NSB El 7
NSB El 7 was a series electric locomotives delivered between 1911 and 1918 to Norsk Transport that operated the Rjukan Line and the Tinnoset Line, where they were designated RjB.1, 2, 3, 6, 7 and 8. The locomotives were built by AEG (motor) and Skabo (chassis). The first three locomotives were delivered to the Rjukan Line along with two smaller units, RjB 4 and 5 (which were given the designation El 6 by NSB). El 7 is exactly two El 6; it has two transformers, four motors instead of two, Bo'Bo' instead of Bo axle arrangement, two pantographs, the same speed, and could haul twice the load. The locomotives cost NOK 52,090 in 1911. When two of the locos (no. 1 and 3) were transferred to Norwegian State Railways in 1920 after NSB took over the Tinnoset Line, where they were designated El 7 and numbered 2501 and 2502. Number 1 was sold back to Norsk Transport in 1932 while number 3 was transferred to Narvik in 1927 after it had been converted from 10 to 15 kV. It returned to Drammen in 1936 and remained there until it was taken out of service in 1956; RjB 6 was retired