Engineering:M7 Priest

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Short description: American self-propelled artillery vehicle
M7 Priest
M7 Priest at APG.jpg
M7 preserved at Aberdeen Proving Ground, Maryland
TypeSelf-propelled gun
Place of originUnited States
Service history
Used byU.S. Army
Argentine army[1]
Austrian Army[2]
Belgian army
British Army
Canadian Army
French Army
Israel Defense Forces
Italian Army
Norwegian army
Pakistan Army
Philippine Army
Philippine Constabulary
Republic of China Armed Forces
Bundeswehr (West German Army)
Yugoslav People's Army[3]
Production history
ManufacturerAmerican Locomotive Company (M7)
Pressed Steel Car (M7B1)
Federal Machine and Welder (M7)
ProducedApril 1942 – July 1945[4]
No. builtM7: 3489, M7B1: 826
M7B2: 127 converted from M7B1[4]
VariantsM7, M7B1, M7B2
Specifications
Mass50,640 lb (22.97 metric tons)
Length19 ft 9 in (6.02 m)[5]
Width9 ft 5 in (2.87 m) with sandshields
Height8 ft 4 in (2.54 m)[5]
9 ft 8 in (2.95 m) over AA machine gun
Crew8[4]

Armour12–62 mm[5]
Main
armament
105 mm M1/M2 Howitzer
69 rounds
Secondary
armament
1 × 0.5 in (12.7 mm) M2 Browning machine gun
300 rounds
EngineContinental R-975 C1/C4
Ford GAA (M7B1)
400 or 340 hp
(298 or 254 kW)
SuspensionVertical volute spring
Operational
range
120 mi (193 km)
Speed24 mph (39 km/h) on road
15 mph (24 km/h) off road

The 105 mm Howitzer Motor Carriage M7 was an American self-propelled gun vehicle produced during World War II. It was given the official service name 105 mm Self Propelled Gun, Priest by the British Army, due to the pulpit-like machine gun ring, and following on from the Bishop and the contemporary Deacon self-propelled guns.

Design and development

During the early stages of World War II, US Army observers realized that they would need a self-propelled artillery vehicle with sufficient firepower to support armored operations. Lessons learned with half-tracks (such as the T19 Howitzer Motor Carriage (HMC) with a 105 mm howitzer on the M3 Half-track chassis) also showed that this vehicle would have to be armored and fully tracked. It was decided to use the M3 Lee chassis as the basis for this new vehicle design, named T32.[6] The pilot vehicles used the M3 chassis with an open-topped superstructure, mounting an M2A1 105 mm howitzer, with a machine-gun added after trials.

The T32 was accepted for service as the M7 in February 1942 and production began that April. The British Tank Mission had requested 2,500 to be delivered by the end of 1942 and a further 3,000 by the end of 1943, an order which was never fully completed.[7][8]

As the M4 Sherman tank replaced the M3, it was decided to continue production using the M4 chassis (the M4 chassis was a development of the M3). The M7 was subsequently supplanted by the M37 105 mm Howitzer Motor Carriage (on the "Light Combat Team" chassis that also gave the M24 Chaffee light tank).[8]

Operational history

A total of 3,489 M7s and 826 M7B1s were built. They proved to be reliable weapons, continuing to see front-line service in the US and other armies well past the end of World War II.[4][9]

North Africa

During the North African campaign, 90 M7s were received by the British Eighth Army in North Africa, which was also the first to use it, during the Second Battle of El Alamein, alongside the Bishop, a self-propelled gun based on the 87.6 mm calibre Ordnance QF 25-pounder gun-howitzer.[10]

The British Commonwealth armies had logistical problems in supplying the M7, as it used US ammunition that was not compatible with standard British artillery pieces or tank guns, and had to be supplied separately.[10] Whereas the Sexton – a rival self-propelled gun developed in Canada - featured the standard British QF 25-pounder (on an M3 or M4 chassis).[6]

Despite supply problems, British Commonwealth forces used the M7 throughout the campaigns in North Africa and Italy.

North-West Europe

During the invasion of Normandy, from June 1944, the artillery regiments of the British 3rd and 50th divisions, and the Canadian 3rd Division were equipped with the M7; however, these were replaced by towed 25-pounder guns in early August.[11][12]

M7 Priest passes by a Humber Scout Car as it moves into position to support an attack on Caen, 8 July 1944.

During the Battle of the Bulge, each US armored division had three battalions of M7s, giving them unparalleled mobile artillery support.[13]

Pacific War

The M7 was also used by US and British forces in Pacific and Asian theaters.

