Bo-Bo-Bo

Italian articulated Bo-Bo-Bo E656 electric locomotive, Rome, June 2, 2006
Russian Bo-Bo-Bo EP20 electric locomotive

A Bo-Bo-Bo or Bo′Bo′Bo′ (UIC classification) is a locomotive with three independent two-axle bogies with all axles powered by separate traction motors.[1] In the AAR system, this is simplified to B-B-B due to the system only taking powered axles into consideration, not traction axles.

The Bo-Bo-Bo configuration is often used to lower axle weight while keeping lateral forces low compared to a locomotive with two three-axle bogies, thus allowing the locomotive to use lightly laid track, in particular narrow-gauge railways.

  1. ^ Rail International. International Railway Congress Association. 1985.