In 1959, CSD had two diesel locomotives built by CKD for shunting service and occasional light line service. In contrast to most Czechoslovakian diesel locomotives, these had hydraulic power transmission and weighed only 46 tonnes. The gearbox allowed the top speed to be switched between 70 and 35 km/h. The driver's cab was in an elevated position roughly above the center of the locomotive. The longer hood essentially housed the power train, while the shorter hood housed the cooling system.

Since the prototypes tended to slip due to their low weight, the production locomotives were made ten tonnes heavier. They were manufactured by Turcianska strojarne in Martin from 1962. 113 examples were built for the state railway and 61 for private customers. Their nickname was “Karkulka” (Little Red Riding Hood) and from 1988 they were listed as class 725. It was phased out by 1992. The T 444.1 was derived from the T 444.0 and had steam heating for passenger cars.