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Bryngwyn Colliery Engine House

A Grade II* Listed Building in Bedwas, Trethomas and Machen (Bedwas, Tretomos a Machen), Caerphilly

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Latitude: 51.5962 / 51°35'46"N

Longitude: -3.2111 / 3°12'40"W

OS Eastings: 316203

OS Northings: 189288

OS Grid: ST162892

Mapcode National: GBR HW.BR0F

Mapcode Global: VH6DT.947P

Entry Name: Bryngwyn Colliery Engine House

Listing Date: 8 February 1999

Last Amended: 8 February 1999

Grade: II*

Source: Cadw

Source ID: 21311

Building Class: Industrial

Location: Located in a small field on the W side of Bedwas village. The building is accessible by footpath, either from Pandy Mawr Road to the W or from Nursery Road (?) to the E. The building is heavily over

County: Caerphilly

Town: Caerphilly

Community: Bedwas, Trethomas and Machen (Bedwas, Tretomos a Machen)

Community: Bedwas, Trethomas and Machen

Locality: Pandy Mawr

Built-Up Area: Caerphilly

Traditional County: Monmouthshire

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The engine house was built for W.S. Cartwright in 1868, probably by Morgan Morgan of Bristol. An original date-stone inscribed 'WSC 1868' is now at Oxford House, Risca. The engine house is said to have contained an inverted single-acting Cornish steam engine. The piston rod, attached to an L-shaped beam, worked the pump rods which were inclined slightly to the horizontal and passed through a wide opening in the plinth. The beam was also attached to a balance box via a rod which passed through an opening in the opposite side of the plinth. The engine may also have been used for haulage in the adjacent drifts. It was in use until 1893.


Two-window ruined engine house of 2 storeys and a plinth. The roof, N wall and part of the W wall are no longer extant. Constructed of coursed rubble sandstone with raised quoins and grey brick facings. Round-headed openings with voussoirs, raised keystones and imposts, and stone sills. Some of the heads are badly eroded, whilst the lower openings may have been enlarged to remove the machinery. The S end of the building has one large opening to each storey. High plinth constructed of larger stones. Tie rods pass through the engine house at 1st floor level, 2 through the S end and 1 through the N end, with circular tie plates.


The cylinder bed is on the N side of the interior at ground floor level, with a pit in the S half within the plinth. Wide round arched openings of large voussoirs provide access through the S wall of the plinth, and beneath the cylinder bed to the N. Horizontal rods are said to have passed through these, those to the S attached to the pump rods, and those to the N connected with a balance box. Round-headed openings in E and W sides of the plinth similar to those above, all with yellow brick soffits. Four large sockets in S wall of plinth at shoulder height of round arch, and also at 1st floor sill level. Further sockets to N end of internal E wall at 1st floor level. Joist holes to 1st floor.

Reasons for Listing

Listed II* as an important survival of the coal industry, of historic interest for the unusual nature of the former engine.

Scheduled Ancient Monument Gm440.

Other nearby listed buildings

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