Pwll Du Tunnel

The Pwll Du Tunnel was the longest horse-powered tramway tunnel to be built in Britain at in length. It started in Blaenavon, Torfaen, Wales, and was originally a coal mine, running northward almost horizontally into a hillside. Later it was extended right through the hill and used to carry limestone from quarries at Pwll Du and Tyla to the ironworks at Blaenavon, and to carry pig iron from Blaenavon to the Garnddyrys Forge. The tramway was extended past Garnddyrys to Llanfoist Wharf on the Brecknock and Abergavenny Canal. The tramway from Pwll Du to the canal fell out of use when the railway came to Blaenavon and the Garnddyrys forge was closed in 1860, but the tunnel continued to be used to carry limestone to Blaenavon until 1926. It is now a scheduled monument and part of a UNESCO World Heritage Site. OriginsThe Blaenavon Ironworks, completed in 1789, was the most advanced in Wales in its day, using coke rather than charcoal for smelting with a steam engine to blow the furnace. The coal and iron ore were extracted from mines at various levels in the north east side of the Afon Lwyd valley. What would become the Pwll Du Tunnel was one of these mines, extending for about into the hillside on a gentle slope. The tunnel was started around 1782 to extract iron ore. The historian William Coxe gave it a length of about in 1801. The Pwll Du limestone quarry, Blaenavon, lay on the north eastern lip of the South Wales Coalfield, on the upland bluff that overlooks Abergavenny. From 1789 limestone was carried south to Blaenanon over the mountain by a cart-road from Pwll Du. A horse-drawn railway was inaugurated in 1796 to take limestone from the Blorenge Mountain quarries to the ironworks.

The Pwll Du Tunnel was the longest horse-powered tramway tunnel to be built in Britain at in length. It started in Blaenavon, Torfaen, Wales, and was originally a coal mine, running northward almost horizontally into a hillside. Later it was extended right through the hill and used to carry limestone from quarries at Pwll Du and Tyla to the ironworks at Blaenavon, and to carry pig iron from Blaenavon to the Garnddyrys Forge. The tramway was extended past Garnddyrys to Llanfoist Wharf on the Brecknock and Abergavenny Canal. The tramway from Pwll Du to the canal fell out of use when the railway came to Blaenavon and the Garnddyrys forge was closed in 1860, but the tunnel continued to be used to carry limestone to Blaenavon until 1926. It is now a scheduled monument and part of a UNESCO World Heritage Site. OriginsThe Blaenavon Ironworks, completed in 1789, was the most advanced in Wales in its day, using coke rather than charcoal for smelting with a steam engine to blow the furnace. The coal and iron ore were extracted from mines at various levels in the north east side of the Afon Lwyd valley. What would become the Pwll Du Tunnel was one of these mines, extending for about into the hillside on a gentle slope. The tunnel was started around 1782 to extract iron ore. The historian William Coxe gave it a length of about in 1801. The Pwll Du limestone quarry, Blaenavon, lay on the north eastern lip of the South Wales Coalfield, on the upland bluff that overlooks Abergavenny. From 1789 limestone was carried south to Blaenanon over the mountain by a cart-road from Pwll Du. A horse-drawn railway was inaugurated in 1796 to take limestone from the Blorenge Mountain quarries to the ironworks.