Powered Incline Drumhouse including chimney

The Powered Incline Drumhouse, which includes a chimney, is an important 19th-century structure originally used for up-haulage in a slate quarry. It is shown on the 1888 Ordnance Survey map and was initially powered by water before switching to steam. The building was converted to electric power around 1911, and the machinery and motor from that time are still intact and in use today. Originally, it served three rail tracks with a triple-drum incline, but as of June 1995, only one track remains operational.

The exterior of the drumhouse is constructed from slate and consists of three sections, all single-storey. The central section serves as the drumhouse and operating platform, positioned above the tracks, featuring inclined multi-pane glazing. To the left is the former engine house, which is slightly advanced and partially built against a rock outcrop, with steps leading to an entrance that has a boarded door. Behind this section is a blocked entrance that likely led to a ruined enclosure, possibly the former wheel pit. The third section is a recessed locomotive shed with boarded entrances on the advanced rear gable and inner face, and a lean-to at the front gable end, also partly built against the rock.

Inside the former engine house, there are three brine bath rheostats for speed regulation, operated by overhead crankshafting. It contains three cabled drums with contemporary housing, as well as clutch and brake controls. There is also a contemporary stove on the observation platform and a boxed generator in the upper locomotive house.

Adjoining the drumhouse and the ruined former engine/wheel house is a large, square chimney that has a kink halfway up, where it passes under a rail track. This chimney is built of slate against the blasted rock and features a plain cornice at the gently tapering upper section.

The drumhouse is listed at Grade II* due to its rarity as an electric winding house with intact machinery and controls, making it one of the few still operational examples. It also has group value with other listed items at this remarkably complete slate quarry level.