From 1968 onwards, the SJ had the T44 built for light freight traffic, which has four axles and a central cab. The engine is an EMD 645 series two-stroke with twelve cylinders. With a production run of 123 in 21 years, it is the most numerous diesel locomotive that the SJ has ever purchased. In addition to freight traffic, they were also used in shunting and, if necessary, in front of passenger trains. In the new millennium, a large number came to private operators, most of them to Green Cargo. The decision was made there in 2007 to equip 100 locomotives with new four-stroke engines and to modernize them in other areas. By 2012, 62 units had been rebuilt in this form and were now given the designation Td. 