 1919-20 British tanks lumbered across the sun-baked steppes of southern Russia, flanked by Cossacks wielding lances and sabres.

In 1916 the Russians had been considering importing tanks from the west. However, in the confusion following the following the revolution of March 1917, this plan lapsed, although a down payment was made by the Provisional Government. However, during 1919 a number of tanks were supplied directly to Denikin’s forces in southern Russia by the British. A dozen French Renaults were also provided but fell into Bolshevik hands. The British supplied small numbers of tanks to other anti-Bolshevik groups. They also supplied other equipment in the hope of influencing the bitter civil war.


The bulk of the tanks supplied to Denikin’s forces from March 1919 were Mark V types: Male (two six-pounder guns, one on each side), Female (machine guns only, two on each side) and Hermaphrodites/Composites (a six-pounder gun on one side and two machine guns on the other). All types also had machine guns between the tracks to the front and rear. Some of the British tanks supplied were captured by the Bolsheviks, including 50 or so Mark Vs.

The first 12 tanks (six Mark Vs and six Medium As, known as `Whippets’) delivered were committed to action on 20 May 1919 northwest of Taganrog where they spearheaded an operation to clear an important railway line. They struck terror into enemies, who broke and ran. This reaction was to become common over the course of the next six months. In June a further 16 machines arrived. Two Mark Vs and two Whippets were dispatched to support the attack on the heavily fortified city of Tsaritsyn (later Stalingrad). The tanks, some with British crews, broke down barbed wire defences and on 30 June entered the city in triumph.

Battle of Tsaritsyn

The battle started when White forces under Ataman Pyotr Krasnov laid siege to Tsaritsyn in the autumn of 1918, pushing back the Red Army defenders into areas surrounding the town on the west bank. The local Bolshevik leaders desperately called Moscow for reinforcements and arms, but received nothing other than orders to stand firm.

The city was saved by the actions of the local chairman of the military committee, Joseph Stalin. Stalin urged his comrades to continue fighting and disobeyed direct orders from Moscow by recalling forces from the Caucasus, nicknamed Zhloba’s ‘Steel Division’. These forces were able to attack the White forces in the rear and defeat them, saving Tsaritsyn for the Bolsheviks. Three major engagements then developed around the city afterwards during the entire duration of the battle but were likewise less successful than the first one.

White general Anton Denikin’s troops temporarily took over the city in June 1919. Major Ewen Cameron Bruce of the British Army had volunteered to command a British tank mission assisting the White Army. He was awarded the Distinguished Service Order for his bravery during the June 1919 battle for single-handedly storming and capturing the fortified city of Tsaritsyn, under heavy shell fire in a single tank; this led to the successful capture of over 40,000 prisoners. The fall of Tsaritsyn is viewed “as one of the key battles of the Russian Civil War”, which greatly helped the White Russian cause. Noted historian B. H. Liddell Hart commented that Bruce’s action is “one of the most remarkable feats in the whole history of the Tank Corps.”

However, Red Army forces under both Stalin and Voroshilov, strengthened by supplies and weapons that had recently arrived from Moscow, staged an all-out assault towards the city and retook it by January 1920. As a result, the defeated White Army, now in danger of destruction, then retreated towards the Crimean Peninsula.

Denikin organised the 73 tanks he’d received by October 1919 into the First and Second Tank divisions. Repair and training facilities, supervised by members of the Royal Tank Corps, were located at Taganrog until late 1919, when the base was overrun by the Red Army.

Lynx Infantry Fighting Vehicle to the U.S. Army

Here’s a short video of the KF41 at the recent NATO Brave Warrior exercises in Hungary, literally driving circles around the M2 Bradleys it might soon replace. The KF41, of which only one is currently in existence, was in Hungary where it had won a competition for 218 new infantry fighting vehicles.

The latest version of the M2 Bradley, the M2A3, 2018.

The U.S. Army’s next-generation infantry fighting vehicle could feature German DNA. German defense contractor Rheinmetall is teaming up with American defense contractor Raytheon to offer the company’s KF41 Lynx infantry fighting vehicle to the U.S. Army. The Army is looking to replace its thousands of M2 Bradley fighting vehicles with a newer design that is not only better in every way, but also has the ability to be remotely controlled on the battlefield.

