Class 52 (BR Swindon/Crewe 2,700hp Type 4 Diesel-Hydraulic)

In the 1960s the Western Region of British Rail experimented with diesel hydraulic transmission as opposed to the rest of BR which used diesel electric transmission for mainline locomotives. The experiment was ultimately a failure with the non-standard diesel hydraulic locomotives being withdrawn from the late 1960s onwards after (in some cases very) short working lives. The Type 4 Class 52 "Western" was the flagship of the WR diesel hydraulic fleet and suitably was the last diesel hydraulic class to survive in BR service, managing to hang on into the late 1970s [1].

Number built: 74
Built: 1961-64
Builder: BR Swindon and Crewe
Engine: 2 Maybach MD655 diesels
Power: 2, 700 hp (2, 014 kW)
Wheel arrangement: C-C

The Westerns along with some of the other diesel hydraulic classes were heavily influenced by German diesel locomotives and indeed had a pair of German made engines, though these proved expensive to maintain and class availability was poor for some time until modifications could be made to improve reliability. A great deal of care was made to the external appearance of the Westerns [2] which included a curved body profile to match those of the Mark 1 coaches it would typically pull. A number of liveries were also proposed and experimented with on the locos including desert sand, maroon and BR locomotive green [3]. Though the class was all in standard BR blue and yellow by the late 1960s in any case.

The Westerns were built to replace the GWR Kings on Western expresses though later were displaced to secondary services and freights as diesel electric locomotives like the Class 50 were transferred to Western Region. The Westerns managed to survive until early 1977 [4], their passing saw the greatest outpouring of enthusiast interest since the demise of steam and indeed they remain one of the most popular diesel locomotive classes, a lot of this popularity probably due to their stylish and distinctive looks. Seven have been preserved and most continue to run on preserved lines (and the occasional main line foray) to this day.
Maroon D1062 at Hampton Loade

D1062 again, now in BR blue & yellow

Another view of D1062, engines opened up!

D1023 at the National Railway Museum
D1062 at Kidderminster

[1] Brian Haresnape, Western Region Diesel Hydraulics (Ian Allan, 1982) p. 61
[2] David Lawrence, British Rail Designed 1948-97 (Ian Allan, 2016) p. 154
[3] John Jennison & Tony Sheffield, Diesel Hydraulics in the 1960s and 1970s (Ian Allan, 2014) p. 19
[4] A. Wyn Hobson, The Last Years of the Westerns (Ian Allan, 1983) p. 70