T25 AT (Fake Tank)

United States of America
Tank Destroyer – Fake

Fake Tankin’

World of Tanks, or ‘WoT’, is a tank combat multiplayer game developed by Wargaming Group Limited. The game features hundreds of playable tanks, including prototypes and designs that never left the drawing board, arranged in ‘tech trees’ grouped by nation and vehicle type. In addition to tanks that have some basis in reality, World of Tanks also features some vehicles that are entirely made up, designed to patch holes in the ‘tech trees’. Among the ‘fake’ designs is the T25 AT, an American tank destroyer. Described in-game as a real design, this is a vehicle that, from the name to the gun, is none other than a product of Wargaming’s think tank. However, there is some information pointing towards the existence of a similar vehicle that could have inspired this ‘fake’ tank.

Wargaming are generous enough to provide a short ‘history’ of their made-up tank both on their ‘wiki’ and in-game.

“The vehicle was developed based on the T23 tank, but the work on the project was discontinued at the concept exploration stage. The Command of the United States Army did not like the electric transmission and poor gun traverse limits.”

While this short summary is mostly accurate, the in-game design differs significantly from any proposed T23-based tank destroyer.

The Name Game

The first step towards deconstructing this ‘fake’ tank is to dissect its fictional name. Contrary to what one could expect, this vehicle is not based on the chassis of the T25 medium tank. Comparing historical photographs of the T25 prototypes and in-game screenshots reveals the differences in suspension between the vehicles.

While the actual T25 used Horizontal Volute Spring Suspension (HVSS), the ahistorical T25 AT uses Vertical Volute Spring Suspension (VVSS). Due to the difference in suspension types between the T25 AT and the actual T25 medium, the chassis on which this design is based is much more likely to be the T23 medium tank, the T25’s predecessor. The chassis of the T23 and T25 were otherwise very similar, so it could have been possible for the designers at Wargaming to confuse the two when creating this fictional tank.

The other half of Wargaming’s T23-based tank destroyer’s name, the ‘AT’, is just as incorrect as the T25. AT is an abbreviation for ‘Anti-Tank’ and is a designation not generally applied to tank destroyers used by the United States Army. American tank destroyers, prototype or otherwise, were instead designated as GMCs (Gun Motor Carriages). Some examples are the M10 GMC or the T40 GMC. A much more historically accurate designation for this vehicle would have been ‘T23 GMC’, with T23 signifying the chassis and GMC denoting its status as a tank destroyer. Even with such a designation, it would still have been incorrect as such a distinct design would have been given a new T-number to distinguish it from the T23 medium tank. However, there is no way to tell what this hypothetical T-number would be. As it stands, T25 AT is an incorrect name back to front, featuring a misleading T-number and an improper designation for a tank destroyer.

American…

To examine the T25 AT, it is first necessary to look at other conventional tank destroyer designs of the time period. During World War II, American tank destroyers were designed to conform with the U.S. Army tank destroyer doctrine, which demanded fast, heavily armed, lightly armored vehicles capable of defending against massed armored attacks. Doctrine also requested that tank destroyers possess anti-aircraft weapons and powerful radios. Almost all of these characteristics were present on many American tank destroyers of the Second World War, such as the M10 GMC, M18 GMC, and M36 GMC. However, many American tank destroyers also possessed common design decisions that, while not outlined in doctrine, have become synonymous with them as a whole, namely, fully rotating turrets and open-tops.

Notably, the T25 AT shares few characteristics with these vehicles. While the T25 AT, equipped with the powerful M3 90 mm gun, is heavily armed, its similarities to standardized American tank destroyers end there. This tank destroyer, as it is based on a medium tank chassis with a few tons of armor added, is not exceptionally mobile. It features reasonably thick armor, no anti-aircraft machine guns, a closed top, and, notably, an armored casemate instead of a conventional turret. However, while the T25 AT bears little resemblance to turreted American tank destroyers, it would be foolish to dismiss other, experimental turretless designs, namely the T40 and T28.

