The 0-4-0 (0-8-0) Series OB
appeared in the early 20th century and was a typical representative of the old Russian school of locomotive construction.
From 1901-1928, no less than 4175, of countless versions, were built at Kolomna and several others Locomotive plants.
Although technically outdated by the new »Series E
«, it more than rectified its nickname »Ovechka« (lamb) due to its robustness and reliability.
During the Great Patriotic War, the »Ovechka« excelled in many ways and on may occasions.
It played a prominent role during the industrial evacuation of late 1941 and also during the Stalingrad battle of late 1942 when it suceeded in delivering supplies to the front line even under the heaviest enemy fire.
And last not least, in its armoured version
it became the steam engine of the well-known armoured trains.