Designed on request.
"A Bo'Bo'-EMD/GM G12 would be one of the models of choice. One purpose-built demonstrator went around Denmark, Sweden and Norway in the early Fifties, and was bought by the swedish SJ in 1956, numbered as T42 205, serving in northern Sweden. In the mid-1950s also the Sydvaranger iron ore mine railway in northernmost Norway introduced another two G12. The GM-demonstrator, later SJ T42, became the forefather of some very successful NoHAB designs as the GM-engined T43."