2-8-4 was a passenger derivative of the Class FD 1’E1’-h2 (2-10-2) freight locomotive and had many parts in common with the Class FD. The Soviet 2-8-4 was the most numerous single Berkshire class built in the world. Kolomna Locomotive Works built the first four locomotives. In 1935, production was transferred to the enlarged and modernised former which was renamed Voroshilovgrad Locomotive Works. A lotal of 649 locomotives of the two variants, Class IS20 and Class IS21 (later Class FDp), were built between 1932 and 1942. After Germany attacked the Soviet Union on 22 June 1941, the Russians evacuated all semi-completed class
2-8-8-8-8-8-2 2-8-8-8-8-8-2 Under the Whyte notation for the classification of steam locomotives, a 2-8-8-8-8-8-2 has two leading wheels, five sets of eight driving wheels, and two trailing wheels. Because of its length, such a locomotive must be an articulated locomotive. It is not longer than a normal articulated; the fourth and fifth sets of drivers are located under the tender. Other equivalent classifications are: UIC classification: 1-D-D-D-D-D-1 (also known as German classification and Italian classification) AAR classification: 1-D-D-D-D-D-1 French classification: 140+040+040+040+041 Turkish classification: 45+44+44+44+45 Swiss classification: 4/5+4/4+4/4+4/4+4/5 The equivalent UIC classification is to be refined to (1'D)DDD(D1'). The Baldwin Locomotive Works