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 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.
List of Sk locomotives
Built in 1931: Sk-151 Sk-152 Sk-153 Sk-154 Sk-155 Sk-156 Sk-157 Sk-158 Sk-159 Sk-150
Built in 1935: Sk-160 Sk-161 Sk-162
Built in 1940:
(During the first Soviet occupation of Estonia, when the factory was renamed "Punane Krull" ("Red Krull"). These locomobiles were decorated by the red star and hammer and stickle figures.) Sk-163 Sk-164 Sk-165
References
External links Mulgi Railway History of Estonian narrow-gauge railways (in Estonian)