The T40 was created by mating the 3 in gun M1918 to the chassis of the M3 medium tank. A turretless design was pursued to lower the vehicle’s profile. Development was canceled in 1942 due to the lack of available guns and the success of its competitor, the soon-to-be-standardized M10 GMC.

The T28 was only considered as a tank destroyer for a short time. This massive tank was designed in 1943 to defeat the defenses of the German Siegfried Line using exceptionally thick armor and a large gun. This vehicle’s lack of a turret was, again, to lower its profile. The history of this vehicle’s designation is complicated. While originally designated as Heavy Tank T28 in 1943, its name was changed to T95 GMC in 1945 due to the tank’s noticeable lack of a turret, something that all U.S. heavy tanks had at the time. However, its designation was changed in 1946 back to Super-Heavy Tank T28 because of nomenclature changes and to reflect the tank’s massive weight. For the sake of comparison, we can consider this as a tank destroyer despite the fact that it was not developed with that role in mind.

Even compared to two other historic turretless American tank destroyers, the T25 AT is fairly unique. It does not quite have the speed, open-top, or light armor of the T40 GMC, a true American to-the-doctrine tank destroyer. However, the T25 AT also does not have the incredibly thick armor of the heavy assault T28. Therefore, it is fair to assume that the T25 AT shares little in common with any contemporary American tank destroyers, experimental or standardized.

Or German?

Conversely, the T25 AT bears a striking resemblance in appearance and overall design to contemporary German Jagdpanzers. Visually, the T25 AT is a combination of German tank destroyer parts cobbled together. The T25 AT’s casemate is similar to that of the Jagdpanther, constructed by extending the upper glacis of the chassis upwards to form a fighting compartment. Additionally, the T25 AT’s gun mantlet is very similar to the Saukopfblende [Eng: boar’s head] gun mantlet used by many Jagdpanzers, including the Jagdpanzer 38 ‘Hetzer’ and Jagdpanzer IV.

While many factors of the T25 AT’s design appear confusing from an American perspective, including its relatively thick armor, closed roof, lack of turret, and average mobility, these are all common characteristics of Jagdpanzers. The Hetzer, Jagdpanther, Jagdtiger, Ferdinand, and Jagdpanzer IV, for example, all had thick frontal armor, fully enclosed casemates, lacked turrets, and had mobility ranging from average to poor. With its relatively thick frontal armor, casemate-mounted gun, fully-enclosed casemate, and average mobility, the T25 AT is extremely similar to these German tank destroyer designs. In contrast, it shares almost no characteristics with American designs of the time period.

Armor and Chassis

	T23 Medium Turret Armor				T25 AT Turret Armor
	Thickness	Angle			Thickness	Angle
Front	76,2mm	0°		Front	88,9mm	47°
Side	63,5mm	0-13°		Side	76,2mm	0-13°
Rear	63,5mm	0°		Rear	38,1mm	0°
Roof	25,4mm	90°		Roof	19,1mm	90°
Mantlet	88,9mm	0°		Mantlet	127-76,2mm	varies

	T23 Medium Hull Armor				T25 AT Hull Armor
	Thickness	Angle			Thickness	Angle
Upper Plate	76,2mm	47°		Upper Plate	88,9mm	47°
Lower Plate	63,5mm	56°		Lower Plate	63,5mm	48°
Front Side	50,8mm	0°		Front Side	63,5mm	0°
Rear Side	38,1mm	0°		Rear Side	50,8mm	0°
Rear	38,1mm	0-30°		Rear	38,1mm	0-30°
Front Floor	25,4mm	90°		Front Floor	25,4mm	90°
Back Floor	12,7mm	90°		Back Floor	12,7mm	90°
Roof	19,1mm	90°		Roof	19,1mm	90°

* all angle measurements taken from vertical

As WoT’s T25 AT is based on an essentially unmodified T23 chassis, the armor values are quite similar. However, a few small modifications were made on the in-game design, including the removal of the T23’s side skirts and hull machine gun. Why the skirts were removed is a mystery, but the machine gun was probably removed because the T25 AT’s status as a tank destroyer rendered it useless. The T25 AT, as a tank destroyer, was intended to fight tanks, not infantry.

