M101 howitzer

Infobox Weapon
name=M101/M101A1 105 mm Howitzer


caption= Marines from 11th Marines, 1st Marine Division fire an M101 105 mm Howitzer during the playing of taps at the Iwo Jima 60th Anniversary Commemorative on 26 March 2005
origin= United States of America
type= Howitzer
is_ranged=yes
is_bladed=
is_explosive=
is_artillery=yes
is_vehicle=
is_UK=
service=
used_by=flagicon|USA USA
flagicon|Bahamas Bahamas
flagicon|Canada Canada
flagicon|Chile Chile
flagicon|Colombia Colombia
flagicon|Croatia Croatia
flagicon|Ecuador Ecuador
flagicon|France France
flagicon|Guatemala Guatemala
flagicon|Indonesia Indonesia
flagicon|Japan Japan - Japan Ground Self-Defense Force
flagicon|Mexico Mexico
flagicon|Paraguay Paraguay
flagicon|Peru Peru
flagicon|Uruguay Uruguay
flagicon|South Vietnam State of Vietnam
flagicon|Serbia Serbia
flagicon|Cambodia Cambodia
flagicon|Yugoslavia Yugoslavia
flagicon|Australia Australia
flagicon|ThailandThailand
flagicon|MyanmarMyanmar
ROC - Republic of China Marine Corps
many others
wars=World War II
Korean War
First Indochina War
Vietnam War

designer=
design_date=
manufacturer= Rock Island Arsenal
production_date=1941-?
number=
variants=
weight= 2,260 kg (4 980 lb)
length= 5.94 m (19.5 ft)
part_length= 22 calibre: 2.31 m (7.58 ft)
width= 2.21 m (7.25 ft)
height= 1.73 m (5.66 ft)
crew=
cartridge=105x372R
caliber=105 mm (4.13 in)
action=
rate=
velocity= 472 m/s (1,548 ft/s)
range=
max_range= 11,270 m (6.9 mi)
feed=
sights=
breech=horizontal block
recoil=hydropneumatic, constant, 42 in
carriage=split trail
elevation=-5° to +66°
traverse=46°

The 105 mm Howitzer M2A1(M101) was the standard medium field howitzer for the United States in World War II, seeing action in both European and Pacific theatres. Entering production in 1941, it quickly entered the war against the Japanese Imperial Army in the Pacific, where it gained a reputation for its accuracy and powerful punch. The M101 fired 105 mm H.E. semi-fixed ammunition and had a range of 11,200 m, making it suitable for supporting infantry. All these important qualities of the weapon, along with its widespread production, led to its adoption by many countries after the war. Its ammunition type also became the standard for many foreign countries' later models. After minor changes in the post war era, the howitzer became known as M101A1. It continued to see service in the Korean War, and Vietnam War. Though a similar model, the M102 howitzer, shared the same roles in battle, it never fully replaced the M101. Today the 101A1 has been retired by the U.S. military, though it continues to see service with many other countries.

The Canadian Forces continued to use the M2A1 as the C1 Howitzer until 1997 when a modification was made to extend its service life. It is now designated the C3. Its improvements include a longer barrel, a muzzle brake, reinforced trails and the removal of shield flaps. It remains the standard light howitzer of Canadian reserve force units.

France and the State of Vietnam used it during the First Indochina War.

A number of M2/M101 howitzers were used by Socialist Federal Republic of Yugoslavia and approximately 50 were inherited by Croatia. Yugoslavia manufactured the M101 as the M56, and 100 of these were inherited by Croatia.

M2 Howitzers are still in service in the Australian Army Reserve, albeit in small numbers. They are gradually being replaced by L118 Light Gun and M198 Howitzers.

This artillery piece was used by 67 countries.

Variants

Gun variants:
*M1920 - prototype.Hogg - "Allied Artillery of World War Two", p 42-49.]
*M1925E - prototype.
*T2, standardized as M1.
*M2 (1934) - minor changes to the chamber to allow use of fixed ammunition.
*M2A1 (1940) - modified breech ring."Technical Manual TM 9-2005 volume 3, Infantry and Cavalry Accompanying Weapons".]
*M3 - lightweight howitzer, with barrel shortened by 27 inches.
*T8, standardized as M4 - vehicle-mounted variant with modified breech and with cylindrical recoil surface.Hunnicutt - "Sherman: A History of the American Medium Tank", p 210.]
*M101 - post-war designation of M2A1 on carriage M2A1.
*M101A1 - post-war designation of M2A1 on carriage M2A2.

