M-1/2

Wooden model of a medium tank with a 100-inch diameter turret ring.

Parallel with the development of the T48 tank during the middle of 1951, other studies were being conducted to consider various improvements and an eventual successor. To review these new concepts, the Questionmark conferences were created to stimulate greater interaction between tank designers and tank users. The first of these conferences was held in March 1952.

One study investigated the advantages of an excessively large 100-inch diameter turret ring. Such a turret ring allowed for the mounting of heavier weapons and increased the available interior space for the crew. Seven medium tank concepts were proposed to explore the use of the enlarged turret ring.

The first concept, the M-1 located the driver just inside the turret ring so he had no exit through the hull, rather would need to enter and leave the vehicle through the turret. The other crew members were in their conventional arrangements. The front hull was to be 4 inches and sloped at 60 degrees from the vertical, doubling the effective thickness. However, the side and rear armor was dramatically reduced, especially compared to the T48 tank. Like the T48, it was armed with the 90 mm Gun T139, but it was powered by Continental AOS-895 found in the T41 light tank. The M-1 was estimated to weigh about 40 tons.

M-2.

The second concept, the M-2, had an estimated weigh of 46 tons. It was visually similar to the M-1, even with an identical armor layout and crew arrangement, but the chassis was lengthened to allow for a larger turret with an increased 108-inch diameter ring. The larger turret was necessary because the M-2 used the more powerful 105 mm Gun T140. The M-2 also used the Continental AVS-1195, which was a supercharged version of the AV-1790 used in the T48. The M-2 was 101 inches tall and 262 inches long. There was also the M-3, which was identical to the M-2 except it placed the driver in the turret.

The vehicle I'm proposing, the M-1/2, is a combination of these two designs and takes advantage of the use of alternate hulls. Aside from the side and rear armor of the turret and hull, everything else I look for is thankfully given. However, I've also given the tank the 90 mm Gun T139E1, found on the M47E2, This was basically the same gun as the T139, but with a concentric recoil mechanism, which improved handling of the gun. 

This tank should be expected to play similarly to its respective Patton peer, however in return for better frontal armor and more powerful top gun, it could receive worse gun characteristics and maneuverability. 

Guns: 90 mm Gun T139; 90 mm Gun T139E1; 105 mm Gun T140

Engines: Continental AOS-895 (500 hp); Continental AVS-1195 (685 hp); GMC AX-1100 (717 hp)

Turrets (Turret Armor (mm)): M-1 (102/??/??), M-2 (102/??/??)

Suspensions/Alternate Hulls, Total Weight (metric tons): M-1 (36.28); M-2 (41.73)

Hull Armor (mm): 102/??/??

Top Speed: 48 km/h

Crew: 4 (Driver; Gunner; Loader; Commander/Radio)



Parent: M-4/5
Children: H-1
See Also: M-7/6

Sources:

Hunnicutt, R. P. Abrams, 2015.