In-game, the T25 AT has armor values that generally resemble the historic T23 medium tank. However, certain parts have been noticeably uparmored, including the side and front plate. The casemate of the T25 AT has similar armor values to the rest of the tank, with its front, rear, and roof armor being the same as the hull. The cast gun mantlet is the thickest bit of armor on the tank, offering a maximum of 127 mm of protection. Being an ahistorical design, the casemate’s armor scheme is a creation of Wargaming and is based on the actual T23 tank design with a helping of game balance added.

The casemate’s side armor is thicker than the hull’s and is curved outwards slightly to add more space for the crew. It broadly resembles the production T23’s turret, the same turret that was mounted on 76 mm armed M4 Shermans. Perched atop the casemate are a commander’s cupola of the same type as mounted on the T23 and a fume extractor.

Meet the Gang

The T25 AT has a crew of four in-game: a gunner, a driver, a loader, and a commander who doubles as a radio operator. The entire crew is crammed into the superstructure and, when looking at the tank from the front, the driver sits to the right of the gun, with the commander to the rear. The gunner sits to the left of the gun and the loader sits behind the breech at the rear of the superstructure. Requiring the commander to operate the radio in addition to commanding duties is most likely a space-saving measure, as there is not any room to spare inside the tank for a dedicated radio operator. This four-man crew layout differs from that of other American tank destroyers, such as the M10 or M18, due to a lack of a radio operator. For such an outlandish design, the T25 AT at least features a feasible crew layout.

Engine Enigma

As a central part of game progression, World of Tanks features many unlockable modules for each tank, and the T25 AT is certainly no exception. Included in the list of available modules for this tank are two different engines and two different suspension systems.

The first engine is the Ford GAN, which was the historical engine used to power the T23 medium tank on which this tank is based. The GAN is extremely similar to the Ford GAA engine used in the M4 Sherman. However, the T25 AT’s Ford GAN in the game is slightly more powerful than the engine in real life. The fake tank’s engine outputs 560 hp compared to the actual engine’s 500 hp. The T25 AT’s engine is also 72 kg (159 lbs) lighter than the T23’s. Therefore, the T25 AT’s Ford GAN engine was the same engine used in the T23 prototypes, but with some ahistorical improvements to decrease its weight and improve its power output, likely for the sake of game balance.

The second unlockable engine is listed as the Continental AV-1790-1. While the AV-1790-1 was in development around the time the T23 prototypes were being tested, it would make little sense to consider mounting it in the tank. The engine project was, from the beginning, designed to give the M26 Pershing a much-needed boost to mobility, not speed up an already fast medium tank. Described in-game as producing 704 hp and weighing 569 kg, this engine has issues with its statistics. In-game, the engine is significantly lighter than in real life, with the actual AV-1790 topping the scales at over 1,100 kg. The real Continental AV-1790-1 had a gross output of 740 hp in optimal conditions and likely would only have produced around 650 net hp or less when configured for use in WoT’s T25 AT. An upgraded version of the same engine, the AV-1790-3, produces 704 net hp, matching the engine described in-game. This is probably an error on Wargaming’s part, with the AV-1790-3 being the engine mounted on the tank but misnamed as the AV-1790-1.

In conclusion, the first of the T25 AT’s engines is the historical Ford GAN engine but with some slight improvements, while the second is a misnomer that was never intended for this chassis.

In addition to two mountable engines, the T25 AT also features two different suspensions, T25T1 and T25T2. However, both suspensions are extremely similar, with their only difference being that the T25T2 has a larger so-called load limit and is required to mount heavier and more powerful modules on the tank, such as a larger gun. Both suspensions look exactly the same and are visually identical to the Sherman-style VVSS present on the T23 prototypes. As such, it can be concluded that these different suspensions and their designations are fictional and are only present in World of Tanks to force the player to grind more experience points.

Radios

The T25 AT is capable of mounting two different radios in-game, the SCR-508 and SCR-506. These radios could both be installed in the actual T23 medium tank, so their configurations on the T25 AT are hypothetically possible.

