Blast Engine house at Cefn Cribwr Ironworks

The furnace was originally powered by a water wheel in a launder running across the E gable end of the building. The present blast engine house is built of local rubble sandstone. No surviving roof. The building is rectangular, with a central cross bob wall to support the main beam of the 50hp low-pressure water-powered blowing engine. The chamber nearest the furnace has a sunken section for a large water tank, and an operating section with doors on the N and S side. A wide gable opening with a segmental brick arch on the W gable end carried the pipes out to the furnace mouths. Four rectangular openings on the S side, and a gable opening at the E end. The two boilers originally stood on a brick base on the S side. A water culvert passes under the W end, possibly fed by draining a drift adit at the rear, and leads to a sump on the S side of the engine house.