The M2 Bradley was first used by the U.S. Army in the 1980s. The vehicle not only could carry infantry, but also offered enough protection to allow them to remain mounted during an attack. This preserved the momentum of an armored assault, ensuring that the attack did not slow down and that dismounted infantrymen didn’t need to be rounded up and board the vehicle to continue an offensive.

The Bradley first saw combat in the 1991 Gulf War, then the 2003 invasion of Iraq and the 2014 war against the Islamic State. Along the way the Bradley has gotten heavier with the introduction of new armor, electronics, and other systems that allowed the vehicle to pace battlefield threats.

After 30-plus years, however, the Army has decided it’s time to start over with a new vehicle that incorporates new tech from the ground up.

German defense contractor Rheinmetall, which developed the M256 gun on the M1A2 Abrams tank, is tossing its hat into the OMFV ring with the KF41 Lynx. KF41 is a tracked vehicle with a crew of three and the ability to carry eight infantrymen and women in the rear. Lynx is armed with a Lancer 2.0 turret incorporating a 35-millimeter autocannon, and the step up in caliber will allow Lynx to engage light armored vehicles and enemy troops at longer ranges at the expense of less onboard ammo.

The Rheinmetall LYNX KF41 (KF stands for “Kettenfahrzeug”, or tracked vehicle in German) is a German-made next-generation family of vehicles that offers state-of-the-art firepower, mobility and protection. The LYNX consists of a modular design that comes in two primary versions: the KF31 and KF41. Both versions have a driver in the hull and a two-man crew in the turret. The engine is in the front and the exhaust in the rear. Weighing up to 38 tonnes, LYNX KF31 can seat 3+6 soldiers.

LYNX KF41 is slightly larger and can carry 3+8 soldiers. Rheinmetall’s LANCE turret for the KF41can support a 30mm or 35mm cannon and the turret ammunition is separated from the crew for added protection. Both versions can be configured for IFV, C2 (command and control), reconnaissance, repair and recovery, and ambulance variants. The vehicle interior has a spall liner, decoupled seats, and mine and IED protection packages that can be exchanged in the field. The KF41 does not have a V shaped hull, but its mine protection is highly effective against heavy blast mines, explosively formed projectile mines and IEDs. The KF41 also has passive and reactive systems to defeat rocket-propelled grenades and antitank guided missiles and provides roof protection against cluster munitions. Rheinmetall’s SOLAR SIGMA Shield Mobile Camouflage System can also be fitted to the entire vehicle to reduce heat loading as well as thermal and IR signatures.

The KF41 weighs 44 tons, significantly more than the 30-ton Bradley. The KF41 is bigger but it’s also more agile, with a horsepower to weight ratio of 26 to 1. The Bradley’s, by contrast, is about 21 to 1.

The KF41 in U.S. Army service would probably look a little different than the vehicle seen in Hungary as the U.S. may want the turret to be equipped with two long range anti-tank missiles, giving OMFV the ability to take on tanks by itself. It may also want an active protection system capable of detecting and shooting down incoming rockets and anti-tank guided missiles. Lastly, KF41 may need the ability to be operated remotely.

Rheinmetall is competing for the Czech IFV contract with their LYNX vehicle that was first shown at Eurosatory in 2016. Two main variants are available: LYNX KF31 with three crew and six dismounts or LYNX KF41 with three crew and eight dismounts. Both are fitted with the Rheinmetall LANCE turret system. The turret will accommodate the MK30-2/ABM 30×173 mm cannon; it can also be fitted with a launcher for the Rafael SPIKE-LR missile system. The Czech Land Forces already use SPIKE-LR on their PANDUR II vehicles.

The new OMFV program will probably run into 2021, or even 2022. It may even fail, yet again, to produce a replacement for the Bradley. If the KF41 does win however it could produce a vehicle that will be the main heavy infantry carrier for the U.S. Army to 2050 and beyond.


