class-44-peak

The BR Class 44 'Peak' was the first series of the celebrated Peak family of 1Co-Co1 diesel-electric locomotives built by British Railways Derby Works in 1959–60, ten in number, all named after British mountain peaks — Scafell Pike, Helvellyn, Skiddaw, Great Gable, Cross Fell, Whernside, Ingleborough, and others — giving the entire family of 1Co-Co1 locomotives its enduring nickname. The Class 44 used the Sulzer 12LDA28A engine rated at 2,300 bhp, making it one of the most powerful diesel locomotives on BR at the time of its introduction and the progenitor of the Class 45 and Class 46 developments that followed.

The 1Co-Co1 wheel arrangement — with a single unpowered carrying axle at each end of each bogie in addition to the three powered axles — was chosen to spread the locomotive's considerable weight across more axles than a pure Co-Co arrangement would allow, reducing the axle loading on the tracks of the Midland Main Line that the Peaks were designed to work. The Class 44 was designed primarily for the demanding Midland Main Line expresses between St Pancras and Manchester and Sheffield, routes that climbed over the demanding gradients of the Peak District and required sustained power over difficult terrain.

Two examples are preserved: D4 Great Gable and D8 Penyghent.