The class L locomotives were one of the more advanced steam locomotives built in the former Soviet Union. They used mechanical stocker to feed coal and had a relatively low axle weight (18 t or 40,000 lb) to be compatible with the war-torn railways of the former Soviet Union. Several examples of these locomotives are still preserved in working order.

First prototype of this locomotive has produced in Kolomna Locomotive Works, (Russia) in 1945. More than 4200 class L steam locomotives were built in Kolomna, Brjansk and Lugansk factories. In Latvia class L locomotives were in operation from 1962 till 1988 as well as sometimes later — for pulling tourist trains.

The steam locomotive class L  No. 0312 was built at Kolomna Locomotive Works, in 1948. Initially the steam engine was sent to Roslawl depot (Western Railway), but since 1963 locomotive was in operation in Baltic Railway: Daugavpils, Jelgava and Riga locomotive depots.

L-0312 is one of the last broad gauge steam locomotive survived in Latvia and it was exhibited in the Latvian Railway history museum since 2010.

Technical data:

Power                                                                         1648 kW

Maximum speed                                                        90 km/h

Driving wheel diameter                                             1500 mm

The total length of locomotive and tender                 23’717 mm

Equipped locomotive and tender weight                    170 t

Fuel                                                                             oil