During the Burma campaign, the Priest played a significant role, in particular, at the Battle of Meiktila and the advance on Rangoon (1945).

From early 1944 it was used in the South West Pacific theater, by the US Sixth Army in the later stages of the campaign in New Guinea and surrounding islands. The M7 also saw action in the Philippines campaign, with the US Eighth and Sixth armies.

After World War II

Korean War
M7 Priests remained in use during the Korean War, where their flexibility, compared to towed artillery units, led the US Army on the path to converting fully to self-propelled howitzers.[14] The limited gun elevation of the M7 (35 degrees) hampered its ability to shoot over the tall Korean mountains, so 127 M7B1s were modified to permit the full 65 degrees elevation in a model known as the M7B2. After the Korean War, many of these were exported to NATO countries, notably Italy and Germany.[15]

Israel
Israel acquired a number of M7 Priests during the 1960s and employed them in the Six-Day War, the War of Attrition and the Yom Kippur War where three M7 units, the 822nd, 827th and 829th Battalions in the IDF Northern Command, supported operations in the Golan Heights.[16]

West Germany
The new West German Bundeswehr received 127 Priests as its first self-propelled artillery vehicle. They entered service in 1956 and were used until the early 1960s.

Surviving vehicles

  • Deutsches Panzermuseum Munster (German Tank Museum, Munster).
  • Generalfeldmarschall-Rommel-Kaserne, Augustdorf Germany
  • Major-Radloff-Kaserne (de), Weiden Germany
  • Australian Armour and Artillery Museum, in Cairns, in a World War II US Army paint scheme.
  • Vermont National Guard Library and Museum, Colchester, Vermont
  • General George Patton Museum of Leadership, Fort Knox, Kentucky
  • National Guard armory, Starkville, Mississippi.
  • An M7B1 and an M7B2 at the Texas Military Forces Museum in Camp Mabry, Austin, Texas .
  • An M7 which was used in the Austrian Bundesheer (Army) after World War II is in the private Robert Gill Collection in Austria.[17]
Austrian Bundesheer SPG M7 Priest at the Heeresgeschichtliches Museum in Vienna, Austria.
Austrian Bundesheer M7 Priest at the Heeresgeschichtliches Museum in Vienna, Austria.
  • An M7 by the main entrance outside the barracks of West Virginia Army National Guard base Camp Dawson in Kingwood, West Virginia.
  • Unrestored hulk in kibbutz Kineret, Israel.
  • Displayed outdoors at the Third Infantry Division Museum at Fort Stewart, GA.
  • Display outdoors at National Guard Armory, Savannah, Georgia
  • One M7 on permanent static display at the Philippine Military Academy.
  • One M7 on outdoor display at the American Legion Post #382 in Sanford, NC
  • One M7 on permanent static display at Camp Guernsey in Guernsey, Wyoming.

Variants

M7 at the Tank Museum Brussels (Belgium)
M7
The first M7s produced were based on modified M3 Lee medium tank chassis. To maintain a low silhouette, the howitzer elevation had to be restricted to 35°. In May 1942, after only a month of production, the vehicle was altered to increase its ammunition stowage from 57 to 69 rounds. This was achieved by placing seven rounds on the left wall and five on the right.[4] The M7 also went through a fairly rapid shift from being based on the M3, to having more commonality with the M4 Sherman. The first major example was an adoption of the M4's three-piece housing, single-piece casting and suspension. In British service, some M7s carried a radio set, which took the place of 24 rounds of ammunition.[9]
M7B1
Completing the shift, the M7B1 was fully based on the M4A3 Sherman chassis. 826 M7B1 were produced from March 1944 to February 1945.[4]
M7B2
During the Korean War, the limited elevation of the howitzer became noticeably problematic. 127 M7B1 were modified to permit an elevation of 65° to increase the effective range of the howitzer. The machine gun mount also had to be raised to give a 360° firing arc.[4]
Howitzer Motor Carriage M7 in Korea (1951)
"Defrocked Priest"
As one part of the Allied effort to capture Falaise and break out from the Normandy beachhead, 72 M7s had their main guns removed in the field for service as armoured personnel carriers and were first used in Operation Totalize. These field modified vehicles were referred to as "Defrocked Priests", "Unfrocked Priests" or as "Holy Rollers". The work was done in one week by 250 personnel from 14 British and Canadian Royal Electrical and Mechanical Engineer units.[18] 36 vehicles each were allocated to the 4th Infantry Brigade of the 2nd Canadian Division and the 154th (Highland) Brigade of the 51st (Highland) Division, which led the attack.[19]
Kangaroo
A Canadian armored personnel carrier conversion of the M7 for use by British and Commonwealth units in northern Europe.[20] The Kangaroo could carry 20 infantry plus a crew of two. A total of 102 were converted between October 1944 and April 1945. The name "Kangaroo" became generic for all conversions of armored fighting vehicles into personnel carriers, including Ram tank conversions.[9]
25pdr Howitzer Motor Carriage T51
M7 fitted with 25 pounder gun in July 1942.[21]

