T42 GMC

 Initially, a new project called for the installation of a 37 mm gun in an open-top turret based on the T9 light tank. Designated as the T42 gun motor carriage, the concept went through several changes. A drawing dated 27 October 1941 showed the 37 mm gun with a coaxial machine gun. A later drawing, dated 11 December 1941, shows the hull lengthened with individually sprung road wheels. A final version dated 15 January the next year lengthened the chassis even more and equipped it with a Christie-type coil spring suspension.

The vehicle was manned by a crew of four. The turret had an armor thickness of 7/8 inches, with a similar thickness on the front hull and 3/8 inches at the side and rear. On 3 April 1942, it was recommended the 37 mm gun be replaced by a more powerful 57 mm gun. This vehicle would go on to become the T49 gun motor carriage.

Above: 11 December 1941 drawing for the T42 GMC
Below: Initial turreted design concept for the T50 GMC

The T42 GMC was the first stage of what would eventually become the M18 Hellcat. However, it also shares several similarities with the T50 GMC. The initial T50 GMC design used a turret and chassis practically identical to the second T42 GMC design, the only real difference between them being the armament. To a further extent, the T50 changes reflected those mentioned for the T42: an elongated chassis and improved suspension. However, these changes for the T50 would transition to a turretless design.

So, I don't think it's too much of a stretch to combine this initial T50 design with the T42 GMC. We can easily borrow the turret from the T50 GMC as an alternate option, along with the 3-Inch gun it was meant to carry. As for engines, we could use the same engine from the M22 Locust and the Continental W-670, used in the T56 GMC (a further development of the T50 project).

This tank should play very similarly to the old (Tier IV) M8A1, but with reduced armor and speed. In return, it could see a comparable improvement in traverse and mobility. If anything, this tank (and the rest of this branch) should play closer to light tanks.

Guns: 37 mm Gun M6; 57 mm Gun M1; 3-Inch Gun T9

Engines: Lycoming 0-435T (192 hp); Continental W-670 (288 hp)

Turrets (Turret Armor (mm)): T42 (22/22/22); T50 (22/22/22)

Suspensions/Alternate Hulls, Total Weight (metric tons): T42 Early (7.43); T42 Late (??)

Hull Armor (mm): 22/10/10

Top Speed: 56 km/h

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


Parent: M22 Locust
Children: T67 GMC
See Also: T50 GMC



Sources:

Hunnicutt, R. P. Stuart. 1992.