Panzer IV with KwK 7.5cm L/24

Panzer IV Aus F with schurzen Kursk 1943

The Panzer IV would remain in production throughout the war. The most numerous and the most versatile tank the Wehrmacht developed, it is also usually considered one of the world’s classic armored vehicles, a strong contender for Top Ten status in any comparative listing. Its origins were unpretentious. The Weapons Office wanted armaments firms to gain experience designing and producing heavy tanks. Lutz and Guderian had from early days seen the need for a support tank. The result was a project for a “battalion commander’s vehicle” of 24 tons—the bridge weight limit—mounting a 75mm gun, which was really a howitzer, only 24 calibers long. Dubbed by its crews as the “cigar butt” and other, cruder names involving length, its high-explosive and smoke shells were intended to provide for close support—not only for tanks but for their accompanying infantry. In the war’s early years, however, a three-inch shell exploding on or near a tank could do significant damage—not least to crew morale. The Panzer IV would acquire from its early days an enduring reputation as a formidable opponent.

The Panzer IV suffered from an embryonic armament industry’s lack of experience producing even moderately large tanks, and from an increasingly overstrained manufacturing capacity. Only about 200 were on inventory by September 1, 1939. That was enough, however, to begin allocating a company to each battalion, and to test the three-to-one combination initially proposed by Lutz and Guderian. The design withstood prototype testing admirably. The Panzer IV’s suspension matched its eventual 20-ton weight, and was so reliable it became standard for all the later versions. Its superstructure was proportioned generously enough to allow for up-gunning. Its turret was electrically powered, improving exponentially the chances of getting off the first shot so often decisive in mobile war. Add standard frontal armor of up to 50mm, with 20mm on the sides and rear, plus a reliable Maybach engine giving a top speed of 20 miles per hour and a 100-mile range, and the Panzer IV was a crew’s delight when it began entering unit service in 1938.

Panzerkampfwagen IV Ausf D (Sd Kfz 161)

History: In January 1938, Krupp-Gruson received an order to produce 200 in the 4th Series BW and 48 in the 5th Series. Of this total, only 229 were completed as gun-armed Pz Kpfw. The other 19 chassis were utilized to produce 16 bridge-laying tanks, 2 self-propelled guns and a Munitionsschlepper for Karl. Later in 1941, in an endeavour to seek a more powerful armament, an Ausf D was rebuilt with a 5cm KwK39 L/60.

Specific features: The main improvements incorporated in the Ausf D were the increase in the side and rear armour from 15 to 20mm, and the provision of an external mantlet for the 7.5cm KwK. The superstructure front was stepped so that the plate in front of the radio operator was farther back than that in front of the driver. The driver had a pistol port to the right front, and the hull MG was reintroduced in front of the radio-operator. Ausf D, produced late in the series, had additional 30mm plates bolted and welded to the superstructure and hull front, and 20mm plates bolted to the hull and superstructure sides. Later, in 1943, several Ausf D were refitted with 7.5cm KwK L/48 for use with training and replacement units.

Combat service: By May 1940, Pz Kpfw production had been sufficient for every tank detachment to have a medium tank company of from six to eleven Pz Kpfw IV. On 10 May 1940, at the start of the campaign in France, there were 280 Ausf A, B, C and D in the Panzer divisions. The Ausf D saw service in France, the Balkans, Africa and Russia. The last few were phased out by attrition early in 1944.

Panzerkampfwagen IV Ausf E (Sd Kfz 161)

History: In January 1938, the order for 223 6th Series BW was issued to Krupp-Gruson, and this total was completed.

Specific features: The main improvements introduced with the Ausf E were a new cupola design, modifications to the turret, and increased armour protection. The turret now had a single bent plate for the turret rear, and an exhaust fan to extract gun fumes. While all Ausf E had a 50mm hull front and 20mm plate bolted to the hull and superstructure sides, several of the early Ausf E were minus the extra 30mm plate on the superstructure front. Minor modifications included a simplified sprocket design, glacis hatches countersunk level with surface of glacis, new design of driver’s visor (pivoting), single signal post on turret roof and an armoured cover for the smoke-candle rack.

Combat service: With the continued production of the Ausf D, and the completion of the Ausf E, sufficient Pz Kpfw IV became available to furnish each medium tank company with ten Pz Kpfw IV for the campaigns in the Balkans, North Africa and Russia. Forty Ausf D and E were taken to North Africa with the 5th and 8th Panzer Regiments, and 438 Ausf B-F were with the seventeen Panzer divisions which attacked the Russians in June 1941. The last Ausf E were phased out by attrition early in 1944.

