Engine House at Sw639322, Trevoole Mine, West Wheal Grenville

The engine house at Trevoole Mine, West Wheal Grenville, is a disused beam engine house dating from the mid to late 19th century. It features granite rubble walls with dressed granite quoins, jambstones, and a granite ashlar bob wall. The building has round-headed brick arches over its openings and a brick upper stage on the chimney. It has a rectangular single-cell plan, with a thicker bob wall on the north side and a round, two-stage chimney that clasps the southwest corner. The machinery, floors, roof, and framed and weatherboarded second floor, along with the gable over the bob wall, have been removed, but the original masonry, including the south gable end and chimney, remains virtually intact. The structure stands three storeys high and has round-headed openings. There is a large opening in the middle of the bob wall on the ground floor, and central openings to each floor of the south gable end wall. Each side wall has an opening to the second floor, with midfloor windows below and slightly to the rear of each. The east wall also has a first-floor opening. The tapered two-stage chimney is made of rubble up to ridge level, featuring a moulded brick collar and topped by a tall brick upper stage with a moulded collar cornice. The engine house was last fitted with a 70-inch pumping engine and is now a picturesque ivy-clad ruin, but it remains an unusually complete example of an engine house.