Two workmen stand on the spiral escalator (or spiral elevator) at Holloway Road station

Spiral escalator (or elevator) built by Jesse Reno at Holloway Road Underground station, Piccadilly line. Photo apparently taken during station construction. Two workmen stand on adjacent 'moving' stairways, encircling a central core like two helical coils. The escalator is located within a vertical shaft, a concrete platform hangs across the central core, supported by vertical iron girders