Sulzer Type 4 Locomotives

The BR modernisation plan of 1955 envisaged the replacement of steam traction with diesel and electric locos by around 1975. Chief among the requirements was a loco more powerful than the 2,000-hp locos that had been produced before then.The Sulzer Company in Switzerland were able to provide an engine of 2,300 hp, which was used in the Class 44. An updated 2,500-hp version was used in classes 45 a...