Would you like to see this in-game?
M4E6 (S/N 30253) w/ High-Speed Reverse Transmission
Hello everybody. I’d like to suggest a specific M4E6 equipped with High-Speed Reverse Transmission for the US ground forces tech tree in War Thunder. This M4E6 had High-Speed Reverse Transmission, which enabled the tank to operate all five gear ratios in reverse, greatly improving its reverse speed and overall ability to reposition and withdraw compared to production Shermans. With its unique transmission and experimental characteristics, the M4E6 would make for a compelling and unique addition to the game as either a Battle Pass reward or a special event vehicle.
History
It was already well known that Shermans suffered from very low reverse speeds, only about 3 mph (5 km/h). This limitation was from the low reverse gear ratio (5.65:1), which had been set to provide adequate hill-climbing ability. While it allowed the tank to back up slopes if needed, it made reverse driving extremely slow on level ground.
Based on combat experience as the first operators of the M4 Sherman in North Africa, the British submitted one of their first requests for an improvement to the reverse speed. In response, the Ordnance Department recommended the design of a High-Speed Reverse Transmission in April 1943 and ordered six tanks with a reduced reverse gear ratio. Early engineering tests confirmed that while the modification substantially improved reverse speed, it compromised the tank’s ability to climb hills or inclines.
The solution was to install a secondary planetary gearbox at the back of the transmission. This allowed the transmission to operate with all five forward gear ratios also available in reverse. The new system included a low-level oiling system that reduced oil capacity from 43 to 20 gallons, lowered operating temperatures, and transmitted an additional 25 horsepower to the sprockets. To extend bearing life, the propeller shaft was also shortened by 5 inches.
On April 30, 1944, OCM 23548 officially recommended testing the high-speed reverse and low-level oil system at Fort Knox. However, trials were running on for nearly a year. In the meantime, the Armored Board received an experimental M4E6 Sherman armed with the 76 mm gun to test the new transmission. This vehicle, registration number 3038783 (serial number 30253), became the primary testbed.
The M4E6 was based on the M4 chassis but carried the 76 mm M1A1 gun. It featured a combination hull with a welded middle and rear and a cast front, along with a cast turret and gun mount developed from the T23 medium tank. The turret basket and floor were removed to accommodate new wet ammunition stowage, giving the loader access to 11 ready rounds in front and 3 to the rear. Two M4E6s were built at Detroit Tank Arsenal and used for testing improvements to the Sherman design.
The vehicle with S/N 30253 was fitted with the high-speed reverse transmission and demonstrated excellent results. It was later tested again at Fort Knox with revised final drives taken from the M4A3E2 Jumbo, using a gear ratio of 3.36:1 instead of the standard 2.84:1. Although this reduced top speed on level ground, cross-country mobility improved significantly. Reports concluded that both the high-speed reverse transmission and the revised final drive ratio should be adopted for all Sherman variants, except the M4A3, which already showed superior performance.
Unfortunately, the tests were completed too late. By the time recommendations were made, the war in Europe and the Pacific had ended, ending further Sherman development and production before these improvements could be introduced.
Specifications
M4E6 (S/N 30253) w/ High-Speed Reverse Transmission
General Characteristics
Crew: 5
Dimensions:
Length: 232 in (589 cm) without gun
Width: 103 in (262 cm) without sandshields
Height: 108 in (274 cm) over turret hatch
Powertrain:
Engine: Continental R975 C4
Net: 400 hp (406 PS) @ 2,400rpm
Gross: 460 hp (466 PS) @ 2,400 rpm
Transmission: High-Speed Reverse Transmission, 5-forward, 5-reverse
Combat Weight: ~35.3 US tons (32.0 metric tons)
Performance:
Power-to-Weight Ratio:
Net: 11.3 hp/US ton (12.4 hp/metric ton)
Gross: 13.03 hp/US ton (14.3 hp/metric ton)
Speed:
Max. Speed: 20.29 mph (32.64 km/h)
Max. Reverse: 17.49 mph (28.14 km/h)
Armament & Armor
Main Armament:
76mm Gun M1A1 in Mount M62 (T80) in turret
Traverse: 360° (hydraulic & manual)
Max. Traverse Rate: 24°/second
Elevation: -10° to +25°
Firing Rate: 20 rpm
Stabilizer System: Westinghouse gyrostabilizer (elevation only)
Ammo:
Ready rounds: 14
Stowed: 57
Total: 71 rounds
Secondary Armament:
1 x .50 caliber MG HB M2 on AA mount
2 x .30 caliber MGs
Armor Protection:
Hull:
Front: 2.5 in (63 mm)
Side: 1.5 in (38 mm)
Back: 1.5 in (38 mm)
Turret:
Gun Shield: 3.5 in (89 mm) @ 0°
Front: 3.0 in (76 mm) @ degrees
Sides: 2.5 in (64 mm) @ 0-13°
Rear: 2.5 in (64 mm) @ 0°
Top: 1.0 in (25 mm) @ 90°
Images
Regular M4E6 for illustrative purposes. The primary differences of the specific vehicle being suggested are mostly internal.
Regular M4E6 for illustrative purposes. The primary differences of the specific vehicle being suggested are mostly internal.
Image and text of the specific vehicle with the high-speed reverse transmission, both taken from “Sherman, A History of the American Medium Tank”, by R.P. Hunnicutt.
Sources
Thank you for taking the time to read my suggestion! 😃
6 Likes
+1 More Shermans! I said More Shermans waiter!
2 Likes
+1 would this be in a folder?
2 Likes
I feel a weird sense of Déjà Vu with this tank, it’s almost like I’ve made posts about it.
2 Likes
+1, this would be a great battle pass vehicle or event! Fantastic suggestion!
1 Like
32 km/h max speed yikes, +1 anyways
Is there an improved version of this, with an M4A3 hull, stronger engine with the same/similar transmission?
1 Like
