There is growing interest in electric locomotives with so-called last mile capability to allow operation for short distances beyond the wires to reach un-electrified terminals or private sidings, but Vossloh has taken this a step further with its EuroDual general-purpose electro-diesel locomotive, which is designed to run on both electrified main lines and non-electrified secondary routes.
 
Vossloh outlined its dual-mode locomotive strategy at InnoTrans 2012 when it displayed a small model of its planned EuroDual locomotive.
 
British project
 
The contract is for 10 class 88 UKDual locomotives awarded by Direct Rail Services (DRS), Britain, through Beacon Rail Leasing.
 
When the locomotives enter service in 2015, DRS intends to use them for mainline diesel haulage rather than simply as a "last-mile" option for work on non-electrified sidings.
 
The locomotives will replace 5MW dual-voltage class 92 electric locomotives, which DRS hires from DB Schenker Rail and are currently being used on key intermodal flows on the West Coast Main Line, as well as to haul passenger trains.

The class 88 will be the first 25 kV ac electro-diesel to be operated in Britain, as the only other electro-diesels in use in Britain are the class 73 units designed for third-rail operation and which date from the 1960s.
 
The class 88 will be based on the class 68 UKLight Bo'Bo' diesel-electric locomotive currently being delivered to DRS.
 
Vossloh is supplying 15 2.8 MW UKLight locomotives which have 16 cylinder Caterpillar engines and ABB AC traction equipment.
 
The class 88 will have a continuous rating of 4 MW when operating in electric mode.
 
For operation on non-electrified lines the UKDual will be equipped with a 700 kW Euro IIIB diesel engine.
 
Traction equipment will also be supplied by ABB.
 
The class 88 will have a tractive effort of 317 kN in both electric and diesel modes, and regenerative braking will be possible.
 
Maximum service speed will be 160 kph.
 
The UKDual will be 20.4 metres long over the buffers, have a tare weight of 86 tonnes, and a 21.5 tonne axle load.
 
The platform strategy adopted by Vossloh for the EuroDual allows the integration of such systems as train-to-wayside communication, driver assistance systems, and a system called Efitren which is designed to enhance train efficiency, and simultaneously, reduce emissions.
 
A wear-free automatic start/stop feature should reduce engine operating hours in diesel-electric mode.
 
Vossloh says dual-mode units have several benefits compared with conventional locomotives.
 
The option of diesel or electric traction offers a high degree of flexibility as trains can be scheduled and rerouted independently of the mode of traction.
 
A dual-mode locomotive should also have a greater operating range due to non-reliance on diesel fuel and the efficiency of electric traction.
 
The EuroDual locomotive complies with US Environment Protection Agency (EPA), and EU Stage IIIB exhaust norms, as well as the latest European standards and regulations for crash behaviour and safety.
 
David Briginshaw.

  Article abridged - data not related to British locomotives deleted.