Panzerkampfwagen IV Ausf F (Sd Kfz 161)

The initial Ausf F order was given to Krupp-Gruson for 500 in the 7th Series BW. This was later increased when Vomag received an order to produce 100 and Nibelungenwerke, 25. Before these series were completed the OKH issued an order to mount the 7.5cm KwK40 L/43 as quickly as possible, resulting in each series being completed as Ausf F2. Twenty-five of the Ausf F1, which had been fitted originally with the short 7.5cm KwK37, were converted to Ausf F2 by mounting the 7.5cm KwK40 L/43, before being issued to the troops.

The major improvement with the Ausf F was the increase of the armour thickness on most surfaces. Minor improvements included 40cm wide tracks with the accompanying dished sprocket and tubular idler, air-intake cowl on the glacis hatches to cool the steering brakes, and new muffler designs for the main and auxiliary engines. The vision ports, pistol ports, driver’s visor, hull machine-gun mount and turret doors were all changed from previous models because of the increased armour thicknesses.

The Ausf F1, which equipped several new units and refitted the 2nd and 5th Panzer Divisions, was mainly issued piecemeal to units at the front, to replace losses. About 208 Ausf B to F1 were available with units in Russia when the summer offensive started in June 1942. This was reduced to 60 available on the entire Eastern front at the time of the offensive at Kursk in July 1943.

Vorpanzer F1, with extra bolted appliqué armour on the sides, gun mantlet and frontal glacis, with the 5th Panzerdivision, Group Center, Russia, winter 1941-1942.

There is a photo of two Pz. IV with Vorpanzers, and the first has the name “Hansi” painted on it. There is no other markings to distinguish which unit it is. But by the overall look of the rest of the vehicles it looks like that it is a Pz Ausb Abt.

Vorpanzer for the Pz.IV Ausf F1

The most complete story of the Vorpanzer for the Pz IV Ausf.F is in the Band 5 (Neu), Begleitwagen, Panzer IV by W. Spielberger.

Here’s a summary:

Conference 7.7.41- The Führer has been informed that in the battles in North Africa that armour-piercing rounds are becoming a problem from English tanks. The Führer asks that new production Panzer be equipped w/ spaced armour in front of the main armour.

Conference 29.11.41- the Fuhrer intends for all unit to be equipped with the new Vorpanzer.

Report from Krupp-Essen, 24.12.41- There is a shortage of material for the Vorpanzer… Due to the situation delivery of the first Vorpanzer is expected on Feb 1, 1942. There is a question, should the turrets be delivered w/ the Vorpanzer or not, that hasn’t been made very clear.

There is more text but is doesn’t mention about shipping of the Vorpanzer to combat units. The idea was dropped with the production of the Ausf.G with the longer 7.5-cm KwK. There is a photo of 2 Pz IV with Vorpanzer, and the first has the name “Hansi” painted on it. There is no other markings to distinguish which unit it is. But by the overall look of the rest of the vehicles it looks like that it is a PzAusbAbt.

Panzer IV in Afrika

The two-year seesaw conflict across North Africa has been so often described in so much detail that it is easy to exaggerate its actual impact on Hitler’s panzers. The campaign involved only three mobile divisions and never more than around 300 tanks at any one time. Technically the Germans maintained a consistent, though not overwhelming, superiority—reflecting as much the flaws in British tank design as the qualities of the German vehicles. The Panzer III, especially the L version with the 50mm/62-caliber gun, was the backbone of Rommel’s armor, admirably complemented by the Panzer IV, whose 75mm shells were highly effective against both unarmored “soft-skinned” vehicles and unsupported infantry, even when dug in.

The Sherman’s mid-velocity 75mm gun, able to fire both armor piercing and high-explosive rounds, made it the best tank in North Africa—except possibly for the later marks of Panzer IV, who brought their even higher velocity 75mm gun on line in numbers too small—never more than three dozen—to make a difference.

Panzer IV D, E, F1, F2 and G models were present. As the campaign went on the later models started arriving like the Pz IV specials with long barrels, version F2 and G’s.

