Western Diesel Hydraulics in Preservation

When BR initiated its Modernization Plan in 1955, its Western Region elected to trial loco designs with hydraulic transmission whilst BR encouraged designs with electric transmission. The Western Region felt the lighter weight of 78 tons for a diesel hydraulic loco producing 2000 hp, compared to an equivalent weight of 132 tons for a diesel electric loco producing 2000 hp, would better meet BR’s requirement for a modern loco. Given the smaller number of diesel hydraulic locos and the larger number of diesel electric locos it was little surprise that by the mid-1960s a cost comparison showed that the build and operation of diesel electric locos was cheaper long term. The preservation of redundant locos was slow but once it was confirmed, by the preservation of ‘Hymek’ Class 35 D7017 in 1975, that public appeals could quickly fund preservation further public appeals followed. In a short space of time 31 locos from a mixed fleet of 358 entered preservation.