BoCo the Diesel Engine

BoCo (voiced by Colm Feore) is a character from Thomas the Tank Engine and Friends. He is a diesel engine who works mainly on Edward's branch line. He was unfortunate enough when he first arrived to be tricked by Bill and Ben, who thought he was an enemy. The misunderstanding was soon cleared up, however, and the twins now have the greatest respect for BoCo.

Steam engines sometimes forget themselves and call him names (James once called him a "buzz-box diesel" and Henry once called him a "mixed-up engine"). He ignores them, because he knows that there is no point in getting worked up about silly name calling. Wise engines know that he is friendly and helpful- he is perhaps the most sensible diesel on the Fat Controller's Railway.

'BoCo' in the UIC classification system used for classifying locomotive power arangements indicates two individually powered axles on the front bogie, with three indidvidually powered axles on the rear bogie.

The fictional engine is likely therefore based on Britain's first (and only) CoBo locomotive, the Metropolitan Vikers Type 2 introduced in 1958. This website has details and pictures.