M-8 Ridgeway Armored Gun System (AGS)

The M-8 Ridgeway Armored Gun System (AGS) was developed by FMC (now United Defense) as a lightweight Airborne tank, a replacement for the M-551 Sheridan Light Tank. Light forces in the U.S. military need more powerful direct support weapons, a niche the air-transportable and air-dropable M8 AGS could fill.

The prototype was named the XM8 Armored Gun System (AGS) incorporating the Rheinmetall 105mm XM35 rifled tank gun on a tracked chassis with a welded aluminum hull. The gun system incorporates an auto-loader which permits operation with a crew of three. It appears to be a tank, but in its base configuration there is no armor, only a thin aluminum skin.

M-8 AGS power pack
M8 AGS Power Pack.

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M-8 Ridgeway Armored Gun System (AGS)

A unique feature of M-8 Ridgeway Armored Gun System (AGS) design provides for rapid installation of add-on, modular armor protection to tailor the M8 AGS to meet the threats expected during a deployment. The three armor levels are:

  • Level I aluminum soft skin
  • Level II resists armor piercing small arms and small cannon fire
  • Level III resists cannon up to 30mm

The armor configuration can be changed on the ground after arrival of the M8 AGS.

Another advanced engineering feature is the power train of the AGS, designed for battlefield sustainability. The M8 AGS engine achieves 90% parts commonality with the HEMTT family of vehicles and uses a standard M2 Bradley Fighting Vehicle transmission. Generating 550hp using JP8 fuel, the engine delivers a higher power-to-weight ratio than the M1. The powerpack can be rolled out to the rear of the vehicle in five minutes and can be replaced in five more minutes.

In 1996 the vehicle was adopted as the M8 Ridgeway AGS but the Army cancelled the program in 1997 after only four vehicles were delivered. The cancellation was due to funding limitations, not deficiencies in the M8 AGS. U.S. allies have tested the M8 AGS but none have ordered production quantities (2005).

Specifications of the M-8 Ridgeway AGS

Main armament 105mm (4.12 in) M35 gun
Secondary armament 7.62mm MG and 12.7mm (0.50in) MG or one 40mm Mk 19 grenade launcher
Crew 3
Weight 23,590 kg (23.2 tons)
Height 8ft 4in (2.55m)
Width 2.69m (8ft 10in)
Length (over gun) 8.97 meters (29ft 3in)
Sustained rate of fire 12 rpm
Road speed 72 km/h (45 mph)
Max range 451 km (280 miles)
Manufacturer United Defense

Thanks to Bob Petit for help with this page.

M-8 AGS

M-8 Ridgeway Armored Gun System during testing. Photo: United Defense
M-8 Ridgeway Armored Gun System during testing. Photo: United Defense.

M-8 Ridgeway Armored Gun System during field tests
M-8 Ridgeway Armored Gun System during field tests.

Loading the M-8 Ridgeway Armored Gun System for air transport
Loading the M-8 Ridgeway Armored Gun System for air transport.

M-8 Ridgeway Armored Gun System, Aberdeen Proving Ground
M-8 Ridgeway Armored Gun System, Aberdeen Proving Ground.

M-8 Ridgeway Armored Gun System, equipped with Level III add-on armor
M-8 Ridgeway Armored Gun System, equipped with Level III add-on armor.