Dyne Steel's Incline is an inclined tramway linking New Pit (NPRN 260310 ) to Hill's Tramroad (NPRN 85860) at Pwll Du.

Site visited D.W.Thomas & B.A.Malaws, 23 November 1999.

The Dyne Steel Incline represents one of the key phases of the development of transport for the Blaenavon Iron Company for the export of its good and the transport of limestone to the iron furnaces. The principal export route for Blaenavon products from 1817 onwards was the Brecknock and Abergavenny Canal in the Usk Valley, while the main source of limestone for the furnaces was at Tyla. This required crossing the mountain ridge from the ironworks to Pwll-du. The earliest routes crossed the mountain near Pen-y-ffordd-goch but were long and arduous. The Pwll-du tunnel was driven through the mountain in about 1814, but this soon became restrictive given the volume of goods being carried. In about 1850 the Blaenavon Company engineer Thomas Dyne Steel (1922-1898) designed a standard gauge railway across almost the highest part of the mountain, between New Pit and Pwll-du village. There was one incline on either side of the mountain, both driven by a stationary steam engine and winding drum at the summit. Most of the route of the incline is still clearly visible on the mountain, with gentle cuttings and embankments. The engine house has been demolished, but the platform for the engine house can still be seen and the engine base and drum base are believed to be well preserved below ground. The summit complex also includes a house platform for the engine driver with a garden, and a well for supplying water to the boilers.

Source: CADW Scheduled Ancient Monument Record (Ref: MM280)