Double Engine House

The Double Engine House is a structure measuring about 7 meters wide by 15 meters long, with an additional annexe at its northeast corner measuring approximately 4 meters by 5 meters. It features irregularly coursed local sandstone masonry, with limestone dressings in the main part and brick dressings in the annexe. Some timber lintels have been restored using concrete. A beam wall runs across the center of the main section, with the blowing cylinders located on its west side. There is a low-level opening in the west wall for the air main to exit, and some holding-down bolts remain on the north side of the building, to the west of the beam wall. The flywheels were situated to the east of the beam wall, but their space is partially obstructed by later masonry.

The original part of the building has round-headed window and door openings. The east elevation is considered the front, featuring projecting voussoirs at the imposts of the arch and a prominent keystone. High up on the east elevation, there is a roundel window approximately 1 meter in diameter, with projecting voussoirs at each of the four cardinal points. The quoins are regularly coursed in limestone, and the side walls also have round arched dressings that are similarly detailed and aligned for symmetry.