The first of the radios is the SCR-508. Introduced in 1942, this was the standard American tank radio until the late 1950s. It was fitted to many vehicles in addition to the T23, including the M5 Stuart, M4 Sherman, M7 Priest, M36 GMC, and M26 Pershing. Because this radio was both standard issue and used by the T23 medium, it is the most historically accurate choice for the T25 AT. If the vehicle existed and was produced, the SCR-508 would have been the radio it used.

The second radio is the more powerful SCR-506, which was also fitted to the T23. However, it was only used by the command variant of the T23. Of the two radio configurations present for the T25 AT, the SCR-506 is certainly the least realistic. This was a radio intended for a command tank, not a tank destroyer. A specialized anti-tank vehicle’s standard radio, for example, the SCR-508, does its job perfectly fine, no upgrades required.

Similar to the two different researchable suspensions available for the T25 AT, the radios serve little purpose in-game other than to extend the amount of ‘experience’ the player needs to earn before they can move on to the next tank. The only difference between the two available radios is their ‘signal range,’ an arbitrary value that serves little to no purpose in World of Tanks. To illustrate the silliness of ‘signal range’ as a game mechanic, the in-game SCR-508’s range is given as a paltry 385 m. However, its actual range is greater than 10 mi, or 16,000 m! Given the largest WoT map has an area of just 9 square km, or 5.59 square mi, maintaining communications with allies should be no problem on any map in the game. The entire gimmick of extremely short radio ranges serves no purpose but to force players to play the game more.

Transmission

The transmission of the T25 AT is also worth a mention, as one of the main reasons why this ‘fake tank’ was supposedly canceled is related to its unreliability. The in-game ‘history’ of the T25 AT states that “One of the reasons given for [the T25 AT’s] cancellation was the Army’s dislike of the tank’s electric transmission.” The T23, as the vehicle on whose chassis the T25 AT is based, also had issues with its electric transmission system.

Mounted at the rear of the tank, this experimental electric transmission was the T23’s main deviation from its predecessor, the T22 medium tank. While this transmission offered many unique and advanced features, including increased engine life and the ability to drive the tank by remote control, Armored Board was not impressed. They saw the remote control feature as superfluous and cited the difficulties with maintaining the complex system as their main reason for canceling the tank in 1943.

Firepower

Fitting with the theme of customization and upgradability, the T25 AT features three gun choices, all of which feature just 10º of traverse to either side. From least to most powerful, they are: the 90 mm M3, 90 mm T15E2, and the 105 mm T5E1.

Of the three guns, the 90 mm M3 is the most historically reasonable choice. It was a useful gun and was used in other designs of the time, such as the T25/T26 medium tank and M36 GMC. The M3 saw extensive service at the end of World War 2 and proved itself in Korea as a serviceable anti-tank weapon.

90 mm M3

	In-game		Historic
Shell	Penetration	Velocity	Penetration	Velocity
M77 AP	160 mm @ 0 m and 0°	853 m/s	140 mm @ 914 m and 0°	823 m/s
M304 HVAP	243 mm @ 0 m and 0°	1066 m/s	201 mm @ 914 m and 30°	1021 m/s
M71 HE	45 mm @ 0 m and 0°	853 m/s	<<45 mm @ 0 m and 0°	823 m/s

In-game, the M3 is capable of firing M77 armor-piercing, M304 high-velocity armor-piercing, and M71 high-explosive rounds. These shell types were available for actual M3 guns, but their penetration values were slightly different than they are shown in-game for the purpose of game balance. The M77 AP performs the closest to real life, with its in-game penetration values reflecting the shell’s actual results reasonably well. The M304 HVAP, however, is significantly less powerful than it should be. Conversely, the M71 HE is much more powerful than it should be. Only guns of very high caliber, 15 cm or larger, have high-explosive shells capable of penetrating that much armor in real life. As for mounting the 90 mm M3 on the T25 AT, its breech and ammunition were the smallest of the three gun choices, so they could have fit the most comfortably inside the already cramped superstructure. The M3 also bears the strongest visual resemblance to the proposed gun for the design this tank is based on.

