A couple of good high speed machining images I found:
Soviet Higher-Speed Tank BT-five. Советский быстроходный танк БТ-5.
Image by Peer.Gynt
The machine is exposed at Museum-Diorama of Relief of Leningrad Blockade. Leningrad Oblast. Kirovsk District.
The BT tanks (Russian: Быстроходный танк (БТ), Bystrokhodny tank, lit. "fast tank" or "high-speed tank") have been a series of Soviet cavalry tanks developed in big numbers between 1932 and 1941. They were lightly armoured, but reasonably properly-armed for their time, and had the best mobility of all modern tanks of the globe. The BT tanks had been known by the nickname Betka from the acronym, or its diminutive Betushka.
The direct successor of the BT tanks would be the renowned T-34 medium tank, introduced in 1940, which would replace all of the Soviet quick tanks, infantry tanks, and medium tanks in service.
The BT tanks have been "convertible tanks". This was a function designed by J. Walter Christie to reduce wear of the unreliable tank tracks of the 1930s. In about thirty minutes the crew could remove the tracks and engage a chain drive to the rearmost road wheel on each side, enabling the tank to travel at quite higher speeds on roads. In wheeled mode the tank was steered by pivoting the front road wheels. Even so, Soviet tank forces quickly identified the convertible selection of small practical use in a nation with couple of paved roads, and it consumed space and added needless complexity and weight. The function was dropped from later Soviet designs.
Christie, a race auto mechanic[citation required] from New Jersey, had tried unsuccessfully to convince the U.S. Army Ordnance Bureau to adopt his Christie tank design and style. In 1930, Soviet agents at Amtorg, ostensibly a Soviet trade organization, used their New York political contacts to persuade U.S. military and civilian officials to give plans and specifications of the Christie tank to the Soviet Union. At least two of Christie’s M1931 tanks (with no turrets) have been later bought in the United States and sent to the Soviet Union below false documentation in which they were described as "agricultural tractors." Each tanks have been effectively delivered to the Kharkov Komintern Locomotive Plant (KhPZ). The original Christie tanks have been designated quick tanks by the Soviets, abbreviated BT (later referred to as BT-1). Based each on them and on previously obtained plans, 3 unarmed BT-two prototypes were completed in October 1931 and mass production started in 1932. Most BT-2s were equipped with a 37 mm gun and a machine gun, but shortages of 37 mm guns led to some early examples being fitted with three machine guns.
The sloping front hull (glacis plate) armor design and style of the Christie M1931 prototype was retained in later Soviet tank hull designs, later adopted for side armor as properly.
The BT-five and later models had been equipped with a 45 mm gun.
BT-1: Christie prototype with no turret.
BT-2 Model 1932: M-5-400 engine (copy of U.S. Liberty engine), three modifications of turret created: with single 37 mm gun 37 mm gun and 1 DT machine gun twin DP machine guns mount and a single machine gun. In late 1932 modified to BT-three but developed beneath identical designation.
BT-3: identical as BT-2, produced according to metric program (alternatively of Imperial method as utilized for BT-2). In official documentation referred to as BT-2.
BT-four: was a design with welded hull and minor modifications in the suspension. three prototypes made (with partially riveted hull)
BT-5: larger cylindrical turret, 45 mm gun, coaxial DT machine gun. BT-5 Model 1933: new turret with twin hatches and larger bustle.
BT-5PKh: snorkelling variant (prototypes only).
BT-5A: artillery support version with 76.2 mm howitzer (couple of created).
BT-five flamethrower tank: (prototypes only).
PT-1A: amphibious variant with new hull (handful of made).
BT-7 Model 1935: welded hull, redesigned hull front, new Mikulin M-17T engine (licensed copy of a BMW engine), enclosed muffler. BT-7 Model 1937: new turret with sloping armour.
BT-7TU: command version, with whip antenna alternatively of earlier frame antenna.
BT-7A: artillery assistance version with 76.two mm howitzer.
OP-7: flame-thrower version with external fuel panniers (prototype only).
BT-7M[three] (1938, prototypes designated A-8 often referred to as BT-8): new V-two diesel engine replacing earlier gasoline engines, 3 DT machine guns: coaxial, in P-40 AA mount on roof and in a ball-mount on turret rear.
BT-42: Finnish assault gun captured BT-7s had been equipped with British 114 mm howitzers.
BT-43: Finnish armoured personnel carrier captured BT-7s equipped with troop accommodation.
BT-IS: Prototype/proof-of-concept platform with heavily sloped armor forerunner of the armor style on the T-34.
BT-SW-2 Cherepakha ("turtle"): Another prototype, which took the armour sloping to an extreme.
A-20: Prototype for a new BT tank, with 20 mm armour, 45mm gun, model V-2 diesel engine, and 8×6-wheel convertible drive. Lost out in trials to the A-32, which was further enhanced and produced as the T-34 medium tank.
