The 642 series locomotive is a diesel-electric shunting locomotive. It is intended for heavy shunting operations and for traction of lighter freight trains. The locomotive is equipped with a new CAT3508B diesel engine with a new hydrostatically driven two-circuit cooling system. The existing main generator has been modified and adapted to the new operating mode. The complete traction electric circuit has been reconstructed and redesigned to allow greater flexibility in the use of the locomotive and more reliable operation adapted to
different operating modes. In the breaking system there were installed new brake valves, a new distributor valve, a new oil-free compressor and an adequate drier. The complete electric system of the locomotive is new and its backbone is the GLC800 computer control system. The GLC800 is a product that Gredelj has specially developed for use on locomotives and it combines governing, control and protection. Into the computer there were installed operating system and driver also produced by Gredelj.
The locomotive computer allows the machine personnel to monitor via PC panels installed on the control stands, more than 50 different parameters of the main and auxiliary drives (divided into different groups and different display forms). In addition, the computer communicates with the machine staff via messages about the state of the locomotive (more than 90 different messages).
The locomotive is equipped with a new digital data recorder in accordance with regulations and applicable standards. Ergonomics and driver’s cab comfort have been improved. There were installed new double headlights in LED technology produced by Gredelj. The whole locomotive lighting (inner and outer) is made in LED technology, providing long life of lights and reducing the maintenance costs over the long term. The power of the traction locomotive has been increased by about 10% compared to the original locomotive in different operating conditions, with much greater reliability, with reduced fuel consumption and increased comfort.