TU6 diesel locomotive  TU6 (ТУ6) is a Soviet narrow gauge diesel locomotive for the track gauge of . The first TU6A was built in 1973 at the Kambarka Engineering Works. 3,915 TU6A locomotives were produced until 1988. The locomotives were used on many narrow gauge railways to move cargo as well as passenger trains. The cab is equipped with efficient heat-system, radio-set and air conditioning. The diesel locomotive TU6A (ТУ6А) has been used as the basis of three other locomotives: