During the 1950s NOHAB of Trollhättan had started a cooperation with General Motors Electro-Motive Division to licence build GM-EMD diesel locomotives for the European market. SJ had bought one EMD G12 locomotive, retrospectively designated T42, in 1953 and after NOHAB had started building the DSB class MY and MX for Danske Statsbaner in 1953 SJ ordered five modified G12 locomotives in 1955 with delivery in 1956. They were originally designated T4, but this was later changed to T41.
The T41 had six axles using an A1A-A1A wheel arrangement and was powered by a GM EMD 12-567C twelve-cylinder, two-stroke cycle, diesel prime mover which produced a power output of 1,065 kW (1,428 hp). Like the G12, the T41 uses a long hood and off-centre cab. However its hood is slightly lower and its cab is enlarged and taller than that of the G12.
