The clutch SA-3, Russian Автосцепка СА -3, is a semi-automatic center buffer coupler, which is distributed mainly in the former Soviet states. In addition, it takes place in Finland in iron ore shipments use where the conventional European screw coupling would be overwhelmed in Iraq and in island operation in the iron ore railway in Sweden and Norway.
Technically, the SA- 3 is a further development of the Willison coupling.
Having been in North America since 1898 ( with extended transition periods at least since 1900) all railways were obliged to use the also semi-automatic Janney coupling, also taught the Founded in 1922, UIC 1928, a working group for the development of such a coupling. Since the planning but not progress beyond a definition of the requirements and instead extended these requirements to a level not feasible, the Soviet Union decided to going it alone. In Germany, Scharfenberg couplers had proved concerning resilience and weather resistance in coal trains to be unsatisfactory; Therefore, it was decided in the Soviet Union for the very robust concept by the American Willison.
After 1933, the concept was ruled successively began in 1935 for the conversion of vehicles. The Second World War delayed the introduction, so that the conversion was completed only in 1953.
- Coupling ( railway engineering )