As America searched for their ideal tank destroyer vehicle, evaluation of a "Cook Interceptor" 8x8 vehicle proved to be successful enough to be considered for a tank destroyer variant holding a 3-inch gun. Initially produced in November 1942 as the 3-inch Gun Motor Carriage T55, the test results and requirements were incorporated into the design of the second unit. The second unit was produced in April 1943 as the 3-inch Gun Motor Carriage T55E1. While the wheeled performance was considered satisfactory, the vehicle's mobility was unsatisfactory against the requirement that the vehicle be as mobile and manoeuvrable as a tank. The vehicle was not accepted into service and was sent to Aberdeen Proving Grounds in August 1943.
Introduced during Update "Hot Tracks" as a reward for Battle Pass: Season II, "Steel Centurion", the 3 inch Gun Motor Carriage T55E1 is a very mobile tank destroyer. The wheeled design brings limitation in is cross-country mobility and turning ability, but gives the T55E1 unprecedented forward and reverse speed for a 3-inch gun platform. The 3-inch gun, being so far forward, gives the luxury of presenting as small a target as possible when exposed towards the enemy to fire, especially when utilizing the vehicle's good gun depression. The T55E1 is a very different tank destroyer compared to the usual American line-up, but its gameplay focusing on its low profile and wheeled car mobility gives the T55E1 great hit-and-run characteristics to quickly get in and out of dangerous situations.
Survivability and armour
The armour on the T55 is next to none, even a random burst from a machine gun can easily knock out or critically wound your crew. However, as the armour is paper thin, APHE shells tend not to detonate inside your tank. Your most dangerous enemies will be vehicles equipped with heavy machine guns or autocannons. The ammo rack is your biggest weak spot, however if you only load 10 or 12 shells, your side racks are empty and your centre rack is mostly empty. Any plane is a danger and you should seek cover and hide from them.
- Structural Steel (hull, gun breech)
- Tires (wheel)
|Armour||Front (Slope angle)||Sides||Rear||Roof|
|Hull||6.4 mm||6.4 mm||3.2-6.4 mm||3.2 mm Main ammo stowage and engine compartment|
- All armour is thin structural steel, meaning even rifle-calibre machine guns penetrate it with ease.
- The crew compartment is open-topped, meaning the crew is fully exposed to enemy aircraft or even to tanks.
The T55 can move at around 80 km/h (50 mph) forward and backwards. It drives more like a car than it does a tank and has a hard time to flip. Your wheels can also allow you to climb to vantage points before anyone else.
|Game Mode||Max Speed (km/h)||Weight (tons)||Engine power (horsepower)||Power-to-weight ratio (hp/ton)|
Modifications and economy
The T55E1 uses the 76 mm M7 as its main and only armament. The 76 mm M7 cannon is a high velocity anti tank gun, and can punch through the armour of most tanks all the way up to 6.7. The M62 APCBC shell has enough explosive filler to take down most tanks in one well aimed shot. This cannon may be familiar to players as it is the same armament present on the M10 GMC as well as the M6A1, as well as being similar to the later Shermans' 76 mm cannon. The vehicle however possesses a noticeably better reload than all the aforementioned vehicles due to having 2 loaders. That said, unlike the previous vehicles, the T55E1 not only lacks a turret but also posses a very limited horizontal guidance.
|76 mm M7||Turret rotation speed (°/s)||Reloading rate (seconds)|
The T55E1 is able to use 3 different types of ammunition: AP, HE, and APCBC.
- M79 shot - The M79 is a stock AP round. It lacks the penetration of the M62 APCBC shell and has little use. Once the M62 shell has been unlocked, the M79 should be replaced.
- M42A1 shell - The M42A1 is the stock HE shell the T55E1 has access to. While such shell can be overlooked on similarly armed vehicles, the lack of a machine gun on the T55E1 can lead to difficulties dealing with targets with exposed crew such as a number of SPAAs. As such, it is recommended to bring a small amount of HE shells in order to counter the threat.
- M62 shell - The M62 APCBC shell is the standard shell the T55E1 should use. It is the highest penetrating shell available as well as having explosive filler. As such, it is recommended to use the shell for most opponents, specially armoured ones, but also for flanking as the explosive fillers can prove deadly when used against enemies side armour. As such, it is recommended to bring a considerable amount of APCBC shells.
|Ammunition|| Type of
|Penetration @ 0° Angle of Attack (mm)|
|10 m||100 m||500 m||1,000 m||1,500 m||2,000 m|
|Ammunition|| Type of
| Fuse delay
| Fuse sensitivity
| Explosive mass
(TNT equivalent) (g)
|42||40 (+2)||37 (+5)||1 (+41)||No|
Usage in battles
You should use the T55 as a flanking vehicle or sniper at the beginning of the match. Your speed outclasses other vehicles and you can use it to get to a flanking position or a sniping point before anyone else. Then use your gun's excellent angles to aim at a place where you can see the enemy's side. As mentioned above, try to avoid MG fire and if you can. It is not recommended to shoot on the move as you will tend to miss your shots.
