The Plymouth and Dartmoor Railway (P&DR) was a 4 ft 6 in (1,372 mm) gauge railway built to improve the economy of moorland areas around Princetown in Devon, England. Independent carriers operated horse-drawn wagons and paid the company a toll. It opened in 1823, and a number of short branches were built in the next few years. The Omen Beam Tramway was an independent tramway for the gathering of peat from the moor above Dartmoor prison, for the manufacturing of naphtha.