  Pz.Kpfw.IV Ausf D

  Pz.Kpfw.IV Ausf. D/E Composite Variant

  Pz.Kpfw.IV Ausf. E

  Pz.Kpfw.IV Ausf. F1 Early, Middle, and Late ‘Typs’

  Pz.Kpfw.IV Ausf. F2 Early, Middle, and Late ‘Typs’

  Pz.Kpfw.IV Ausf. G Early and Middle ‘Typs’

The German Afrika Korps only started to receive Panzer IV with the L/48 75mm gun, arriving in front line units (in small numbers) for the battle of Alam Halfa 30 August 1942 (although by 1st Alamein their numbers had increased dramatically).

From early 1941, when the embryonic DAK armoured units first arrived in North Africa, they were equipped with the Panzer IV, Ausf C and D and then later, the Ausf E and F1, which were equipped with the 75mm KwK L/24 gun, which fired exactly the same HE projectile as the Panzer IV, Ausf F2, (referred to as the “special” by the British) which was equipped with the 75mm L/43.

Panzerkampfwagen IVs, which were sent to North Africa (1941-43), were equipped with additional tropical filters (Tp) and improved ventilation system.

Actually there weren’t that many Pz IVs with the DAK, short-barrelled or otherwise. The four Panzer Abteilungen with the DAK’s two Panzer Regiments were organized along traditional mid-war lines, with one medium company (usually with L24 equipped Pz IVs) and three light companies with Pz III (either L42 or L60) At theoretical max strength – never attained for the DAK as far as I know – and allowing all DAK Pz IVs as F1s, that would still only account for a max of 88 Pz IVs with the DAK.

Chamberlain and Doyle state in their much-maligned book that the majority of Pz IV F1s were used to re-equip the 2nd and 5th Panzer Divisions, units which were never sent to North Africa.

However, additional L24 equipped Pz IVs formed part of the 10th Panzer Division shipped to Tunis as part of 5th Panzer Army. It’s more probable that these tanks were F1s because the DAK was in North Africa before the first Pz IV F1s rolled off the production lines. All told, theoretical max Pz IV F1 strength of the 5th Panzer Army comes up to 45 tanks with the 10th PD, Pz. Abt. 190 and s. Pz. Abts. 501 and 504, not counting tanks which ended at the bottom of the Mediterranean.

I can trace 45 PzKpfw IV armed with KwK 7.5cm L/24 in North Africa in 1941. Most of these were Ausf D & E.

10 Pz.IV F2 delivered May 1942 actually 9, one broke down in Italy and came later.

18 More arrived in January 1942, these would have been of a higher proportion of Ausf F than in 1941.

22 Arrived in February 1942.

9 in April, but some would have been Ausf G

10 in May, but some/most/all would have been Ausf G

20 Arrived in Tripoli in August 1942.

12 Arrived in Tripoli in September 1942.

The British Tanks Without a War I

These are pictures of the A.I6EI. One would presume that the ECLA smoke mortar would be fitted into the opening on the top right of the turret front.

In 1936 General Wavell and Lieutenant General Martel were part of a military mission to Russia to view manoeuvres near Minsk. The mission took an overland route and passed through Berlin where they met Colonel Frederick Hotblack, the British military attaché in Hitler’s Third Reich.

After this brief interlude the military observers continued to the Minsk exercises where they spent four days watching about 1,200 Soviet tanks in action. This was a fraction of the total Soviet Union’s tank force of the time which was over 13,000. Just eight years earlier, during a debate on how tanks were used, and how to defend against them, a British staff officer was on record as saying:

infantry are set upon by tanks and other horrible devices until the poor infantry officer has very little time to think about carrying out his job. It is important to train in all these things, but we are getting a wrong sense of proportion as to what we are to expect in a war. To produce sufficient armoured vehicles to attack us in anything like the way we attack our own infantry in peacetime, the enemy will require 4,000 at least.I don’t know of an army which has any intention of producing anything like this number of armoured vehicles. I cannot believe that our infantry will ever be attacked in anything like the way we attack our infantry in peace training.

