the outdated T-26 from production in 1940 and replace it with a completely new model, the T-50 light tank. The German-Soviet War The T-26 formed the backbone of the Red Army's armoured forces during the first months of the German invasion of the Soviet Union in 1941. On 1 June, the Red Army had 10,268 T-26 tanks of all models, including armoured combat vehicles based on the T-26 chassis. The T-26 made up 39.5 percent of the tank strength, by number. T-26s composed a majority of fighting vehicles in Soviet mechanized corps of border military districts. For example, the Western Special Military District had 1,136 T-26 tanks on 22 June 1941 (52% of all tanks in the district). Mechanized corps of the Southwestern Front (formed from units of Odessa Special Military District and some units of Kiev Special Military District after the beginning of the war) were equipped with 1,316 T-26 tanks, making up 35% of all tanks on the front. All in all there were 4,875 T-26 tanks in western military districts on 1 June 1941. However, some T-26 tanks were not operationally ready because of shortages of parts like batteries, tracks, and road wheels. Such shortages left around 30% of available T-26 tanks disabled. Additionally, about 30% of the available T-26 tanks had been produced in 1931–1934 and had limited service life. Thus five Soviet western military districts had about 3,100–3,200 T-26s of all models in good order (approximately 40% of all tanks in the districts in question), which was only slightly less than the number of German tanks intended for invasion of the USSR. By the summer of 1941, most of the Red Army's vast numbers of tanks were suffering from serious wear and tear. Poor quality roads, the vulnerabilities of track design in the early 1930s, and inadequate maintenance, recovery and repair services all took their toll. In some of the front line armoured units, up to half of the T-26, T-28 and BT tanks had major drive train components (engine, transmission or suspension) which were broken down or completely worn out, and these disabled tanks were parked and cannibalised for spare parts to keep the rest running. Tanks damaged during the 1939 Winter War with Finland were also cannibalised for parts. The planned replacement for the T-26 was the T-50 light tank, adopted for the Red Army in February 1941. The sophisticated T-50 was developed