|Builder:||BR Swindon and Crewe|
|Engine:||2 Maybach MD655 diesels|
|Power:||2, 700 hp (2, 014 kW)|
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  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 . 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 , 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|
 Brian Haresnape, Western Region Diesel Hydraulics (Ian Allan, 1982) p. 61
 David Lawrence, British Rail Designed 1948-97 (Ian Allan, 2016) p. 154
 John Jennison & Tony Sheffield, Diesel Hydraulics in the 1960s and 1970s (Ian Allan, 2014) p. 19
 A. Wyn Hobson, The Last Years of the Westerns (Ian Allan, 1983) p. 70