Then, after this demonstration at Minsk, the military mission travelled on to Moscow. From this hub they travelled around the region, visiting several military bases and manufacturing complexes. Martel and Wavell both came to different conclusions from this demonstration of the Soviet tank force. Wavell, one presumes, took the demonstration of speed and Christie suspension to heart and maybe thought back to his part in the 1929 conference. Martel, however, had other ideas forming on the way home.

This train of thought was briefly interrupted when leaving Minsk and about to cross the Russian border into Poland. At the time the Soviet Union had strict currency controls in place, which prevented the removal of roubles from the country. At the border an official appeared and asked the travellers if they were carrying any money. The British officers admitted that they were, and also said that they realised they would have to surrender it. The Russian official helpfully pointed out that this sort of eventuality had been foreseen and there was a list of societies that a traveller could join, and to which they could donate their monies. After reading the list the British officers all started laughing and instantly subscribed to the ‘Society for the assistance of Individuals in Russia who were being persecuted by the communists’. The Russian officials found this quite hilarious as well.

Upon their return it is likely that Wavell began to agitate for the Christie suspension, and cruiser tanks, or at least someone who read his reports did, and the rest they say is history. Wavell would put his theories of armoured warfare to good use against the Italians in the North African desert.

As we have seen, Martel, now appointed to the Master General of the Ordnance department, was quite happy to be designing and building his own tanks and so started a new project, this time to design a full-sized medium tank. In his endeavours, he set up a small cabal of tank officers, including Liddell Hart. The medium tank Martel designed seems to have gained the nickname ‘Monster’. For a year the group worked its influence but the Master General of the Ordnance, Lieutenant General Sir Hugh Elles, and Major General Alexander Elliott Davidson, the Director of Mechanisation, were opposed to the tank. By June 1937 these officers were considering tanks for the 1938 financial year. Although the A.7 was still about and technically a medium, it in no way fulfilled the General Staff requirements for a medium tank. The A.6 was closer to meeting the requirements, although falling some way short, which supports the claim that the A.6 was a tank ahead of its time.

On 9 June, Davidson forwarded two blueprints for consideration. One was a curiosity of which we have just a description. Based on the hull of an A.12 Matilda, how it differed from a normal infantry tank, or even what the turret looked like, we do not know. The second set of plans were the ones on which Martel had been working previously, and would in time become the A.14E1. A board met in committee on the 15th to review the situation and decide upon a course of action. After the current designs, A.6 and A.7, were reviewed, the board agreed that, if a Wilson-style steering was used, then a mere 15hp per ton would be sufficient to meet the General Staff requirements.

From this starting point the board reverse-engineered the maximum upper limit for the weight of the tank by comparing it to available engines and their horsepower. The four engines considered were the Liberty, with 400hp giving a tank of 24 tons, and the Meadows V12 with 430hp, giving a tank weight of 26.5 tons. Then came an interesting consideration, the Napier Lion engine, already fitted to the Supermarine S.4 and S.5 racing seaplanes, which would, eventually, lead to the Spitfire. The engine was also fitted to the British powerboat companies Type 2 high-speed launch, a craft that would later be used by the RAF’s search and rescue units during the Second World War. The Lion produced the same 430hp as the Meadows V.12.

The engine finally selected was the Thornycroft RY12, which had an output listed at 575hp. This gave the tank weight of 32.5 tons. The 575hp output is curious since the original engine only produced 548hp but, by the end of April, a set of Simms dual ignition had been fitted which pumped its power output up to 607hp. After selection for the medium tank, the power requirements were reviewed and the engine derated by carburettor adjustment. After this modification, a test programme was run with the engine doing eighty-five hours at differing speeds and loads without a single problem. Furthermore, a second of these engines, linked to a specially-designed Borg and Beck clutch, was able to complete a test programme of 500 hours running when fitted to the A.6E3.

The board then turned its attention to the two blueprints on offer. The A.12-based one was rejected for unspecified reasons, but the second was much better liked, although it did have its flaws. In the eyes of the board the main difficulty was that it only had a single sub-turret on the left side. The board noted that if Martel’s original design could be altered to carry two sub-turrets, the Martel design would be viewed favourably.

