British Rail Class ES1 (Electric Shunting 1) was a class of two electric locomotives commissioned by the North Eastern Railway in 1902. They were of steeplecab design. Both locomotives passed to the London and North Eastern Railway in 1923 and then to British Railways in 1948, but both were withdrawn before TOPS. The North Eastern Railway was an enthusiastic and relatively early adopter of electric traction for railways. As part of a 1902 scheme to electrify the suburban railway networks in the Tyneside area, the NER's Chief Mechanical Engineer, Wilson Worsdell, also wished to electrify a 3/4 mile, horseshoe-shaped freight line that went from Trafalgar Yard in Manors to Newcastle Quayside Yard. Passing through three tunnels, this line had gradients as steep as 1:27 and a number of sharp curves: it presented a formidable challenge for steam traction. Working conditions inside the tunnels were atrocious because the locomotives had to work exceptionally hard to manage the gradients which meant they produced vast quantities of choking fumes that could not disperse from the tunnels; the sparks they produced were a constant fire risk to the flammable packing materials in the yards.