Early C20 power house which provided power for dock gates and machinery. Single storey plus tower; in red brick with slate roofs; roofs with longitudinal ventilators. Walls with shallow brick buttresses at corners and corbelled eaves courses. Two blocks, broader and taller NW block has, to sides, 4 bays of round-headed arches (now blocked), and facing NW, gable end with small round window near apex, below which are 4 round-narrow-headed windows (now blocked and with some rebuilding to W corner). Narrower and lower SW block also with 4 bays of round-headed arches to each side, but offset to align with north-east elevation of larger block. SE gable end with small round window near apex of gable. Bewteen blocks, on NE elevation, square-headed doorway with concrete lintel, and slinding wooden door. In angle between blocks, square tower with parapet and blocking course; to SW, tall round-headed window with metal glazing, above round-headed doorway. Interior of tower has riveted metal vertical cylinder.
(Source: Cadw Listings database) S Garfi 8/11/06