Franz Krull Sk class
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
- Sk-160
- Sk-161
- Sk-162
- Sk-163
- Sk-164
- Sk-165