M102 howitzer
M102 | |
---|---|
Production history | |
Designed | 1962 |
Manufacturer | Rock Island Arsenal |
Specifications | |
Mass | 1,496 kg (3,298 lb) |
Length | Travel: 6.40 m (21 ft) |
Barrel length | 32 calibres[1] |
Width | Travel: 1.96 m (6 ft 5 in) |
Height | Travel: 1.59 m (5 ft 3 in) |
Crew | 8 |
Shell | 105 × 372 mm R |
Caliber | 105 mm (4.1 in) |
Action | Vertical sliding-wedge |
Recoil | Hydro-pneumatic |
Carriage | Box trail |
Elevation | −5° to +75° |
Traverse | 360° |
Rate of fire | Maximum: 10 rpm Normal: 3 rpm |
Effective firing range | 11.5 km (7.1 miles) |
Maximum firing range | 15.1 km (9.4 miles) with rocket-assisted projectile |
The M102 is a light,
.Overview
The M102 105 mm howitzer is used in air mobile (helicopter), attack plane, and light infantry operations. The weapon carriage is lightweight welded aluminum, mounted on a variable recoil mechanism. The weapon is manually loaded and positioned, and can be towed by a 2-ton truck or
Resistance to change
Units were initially equipped with the
Many of the more seasoned artillerymen did not want the old cannon replaced. Over the years they had become familiar with its every detail and were confident that it would not disappoint them in the clutch. These experienced artillerymen could offer some seemingly convincing reasons why the M101 was still the superior weapon: its waist-high breech made it easier to load; it had higher ground clearance when in tow; but most important, it was considerably less expensive than the M102.[2] Their arguments, however, were futile.
The new M102 was substantially lighter, weighing little more than 1.5 short tons (1.4 t) whereas the M101A1 weighed approximately 2.5 short tons (2.3 t);
Design
The 105 mm howitzer M102 is a lightweight towed weapon, which has a very low silhouette when in the firing position. The M102 howitzer fires a 33 lb (15 kg) projectile of semifixed ammunition and at charge 7 it will fire to 11.5 km (7.1 mi). It has a muzzle velocity of 494 m/s (1,620 ft/s). The maximum rate of fire is 10 rounds per minute for the first 3 minutes, with a sustained rate of 3 rounds per minute.[3]
A roller tire attached to the trail assembly of the M102 permits the weapon to be rotated 6,400 mils (360 degrees) around a firing platform, which provides the pivot for the weapon. It can be elevated from −89 mils (−5 degrees) to a maximum of 1,333 mils (75 degrees). The panoramic telescope has a four power, fixed focus optical system, with 178 mils (10 degrees) field of view. It contains dry nitrogen gas to retard fogging and condensation. The parallax shield used during boresighting protects the lens.[3]
The trails are made of aluminum alloy. They are a single box trail in wishbone shape, and serve three purposes: mobility; stability; and stowage of section equipment. The lunette is the towing pintle that allows the weapon to be connected to the vehicle. When towing, vehicle has a fixed or seized tow pintle; remove the lock plate located under the lunette. The drawbar has two positions: lowered for travel and raised for firing. There are two lifting brackets to connect slings to when the howitzer is being lifted by helicopter. A third bracket is located on front yoke. The carriage handles are used by crew members to lifting and shifting the howitzer during loading, unloading, and emplacing the howitzer.
The firing platform attaches to the howitzer lower carriage by using a socket and a locking handle. The eight holes are for the stakes needed to stake the howitzer in position. Platform stakes are issued in three sizes. There are four 15 in (38 cm) stakes issued for use in frozen or rocky terrain, and are normally issued only where needed, such as extremely cold areas. There are eight 24 in (61 cm) stakes issued, and are used for hard packed ground. Four 38 in (0.97 m) stakes are issued for use in soft ground.
The first production versions were displayed with a muzzle brake, most likely to allow long range 105 mm rounds to be fired, but was discontinued before shipment to Vietnam.[4]
Current usage
While the M102 is no longer in active use by the United States Army, having been replaced by the
The M102 is also used on the United States Air Force's Lockheed AC-130 gunship. The M102 105 mm cannon was modified to be fired from the left rear side door of the AC-130. To accommodate the cannon, the rear side-firing 40 mm guns were replaced by the radome that formerly had been installed in the door cavity. That change provided enough space for the 105 mm gun to be mounted in the doorway in place of the radome. The gun was first used in the later stages of the Vietnam War.[5] The latest AC-130J Ghostrider gunship was not originally planned to include the 105 mm, but designed with enough spare power and room to mount it at some later point. The Air Force decided to include it in January 2015, starting installation on the third aircraft, then having the first two be retrofitted when guns become available; M102s will be pulled off retiring AC-130Us and put into the AC-130Js.[6]
The M102 is used in extremely limited roles by the United States Marine Corps, primarily for firing salutes.
The
Characteristics
- Caliber: 105 mm (4.13 in)
- Length: 21.8 feet (6.4 m)
- Barrel Length: 32 calibres[1]
- Width: 6.4 feet (2 m)
- Height: 5.2 feet (1.6 m)
- Weight: 1.5 tons (1.4 t)
- Crew: 8
- Rate of fire: 10 rounds per minute maximum, 3 rounds per minute sustained
- Range: 11,500 m (7.1 miles), 15,100 m (9.4 miles) with rocket-assisted projectile
Operators
- Brazil 19
- El Salvador 24
- Jordan 50
- Kurdistan 84 – Used by the Peshmerga[7]
- Lebanon 18[8]
- Malaysia 40[9]
- Oman 36
- Philippines 24
- Saudi Arabia 140
- Turkey
- Thailand 12
- United States – Used on the AC-130J gunships
- Uruguay 15
- Vietnam – Captured from the Vietnam War
Former operators
- Khmer Republic
- South Vietnam – Unknown number used by the Republic of Vietnam Airborne Division
See also
- M101 howitzer – previous American 105 mm towed howitzer
- M119 howitzer – current towed 105 mm howitzer in US Army service
- List of artillery
- List of crew served weapons of the US Armed Forces
References
- ^ ISBN 978-0-415-71068-8. Retrieved 29 October 2016.
- ^ a b c d Global Security. Org, M102 105 mm Lightweight Towed Howitzer
- ^ a b TM 9-100-202-14, TM 9-1015-234-12, TM 9-1015-234-10, AND LO 9-1015-234-10
- ^ "Howitzer Fires In All Directions." Popular Science, September 1966, p. 95, bottom of page.
- ^ "M102 105mm Cannon".
- ^ Ghostrider’s Big Gun: AC-130J Gets 105 ASAP; Laser Later – Breakingdefense.com, 27 January 2015
- ^ Military Balance 2016, p. 491.
- ^ SIPRI Arms Transfers Database
- ^ "SIPRI arms transfer database". Stockholm International Peace Research Institute. 17 June 2011. Retrieved 17 June 2011.
Works cited
- ISBN 978-1-85743-835-2.
External links
- The Army Fact File
- The short film STAFF FILM REPORT 66-19A (1966) is available for free viewing and download at the Internet Archive.