A casing between the dome and chimney covered a steam drier pipe.

It was designed and built by the Kolomna Locomotive Works shortly after World War II under supervision by L.C.

In conjunction with the FD class 2-10-2, it was primarily used to haul mainline goods across the terrain of the Soviet Union.

Over 4,000 L class locomotives were constructed from 1945-1955, and they operated with the Soviet Railways until 1975.

Today there are over 300 example of L class locomotives surviving in various states of repair in the former Soviet Union, constituting the single largest surviving class of locomotives in the world.