T19 Howitzer Motor Carriage

The T19 Howitzer Motor Carriage (HMC), was a World War II United States Army self-propelled gun mounted on a half-track chassis. Its principal armament was a 105 mm (4.1 in) howitzer with an air-cooled .50 in (13 mm) M2 machine gun for local defense. It was produced by Diamond T between January 1942 and April 1942.

It principally served in the North African Campaign, although some served in the Allied invasion of Sicily and the subsequent Italian Campaign, and even as late as the invasion of southern France in 1944.

The T19 Howitzer Gun Motor Carriage was similar to the M3 Half-track. The T19 was 20 ft 2 in long, 6 ft 5 in wide, 7 ft 8 in high, with a weight of 9.54 short tons (8.65 t). The suspension consisted of semi-elliptical longitudinal leaf springs for the wheels and vertical volute springs for the tracks. Powered by a White 160AX, 147 hp (110 kW), 386 in3 (6.33 l), six-cylinder petrol engine with a compression ratio of 6.3:1, it was capable of a maximum road speed of 45 mph (72 km/h). The power-to-weight ratio was 14.7 hp/tonne. The vehicle was operated by a crew of six. Maximum armor was only 0.5 inch (12.7 mm) at the windshield. The armament consisted of one 105 mm (4.1 in) M2A1 howitzer with a single .50 caliber (12.7 mm) M2 Browning machine gun for local defence.

T19 Howitzer Motor Carriage
Class Vehicle
Type Self-Propelled artillery
Manufacturer Diamond T
Production Period 1942 - 1942
Origin United States of America
Country Name Origin Year
United States of America 1942
Country Name Operational Year Retirement Year
United States of America 1942 1945 View
ManufacturerName Production From Production To Quantity
Diamond T 1942 1942 234 View

In the autumn of 1941, when the Armored Force expanded, an urgent need for self-propelled artillery arose. Although a full-track chassis was preferred, the situation required the use of whatever vehicles were immediately available. The M3 half-track was selected to carry a 105 mm M2A1 howitzer. Although this design had originally been suggested in September 1941, it had not been taken up. However, the urgency of the requirement resulted in the approval by Adjutant General and the construction of a pilot was authorized by OCM 17391, dated 31 October 1941; the new vehicle designated as 105 mm Howitzer Motor Carriage T19.

As with other American self-propelled guns of early World War II, the pilot was assembled and tested at Aberdeen Proving Ground. The M2 recoil mechanism and other parts of the M2 howitzer carriage were used in the vehicle mounting. After several tests, the gun carriage proved fragile on bumpy terrain. The problem was corrected by reinforcing the frame, and redesigning the howitzer mount. Demountable headlights were recommended because of the muzzle blast, although they were not available for early production models. Early models had no shield for the howitzer either, but a foldable shield was added during testing. The gun faced forward, like many other halftrack models. The total traverse was 40 degrees and the elevation was from -5 to +35 degrees. The armored windshield cover was remounted so it could fold onto the hood. After further testing, it was accepted for production.

After the design was accepted, a pilot was shipped to Diamond T as a guide for production. The first production vehicle was delivered to the US Army in January 1942. A total of 324 T19s had been made by the time production ended in April 1942.

The T19 HMC was designed as a stopgap measure until better self-propelled artillery pieces were made; it served in the Tunisia Campaign in North Africa in 1942–43, but the M7 Priest, a 105 mm howitzer on a fully tracked chassis, soon replaced it in armored divisions. On one occasion in Sicily, a T19 company (part of the 16th Infantry Regiment) halted a German tank attack by destroying six tanks, for the loss of one T19. That unit was later awarded the Presidential Unit Citation. A few served in Sicily, Italy, and southern France, as late as 1945. It was finally declared obsolete in July 1945. That month, the contractor Brown & McLaughlin converted 90 T19s into M3A1 Halftracks.

Type Self-propelled gun
Place of origin United States
Service history
In service 1942–45
Used by United States
Wars World War II
Production history
Designer Aberdeen Proving Ground
Designed 1941
Manufacturer Diamond T
Produced January – April 1942
Number built 324
Weight 9.54 short tons (8.65 t)
Length 20 ft 2 in (6.15 m)
Width 6 ft 5 in (1.96 m)
Height 7 ft 8 in (2.34 m)
Crew 6
Armor Howitzer shield: 0.25 in (6.4 mm)
Windshield: 0.50 in (13 mm)
Sides and rear: 0.25 in (6.4 mm)
M2A1 105 mm Howitzer (8 rounds)
.50 cal (12.7 mm) M2 Browning machine gun
Engine White 160AX, 386 in3 (6,330 cc), 6-cylinder, gasoline, compression ratio6.3:1
147 hp (110 kW)
Power/weight 14.7 hp/tonne
Suspension front: semi-elliptical longitudinal leaf spring
rear: single vertical volute spring bogie
Fuel capacity 60 US gal (230 l)
200 mi (320 km)
Speed 45 mph (72 km/h)

End notes