Steam loco, steam locomotive, EM 0-10-0

Notes: The Em (modernizirovannyi - modernised) was developed from the Eu with a higher boiler pressure. Series production commenced at the end of 1931 in parallel with the Eu, and continued at least until the end of 1935, overlapping with the introduction of the Er .32) - there were even a few examples of Em in series 743 and 751, and there were many rebuilds from Eu. An unknown number of Em were built for industrial use with non-MPS numbers such as Em-3732 and -3873, and some of these were eventually taken into MPS stock. Improvements during the production run included welded construction, increased heating surface, and removal of the water purification apparatus; a small number of engines -probably about 20 - were fitted with condensing tenders by Kolomna in 1937-38 for operation in desert conditions but these were rebuilt as standard by the 1950's.