Deep Navigation Colliery

Located next to the co-developed village of Treharris in the borough of Merthyr Tydfil, on development it was the deepest coalmine in South Wales Coalfield by some 200 yards . Producing the highest quality steam coal, it powered both the Cunard passenger steamers RMS Mauretania and RMS Lusitania in their successful attempts at the Blue Riband prize for the most rapid Atlantic Ocean passage. The mine is also thought to have been one of several locally that provided coal to the RMS Titanic; tests carried out on coal found in the ship's wreck have shown that most of the coal on board originated in South Wales. One of the first collieries in South Wales to have shafts wound by electricity, it was the first colliery in South Wales to have pit head baths for its miners. Profitable due to the quality of its coal, but financially degraded by huge volumes of water ingress throughout its working life, it was closed by British Coal on Good Friday, 1991.

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