90 mm T15E2

The 90 mm T15E2, the same gun used by the much heavier T32 and experimental T26E4, is neither a sound nor a historically accurate weapon for mounting in a small vehicle like the T25 AT. The T15E2 was developed to compete with the firepower of the German 88 mm KwK 43 and is a reconfiguration of the T15E1 cannon used on the first T26E4 ‘Super Pershing’, with the only main difference being the rechambering of the gun for two-piece 90 mm rounds. This caused a decrease in the gun’s rate of fire but fixed the awkwardness of loading such a long shell in the confines of a tight turret. However, this gun was developed in 1945, long after the T23 had been ‘canceled’ in 1944.

90mm T15E2
	In-game			Historic
Shell	Penetration	Velocity	Shell	Penetration	Velocity
M77 AP	170 mm @ 0 m and 0°	945 m/s
M304 HVAP	258 mm @ 0 m and 0°	1219 m/s	T44 HVAP	373 mm @ 9 m and 0°	1143 m/s
M71 HE	45 mm @ 0 m and 0°	975 m/s	T42 HE	<<45 mm @ 0 m and 0°	975 m/s

The T15E2 is listed as firing the same rounds as the shorter 90 mm M3 in-game, which is partly historically accurate. While the T15E2 and M3 could fire the same projectiles, the shells themselves are not identical. For use in the T15E2’s two-piece breach, the projectiles had to be separated from their propellant. The shells also underwent slight modifications to their rotating bands, which allowed them to function properly when used with the new high-velocity gun. The shells used by the T15E2 in-game that underwent this transformation, M304 and M71, were redesignated as T44 and T42 respectively to avoid confusion with their unmodified predecessors. The M77 round did not receive these modifications because it was superseded by its improved derivative, the T33 AP round. The T33 was, in turn, modified for use in the T15E2 gun and redesignated as T43.

The addition of a longer gun with larger ammunition and breech would certainly have created an issue of crew comfort and ammo stowage within the casemate. The T15E2 was never intended to be mounted in anything but the T32 heavy tank and serial versions of the T26E4. Its configuration on the T25 AT is a much larger break from reality than the 90 mm M3’s.

105 mm T5E1

	In-game		Historic
Shell	Penetration	Velocity	Penetration	Velocity
T32 AP	198 mm @ 0 m and 0°	945 m/s	177 mm @ 914 m and 30°	914 m/s
T29E3 APCR	245 mm @ 0 m and 0°	1181 m/s	381 mm @ 0 m and 0°	1173 m/s
M11 HE	53 mm @ 0 m and 0°	945 m/s	<<53 mm @ 0 m and 0°	914 m/s

Capping off the arsenal of guns the T25 AT has at its disposal in-game is the massive 105 mm T5E1 cannon. This gun was developed in 1943 and mounted in various heavy prototype vehicles, such as the T29 heavy tank and T28 super-heavy tank. It has three rounds available in-game: the T32 AP round, the T29E3 APCR round, and the M11 HE shell. In real life, the T5E1 gun was able to fire both the T32 and T29E3 rounds. However, there is no mention of the M11 round ever being used.

In-game, the T32 AP round is reasonably accurate to its actual performance, if slightly less powerful than it should be. The T29E3 APCR round, however, is significantly less powerful than it should be. Compared to historical firing tests, the in-game shells have about one and a half times less penetration than they should. Conversely, as is the case in World of Tanks, the M11 HE round is much more powerful than it should be. High-explosive rounds are given exaggerated penetration capabilities in WoT to give them some use in-game, that being increased effectiveness against lightly armored targets. All of these changes to penetration values are in the name of game balance, as unrealistic as they are. After all, in game terms, it is not very fun or fair to fight against a gun that can negate the armor of anything it can possibly fight.

However, there is a good reason why only very heavy tanks with very large turrets or hefty casemates mounted the T5E1 gun. It had a large breech, a long recoil distance, and large shells. Attempting to cram a gun this large in a casemate as small as the T25 AT’s would likely have resulted in many issues. These would include the loader not having enough space inside the tank to load the gun’s large rounds, a severe lack of ammunition stowage, reduced gun traverse limits due to crew positions obstructing the breech’s rotation, severely limited gun depression, and the gun’s weight making the tank front heavy, to name a few.

