Tuesday, 3 May 2016

Class 35 (Hymek)

After building hundreds of Type 1s and 2s British Rail saw that it needed a more powerful set of Type 3 locos to bridge the gap between the small locos (which often needed to double header) and the large Type 4 locos in it's fleet. The Class 35 was the Western Region diesel-hydraulic version of the Type 3s which began to fill out the BR fleet in the mid-1960s and was seen as the true diesel replacement for types like the famous Hall class of mixed-traffic locos [1].

Number built: 101
Built: 1961-64
Builder: Beyer Peacock (Hymek)
Engine: Maybach MD870
Power: 1, 700 hp (1, 270 kW)
Power: B-B

The Class 35s, which became known as the Hymek - a name derived from the Mekydro hydraulic transmission, were true examples of BR's second generation of diesel locomotive with much effort being taken in the exterior design as well as the interior with input from Ted Wilkes [2] who also advised on the Class 47 hence the similarity in their looks [3].

The Class 35 served throughout the Western Region and proved versatile locomotives though suffered with problems with the hydraulic transmission early on which led to the fleet requiring modifications until they could reach acceptable levels of service [4]. After this they quickly became the most popular and reliable diesel-hydraulic design along with the Westerns [5].

Unfortunately for the Class 35 Western Region was ending its experiment with diesel-hydraulics and withdrawals began in the late 1960s, by the mid-1970s all has been withdrawn from revenue service [6]. Luckily 4 have been preserved.
D7076 at Kidderminster

D7029 at Kidderminster

[1] Brian Haresnape, Western Region Diesel-Hydraulics (Ian Allan, 1982) p. 52
[2] John Jennison & Tony Sheffield, Diesel Hydraulics in the 1960s and 1970s (Ian Allan, 2014) p. 12
[3] Haresnape p. 11
[4] Colin J. Marsden (ed.), Modern Locomotives Illustrated No. 212 April-May 2015 (Class 35 'Hymek') p. 11
[5] Michael Welch, Diesels on the Western (Capital Transport, 2013) p. 68
[6] Jennison & Sheffield p. 88