Carriage variants:
*M1920E - prototype, split trail.
*M1921E - prototype, box trail.
*M1925E - prototype, box trail.
*T2, standardized as M1 - split trail, wooden wheels.
*M1A1 - M1 carriages rebuilt with new wheels, brakes and other parts.
*T3 - prototype.
*T4 - prototype.
*T5, standardized as M2 (1940) - split trail, steel wheels with pneumatic tires.
*M2A1 - electric brakes removed."Technical Manual TM 9-1325, 105mm Howitzers M2 and M2A1; Carriages M2A1 and M2A2; and Combat Vehicle Mounts M3 and M4".]
*M2A2 - modified shield.

elf-propelled mounts

*Medium Tank M4A4E1 - M2A1 in mount T70.Hunnicutt - "Sherman: A History of the American Medium Tank", p 568.]
*Medium Tank M4(105), M4A3(105) - M4 in mount M52.
*Medium/Heavy Tank M45 - M4 in mount M71.Hunnicutt - "Pershing: A History of the Medium Tank T20 Series", p 233.]
*Experimental mount on Holt tractor - M1920.Hunnicutt - "Stuart: A History of the American Light Tank", p 317.]
*Experimental chassis designed by J Walter Christie - M1920.
*105mm Howitzer Motor Carriage T9 (based on Cletrac MG-2 tractor).Hunnicutt - "Stuart: A History of the American Light Tank", p 329.]
*105mm Howitzer Motor Carriage T19 (based on M3 halftrack) - M2A1.Hunnicutt - "Half-Track: A History of American Semi-Tracked Vehicles", p 236.]
*105mm Howitzer Motor Carriage T32 / M7 - M2A1.
*105mm Howitzer Motor Carriage T76 / M37 (Light Tank M24 chassis) - M4 in mount M5.
*105mm Howitzer Motor Carriage T88 (76mm GMC M18 chassis) - M4 in mount M20.Hunnicutt - "Stuart: A History of the American Light Tank", p 334.]

Ammunition

The gun fired semi-fixed ammunition, with 105mm Cartridge Case M14. The propelling charge consisted of base charge and six increments, forming seven charges from 1 (the smallest) to 7 (the largest). Use of M1 HE rounds prepared for the 105mm howitzer M3 (same projectile and cartridge, but different propelling charge) was authorized."Technical Manual TM 9-1901, Artillery Ammunition", p 167-178.]

HEAT M67 Shell was originally designed as fixed round, with Cartridge Case M14 type II. It was later changed to semi-fixed type with the standard cartridge, but with non-adjustable propelling charge. For blank ammunition, a shorter Cartridge Case M15 with black powder charge was used.

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Notes

References

* cite book
last = Hogg
first = Ian V.
authorlink = Ian V. Hogg
coauthors =
others =
title = Allied Artillery of World War Two
publisher = Crowood Press, Ramsbury
series =
date = 1998
isbn = 1-86126-165-9
* cite book
last = Hunnicutt
first = R. P.
authorlink =
coauthors =
others =
title = Pershing: A History of the Medium Tank T20 Series
publisher = Feist Publications
series =
date = 1971
isbn =
* cite book
last = Hunnicutt
first = R. P.
authorlink =
coauthors =
others =
title = Stuart: A History of the American Light Tank
publisher = Presidio Press
series =
date = 1992
isbn = 0-89141-462-2
* cite book
last = Hunnicutt
first = R. P.
authorlink =
coauthors =
others =
title = Sherman: A History of the American Medium Tank
publisher = Presidio Press
series =
date = 1994
isbn = 0-89141-080-5
* cite book
last = Hunnicutt
first = R. P.
authorlink =
coauthors =
others =
title = Half-Track: A History of American Semi-Tracked Vehicles
publisher = Presidio Press
series =
date = 2001
isbn = 0-89141-742-7
* cite book
last =
first =
authorlink =
coauthors =
others =
title = Technical Manual TM 9-1325, 105mm Howitzers M2 and M2A1; Carriages M2A1 and M2A2; and Combat Vehicle Mounts M3 and M4
publisher = War Department, 1944
series =
date =
isbn =
* cite book
last =
first =
authorlink =
coauthors =
others =
title = Technical Manual TM 9-1901, Artillery Ammunition
publisher = War Department, 1944
series =
date =
isbn =
* cite book
last =
first =
authorlink =
coauthors =
others =
title = Technical Manual TM 9-1904, Ammunition Inspection Guide
publisher = War Department, 1944
series =
date =
isbn =
* cite book
last =
first =
authorlink =
coauthors =
others =
title = Technical Manual TM 9-2005 volume 3, Infantry and Cavalry Accompanying Weapons
publisher = War Department, 1942
series =
date =
isbn =

External links

* [http://www.fas.org/man/dod-101/sys/land/m101a1.htm FAS Military Analysis Network]
* [http://www.pakdef.info/pakmilitary/army/artillery/m101.html Pakdef.info]