Everything about this gun and its configuration on the T25 AT is a pipe dream. There would have been no way for a cannon of the T5E1’s length and weight to fit inside the casemate of a vehicle like the T25 AT without many significant issues that would render it next to useless. Of the three guns that the T25 AT has at its disposal in-game, the T5E1 is certainly the most egregious.

Shreds of Truth

While the T25 AT represented in-game is a confusing mess of antiquated design and historically questionable upgrades, it would appear as though a design similar to this was actually proposed. However, very little is known about this obscure vehicle. According to R. P. Hunnicutt’s Pershing,

“In early 1943, a design study called for the mounting of the 90 mm antiaircraft gun on the medium tank T23 chassis and in March such an installation was demonstrated to General Devers, General Barr, and other officers. These tests proved useful in the design of the T25 and T26 tanks later in the year.”

Almost nothing is known about this vehicle other than that it mounts the M1 90 mm anti-aircraft gun and is based on the T23 medium tank chassis. While the T25 AT is most likely inspired by this real, mysterious design, WoT’s interpretation differs drastically on almost all points except being based on the same chassis.

Conclusion

As Wargaming’s official ‘history’ of the tank states, the Army would have been dissatisfied with the horizontal limits of the gun. They would soon have two designs mounting the same gun in a fully rotating turret, the M26 and M36. They also would not have been fond of the electric transmission, as evidenced by their rejection of the T23.

The T25 AT, as present in Wargaming’s World of Tanks, is without a doubt a fake vehicle. It is not the worst of Wargaming’s fake tank crimes, as a historical project that bears some likeness to it existed at some point in the past. However, the in-game representation of this idea is entirely incorrect. It hardly resembles the mock-up visually, if at all, and features modules that could have, within reason, been mounted on such a design, such as the 90 mm M3 gun and Ford GAN engine, juxtaposed by laughably impractical, inaccurate, and downright anachronistic modules, such as the T5E1 gun and Continental AV-1790-3 engine.

T25 AT (Fake Tank) Specifications
Weight	42.72 tons, battle-ready
Armament	90 mm M3 gun (56 rounds) 90 mm T15E2 gun (56 rounds) 105 mm T5E1 gun (40 rounds)
Armor	Hull Upper plate: 88.9 mm Lower plate and side: 63.5 to 50.8 mm Rear: 38.1 mm Roof: 19.1 mm Belly: 25.4 to 12.7 mm Superstructure Front: 88.9 mm Side: 76.2 mm Rear: 38.1 mm Roof: 19.1 mm Detailed armor model available at tanks.gg
Crew	4 (commander, gunner, driver, loader)
Propulsion	Ford GAN, 560 hp, 13.11 hp/t Continental AV-1790-3, 704 hp, 16.48 hp/t
Speed	56 km/h, theoretical maximum
Suspension	Vertical Volute Spring

Sources

Ford Tank Engines (Models GAA, GAF, and CAN)
Patton – A History of the American Main Battle Tank by R. P. Hunnicutt
Pershing – A History of the Medium T20 Tank Series by R. P. Hunnicutt
Firepower – A History of the American Heavy Tank by R. P. Hunnicutt
British Army Staff – AFV Technical Situation Report No. 34, May 1945
Seek, Strike, and Destroy: U.S. Army Tank Destroyer Doctrine in World War II by Dr. Christopher R. Gabel
Images of War: German Assault Guns and Tank Destroyers 1940-1945 by Anthony Tucker-Jones
Heavy Jagdpanzer by Walter J. Spielberger, Hilary L. Doyle, Thomas L. Jentz
Radio Set SCR-508
http://www.radiomilitari.com/scr508.html
Armor-Piercing Ammunition for Gun, 90-mm, M3, Office of the Chief of Ordnance, January 1945 (Lone Sentry)
Sherman turret cupolas
Chieftain Talks: Developing the Pershing
Cartridge, 90mm AP-T, M77
Medium Tank T23
T25 AT – World of Tanks from tanks.gg
T25 AT from the WoT Wiki
T25 AT internal modules and crew | Armor Inspector from wotinspector.com