Class 378

The Class 378 "Capitalstar" was the centre piece of the modernisation of Transport for London's commuter rail network which was reorganised as London Overground. The Class 378 is part of Bombardier's highly successful Electrostar family though there were a number of differences for London Overground [1] including tube style longitudinal seating, wide gangways and LU tripcocks. Originally they were built as 3-car sets but were soon augmented with a 4th car. Later on increasing demand saw them further strengthened to 5-car sets.

Information
Number built: 285 (57 5-car sets)
Built: 2009-15
Builder: Bombardier
Engine: 3 Bombardier traction motors per motor car (750c DC third rail or 25kV AC OLHE)
Power: 3, 200 hp (2, 400 kW)
Formation: 378/1: Driving Motor Open Standard (DMSO)+Motor Open Standard (MOS)+
Trailer Open Standard (TSO)+MOS+DMSO
378/2: DMSO+MOS+Pantograph Trailer Standard Open (PTSO)+MOS+DMSO

The Class 378s operate on most lines in the London Overground network with the 378/1s being 750v DC third rail equipped and the 378/2s dual voltage with 25v AC overhead line electric collection as well [2]. Strengthening of the fleet to 5-car sets has now been completed [3] though overcrowding continues to be a problem on the Overground, and likely will continue until new EMUs begin to displace the 378s in a couple of years time from some routes allowing service frequencies to be increased.
378 144 at Peckham Rye

378 213 at Queen's Park

378 151 and 378 141 at Dalston Junction

378 223 at Imperial Wharf

[1] John Glover, London's Overground (Ian Allan, 2012) p. 106
[2] Colin J. Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013) p. 290
[3] Underground News No. 654 (June 2016) p. 348