 In fact granite quarries provided the dominant traffic.The main line descended from Princetown to Crabtree, east of Laira, following a very sinuous course in an attempt to limit the maximum gradient for the uphill haul; extremely small-radius curves were adopted in places to avoid major earthworks.Priestley, writing in 1831 said
Commencing at Bachelor's Hall in the parish of Lydford, at no great distance from the prison erected for the reception of prisoners of war on Dartmoor, the Plymouth and Dartmoor Railway runs in a very circuitous course from north to south by Moortown, Grenofen, Buckland Abbey, Hoo Meavy, and Borringdon to Crabtree in the parish of Egg Buckland, where it crosses the turnpike road from Plymouth to Exeter, and where the original line terminated; from thence, however, its course was continued, under powers granted by subsequent acts, to the sound at Sutton Pool, a short distance south of Plymouth.