Plymouth and Dartmoor Railway - Princetown and Plympton

Princetown and Plympton

The 4 ft 6 in (1,372 mm) gauge line was proposed from Crabtree, on Plym estuary east of Plymouth, to Princetown by Sir Thomas Trywhitt to facilitate the development of Dartmoor. An Act of Parliament passed on 2 July 1819 authorised the work, incorporating the Company with a share capital of £27,783, and authority to rasie a further £5,000 if found necessary.

A second Act on 8 July 1820 provided for an extension at the Plymouth end to Sutton Pool, with additional capital for the purpose of £7,200. The first section, from Crabtree (at Laira) to King’s Tor (below Princetown), was opened on 26 September 1823. The extension to Sutton Pool was opened towards the end on 1825, and the remainder of the line into Princetown was in use the following year. In 1829 a branch was opened to connect with the Cann Quarry Canal, and this was extended to both the quarry itself and Plympton five years later.

Thomas Tyrwhitt died in 1833; by the 1840s the railway was in the hands of John and William Johnson; they sold two parts of it to the South Devon Railway Company (SDR). Firstly, the section from Plympton to the River Plym was closed in 1847 to allow it to become part of the new 7 ft 1⁄₄ in (2,140 mm) broad gauge Exeter to Plymouth main line. In 1851 the line from Laira to Sutton Pool was also sold, but this time the two gauges shared the route so that trucks on both gauges could run to Sutton Pool. Wharves were also provided at Laira and near the road bridge to Plympton.

The line was 25+1⁄₂ miles (41 km) long, even though the termini were only about 13 miles (21 km) apart on a map, in order to allow the track to follow the shallowest gradients. One tunnel was required at Leigham near Marsh Mills; this was 620 yards (570 m) long and just 9.5 feet (2.9 m) high and 8.5 feet (2.6 m) wide. Rails were carried on granite setts; the initial rails were bolted to cast iron chairs, but later track was spiked directly to the setts. Instead of using iron rails, many sidings were laid with granite rails about 1 foot (30 cm) long.

In 1852 part of the Princetown and Cann Quarry lines were sold to the South Devon and Tavistock Railway for their proposed route. The SDR closed the Laira to Sutton Pool line in 1856 so that it could be rebuilt for locomotive working (it had been worked solely by horses until then). When it reopened in 1857 the 4 ft 6in gauge had been given its own route alongside the broad gauge line, but only from Laira to Prince Rock and Cattewater; the line to Sutton Pool was now purely broad gauge.

An Act passed on 3 May 1865 reconstituted the Plymouth and Dartmoor Railway Company with all the preference shares owned by William Johnson. The new company was sufficiently profitable to be able to pay a 0.25% dividend in 1870. The remaining portion of the original line, from Yelverton to Princetown, was transferred to the newly authorised Princetown Railway in 1878. This new 4 ft 8 1⁄₂ in (1,435 mm) gauge line was opened in 1883 and connected with the Tavistock line.