T19 Howitzer Motor Carriage

T19 Howitzer Motor Carriage
A T19 Howitzer Motor Carriage.
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	Ordnance Department
Designed	1941
Manufacturer	Diamond T
Produced	January – April 1942
Number built	324
Specifications
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)
Main armament	M2A1 105 mm Howitzer (8 rounds)
Secondary armament	.50 cal (12.7 mm) M2 Browning machine gun
Engine	White 160AX, 386 in^3 (6,330 cc), 6-cylinder, gasoline, compression ratio 6.3:1 147 hp (110 kW)
Power/weight	14.7 hp/ton
Suspension	Front: semi-elliptical longitudinal leaf spring rear: single vertical volute spring bogie
Fuel capacity	60 US gal (230 l)
Operational range	200 mi (320 km)
Speed	45 mph (72 km/h)

The T19 Howitzer Motor Carriage (HMC), was a 105 mm (4.1 in) howitzer mounted on a M3 Half-track chassis. It saw service during World War II with the U.S. Army. Its secondary armament consisted of 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.

Specifications

The T19 Howitzer Gun Motor Carriage was similar to the M3 Half-track, as it shared the same chassis, engine, suspension, armor, and fuel tank. It was 20 ft 2 in long, 6 ft 5 in wide, 7 ft 8 in high, with a weight of 9.54 short tons. The suspension consisted of semi-elliptical longitudinal leaf springs for the wheels and vertical volute springs for the tracks. It was powered by a White 160AX, 147 hp, 386 in³, six-cylinder gasoline engine with a compression ratio of 6.3:1. It was capable of a maximum road speed of 45 mph. The power-to-weight ratio was 14.7 hp/ton.^[1][2]

The vehicle was operated by a crew of six. Maximum armor was only 0.5 inch at the windshield and 0.25 inches everywhere else. The armament consisted of one 105 mm M2A1 howitzer (equipped with eight rounds of ammunition) with a single .50 caliber (12.7 mm) M2 Browning machine gun (equipped with 300 rounds of ammunition) for local defense.^[1][2]

Development

A T19 near Newport News, Virginia.

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 the Adjutant General and the construction of a prototype was authorized by OCM 17391, dated 31 October 1941; the new vehicle designated as the 105 mm Howitzer Motor Carriage T19.^[3][4][5]

As with other American self-propelled guns produced during the early World War II period, the prototype was assembled and tested at the 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 half-track 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.^[6][7]

After the design was accepted, a prototype 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.^[7][8][9]

Service history

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. It was employed mainly in most battalions' headquarter platoons, and the "cannon companies" of infantry divisions.^{[lower-alpha 1]} The T19 was soon replaced in armored divisions by the M7 Priest, a 105 mm howitzer on a fully tracked chassis.^[11][12][13]

It served with only a few units in Sicily and Italy. 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.^[11][12][13] A few served as late as 1945 in southern France.^[11][14][15] It was finally declared obsolete in July 1945. That month, the contractor Brown & McLaughlin converted 90 T19s into M3A1 Half-tracks.^[7][16]

See also

• List of U.S. military vehicles by supply catalog designation

References

Notes

1. A "cannon company" was a unit included in most infantry divisions, which normally consisted of six T30 HMCs and two T19s.^[10]

Citations

1. Hunnicutt 2001, p. 220.
2. Berndt 1993, p. 152.
3. Hunnicutt 2001, p. 112.
4. Zaloga 1994, p. 37.
5. Hunnicutt 1992, p. 329.
6. Zaloga 1994, pp. 37–38.
7. Hunnicutt 2001, p. 113.
8. Ness 2002, p. 196.
9. Doyle 2011, p. 393.
10. Zaloga 1994, p. 36.
11. Zaloga 1994, pp. 37–39.
12. Chamberlain & Ellis 1969, p. 191.
13. Green & Green 2000, pp. 49–50.
14. Green 2014, p. 297.
15. Zaloga 2014, p. 243.
16. Berndt 1994, pp. 26–30.

Bibliography

• Berndt, Thomas (1993). Standard Catalog of U.S. Military Vehicles. Iola, WI: Krause Publications. ISBN 0-87341-223-0.
• Berndt, Thomas (1994). American Tanks of World War II. Minnesota, MN: MBI Publishing Company. ISBN 0-87938-930-3.
• Chamberlain, Peter; Ellis, Chris (1969). British and American Tanks of World War II. New York, NY: Arco Publishing Inc. ISBN 0-668-01867-4.
• Doyle, David (2011). Standard Catalog of U.S. Military Vehicles (Second ed.). Iola, WI: Krause Publications. ISBN 1-4402-2572-9.
• Green, Michael; Green, Gladys (2000). Weapons of Patton's Armies. Minneapolis, MN: MBI Publishing Company. ISBN 0-7603-0821-7.
• Green, Michael (2014). American Tanks & AFVs of World War II. Oxford, UK: Osprey Publishing. ISBN 1-78200-931-0.
• Hunnicutt, R. P. (1992). A History of the American Light Tank: Stuart. Navato, CA: Presidio Press. ISBN 0-89141-462-2.
• Hunnicutt, R. P. (2001). Half-Track: A History of American Semi-Tracked Vehicles. Navato, CA: Presidio Press. ISBN 0-89141-742-7.
• Ness, Leland (2002). Jane's World War II Tanks and Armored Fighting Vehicles. London, UK: HarperCollins. ISBN 0-00-711228-9.
• Zaloga, Steven J. (1994). M3 Infantry Half-Track 1940–1973. Oxford, UK: Osprey Publishing. ISBN 1-85532-467-9.
• Zaloga, Steven (2014). Armored Attack 1944: U.S. Army Tank Combat in the European Theater from D-Day to the Battle of the Bulge. Mechanicsburg, PA: Stackpole Books. ISBN 978-0-8117-4478-2.

Further reading

• Fitzsimon, Bernard (1979). The Illustrated encyclopedia of 20th century weapons and warfare. Milwaukee, WI: Purnell Reference Books. ISBN 978-0-839-36175-6.
• Hogg, Ian V. (1976). Guns, Nineteen Thirty-Nine to Forty-Five. New York, NY: Random House. ISBN 0-34524-9917.
• Hogg, Ian V. (1976). The Guns of World War II. London, UK: MacDonald and Jane's. OCLC 602933317.
• Hogg, Ian V.; Perrett, Bryan (1989). Encyclopedia of the Second World War. Harlow, UK: Longman. ISBN 978-0-582-89328-3.

External links

• T19 105 mm Howitzer Motor Carriage