Cusvey Mines, Engine House at SW 757419 SE Part of the Consolidated Mines

Cusvey Mines Engine House is a ruin of a beam engine house dating from the early 19th century. It features walls made of killas rubble with dressed granite quoins, jambstones, and voussoirs. Most of the openings have timber lintels. The building has a rectangular single-cell plan with a thicker bob wall on the northeast side. Originally, it had three floors. The bob wall, which is two floors high, includes a ground floor doorway with a segmental granite arch that has a projecting keystone. There is a smaller segmental external arch that is splayed internally to a larger round-headed rear arch. This design maximizes load-bearing capacity, as the inner arch benefits from greater support due to the mass of the return walls.

The northwest wall is fairly intact and has a ground floor window opening spanned by a large granite lintel, while other openings generally have timber lintels. The southwest wall features a large door opening spanned by a round-headed brick arch. Some walling of the gable end survives above, but the southeast wall is half-fallen. There is a detached chimney located on higher ground to the south, which is similar in design but likely slightly older than the engine house at the Consolidated Mines.