Penallta Colliery Engine Hall and Fan House

Cadw's description

Location

Situated between Ystrad Mynach and Gelligaer, on the east side of Penalltau Road. The Engine Hall is at the north side of the colliery complex.

History

Penallta Colliery was built between 1905 and 1909, at the height of the South Wales coal trade. It was established by the Powell Dyffryn Steam Coal Company, the region’s largest mining company, on the most modern principles as the ‘super-pit’ of its day. The surface buildings were laid out in matching architectural style in a spacious, artificially levelled area, on a rectilinear plan giving the ideal spatial arrangement of activities. The design of the enormous engine hall in particular was an important innovation copied at many later collieries. The colliery became one of the largest in Wales with 3,200 miners and a high output of top-quality steam coal. By 1935, Penallta held the European record for coal produced in a single week.

The engine hall at Penallta was both innovative and influential for the design of colliery buildings. Whereas collieries before this date in Britain had several discrete engine houses for functions such as driving fans, power generation or winding, at Penallta all power needs were answered within one huge building. This arrangement was considered more efficient as it reduced building costs and provided more flexible space, it reduced the need for steam pipes to be carried around the colliery, it reduced labour and supervision costs, and it permitted the use of one large overhead crane to service all the equipment. Although such an arrangement was developed simultaneously in Germany, this was probably the first building of its type in Britain. It was the subject of a paper by its designer, George C Hann, to the South Wales Institute of Engineers in 1910 and was discussed formally on three further occasions, with some of the most eminent mining engineers of their day praising it as an important innovation.

Exterior

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.

Interior

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.

Reason for designation

Listed Grade II* for its impressive architectural qualities, its rarity as an example of surviving large colliery buildings in South Wales, and its important influence on the development of colliery buildings in Britain. Group value with other listed items within this exceptionally fine colliery complex.