 Considerable earthworks were necessary in places — crossing the Carnon Valley in particular — in order to avoid excessive gradients, and there was a 600 feet vertical interval between the summit of the line and the wharves at Devoran.In fact there was a gradient of 1 in 35 falling from Lanner to Carharrack.The track gauge was this was commonly employed in South Wales, with which the engineering of the mines had close contact at that time, and edge rails were used