M15 Half-track

M15 Combination Gun Motor Carriage
An M15A1 CGMC displayed at the Fort Lewis Military Museum.
Type	Self-propelled anti-aircraft gun
Place of origin	United States
Service history
In service	1943–53
Wars	World War II Korean War
Production history
Designer	United States Army
Designed	1940–42
Manufacturer	White Motor Company,
Produced	1942–44
No. built	2,332
Specifications
Weight	10 short tons (9.1 t)
Length	20 ft 3 in (6.17 m)
Width	7 ft 4 in (2.24 m)
Height	7 ft 10 in (2.39 m)
Crew	7
Armor	0–12 mm (0.00–0.47 in)
Main armament	M1 37 mm (1.5 in) gun with 2 × .50 cal (12.7 mm (0.50 in)) M2 Browning machine guns
Engine	White 160AX, 386 in3 (6,330 cc) 6-cylinder, gasoline, compression ratio 6.3:1 128 hp (95 kW)
Power/weight	15.8 hp/ton
Suspension	Halftrack, vertical volute springs; front leaf spring
Fuel capacity	60 US gal (230 l)
Operational range	150 mi (240 km)
Speed	41.9 mph (67.4 km/h)

The M15 Halftrack, officially designated M15 Combination Gun Motor Carriage, was a self-propelled anti-aircraft gun on a halftrack chassis used by the United States Army during World War II. It was equipped with one M1 37 millimeter (1.5 in) gun and two water-cooled 0.5 inch (12.7 mm) M2 Browning heavy machine guns. Based on the M3 Halftrack chassis, it was produced by the White Motor Company and between July 1942 and February 1944, and served alongside the M16 Multiple Gun Motor Carriage.

The M15 evolved from the T28 project, an outgrowth of a 37 millimeter (1.5 in) gun mounted on a M2 Halftrack. Initially designated as the T28E1 Combination Gun Motor Carriage (CGMC), it was accepted into service in 1943 as the M15. While conceived as an anti-aircraft weapon, its 37 mm gun was often used as an infantry support weapon during the later stages of World War II. The M15A1 was an improved variant with air-cooled machine guns mounted below the 37 mm gun. The M15 "Special" was an M15 which mounted a single Bofors 40 mm gun.

During World War II the vehicle served the U.S. Army throughout the Mediterranean, European, and Pacific Theaters of Operations. In the Korean War the M15 served alongside the M16 providing infantry support.

The M15 was based on the M3 Halftrack chassis, adding a coaxially mounted armament of a fully automatic M1 37 mm (1.5 in) gun and two superior placed .50 cal (12.7 mm) M2 Browning machine guns. Manned by a crew of seven, it was 20 feet 3 inches (6.17 m) long, 7 feet 4 inches (2.24 m) wide, 7 feet 10 inches (2.39 m) high, and had a wheelbase of 135.5 inches (3.44 m). The vehicle's armor was up to 12 mm thick and the vehicle itself weighed 10 short tons (9.1 t). The suspension was leaf spring on the front axle and vertical volute spring for the tracks. A 386-cubic inch (6.330 cc) White 160AX, 128 horsepower (95 kW) 6-cylinder gasoline engine gave the M15 a power-to-weight ratio of 15.8 horsepower per ton and a maximum road speed of 41.9 mph (67.4 km/h). Its 60 US gal (230 l) fuel tank provided a range of 150 mi (240 km).