British SPG naming scheme

A British self-propelled gun armed with the Ordnance QF 25-pounder in design from 1941 was nicknamed Bishop as its appearance was said to resemble a bishop's mitre and a replacement, the US 105 mm Howitzer Motor Carriage M7, was called "Priest", as part of its superstructure was said to resemble a pulpit. Following this line of names, a 1942 self-propelled gun armed with the QF 6 pounder was named Deacon and a 1943 weapon carrier with the QF 25-pounder was called Sexton.

See also

  • G-numbers (SNL G128)
  • List of "M" series military vehicles
  • M108 howitzer

Notes

  1. Tracol, Xavier (October 2011). "Blindorama : L'Argentine 1926–1945" (in fr). Batailles et Blindés (Caraktère) (45): 4–7. ISSN 1765-0828. 
  2. "Rearming Austria: WWII weapons". 14 June 2015. https://wwiiafterwwii.wordpress.com/2015/06/14/rearming-austria-wwii-weapons/. 
  3. Kočevar, Iztok (August 2014). "Micmac à tire-larigot chez Tito: L'arme blindée yougoslave durant la Guerre froide" (in fr). Batailles et Blindés (Caraktère) (62): 66–79. ISSN 1765-0828. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Zaloga, Steven J. (2013). M7 Priest 105mm HMC. Oxford, United Kingdom: Osprey Publishing. p. [page needed]. ISBN 978-1-78096-023-4. 
  5. 5.0 5.1 5.2 Icks, AFV No. 26
  6. 6.0 6.1 Bishop, p. 120.
  7. Icks, R. AFV Profile 26 – Hellcat, Long Tom and Priest
  8. 8.0 8.1 Chamberlain & Ellis British and American Tanks of World War II 1969 p. 138
  9. 9.0 9.1 9.2 Norris, John (2012) World War II Tanks and Trucks The History Press. ISBN:0-75249-073-7
  10. 10.0 10.1 Bishop, p. 121.
  11. John Keegan, Six Armies in Normandy, The Viking Press, New York, 1982, pp. 126–27
  12. Advanced Squad Leader, British Vehicle Notes, The Avalon Hill Game Co., Baltimore, MD, 1988, p. H61
  13. Collins, Michael. King, Martin. Voices of the Bulge: Untold Stories from Veterans of the Battle of the Bulge. MBI Publishing Company, 2011. p. 193
  14. Gourley, Scott R.. "The Korean War's Land Battle Legacy". http://www.defensemedianetwork.com/stories/the-korean-wars-land-battle-legacy/. 
  15. Zaloga, Steven J. (2013). M7 Priest 105mm Howitzer Motor Carriage. Osperey Publishing. p. 45. ISBN 978-1-78096-025-8. https://books.google.com/books?id=yrSdCwAAQBAJ&q=israeli+m7+priest&pg=PA46. Retrieved 31 March 2016. 
  16. Asher, Dani (2014). Inside Israel's Northern Command: The Yom Kippur War on the Syrian Border (2016 US ed.). Lexington, Kentucky: University of Kentucky Press. ISBN 978-0-8131-6766-4. https://books.google.com/books?id=zyONCwAAQBAJ&q=180mm+gun+syria&pg=PT29. Retrieved 31 March 2016. 
  17. militarymuseum.at Vehicle register (listed under "Various SPG")
  18. Ken Tout, A Fine Night For Tanks – The Road to Falaise, Sutton Publishing Ltd., Stroud, Gloucestershire, UK, 1998, pp 40 – 41
  19. Advanced Squad Leader, British Vehicle Notes, The Avalon Hill Game Co., Baltimore, MD, 1988, p. H63
  20. Jones, Richard. Tanks. Zenith Imprint, 2004. P.44
  21. Chamberlain & Ellis,p139

References

External links