Tags: Locomotive.
The Franz Krull Sk-class is a class of steam locomotive built by the Franz Krull metal works of Tallinn Estonia between 1931-1940. The Sk-class is the first and only Estonian-built steam locomotive.The Sk were narrow-gauged and used oil shale as fuel since it is the primary energy source in Estonia. A total of 16 units were produced of which none has survived. The last Sk Sk-156 was scrapped in 1980 in Beloretsk Russia where it was actively used until scrapping.