Pros and cons
- Low profile
- Powerful 76 mm cannon
- -10 degrees gun depression gives good capacity in hilly battlefields
- Very high forward and reverse speed
- Great off-road capabilities
- Unparalleled mobility and acceleration
- No armour (even heavy machine guns can knock you out)
- No turret for the tank and cannot turn in place
- Taking damage to one wheel can severely hamper performance
- Doesn't turn very well
- Narrow gun arc
- Heads of crew members stick out of the vehicle - easy to knock out with machine guns
|The T55 and T55E1 GMCs were given the nickname "Cook Interceptor" due to them being designed by the Cook Brothers.|
The Cook Brothers Equipment Company designed an experimental 8x8 wheeled desert vehicle which a prototype of was completed by 1942, according to photographic evidence. The vehicle used a chain drive, and the wheels were set up in two 4x4 bogies, each with it's own engine. The desert vehicle was used as the basis of a wheeled tank destroyer after they received a contract from the US Army in August 1942. One prototype was built by the Allied Machinery Manufacturing Company and was called the T55 GMC (GMC standing for Gun Motor Carriage). The T55 had the front engine moved to the rear of the hull in order to fit the main armament, a 3 inch or 76.2 mm M7 gun, at the front of the hull. After initial testing of the T55 GMC in December 1942, the Cook Brothers were requested by the Army to design an improved version.
The redesigned version of the T55 GMC was named the T55E1 GMC and it was basically a simplified version of the T55; both the T55 and T55E1 gained the unofficial nickname of "Cook Interceptor", signifying their designers. The largest visual difference was a much lower profile. The T55E1 GMC retained the 76.2 mm M7 gun from the T55 GMC, which was mounted in the front of the hull; it was casemate mounted rather than turret mounted. The T55E1 was lighter than the T55 it was based on, and as such it had a significantly improved driving performance. Powered by two Cadillac engines at the rear, the maximum speed of the T55E1 was 80 kilometers per hour or 50 miles per hour.
The single T55E1 GMC prototype was completed in early 1943 and underwent testing at the desert proving grounds of Fort Irwin in California. In the same year the Army decided that all self-propelled gun designs would be based on tracked tank chasses rather than on wheeled chasses. As such the T55E1 GMC project was dropped and it never entered production.
The American T55E1 wheeled tank destroyer was created on the chassis of an experimental all-terrain 8x8 vehicle. The Cook Brothers company received an order for the development of the project in August 1942, and in the fall, the first prototype, named the T55, was ready at the Allied Machinery Manufacturing facility. After the first tests, the military suggested that the designers modify the vehicle, since some issues appeared during the tests. So, at the beginning of 1943, the T55E1 appeared - a more densely assembled and improved version of a promising self-propelled gun.
The T55E1 role in combat was assumed as fire support of advancing infantry, while being able to operate on any type of surface. The T55E1 had no turret, and the massive 76 mm M7 gun was located on the front of the vehicle. This arrangement required the shifting of the power plant of two 110-horsepower engines to the vehicle's rear. At the same time, the SPG received a low profile, sufficient traverse angles and excellent elevation angles. The upgraded T55E1, due to improved driving characteristics and a decrease in total weight, showed a speed of just over 50 mph (80 km/h) in tests and good results in overcoming obstacles. At the same time in 1943, a special commission recommended that the army completely abandon the use of armoured wheeled vehicles in favor of tracked platforms, and the Cook Brothers project was closed. But we are sure that this curious tank destroyer will definitely find a place in War Thunder!
- Other vehicles of similar configuration and role
|USA tank destroyers|
|M36||M36 GMC · M36B2|
|T95||T28 · T95|
|ATGM||LOSAT · M901 · XM1069|
|Wheeled||M3 GMC · T55E1|
|Other||M8 HMC · M50 · M56|
|USA premium ground vehicles|
|Light tanks||LVT(A)(4) · M2A4 (1st Arm.Div.) · M3A1 (USMC) · ▃Stuart VI (5th CAD) · M8 LAC · M8A1 GMC|
|M18 "Black Cat" · Super Hellcat · T18E2 · T114 · M1128 Wolfpack|
|Medium tanks||▃Grant I · M4A5 · Calliope · T20 · M26 T99 · M26E1 · M46 "Tiger" · T54E1 · T54E2 · ▃Magach 3 (ERA) · M728 CEV|
|XM-1 (GM) · XM-1 (Chrysler) · M1 KVT|
|Heavy tanks||T14 · Cobra King · M6A2E1 · T29 · T30|
|Tank destroyers||T28 · T55E1|