The board’s requirements for a medium tank are worth studying. The requirements were called ‘1938 class medium tank’ and, in most respects, match those of the A.14E1 as eventually produced. However, there was a noticeable difference at first glance. The A.14 had a six-man crew, but the requirements had a seven-man crew, the spare man being located in the turret. Presumably, he was there to help take care of the plethora of weaponry crammed into the turret, which included a high-angle smoke mortar, a dedicated .303 anti-aircraft machine gun (which may also have had its own sub-turret at the rear of the tank; differing sources state different things) and, most intriguingly of all, the main gun was listed as a 2-pounder with an ‘automatic feed’. There was also the requirement that a howitzer could be fitted if need be.

Some more modern sources indicate that all the machine guns on the tank were to be air-cooled, and the Czech ZB machine gun (later the Besa machine gun) was discussed as a possible candidate. These were located with two twin-mountings in each sub-turret and a single machine gun mounted co-axially to the main gun. Another difference was that the requirement was for 25 tons in weight. When the A.14 was produced, it had a weight of 29 tons, and the board was hoping to fit in an extra man, and automatic feed for the gun, as well as fifty more rounds and the same difference in number of miles range, all under the same armour protection. This was a wildly optimistic weight. The armour on the tank was given as 30mm basis, 20mm protecting the engine and everywhere else as 25mm.

On 17 June another meeting was held. As well as the officers present before, Percy Hobart and Martel were also there. This meeting’s goal was to determine what tank would be built immediately. As well as the A.14, the A.7, A.9 and A.10 were all discussed. Hobart led a determined case for the idea of the sub-turret to be retained, stating that it was the only fitting that gave sufficient arcs of fire and, to avoid a blind side, two turrets were needed. Hobart, however, fared less well in his second point of contention. He was opposed to producing the A.9 as a stop-gap, which became the board’s first decision. While the A.9 was being produced, in the medium term two of the new mediums would be produced. At this point the tank received its official designation of A.14. The long-term goal, however, was not production of the A.14; the tank was to be redesigned to give experience in the class so that a new medium tank could be designed meeting the requirements issued by the General Staff. The tank to meet the requirements would be numbered A.15. The designation A.15 was later re-issued for the A.15 Crusader. The medium tank to follow on from the A.14 had nothing to do with Crusader. This view was re-affirmed, when, in late February 1938, the Director of Mechanisation described the role of the A.14 as:

The A.14 is a prototype of a medium tank which it is proposed to develop as rapidly as possible, so that if a heavy and fast medium tank of this nature is needed in the future, we shall be ready.

Some branches in the Mechanisation Board were opposed to the 1938 class specifications on several grounds, such as the range of the weaponry, which ‘clashed badly’, the complicated armour layout, and the four-man turret which would increase the width of the tank. It was this last point that caused the 1938 class to fail. After several discussions and changes of mind over the rail-loading gauge (even at one point considering using the continental loading gauge) the tank was dropped due to its width.

Before that, on 24 June, official confirmation that the A.14 was to be progressed was issued. For once, the A.14 was issued a name, albeit a slightly dismissive one. It may also have just been an internal description from Davidson, who referred to it as ‘Modified Monster’.

At the very end of June, the subject of engines was revisited. As well as the ones mentioned before, the Paxman Ricardo V12 and Rolls Royce Kestrel were considered, as well as two foreign engines, listed only as the ‘Isotta Fraschini’ and the ‘Lorraine’. The latter two were dismissed due to difficulties in obtaining large numbers, and on the grounds of not having a secure supply under the government’s control. There was also some concern that minor variations were being constantly worked into these two engines during production, which could lead to non-standard parts. In the end the meeting confirmed the previous decision.

The meeting also considered the suspension. It was decided to use Vickers-Horstman type suspension as that would lead to development work on the type. The meeting saw no point in having two companies (Nuffield Mechanisation Ltd was working on Christie-type suspension) work on the same suspension design and would rather develop two separate designs so that, should one prove clearly superior, it could be used as the standard.

Now that a plan of action had been selected the War Office started trying to fit the modifications into the ‘Monster’. From the start, this monster put up a fight. The General Staff requirement was for a tank of 25 tons, but with the redesign to incorporate the twin sub-turrets, the projected weight climbed rapidly to 28 tons. Why, one would, ask was this a problem, since the earlier meeting had worked out that the Thornycroft RY12 could move a tank of over thirty tons? At the meeting on the 17th, and later, the complaint was that design trends in British tanks were to fit underpowered engines, and so the board wanted to keep plenty of power in reserve which, in turn, would allow further development of the chassis.

