Penallta Colliery Engine Hall and Fan House

Giant engine hall incorporating fan house at E. The building is a large open hall on an E/W axis, and thus at right angles to the other buildings on the main complex, is a large open hall roughly 100m long from west to east and 23m wide, with areas for the fans attached to the building at E end. The roof is gabled and has a replaced corrugated covering on the original steel trusses. The parapetted gables show the original roof profile: raised ventilator and roof light at top and a broken gradient to the main roof for a slate upper part and glazed lower part. Built of Pennant sandstone, part rendered, with dressings of red brick, which comprise pilasters dividing the bays, end piers, stepped parapets, plinth, dentilled window and door surrounds incorporating keystones. The main facade is 16 bays long with tall segmental arched windows with deep angled jambs at ground level and a row of smaller windows above. Some original metal-framed small pane glazing still in situ, but S ground floor windows are blocked. Central double doorway with a tablet above marked ‘P.D. 1906’; taller doorway end right. W gable end has 4 bays with rendered panels between pilasters, 2 rows of windows and one doorway, all in red brick. E end has a low extension for the fans and fan engines with windows in the gable above, and a sloping brick tunnel from the fan drift to a tall evisee to expel the air. Attached retaining wall extends from base.

The interior is remarkable for its continuous arcading on all four sides, with carved pilasters to each bay with carefully detailed Doric capitals and arch rings picked out in green and cream. There is a tiled dado with many coloured tiles and floral designs. Runners for a travelling crane are set above the arcade, and the original lattice-girder crane is still in place. The original steam engines were all replaced in 1962-3 by electrically powered equipment, and the building now houses two winding engines, a compressor, three generators, and switchgear. The original black and cream tiled floor and cast iron railings have survived in a few areas. Openings in the floor connect to a basement level for servicing the engines, accessible through doors on the north side.