TTBT-five, TTBT-7: teletanks, remote-controlled tanks.
BT tanks saw service in the Spanish Civil War, Battle of Khalkhin Gol (Nomonhan), the Winter War in Finland, the Polish campaign, and in the whole Globe War II.
They first saw action in the Spanish Civil War. A battalion of BT-5s fought on the Republican side, and their 45 mm guns could effortlessly knock out the opposing German and Italian light tanks
Battle of Khalkhin Gol (Nomonhan)
See also: Soviet–Japanese Border Wars
Throughout the Battles of Khalkhin Gol (also recognized as the Nomonhan Incident), which lasted from May possibly to September in 1939, BT tanks had been simply attacked by Japanese "close quarter" teams (tank killer squads) which had been armed with petrol bottles (later named "Molotov Cocktails"). The Soviet BT-five and BT-7 light tanks, which had been operating in temperatures greater than 100F on the Mongolian plains, simply caught fire when a molotov cocktail ignited their gasoline engines.General Georgy Zhukov created it 1 of his "points" when briefing Joseph Stalin, that his "…BT tanks were a bit fireprone…." Conversely, several 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, than they’d notice a hole in their tank, adding that the Soviet gunners were accurate as well!"
Soon after the Khalkhin Gol War in 1939, the Soviet military had broken into two camps 1 side was represented by Spanish Civil War veterans Common P. V. Rychagov of the Soviet Air Force, Soviet armour specialist Basic Dimitry Pavlov, and Stalin’s favored, Marshal Grigory Kulik, Chief of Artillery Administration. The other side consisted of the Khalkhin Gol veterans led by Generals Zhukov and G.P. Kravchenko of the Soviet Air Force. Below this cloud of division, the lessons of Russia’s "first genuine war on a massive scale using tanks, artillery, and airplanes" at Nomonhan (Khalkhin Gol) went unheeded. Consequently, for the duration of the Finland War (Winter War) the BT-2 and BT-five tanks have been significantly less profitable, and it took the Soviet Union three and a half months, and over a million guys to do what Zhukov did in just ten days at Nomonhan.
Following the German war broke out, the Spanish Civil War faction fell in disfavor, with Marshal Kulik in certain getting court-martialed and demoted. Gen. Zhukov and the majority of his surviving Nomonhan veterans had been appointed to commands all through European Russia, in time to engage the German armies.
Globe War II
For the duration of the Second Globe War, BT-5 and BT-7 tanks have been used in the 1939 Soviet invasion of Poland, and in huge numbers in the battles of 1941 – during which thousands were abandoned or destroyed. A couple of remained in use in 1942, but were rare soon after that time. The Red Army planned to replace the BT tank series with the T-34, and had just begun carrying out so when the German invasion (Operation Barbarossa) took spot.
Throughout the final weeks of World War II, a significant quantity of BT-7 tanks took component in the invasion of Japanese-occupied Manchuria, in August 1945. This was the final combat action of BT tanks.
The BT tank series was many, forming the cavalry tank arm of the Red Army in the 1930s, and had a lot far better mobility than other contemporary tank styles. For these motives, there were numerous experiments and derivatives of the design, mostly carried out at the KhPZ factory in Kharkov.
The most important legacy of the BT tank was the T-34 medium tank, arguably the most critical tank of the complete Globe War II. In 1937, a new style group was formed at the KhPZ to produce the next generation of BT tanks. Initially, the chief designer was Mikhail Koshkin and, soon after his death, Morozov. The group built two prototypes. The light 1 was known as the A-20. The much more heavily armed and armoured BT derivative, the A-32, was a "universal tank" to replace all the T-26 infantry tank, BT cavalry tanks, and the T-28 medium tanks. Such strategy was controversial, but concerns about tank performance below the threat of German blitzkrieg led to the approval for production of a nonetheless far more heavily-armoured version, the T-34 medium tank.
Along the way, an critical technical development was the BT-IS and BT-SW-2 testbed cars, concentrating on sloped armour. This proof-of-concept led straight to the armour layout of the T-34.
BT tank chassis have been also employed as the basis for engineering assistance vehicles and mobility testbeds. A bridgelayer variant had a T-38 turret and launched a bridge across little gaps. Common tanks were fitted as fascine carriers. The RBT-5 hosted a pair of big artillery rocket launchers, a single on each side of the turret. Several styles for incredibly wide tracks, such as, oddly, wooden ‘snowshoes’ had been attempted on BT tanks.
The KBT-7 was a completely modern day armoured command automobile that was in the prototype stage when World War II broke out. The style was not pursued during the war.
In the Kiev maneuvers of 1936, foreign military observers were shown hundreds of BT tanks roll by a reviewing stand. In the audience have been British Army representatives, who returned residence to advocate for use of Christie suspension on British cruiser tanks which they incorporated from the Cruiser Mk III onwards. Interestingly, the pointed shape of the hull front armor on the BT tank also influenced the design and style of the British Matilda tank.