NSB class 91 diesel-hydraulic multiple unit

This was a development of the Class 86 of which constriction began in 1938, Class 91 was delivered as a series of ten motor cars (no. 1–10) and ten trailers, with four trailers delivered in 1954, the motor cars in 1955 and the last trailers in 1956. That year, NSB changed their numbering scheme, changing Class 6 to 86 and Class 11 to 91. Starting in 1962, NSB began replacing the prime movers with Rolls-Royce C6SFLH; this was done on the e-series, the f-series and no. 53, 55 and 57 through 59 in the d-series, as well as Class 91. The remaining units were retired. Other renovations and upgrades were made, resulting in new series; by the class' retirement, the designation had reached m.

More