With the imminent introduction of Class 800 units and Class 88 locomotives, which are able to bridge the gaps in the electrified network by running on diesel power, the age of the bi-mode is upon us.
THE restricted reach of the electrified network has always been a headache for freight and passenger operators where traffic demand requires trains to operate beyond the wired or third-rail boundary. So the technical advances represented by a new generation of bi-mode traction and rolling stock will offer the opportunity to maximise the use of the electrified network while preserving the ability to provide through services to destinations with lower traffic densities.
There is nothing new in the electro-diesel concept other than the current description of ‘bi-mode’. In 1962, the first of 49 Class 73 locomotives emerged from Eastleigh Works, which built six locomotives using English Electric components that entered service as Nos. E6001-6 (later Class 73/0). Their performance was successful and a further 43 locomotives numbered
Nos. E6007-49 (Class 73/1) were built by English Electric at its Vulcan Foundry (Lancashire) between 1965 and 1967.
The locomotives were allocated to the Southern Region and were designed to operate at 90mph using third-rail current collection, which provided 1420hp – but, in addition, had a diesel engine rated at 600hp to allow use on non-electrified lines. The machines have had great longevity, with a number remaining in service in their original form, and other examples being rebuilt for both Network Rail and GB Railfreight.
Read more in the March Issue of RE – out now!