M5 3-inch Gun Motor Carriage

This is an early version of the 3-inch Gun Motor Carriage (GMC) M5. Many changes to stowage and the crew's positions were made during development, and a muzzle brake, shields for the crewmen seated in front of the gun shield, and a rear stabilizing spade were eventually fitted.

The 3-inch Gun Motor Carriage M5 was the first U.S. tank destroyer to carry a heavier gun than the 37mm anti-tank gun, but it was never a popular design and the project was abandoned before production got under way.

In 1941 U.S. Army Ordnance had designed the M6 37mm gun motor carriage, a tank destroyer that carried the standard 37mm anti-tank gun of the day on the back of a ¾-ton truck chassis. 5,380 of these vehicles were produced between April and October 1942, but by then it was clear that the 37mm anti-tank gun was obsolete.

Work began on a series of designs for tank destroyers with heavier guns. The first to get underway was the 3-inch Gun Motor Carriage T1. This mounted a 3-inch anti-tank gun on a chassis based on the Cleveland Tractor Company high speed tractor, an aircraft towing vehicle used by the USAAF. Work began at the end of 1940, and the T1 was standardized in November 1941 as the 3-inch Gun Motor Carriage M5.

The M5 was powered by a 160 hp Hercules diesel engine. The 3-inch gun was mounted at the back of the vehicle, with an open gun shield. There was no crew platform, and the crew operated the gun from the ground behind the vehicle.

The resulting vehicle was disliked by Brigadier General Andrew Bruce, commander of the Tank Destroyer Force. He refused to accept the M5 for his tank destroyer battalions, and instead wanted the 75mm Gun Motor Carriage M3, which was based on a half-track personnel carrier. Although work on this project only began in June 1941 it was standardized in October 1941 and was much more popular than the M5. As a result the M5 program was cancelled before the start of series production.

Rear view of 3-inch GMC M5.

Another view of the same 3-inch GMC M5.

Same 3-inch GMC M5 with modifications.

Later version of the 3-inch GMC M5 with added protection for the crew.