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The BT tanks (Russian: Быстроходный танк (БТ), Bystrokhodny tank, light. "fast tank" or "high-speed" tank[1]) were a series of Soviet cavalry tanks produced in large numbers between 1932 and 1941. They were lightly armoured, but reasonably well-armed for their time, and had much better mobility than other contemporary tank designs. The BT tanks were known by the nickname Betka from the acronym, or its diminutive Betushka.[2]
The direct successor of the BT tanks would be the famous T-34 medium tank, introduced in 1940, which would replace all of the Soviet fast tanks, infantry tanks, and medium tanks in service.
During the Battles of Khalkhin Gol (also known as the Nomonhan Incident), which lasted from May to September in 1939, BT tanks were easily attacked by Japanese "close quarter" teams (tank killer squads which were armed with petrol bottles[9] (later called "Molotov Cocktails"). The Soviet BT-5 and BT-7 light tanks, which had been operating in temperatures greater than 100F on the Mongolian plains, easily caught fire when a molotov cocktail ignited their gasoline engines.
General Georgy Zhukov made it one of his "points" when briefing Joseph Stalin, that his "...BT tanks were a bit fireprone....Conversely, many Japanese tankers held the Soviet 45mm anti-tank/tank guns in high esteem, noting, "...no sooner did they see the flash from a Russian gun, then they'd notice a hole in their tank, adding that the Soviet gunners were accurate too!