Hydraulic Engine House

The Hydraulic Engine House, built around 1890, is part of the London and North Western Railway Company's Wolverhampton High Level development. Constructed in Flemish stretcher bond, it features a double-gabled Welsh slate roof with rooflights. The building has a square plan divided into two bays, with a boiler and engine house in each bay. A hydraulic accumulator was located next to the engine house on the east elevation at the north end. It is a single-storey structure with all elevations displaying two recessed panels. The side elevations feature dog-tooth cornices made of blue brick. The west elevation, which faces The Old Steam Mill (also listed grade II), includes semi-circular arches leading to double-leaf plank doors. The north elevation has two similar arches with cast-iron multi-panelled windows that have centre-hung top radial lights. The south elevation has an infilled window, and the east elevation has two segmental-arched openings that were once used for boilers.

Inside, the building has iron roof trusses. Historically, it served as an essential functional component of a notable group of industrial structures around Corn Hill. The interior originally housed two boilers and a cylinder steam engine, which generated hydraulic power used to operate cranes and ramps in the nearby Mill Street Goods Depot, also listed grade II.