The rock was removed by means of a series of tramroads or tramways which linked north via steep inclines to a wharf on the Monmouthshire and Brecon Canal at Llangattock and south to Brynmawr and the ironworks at Nant-y-glo by two tramroads which contoured the eastern end of the hill.
Brynmawr |
It starts again at Hereford, crosses the Wales-England border over the River Monnow, continues south to Abergavenny and Brynmawr, then continues west along the heads of the valleys, past Ebbw Vale, Tredegar, Rhymney, Merthyr Tydfil, Hirwaun and Glynneath.
The viaduct was built by the engineer John Gardiner between 1871 and 1874 to extend the LNWR line that principally carried coal from Brynmawr and Blaenavon to meet the Great Western Railway at Abersychan and Talywain.