In addition to a new boiler and firebox, advancements over the class L included a centralized lubrication system, pneumatic grates, power reverse, and roller bearings on all axles.

[1] Upon arrival at the SZD testing facility in June 1952 the prototype locomotive was closely examined and found to exceed previous types in tractive effort and horsepower.

Initially it was planned to construct 3,000 locomotives of class LV, but in February 1956 at the 20th Communist Party Congress it was decided that a broad program of railway modernization would be embarked upon.

[1] The first prototype of class LV entered service on the Moscow-Kursk-Donbas line, operating out of Lublin Depot from August 1953 to April 1954 in testing.

Production locomotives entered service on the South Urals, East Siberian and Krasnoyarsk railway lines, where following their introduction train weights increased by 25-30% and coal consumption fell 12-14% on average.

Despite good operational results there were obstacles in introducing the locomotives, including the length of locomotives with six-axles tenders, which made it impossible to turn them at depots with turntables smaller than 30 metres (98 ft).