MT-55

The MT-55A (Mostní tank) is an armoured vehicle-launched bridge (AVLB) tank, manufactured by ZTS Martin in Slovakia. The AVLB is based on a T-55A medium tank chassis, with the turret detached and replaced by a special bridge launching equipment.

The MT-55A was produced for the armies of the Warsaw Pact - including the Soviet Army -, as well as for export clients.

Design and development
The MT-55A was designed and produced by ZTS Martin from 1962 (the former Czechoslovakia was one of the countries that build the T-54/55 series under licence). The development phase ended in 1967 after which 5 pre-series vehicles were built. Series production started in 1969.

The transformed T-55A chassis differs only by the arrangement of the compartments in the hull. The bridge tank is proposed for an easy and swift crossing of antitank barriers (trenches) and other obstacles with the purpose of facilitating the passage of mechanised and tank units.

The bridge initiating equipment is controlled by a system of hydraulic cylinders; the allocation of hydraulic oil can be controlled both manually by mechanical levers and automatically. The pressure of the liquid is provided by high-pressure piston pumps motorized by the tank engine. All mechanisms of the MT-55A used for laying and recovering of the bridge can be controlled by the crew from the inside of the tank, with hatch covers closed.

To begin the launching process, the vehicle stops short of the gap; then, the bridge swings ahead and down while its two sections open like scissors. The MT-55A span is 18 meters long and can hold up loads up to 50 tons. Later the MT-55A was modified with gap measuring mechanism and infrared equipment for bridge laying at darkness.

Of the MT-55A, a total of 1,762 were produced between 1969 and 1983, including 183 export versions MT-55KS (from 1971) and 301 hulls for East Germany's BLG-60 programme.

Variants

 * MT-55 - Pre-series model, equipped with the bridge of the MT-34 bridge-layer. In Western sources, this model is often erroneously referred to as the MT-55L with "long" bridge.
 * MT-55A - Standard model, as described.
 * MT-55KS (Kapitalstické Státy) - Export model for "capitalist" non-Warsaw Pact countries. Based on the T-55 both otherwise similar.
 * PM-55 (Přepravník Mostu) - Wheeled version, based on a Tatra 813 "Kolos" 8x8 truck.
 * BLG-60 - East German/Polish variant.
 * BLG-67 - Romanian variant.

Operators

 * Egypt - MT-55KS
 * Belarus - MT-55A
 * the Czech Republic - MT-55A
 * Georgia - MT-55A
 * India - MT-55KS, known as Bridge Laying Tank MT-55
 * Iraq - MT-55KS
 * Israel: Israeli Defence Forces (IDF) were able to capture some small number of MT-55KSs from their Arab counterparts and used by the IDF with some small modifications. Most of these were captured on the Southern front (Gaza Strip and Sinai Peninsula) of Six day war.
 * North Korea
 * Romania - MT-55A
 * Russia - MT-55A, known as MTU-55
 * Serbia - MT-55A
 * Slovakia - MT-55A
 * Slovenia
 * Sri Lanka - In 2000 Sri Lanka Army brought eight MT-55As from Czech Republic along with 40 T-55AM2 tanks, 16 VT-55 recovery vehicles, three mobile workshop vehicles, and 12 Tatra T815 tank transporters and several RM-70 122 mm multiple rocket launchers.
 * Syria - MT-55KS
 * Ukraine - MT-55A