GWR condensing class 57XX 0-6-0PT No 9702 at Old Oak Common shed on August 27, 1961.
Peter Kerslake says "9702 basks in the sunshine at Old Oak Common, the engine being the second of the ten built in 1933 fitted with steam condensing equipment to permit their use on the Metropolitan underground line to Smithfield.
Incorporating larger capacity water tanks of a total capacity of 1230 gallons together with larger cab windows, the ten engines became eleven when the prototype, originally numbered 8700 later joined them, renumbered as 9700.
Emergency brake equipment was also fitted whilst the G.W.R. designed Automatic Train Control box and its pick up could be clipped up away to avoid fouling the electrified underground sections of line. The massive Weir feed pump shows up well in this view as does this side's large pipe running from the smokebox to the water tanks."
Photo: K.L. Cook/Rail Archive Stephenson