Draft:BT-5

The BT-5 was the second tank in the Soviet BT series of tanks. The BT-5 improved on the previous BT-2, such as a new turret fitted with a 45 mm cannon that was also used on the T-26 and the BT-5's younger brother, the BT-7. The BT-5 had a radio in the turret. The BT-5 would enter service in 1933, with the red army first seeing action with the Second Spanish Republic in the Spanish Civil War in 1937 until the end of World War 2, with between 1884 and 2108 units being produced. Production of the tank began in March 1933.

Design
The BT-5 had no armor improvements over the BT-2, with its thickest armor being 13 mm thick and the thinnest being 6 mm thick. The suspension was a Christie suspension, which could have the tracks taken off to have road-wheels to use on the road. To turn the tank without the tracks, the driver had a steering wheel that turned the first two wheels. It took about a half hour to take off the tracks. The origins of the Christie suspension came from American race car designer J. Walter Christie. When he failed to get the US army interested, he sold the idea to the USSR. Due to American sanctions on the USSR, Christie sold the design as tractors. The armaments of the BT-5 were the 45 mm anti-tank gun M1932 (19-K) cannon and one 7.65 mm DT machine gun with 115 rounds of ammunition for the main cannon. The BT-5 had a crew of three: a commander/gunner, a loader, and a driver. Both the commander/gunner and loader sat in the turret, and the driver sat in the front of the hull. The ammunition was stored in the turret and under the commander, gunner, and loader. The fuel tank could hold 360 liters of fuel, and the BT-5 had an operational range of 200 kilometers. The BT-5 had a maximum speed of 72 kilometers per hour, or 45 miles per hour, on flat roads. The BT-5 had a 400-horsepower M-5 engine and a power-weight ratio of 35 horse power per tonne. The BT-5 was 5.58 meters long 2.23 meters wide 2.25 meters tall and weighed 11.5 tonnes.

Combat History
The first conflict the BT-5 saw was the Spanish Civil War, where 100 BT-5s saw action with the Second Spanish Republic. Francoist Spain would also use some that were captured. The next conflict the BT-5 saw was the Soviet-Japanese Border Conflict. The BT-5 played a major role in the Battle of Khalkin Gol, as they were so fast that Japanese AT gunners could not hit them. But the BT-5 was vulnerable at close range to Japanese soldiers with Molotov cocktails.

The next time the BT-5 saw combat was when the USSR invaded Poland. In the joint Soviet-German invasion of Poland, they did not see much action. The first real challenge for the BT-5 was the Winter War against Finland, where the BT-5 was unable to get past the Finnish defensive line, the Mannheim line, where their thin armor was easily penetrated by Finnish AT guns. The Soviets lost many BT-5s during this conflict. Finnish soldiers used Molotov cocktails and threw them at a weak point near the engine, which, when hit, would cause the engine to catch fire and explode.

After the Winter War, there were still hundreds of BT-5s in service, but many were replaced with the BT-7 and other tanks. On June 22, 1941, Nazi Germany launched Operation Barbarossa, the invasion of the Soviet Union, which caught the Soviets off guard. Soviet losses were appalling at the beginning of the invasion. The BT-5 would be used throughout the rest of the war, but not as much as its younger brother, the BT-7, or the T-34, due to a lack of spare parts. The BT-5 was used more at the beginning of the invasion of the Soviet Union and near the end of the war when spare parts were available.

In Spanish service
About 100 BT-5s were used by the Second Spanish Republic in the Spanish Civil War. The crew of these BT-5s were members of the International Brigades that were trained in the Soviet Union by Soviet tankers. The tanks first saw action in the Zaragoza Offensive on October 13, 1937. 13 tanks were lost, and 12 more were later lost between December 1937 and February 1938 at the Battle of Teruel. A few BT-5s were captured by Francoist Spain and used against the Second Spanish Republic.

In Chinese service
The Chinese Nationalist Army used 4 BT-5's against the Imperial Japanese Army in the Second Sino-Japanese War.

In Finnish service
Finland used many BT-5's they captured during the Winter War. The Finnish Army mainly used them in a defensive role as they were mainly on the defense during the Winter War.