M13 Half-track

The M13 Multiple Gun Motor Carriage (M13 MGMC) was produced by the White Motor Company when the United States needed a mobile anti-aircraft vehicle. Production commenced in July 1942 and ended in May 1943. The only time it was ever used was when the Americans landed at Anzio in January 1944. It was replaced by the M16 Half-track in April 1944.

The M13 evolved from a series of unsuccessful prototypes that were trialed in the period from 1940 to 1942 until it finally started production. It turned out to be an interim solution as the better armed M16 MGMC arrived in 1944. Half of the M13 production were converted into M16s on the production lines.

Design
The M13 Half-track was 6.50 m long, 2.16 m wide, 2.34 m high with a wheelbase of 135.5 in. It had leaf spring suspension for the wheels and vertical volute springs for the front tread. It had a 60 USgal fuel capacity and a 150 mi. The vehicle was powered by a White 160AX, 128 hp, 386 in3, 6 cylinder, gasoline engine, with a compression ratio of 6.3:1. It had a power to weight ratio of 15.8 hp per tonne and weighed 9 tonnes. The armor across most of the vehicle was 0.25 inch (6 mm) thick with a 0.5 inch (12 mm) thick windscreen visor. The vehicle was armed with two M2 Browning machine guns.

T1, T1E1, and T1E2
The first development version of the M13 was the T1, which had two M2 machine guns on a Bendix machine gun mount—as used on jeeps—mounted on an early version of the M2 Half Track Car. This early version was designed in 1940 and was just a prototype. Next came the T1E1 and T1E2 which were much the same, but the T1E2 had the M33 Maxson mount instead of the Bendix mount. (The T1E2 became the M16 Half-track by replacing the M33 with the M45 mount).

T1E3, T1E4 and M13
The T1E3 version came with a Martin Aircraft turret, as used on bombers, with all of the electric systems included. As the last version of the M13, the T1E4 had the same armament as the T1E2 but used the longer hull of the M3 Half-track, which was accepted into production as the M13 Multiple Gun Motor Carriage on 27 July 1942.

With acceptance into production as the M13 Multiple Gun Motor Carriage, a total of 1,103 were produced from 27 July 1942 to 15 May 1943. Half of them (583) were converted into M16s before reaching the army.

Service history
The M13 served at the Battle of Anzio with the VI Corps (United States) of the Fifth United States Army in January 1944. It was used as an anti-aircraft support weapon during the landing at Anzio and then later to repel heavy German panzer attacks on the beachhead. It was replaced three months later by the M16 Half-track in April 1944. Only 139 were deployed overseas by the United States Army.

Variants

 * T1 – Two M2 Browning heavy machine guns mounted on a Bendix mount on early model of a M2 Half Track Car. This model, like most of the others, was a prototype.
 * T1E1 – A modified version of the T1E1. This was another prototype.
 * T1E2 – Same as the T1E1 except the Bendix mount was replaced with the M33 Maxson mount. After the M33 was replaced with the M45 Quadmount it was accepted as the M16 Half-track.
 * T1E3 – Replaced the M33 with a Martin turret designed for use on bombers.
 * T1E4/M13 – The Martin turret was replaced by the M33 and was based on the M3 Half-track. It was accepted as the M13 Half-track in July 1942. Saw action at the Battle of Anzio to repel heavy German attacks. Replaced by the M16 in April 1944.
 * M14 Half-track – Same armament as the M13 but based on the M5 Half-track. Mostly supplied to Britain, where they were converted back to regular half-tracks.