Explosives store of former Llantrisant Colliery

Location

Located in the SW corner of a field NW of the colliery complex.

History

Llantrisant or Ynysmaerdy Colliery was established by the Powell Duffryn Steam Coal Company after World War I. It closed in 1942 following an underground explosion. It was constructed on the efficient modern model developed by the Powell Duffryn Company, with a single engine hall containing the main power equipment needed on the surface. The site is a particularly complete and impressive colliery complex, containing the engine hall, workshops and stores, ruined offices, a separate winding engine house, railway lines, tips, a long revetment wall, a reservoir, and an explosives store. It was associated with the planned housing estate at Ynysmaerdy.

Exterior

The explosives store was situated away from the colliery buildings to minimise the damage caused by any explosions. It is typical of magazines of this date in being of brick with no internal materials likely to create sparks, a vaulted roof and thick walls; but it is unusual in having a reinforced concrete roof instead of the more common brick vault. It is a small brick and concrete single-storey building on a level platform cut into the steep hillside. The walls have a pronounced batter. The whole structure is rendered to the outside to protect from damp and frost. There is a tall window at a high level at each end, and small square ventilation holes all around. The steel door is at the E end hanging on iron hinges on the outside of the building and has screw holes for fixing timber panelling to the inside to avoid sparks. It is rare that such doors remain in place.

Reason for designation

Listed as well preserved example of a colliery explosives store and for group value in this unusually complete and impressive colliery complex.