Former Lewis Merthyr Colliery Bertie pithead, headframe, tram circuit and tippler

The former Lewis Merthyr Colliery Bertie pithead, which is listed as Grade II*, features a stone and brick pitbank topped with a corrugated roof. Rising through this roof is a lattice girder headframe paired with a steel-framed tippler. The pitbank is constructed from a plinth of rubble sandstone, with irregular openings that provide access to service tunnels. The northeast side includes a round-arched access doorway to the shaft at the base of the pitbank, along with stone steps. The superstructure is made of brick and corrugated metal, and the building has a jettied rear with a jack-arched floor. Inside the covered building, the tram circuit and pit cage remain in place, along with two hoppers for loading stowing material into drams.

The headframe, made of wrought iron in a lattice girder style, rises through the roof and features four splayed legs over the shaft, with two sweeping supports extending from the axle of the sheaves to plinths against the north wall of the adjacent winding engine house. These supports are connected to the headframe legs by diagonal braces. The sheaves are surrounded by a maintenance platform, which is accessible via a ladder and covered by a steel gantry for lifting equipment. The tippler, located to the northwest of the covered building, consists of a steel A-frame with a plated hopper and a raised cabin. It is designed to raise coal drams and invert them to dump their contents into a hopper positioned beneath, where wagons can be placed.