The T43 was a diesel-electric locomotive built by NoHAB for the SJ with a 1,450 hp EMD 12-567C two-stroke engine. Its generator and traction motors came from ASEA. It had only one cab that was mounted in an off-centre position. The long hood mainly housed the diesel engine and generator, while some auxiliaries were located below the shorter hood. A total of 50 were built between 1961 and 1963, of which eight were equipped with multiple controls. Although built for both passenger and freight service, only the first one was delivered with a train heating boiler.

Thanks to these locomotives, the SJ was able to withdraw their last steam locomotives which were stored as a reserve. From the eighties, more and more tasks of the T43 were taken over by the T44 that also has an EMD engine. In the nineties, they were passed to Banverket (the national rail administration) and to the TGOJ. In the years to come, they were used in freight, shunting and construction service by several private operators like Green Cargo and Hector Rail. In 2001, a single locomotive was rebuilt with a new, more environment-friendly engine. Four years later, another one was rebuilt into a battery-diesel hybrid locomotive. Nevertheless, a number has been scrapped in the meantime.