One of the steps suggested to cut the weight of the tank was to lower the radius of operation to 150 miles, from 200, and fit a new engine. The engine picked for this diet was simply described as a ‘Junkers engine’. One would immediately see that the complaints against the use of foreign engines still stood, while Martel, now promoted to Assistant Director of Mechanisation, was on hand to point out that the Junkers engine was still extremely immature, and therefore should not be included. Although there would have been some certain irony in a German engine powering a new line of British tanks, just as the Rolls Royce Kestrel engine powered the first of the Luftwaffe’s new planes, this idea never came to pass.

The next weight-saving idea was to use cutting-edge technology. At that time, the frames of the tanks were built by riveting steel together, to which the armour was fixed. The suggestion was to use high-tensile steel with the joints welded for the frame. The design department had no idea if this was even possible, or if the technique had been perfected, and thus the Institute of Welding was to be contacted to find out if the suggested method was possible and, if not, if research into this field could be conducted.

Another meeting was held on 26 August to select a parent company for the building of the two prototypes. At first Vulcan Foundry was chosen but that company was producing the A.12 Matilda, a tank requiring a large amount of hand grinding to get the hull to the correct armour thickness. This, in turn, slowed the process of construction. With so much capacity taken up by the A.12, another company was considered. This time LMS Railway of Crewe was selected, maybe not entirely by chance it appears. The locomotive engineer selected to build the A.14 was Mr H. Ivatt, a friend of General Davidson; they had known each other since the First World War. Equally, the discussions on width and railway loading gauge for the A.15 may have influenced the choice of a railway construction company.

In November the mock-up of the A.14 was complete, and three officers from various armour schools were selected to view it with a fighting officer’s eye but there is no record of the report that Major Harland and Captains Carmichael and Berkley-Miller filed.

With a war hurtling towards the British, in 1938 the confusing mess of cruiser, heavy cruiser and, potentially, a new class of medium began to make itself felt. Indeed, it seems that an awful lot of effort was expended by the War Office determining what each tank was and explaining the minute differences between tanks. Here the story starts to get mixed up with several other tanks, and indeed spawns new ones.

For nearly a year until December 1938, the A.14 project disappeared from the record. Then things started to move when a limited production of A.14s was scheduled to start in 1939. At the same time, increasing the armour value of the A.14 above 30mm was to be investigated. The branch detailed to review the armour arrangements had already been at work on redesigning the A.14. This proposal was to mount a V8 version of the standard Thornycroft RY12 engine (termed the RY8), transversely across the hull, not lengthways as was normal, which would enable the tank to be shorter. This proposal also included the idea of removing the sub-turrets on the front of the hull; however, they were re-installed on the roof of the main turret, complete with the gunners for each sub-turret, creating a five-man turret! One cannot, even now, begin to work out how this arrangement was to work as the machine-gun turret gunners’ legs, at the very least, would have been protruding into the fighting compartment. This contraption was given the designation A. 19 and it seems from later suggestions that the turret ring would have been the massive size for that time, of 64 inches (5 feet and 4 inches/1.6 metres). It is curious, considering that the A.15 project was ended due to its four-man turret, that the mechanisation board thought they could succeed with a five-man turret, where they had previously failed with a smaller number of crew.

Due to the large number of unknowns involved in the design, and the lack of power plant, it was agreed that the A. 19 could not be produced in 1939. However, authorisation was given to continue work on the tank. The main sticking point was that the Thornycroft RY8 did not as yet exist. Indeed it was later stated that the entire A.19 project was dependent on the RY8. In January 1939 a meeting was held at the John Thornycroft works in Reading where the War Office laid out the requirements: the RY8 needed to produce 200hp at 2,000rpm with an emergency back-up of running at 2,400rpm for one hour required. It had to be able to run on grade three fuel.

With several tanks needing this engine, there was some pressure to produce it and, foreseeing a bottleneck in producing crank components, it was urged that an order for two engines be placed immediately. Thornycrofts had submitted a price of £7,000 for two engines but had stressed that this was not a carefully worked out estimate.