Cab unit

Recent years have seen carbody construction revived in the quest for greater fuel efficiency with passenger locomotives.

For that reason, cab or carbody units are mostly used in situations where rear visibility is not important, such as power for through freight and passenger trains.

This allows manufacturers to cheaply and easily create full-width locomotives from their hood unit designs by simply adding cowling.

The traditional makers continued to use heavyweight frames and cowl units instead.

The LMS twins 10000 and 10001 used the design and later locomotive types such as the British Rail Class 37, and British Rail Class 40 utilised cab units but the term "cab unit" is not used in Britain.