MT-55A Russian Armored Vehicle-Launched Bridge (AVLB)

The MT-55A (Slovak: Mostný tank) is an armored 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 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. The MT-55, Base T-55, was designed and produced by ZTS Martin in 1962 (former Czechoslovakia was one of the countries that build the T-54/55 series under license). The development phase ended in 1967 after which five pre-series vehicles were built. The MT-55A, Base T-55A, series production started in 1969. The transformed T-55A chassis differs 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 mechanized 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 the bridge can be controlled by the crew from inside the tank with the 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 20 meters long and can support loads of up to 50 tons. Later, the MT-55A was modified with a gap measuring mechanism and infrared equipment for bridge laying in darkness. Total production of the MT-55A between 1969 and 1983 amounted to 1,762 vehicles, including 183 export versions MT-55KS (from 1971) and 301 hulls for East Germany's BLG-60 program.