This second route served two major purposes, as it enabled Treffry to develop Carbeans and Colcerrow granite quarries in the upper valley, and was also used by a leat carrying water to supply the mine at Fowey Consols. Two further granite quarries, known as Rock Mill and Orchard, operated lower down in the valley. In 1870 these were linked to Pontsmill by a third tramway along the valley floor.
A secondary route played a dual role, facilitating Treffry's development of Carbeans and Colcerrow granite quarries in the upper valley, as well as supplying water to the mine at Fowey Consols via a leat. Two lower-lying granite quarries, Rock Mill and Orchard, were linked to Pontsmill by a third tramway in 1870.