British Rail Class 44
class of 10 (1Co)(Co1) 2300hp diesel-electric locomotives

The British Rail Class 44 or Sulzer Type 4 diesel locomotives were built by British Railways' Derby Works between 1959 and 1960, intended for express passenger services. They were originally numbered D1-D10 and named after mountains in England and Wales, and, along with the similar Class 45 and 46 locomotives, they became known as Peaks.
Overview
In part inspired by LMS prototypes 10000 and 10001, and by Southern Railway 10201-10203, the Class 44 diesels were some of the first big diesels commissioned for the British Rail modernisation project and were the precursors to the Class 45 and Class 46 locomotives of similar design. They were originally designed to have a Co-Co wheel arrangement, but it proved impossible to keep below the 20 long tons (20,000 kg) axle loading limit imposed by the British Railways Civil Engineer. A 1-Co bogie design originally used on the Southern Railway 10201 was used instead.
Construction began in the summer of 1958, although the first example was not completed until April 1959. The ten locomotives were originally allocated to Camden motive power depot and used on the West Coast Main Line, although also often seen on the Midland Main Line. However, with the advent of large numbers of Class 45 locomotives the 10 Class 44 locomotives were transferred to Toton.
Powertrain
A 2,300 bhp Sulzer 12LDA28-A diesel engine drove a Crompton Parkinson GC426-A1 main generator which supplied power to six Crompton Parkinson C171-B1 traction motors. When initially put into service, the locomotives were fitted with multiple working.
The public source identifies “British Rail Class 44” as class of 10 (1Co)(Co1) 2300hp diesel-electric locomotives. This brief keeps that definition visible, then builds a research path around British, Rail and Class.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jul 14, 2026. The linked authority identifier is Q3306567. The Library of Congress control number is sh86008190. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1959, 1960 and 1958.
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This entry incorporates text from “British Rail Class 44” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.