What is a Distributed Power unit in relation to locomotives?

A Distributed Power unit refers to a system used in locomotives that assists in distributing power throughout a train. This concept is particularly beneficial for long freight trains, where multiple locomotives are used. By having Distributed Power units positioned at various locations along the train, such as at the front or rear, power can be evenly distributed, leading to improved traction and better overall control of the train. This arrangement helps to mitigate issues related to slack action (the delays in response time between trains in a long consist), allowing for smoother acceleration and braking.

Using this system also enhances performance by enabling trains to traverse steep grades more effectively, as the load is shared among the locomotives. Additionally, the use of Distributed Power allows for reduced stress on the couplings and the train itself, improving the longevity of both the rolling stock and the track infrastructure. Thus, the primary function of a Distributed Power unit is to manage and distribute locomotive power optimally across the entire train.