M47M Armoured Vehicle-Launched Bridge (AVLB)

DESCRIPTION :

The Military Vehicle Research and Development Establishment at Rawalpindi, has developed an Armoured Vehicle-Launched Bridge (AVLB) based on the turretless chassis of an M47M tank for the Pakistan Ministry of Defence. The project has been described as a step towards indigenous development and self-reliance. For details of the original M47M tank refer to Jane's Armour and Artillery 1994-95 page 140. The bridge-launching mechanism is installed on the hull of the turretless M47M and is used to launch an aluminium alloy folding scissors bridge with a maximum span of 21.4 m. The bridge has a maximum clear span of 20.3 m. The vehicle has a crew of two, a driver and a commander/operator who uses 13 hydraulic cylinders to launch the bridge in about 3 minutes. Power for the hydraulic system is provided by the M47M launch vehicle's main engine.

The bridge-launching sequence commences with the main launching cylinder lifting the main launching beam from its transport position. When the bridge reaches an angle of 45 the bridge unloading cylinder is operated and starts to retract. As it retracts it pulls a set of two steel ropes, passing over a system of pulleys and joined to the further part of the bridge. This initiates the bridge unfolding sequence. The travel of the main launching cylinder and the bridge-operating cylinder continues until the nearest part of the bridge rests on the ground in front of the launcher. In this position the launching cylinders block the movement of the launching frame and the bridge is pushed further by auxiliary cylinders. The fulcrum of operation shifts and the operation of the bridge-opening cylinders continues until the bridge is fully open. The bridge is then lowered into position by the main operating cylinder. At this point the operator actuates three unlocking cylinders disengaging the launching beam from the bridge. A mechanical lock is opened at the same time allowing the launching vehicle to move away from the bridge. The bridge is recovered in the reverse sequence. If the launch vehicle engine or the hydraulic pumps fail, there is provision for manual launching of the bridge. The M47M launcher can also be used to lay a short single-span bridge. This bridge is one half of the folding 21.4 m bridge fitted with an extra set of folding ramps. No details are available regarding this variant but it is assumed that it is launched in the same manner and sequence as the full-size folding bridge.

SPECIFICATIONS :

AVLB
Crew: 2
Weight: 54,000 kg
Width: 4 m
Height: 3.83 m

Bridge
Weight: 9,800 kg
Max span of bridge: 21.4 m
Max clear span: 20.3 m
Bridge width: 4 m
Distance between treadways: 0.96 m

STATUS : Prototype.

COMPANY NAME : Military Vehicle Research and Development Establishment