Location:

Treharris, Taff Bargoed Valley

Sunk:

1878

Closed:

1991

Sinking costs at Deep Navigation Colliery amounted to £300,000 with 168 employed men - seven of which were killed during these operations. In 1913 the colliery was owned by the Ocean Company employing 1,880 men and the steam coal produced was used by the Cunard Company steamers Mauretania and Lusitania in their record for the most rapid Atlantic passage.

The first head pit baths in the South Wales Coalfield were constructed here in 1916 and by 1935 the colliery employed 363 men on the surface and 1,875 underground. The colliery continued through the troubled 1980s until March 1991 when British Coal closed Deep Navigation with 766 men on the books.