The British Rail Class 57 is a type of diesel locomotive that was remanufactured from Class 47s by Brush Traction of Loughborough between 1998 and 2004. In reference to these locomotives being re-manufactured, they are often referred to by enthusiasts as Bodysnatchers or Zombies. The Class 57 was produced in response to an order placed in November 1997 by the recently privatised freight operator Freightliner. The company sought to have its aging Class 47s, some of which had become increasingly unreliable and uncompetitive in comparison to new-build counterparts. Accordingly, redundant locomotives were handed over to Brush, where they were fitted with re-conditioned Electro-Motive Diesel (EMD) engines and the same model of traction alternator as that fitted to the Class 56 heavy freight locomotive. As a result of this scheme, improved reliability and performance was recorded; Freightliner placed multiple follow-on orders for more to be rebuilt, as would other operators. However, Freightliner abandoned its long term plans to acquire 25 Class 57 locomotives in favour of new-built Class 66 locomotives instead. There are three variants of the Class 57, one designed for freight traffic (57/0) and two to perform passenger operations. During April 2002, Virgin Trains West Coast signed a deal with the rolling stock lessor Porterbrook for the rebuilding of 12 Class 47s into Class 57/3s to conduct rescue duties as well as to drag electric trains along routes that lacked overhead wires to power them directly; further examples would be later ordered to expand Virgin's fleet. The company named its Class 57 locomotives after characters and vehicles from Thunderbirds. Other passenger train operators that used the type included Arriva Trains Wales and Great Western Railway. Various freight haulage firms, and mixed traffic operators, opted to procure Class 57 locomotives as well; these include Direct Rail Services, Rail Operations Group, Advenza Freight, and Colas Rail; many of these obtained units as a result of Freightliner having made its own fleet redundant after procuring new-build locomotives. Background The Class 57 is a re-engineered diesel locomotive that was rebuilt from redundant Class 47 locomotives by Brush Traction at their Loughborough facility. The locomotives are fitted with a refurbished Electro-Motive Diesel (EMD) engine and a re-conditioned alternator, improving reliability and performance. There are three variants of the Class 57, one designed for freight traffic (57/0) and two to perform passenger operations. Each locomotive reportedly cost £300,000, about one-third that of a new-build locomotive.