Distributed Power Unit

Two diesel locomotives used as DPUs in the middle of the train on the Mount Newman Railway in Australia .

As Distributed Power Unit (English: "Distributed traction unit "), abbreviated as DPU is a locomotive called that middle or end of a train remotely supported is used and the locomotives at the Zugspitze. The term is mostly used for railways that are operated according to AAR standards.

This variant of train formation is used in Canada , the United States , Australia and South Africa for heavy freight trains . It avoids strains in the several kilometers long trains, which can lead to clutch breaks. The distributed traction allows the railway companies to carry more tonnage with the same staff.

The intermediate and push locomotives are usually lined up after about 100 cars. On the one hand, they introduce the traction force at several points in the train, on the other hand, they allow the pressure in the main line of the compressed air brakes to be reduced at the same time , so that the braking effect is applied at several points on the train at the same time and not just from the tip of the train. This also reduces the train's braking distance.

At the terminus stations, trains with DPUs are often dismantled in such a way that loading and unloading is easier to manage. The DPU locomotives lead their train part as the top locomotive through the corresponding systems.

control

The remote control of the DPUs is usually done via radio and is referred to as RDP , which stands for Radio Distribute Power . In rare cases, an existing cable of the electropneumatic brake is used for the remote control signals. The train driver has the choice of controlling the pulling forces of the remote-controlled locomotives proportionally to that of the top locomotive or independently of it. The RDP controls are manufactured by General Electric and Wabtec .

Manned locomotives that are used as push locomotives at the end of the train are known as helpers in the USA , and unmanned ones as DPUs.

The Distributed Power Mode is not to be confused with a train in push-pull mode (see also push-pull train ), in which locomotives are located at both ends in order to be able to travel in both directions without shunting the locomotive .

literature

• Sayre C. Kos: Distributed power . In: Trains Magazine . June 2007 (Vol. 67), No. 6) . Kalmbach Publishing, 2007, ISSN  0041-0934 , p. 72 .

Individual evidence

1. ↑ ^{a b} Locotrol® Distributed Power System. General Electric , accessed April 1, 2017 .