The TR-85 is a main battle tank designed for the armed forces of Romania. Based on the TR-77-580 (Romanian-built version of the Soviet T-55 tank), the TR-85 tank was developed from 1978 to 1985 and produced from 1986 until 1990. A modernization program was initiated in March 1994 in order to upgrade the TR-85 tanks to NATO standards. The result was the TR-85M1 main battle tank, currently the most modern tank in service with the Romanian Land Forces. Although a further development of the T-55, the TR-85M1 uses a T-block powerpack (similar to the one used in the Leopard 1) based on a V8 German 830 hp diesel engine, an improved turret, a locally-designed "Ciclop" fire control system (with cross-wind sensor, laser rangefinder and night vision), new 100 mm BM-412 Sg APFSDS-T projectiles and a completely redesigned suspension with 6 road wheels on each side, protected by metal side skirts. Its combat weight is 50 tons.