For pushing operations on the new hump yard, five new engines were ordered.
They were identical to late series T class locomotives of 1000hp but had some differences:
The engines were delivered 1968/1969 as T 413 - 417. Prior to service the locomotives were given a new class - "H".
The units were not "ballasted" as such by external additional weight. The loco frames were made of heavier beams similar in thickness to VR "X" loco frames.
As well as hump duries they occasionally strayed into freight and passenger work depending upon loco shortages.
The class was numbered 1 to 5.