M8 Armored Gun System

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M8 Armored Gun System
The M8 Armored Gun System with 105 mm gun
Type Light tank
Place of origin  United States
Weight 19.25 tons (Level I Armor)
22.25 tons (Level II Armor)
24.75 tons (Level III Armor)
Length 8.9 m
Width 2.69 m
Height 2.55 m
Crew 3 (Commander, Gunner, Driver)

Armor Titanium
XM35 105 mm rifled gun (30 rounds)
7.62 mm Coaxial MG (4500 rounds)
Commander: 12.7 mm M2 Browning (210 rounds)
Engine Detroit Diesel Corporation DDC 6V 92TIA
550 hp at 2400 rpm (JP-8),
580 hp at 2400 rpm (diesel)
Power/weight 29.1 hp/ton (32.1 hp/tonne) (Level I)
Suspension Hydropneumatic
Fuel capacity 150 gal.
280 mi (451 km)
Speed Road: 45 mph (72 km/h)
Off road: 30 mph (48 km/h)

The United Defense M8 Armored Gun System is a light tank that was intended to replace the M551 Sheridan in the 82nd Airborne Division, as well as being expected to replace TOW-equipped Humvees in the 2d Armored Cavalry Regiment (2nd ACR). The M8 project was eventually canceled. Its role in the 2nd ACR was eventually taken by the M1128 Mobile Gun System.


In the 1980s, the United States Army began looking for a replacement for their M551 Sheridan light tanks. Several attempts over the years to update or replace the Sheridan had proved unsuccessful. The Armored Gun System (AGS) competition was initiated and in 1992 FMC/United Defense's vehicle was selected. In addition to being expected to replace the Sheridan in the 82nd Airborne Division, it was expected to replace TOW-equipped Humvees in the 2d Armored Cavalry Regiment.

A total of six prototypes were eventually built for the U.S. Army under the designation of the XM8 AGS. The M8 was later type-classified by the U.S. Army in late 1995 and initially slated for production in 1996. The M8 project was canceled in 1997 to free up money for other fledgling programs. In March 2004 at the 82nd Airborne Division's request, the Army approved the transfer of four production vehicles from United Defense's facility in York, Pennsylvania to the 82nd at Fort Bragg in North Carolina. However as of June 2004, this transfer was on hold pending an "ongoing analysis."[1] The M8's role in the 2nd ACR was eventually taken by the Stryker.

United Defense had reportedly sought overseas customers, without success. In late 1997 they parted with FNSS Defence Systems to offer the M8 AGS to the Turkish Land Forces Command. As of 2006, Taiwan at one point expressed interest as a replacement for its fleet of M24 Chaffee/M41 Walker Bulldog light tanks but would not commit following cancellation by the U.S.

Ultra Light Combat Vehicle[edit]

In September 2013, Army leaders revealed that they were looking to procure a mobile airborne protected firepower platform for forced-entry style missions that would be able to contend with future heavily armed adversaries. The role had previously been filled by the M551 Sheridan Armored Reconnaissance Airborne Assault Vehicle, which was removed from service in July 1997. During operations in Iraq and Afghanistan, air assault forces like the 82nd Airborne Division relied on fire support from strike fighters, which risked civilian casualties and was not effective at destroying concealed or covered positions. The Army will spend 24 months narrowing down up to 140 non-developmental platforms to 10 vehicles. The plan is to provide the XVIII Airborne Corps with a light tank which can be flown by C-130 cargo planes and airdropped into a combat zone. The vehicle must have a base armor package capable of defending against 14.5 mm ammunition, be able to bolt on additional armor packages after follow-on forces arrive, and be able to drive off road. Both tracked and wheeled vehicles are being considered, and no specific caliber gun has been chosen. After a light tank is selected, they will buy some for testing and give them to the XVIII Airborne Corps for trials. The Airborne Corps will be equipped with a flotilla of vehicles in a distribution plan called 4-14-44: 4 per platoon; 14 per company; 44 per battalion. Unlike the previous Future Combat Systems program, which sought to create light transportable vehicles for the entire service and was cancelled in 2009 from cost overruns and other factors, the light tank effort is meant specifically to support the airborne mission with armored capabilities. One of the vehicles that could be considered is the Armored Gun System, which was being considered to replace the Sheridan in the late 1990s. The Army was able to buy only six vehicles before the program was terminated. Fort Benning officials say it meets the requirements like it did in 1996, described as "old technology that kills T-72 tanks."[2][3]

On 22 January 2014, the Army issued a notice to industry for a commercial-off-the-shelf air-droppable Ultra Light Combat Vehicle (ULCV). The notice came just as the Ground Combat Vehicle program had its funding drastically cut by 83 percent, leaving it too little to continue fully but enough to be kept as a study effort until budgets are increased. The GCV Infantry Fighting Vehicle is intended to replace some 2,000 M2 Bradley vehicles, which cannot carry a full squad and does not have adequate underbody protection. Protection requirements lead to weight estimates of 60-70 tons for the GCV IFV, too much for the Army's post-Afghanistan expeditionary posture. The ULCV is to be small and light enough to be air-dropped from C-130 and C-17 Globemaster transport planes, fit inside a CH-47 Chinook transport helicopter, and be under-slung from a UH-60 Blackhawk. Vendors must provide a vehicle with a "medium caliber" gun and that is able to carry a nine-man squad, the same number required of the GCV, which is equivalent to a 3,200 lb (1,500 kg) payload. The vehicle will mainly utilize superior mobility to survive in combat environments, rather than heavy armor protection packages. Range on internal fuel is 300 mi (480 km) and it must travel cross-country on trails, over rubble in urban combat zones, and on high-altitude ridges and summits. The mobile protected firepower requirement the proposed vehicle would fill is not currently approved, and the effort is not to create an alternative to the GCV; it is to recognize vehicle protection and mobility shortfalls for special infantry forces like the 82nd Airborne, and is currently just for demonstrating potential capabilities. Potential vendors include General Dynamics, which could offer a version of the Stryker; it has been experimentally air-dropped and is being tested with a 30 mm cannon. BAE developed the M8 Armored Gun System in the 1990s, which was ended in favor of supporting the Stryker and the ill-fated FCS program. Interested industry members had until February 21 to respond to the sources sought notice.[4][5]

Heavy armored vehicles are still suitable in Heavy Brigade Combat Teams that need to survive high-speed avenues of approach like roads that are more likely to be targeted. To avoid this, the ULCV is planned to travel across country on trails 75 percent of the time. The ULCV effort is not meant to compete against the Joint Light Tactical Vehicle program to replace the Humvee light vehicle. Its purpose is to increase the mobility of Infantry Brigade Combat Teams, which is restricted to the speed a soldier can travel on foot, leaving them vulnerable. Dismounts can be carried by Blackhawk helicopters, so the ULCV has to weigh about 4,500 lb (2,000 kg) to be transported with them sling-loaded under a Blackhawk. Some proposed vehicles are similar to open all-terrain vehicles without an enclosed cab. It is unknown how many vehicles the Army would buy, but it will not be standard for every infantry battalion and will not fully motorize IBCTs.[6]

From 9–13 June 2014, the Army will hold a Platform Performance Demonstration (ULCV-PPD) at Fort Bragg for interested ULCV vendors to demonstrate their vehicles' ability to be utilized by infantry squads. Because the effort is not at the acquisition phase, all activities and materials will be provided at no cost to the government. The PPD will have vehicles demonstrate a range of threshold requirements including being driven onto and out of a CH-47 with a full 9-man squad and their equipment on board, ability to operate on various forms of terrain, be rigged and de-rigged by two soldiers within two minutes for sling-load operations, and others. Threshold requirements identify the maximum curb weight of the vehicle at 4,500 lb with a range of 250 mi (400 km).[7]


The basic hull of the M8 is made of welded aluminum alloy, with a unique modular armoring system that allows the vehicle to be equipped according to requirements. The Level I (basic) armor package is designed for the rapid deployment role and can be airdropped from a C-130 Hercules and protects the vehicle against small-arms fire and shell splinters. The Level II armor package can still be carried by C-130, but must be airlanded and is designed for use by light forces in a more serious threat environment, while level III armor is designed for contingency operations and is supposed to provide protection against light handheld anti-tank weapons. Level III armor cannot be carried by C-130. All versions are air-transportable by C-5 Galaxy and C-17 Globemaster III (five and three respectively).

The M8 is armed with the M35 rifled autoloading 105 mm cannon main gun with an M240 7.62 mm machine-gun mounted co-axially. The M35 has a rate of fire of approximately 12 rounds per minute, with a ready capacity of 21 rounds with 9 more in stowage. Power is provided by a Detroit Diesel 6V-92TIA diesel developing 580 hp.


"Thunderbolt" Armored Gun System (Block II)

This technology demonstrator was a test bed to bring Future Combat System technologies to the current force in the near term. Advanced technologies incorporated into this variant include hybrid electric propulsion, band track, improved ceramic/composite armor, Second Generation FLIR Night Vision technology, digitization, a XM-291 120 mm main gun along with its 120 mm auto loader. This demonstrated system upgrade retains the M8's C-130 Hercules air transport capability, as well as the AGS 3-man crew.


  1. ^ Nathan Hodge (4 June 2004). "Seeking `Options,' Army Plans Stryker Gun Airdrop". DEfense Daily. Retrieved 22 September 2013. 
  2. ^ Matthew Cox (20 September 2013). "Army Looks to Mount 30mm Cannons on Strykers". Military.com. Retrieved 22 September 2013. 
  3. ^ U.S. Army in the Market for ‘Light’ Tanks - Nationaldefensemagazine.org, 7 October 2013
  4. ^ Army Seeks Information On Air-Droppable Ultra Light Combat Vehicle - Insidedefense.com, 24 January 2014
  5. ^ Army Looks to Build Air-Droppable Armored Vehicle - Military.com, 28 January 2014
  6. ^ Army Considers Trading Armor for Speed - Military.com, 12 February 2014
  7. ^ "Show up or shut up time" for Ultra Light Combat Vehicle creators - Military1.com, 16 April 2014
  • Miller, D. (2000). The Illustrated Directory of Tanks of the World. pp. 478–480. Osceola, MI: MBI Publishing.
  • Plummer, A. (15 March 2004). Inside the Army. Army To Transfer Four Armored Gun Systems To 82nd Airborne Division.
  • United Defense Unveils Thunderbolt 120 mm Demonstrator. Accessed 24 September 2006.
  • Shirley A. Kan, "Taiwan: Major U.S. Arms Sales Since 1990", November 29, 2012, RL30957, Congressional Research Service, 7-5700, www.crs.gov

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