The T30 howitzer motor carriage (HMC) was a
United States Army
The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...
self-propelled gun
Self-propelled artillery (also called locomotive artillery) is artillery equipped with its own propulsion system to move toward its firing position. Within the terminology are the self-propelled gun, self-propelled howitzer, self-propelled mo ...
used in
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
. Its design was based on requirements for an assault gun issued by the
Armored Force in 1941 and it was built as an interim solution until a fully tracked design was complete.
Produced by the
White Motor Company, the vehicle was simply a
75 mm Pack Howitzer M1 mounted on a modified
M3 Half-track. It was first used in combat in the
North African Campaign
The North African campaign of World War II took place in North Africa from 10 June 1940 to 13 May 1943, fought between the Allies and the Axis Powers. It included campaigns in the Libyan and Egyptian deserts (Western Desert campaign, Desert Wa ...
in November 1942. It later served in
Italy
Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...
and
France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...
, and possibly in the Pacific. Some were later leased to
French forces and the type was used as late as the
First Indochina War
The First Indochina War (generally known as the Indochina War in France, and as the Anti-French Resistance War in Vietnam, and alternatively internationally as the French-Indochina War) was fought between French Fourth Republic, France and Việ ...
in the 1950s.
Specifications
Based on the
M3 Half-track, the T30's specifications were similar to its parent vehicle. It was 20 ft 7 in (6.28 m) long, 7 ft 3.5 in (2.22 m) wide,
[Ness (2002), p. 207.] 8 ft 3 in (2.51 m) and high, and weighed 10.3 short tons (9.3 t).
[Bishop (1998), p. 81.] The suspension consisted of
vertical volute springs for the tracks and
leaf springs for the wheels, while the vehicle had a fuel capacity of 60 US gallons (230 L). It had a range of and had a speed of 40 mph (64 km/h),
[Berndt (1993), p. 152.] and was powered by a White 160AX, 147 hp (110 kW),
386 in
3 (6,330 cc), six-cylinder,
gasoline engine
A petrol engine (gasoline engine in American and Canadian English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as Autogas, liquefied petroleum gas and Common ...
, with a
compression ratio
The compression ratio is the ratio between the maximum and minimum volume during the compression stage of the power cycle in a piston or Wankel engine.
A fundamental specification for such engines, it can be measured in two different ways. Th ...
of 6.3:1. It had a
power-to-weight ratio
Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement ...
of 15.8 hp/ton.
Gun specifications
The T30's main armament was a short barreled
pack howitzer. The 75 mm Pack Howitzer M1 as mounted could depress nine degrees, elevate 50 degrees, and traverse 22.5 degrees to each side. The vehicle had stowage for sixty rounds of 75 mm ammunition and, although it was not designed for anti-tank use, it had a
high explosive anti-tank (HEAT) shell that could penetrate of armor. The gun shield had 0.375 in (9.5 mm) thick armor, designed to stop a .30 cal (7.62 mm) bullet from away.
[Yeide (2008), p. 40.]
Development
The T30 HMC was originally conceived in 1941 as an interim design to fulfil the
Armored Force's requirement for an
assault gun
An assault gun (from , , meaning "assault gun") is a type of armored infantry support vehicle and self-propelled artillery, mounting an infantry support gun on a protected self-propelled chassis, intended for providing infantry with heavy di ...
to equip tank and armored reconnaissance units.
[Hoffman & Staary (2013), p. 149.] The Ordnance Department design was based on the M3 Half-track in order that it could be brought into service quickly. A prototype vehicle was authorized in October 1941 armed with an M1A1 75 mm Pack Howitzer and a mount that was designed to fit on a simple box structure in the back of an M3 Half-track.
Authorization for the production of two prototypes was given in January 1942;
[Chamberlain & Ellis (1969), p. 189.] first deliveries of the vehicle were made the following month from the
White Motor Company.
[Doyle (2011), p. 393.] As it was seen as a temporary solution it was never given type classification.
[Zaloga (1994), pp. 36–37] In September 1942, the T30 was partially replaced by the
howitzer motor carriage M8 (the same gun, but mounted on an
M5 Stuart). After that, it was declared as "
limited standard".
[Green & Green (2000), pp. 45–46] A total of 500 were produced,
[Ness (2002), p. 193.] all by the White Motor Company.
[Hunnicutt (2001), pp. 118–121]
Service history
The T30 HMC entered service in November 1942, seeing action for the first time in the
North African Campaign
The North African campaign of World War II took place in North Africa from 10 June 1940 to 13 May 1943, fought between the Allies and the Axis Powers. It included campaigns in the Libyan and Egyptian deserts (Western Desert campaign, Desert Wa ...
. In the
1st Armored Division, each armored regiment was issued twelve T30s. Of these, three were used in each regimental reconnaissance platoon, and three were used in each of the assault gun platoons in the three battalion headquarters companies. In addition, the 6th and 41st Armored Infantry Regiments were each issued with nine T30 HMCs, three of them being allocated to each assault gun platoon in the headquarters companies of the armored infantry battalions.
Most infantry divisions in the North African Campaign deployed a "cannon company"
[Zaloga (2011)] equipped with six T30s and two
105 mm T19 HMCs. In one encounter in North Africa, the T30 was used in an attempt to destroy German tanks. Although the T30s fired several volleys, the German tanks were barely damaged by the low-velocity howitzer fire and the T30s were ordered to retreat under the cover of smoke to prevent losses. After several similar experiences, U.S. forces ceased the practice of employing
self-propelled howitzers or mortars in direct combat with tanks.
[Zaloga (1999), pp. 21–22.]
The T30 also served during the
Allied invasion of Sicily
The Allied invasion of Sicily, also known as the Battle of Sicily and Operation Husky, was a major campaign of World War II in which the Allies of World War II, Allied forces invaded the island of Sicily in July 1943 and took it from the Axis p ...
in 1943, the
war in Italy in 1944,
[Zaloga (2013), p. 21] and possibly in the Pacific. It was removed from infantry division use in March 1943, following changes in the organization of US infantry battalions, and was replaced by towed howitzers. The T30 was eventually replaced by the M8 HMC, which was based on the
M5 Stuart light tank, and which began entering service around the same time as the T30. Only 312 T30 HMCs were delivered in their original configuration, as the last 188 were converted back into M3 Half-tracks before they were delivered. Later on, the U.S. leased several to
French forces and some were used as late as the
First Indochina War
The First Indochina War (generally known as the Indochina War in France, and as the Anti-French Resistance War in Vietnam, and alternatively internationally as the French-Indochina War) was fought between French Fourth Republic, France and Việ ...
before the vehicle was retired from service in the 1950s.
[Green (2014), p. 298.]
See also
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List of U.S. military vehicles by supply catalog designation (G-102)
References
Notes
Citations
Bibliography
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Further reading
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External links
T30 75 mm Howitzer Motor Carriageat ''History of War'' website]
{{WWIIAmericanAFVs
World War II armored fighting vehicles of the United States, T30
World War II half-tracks
World War II assault guns
Half-tracks of the United States
World War II self-propelled artillery
Self-propelled artillery of the United States
Military vehicles introduced from 1940 to 1944