Plymouth and Dartmoor Railway

Near Foggintor looking south-west to the lower alignment

Sir Thomas Tyrwhitt was a substantial and philanthropic landowner in Devon and Cornwall. He had founded the settlement that he called Princetown, on Dartmoor, and he was anxious to improve the living conditions of the inhabitants. Dartmoor prison had been completed at Princetown in 1809[1] as a prisoner-of-war detention facility, but the peace following 1815 emptied the prison. Tyrwhitt wished to improve agriculture and extractive industries on Dartmoor, and he conceived the idea of a railway to connect Princetown and Plymouth. This was to bring lime and sea-sand up to the Moor for the improvement of land, together with timber and coal. Granite, peat, mineral products and agricultural produce would be carried down. Goods would be conveyed in wagons drawn by horses, on the turnpike principle, in which all-comers might run their wagons on the railway on payment of a toll.[2][3][4][5][6][7]

He put forward proposals at Plymouth Chamber of Commerce in 1818 suggesting an 18% return on capital, and obtained subscribers, and a line was surveyed by William Shillabear of Walkhampton, a schoolmaster and surveyor. William Stuart was the engineer supervising the construction of the Plymouth Breakwater at the time, and this had a primitive internal tramway at the stoneyard. Stuart provided a cost estimate for the construction,[8] and a Parliamentary bill was submitted to form the Plymouth and Dartmoor Railway, with Stuart as its Engineer.[2] It was incorporated by Act of Parliament on 2 July 1819 with capital of £27,783, authorising it to build from Crabtree to Princetown.[2][5][note 1]

Tyrwhitt ceremonially laid the first rail on 12 August 1819, but in fact contracts had not yet been let for the construction, and some re-appraisal of the engineering of the railway was to intervene. At a Committee meeting on 26 July 1819 Stuart had been instructed to re-survey the line.[2][8]

The Plymouth and Dartmoor Railway as built, 1823 to 1834

The line was to run from Crabtree to Princetown; Crabtree was chosen because it gave access to tidal water, at a small dock on the River Plym near the Rising Sun Inn there. The location was about 2½ miles (4 km) east of the centre of Plymouth. However the wharf would only be accessible at high tide and the river approach was lengthy and awkward, and it was decided to extend the course of the railway westward to reach Sutton Pool. Accordingly, a further Act of Parliament, passed on 8 August 1820, was needed authorising the extension, and also a branch to the Cattewater. This added £7,200 to the projected cost of the line. The whole of this extension was referred to as the branch railway, being considered a branch from Crabtree. William Stuart was now appointed to superintend the construction. At this time the Company had contemplated acting as dealers in granite, that is suppliers of the mineral at Plymouth, rather than simply carriers. There is reason to believe from Committee minutes that they intended to do so, but the necessary clauses were not inserted into the 1820 Act.[2]

In April 1820, contracts had been let to William Bailey for the supply of cast iron rails; they were to be of the fishbelly pattern 2 ft 10 in (864 mm) long and 6 inches (150 mm) deep; they were to be butt jointed at the supports on stone blocks. The gauge was to be 4 ft 6 in (1,372 mm), it is not clear who chose this, or why. A contract for the construction of the formation was let to Hugh McIntosh of London in June 1820, for 9s 3d per yard; it was to be a single line with a number of passing sidings (referred to as "turnouts")—two per mile. Some sidings — at least at Roborough and Yelverton — were to be constructed of granite blocks dressed to as to provide a flange guide, similar to the construction of the main line of the Haytor Granite Tramway.

North of Kings Tor; the P&DR route goes straight ahead, and the later Princetown Railway route turns left

On 21 September 1820 the Committee signed a momentous agreement with the firm of Johnson and Bryse. They had acquired tenancy rights to extract granite from Dartmoor and needed to bring it down to Plymouth for use there in the breakwater project, and to coastal shipping for onward transit. They would pay a flat rate of 2s 6d per ton irrespective of distance for a volume averaging 8,000 tons per annum: a steady income of £1,000 a year for the Company. This was ratified at a meeting of all the proprietors on 3 March 1821.[2]

On 26 December 1820 the engineer Stuart reported that Shillabear's route as far as Jump (later called Roborough) which ran via Fursdon was too steep for horse traction. He proposed a variation of the route on "Mr Archer's Land" that would reduce the gradient from 22" to 18" in the chain. (From 1 in 36 to 1 in 44; Kendall comments "as opposed to the estimated 1 in 72 maximum".) This required a further revision of the route immediately after obtaining the second Act of Parliament, and after the letting of contracts for construction, and Stuart's report was unwelcome. Some embankment works near Roborough had already been undertaken. The Committee held Stuart responsible and brought in Roger Hopkins as Assistant Engineer. In due course a new route with easier gradients was surveyed and approved; its course ran to the east of the earlier proposed route, but required a tunnel (Leigham Tunnel) and added a further £5,000 to the cost of the line. An Act authorising this was passed on 2 July 1821.[7][8] The total estimated cost thus became £40,000 and the length 25½ miles (41 km).

Foggintor quarry looking north

The new route needed to pass through the lands of the Earl of Morley, and he had a slatestone quarry at Cann; this was not far from the proposed line, but at a lower level in steeply sloping terrain, and the other side of the River Plym. He demanded a connection from the line to serve the quarry, and this was formally (but perhaps injudiciously) agreed to by three committee members on 6 June 1821 without reference to the full Committee. The connection might be a conventional branch line, or an incline crossing the Plym.[2][8]

The Engineer William Stuart engaged in a dispute with the Committee over responsibility for the route selection, and was dismissed in October 1821. The contractor McIntosh was also dismissed amidst controversy over construction standards in June 1822, and Johnson Brothers (as successor to Johnson & Bryse) took over the work. Hopkins was now in charge as sole Engineer, he modified the specification for the later batch of rails; they were to be 3 ft 10 in (1,168 mm) long, with lapped joints at the sleeper blocks.[8]

The P&DR was not planned, or authorised, as a passenger railway. However Kendall reports an extract from a "chronicle in diary form compiled by one William Bray, sometime Rector of Tavistock"; approaching King's Tor he found that

Some huts, one a blacksmith's shop now presented themselves, and before this stood a vehicle not much unlike a rude kind of vis-a-vis with an awning. This I had observed passing on with some degree of rapidity before us. I conclude that in these carriages with iron wheels, though as cumbrous and uneasy as the scythed cars of the Britons, many pleasure parties make excursions from Plymouth, for a man accosted me and said that if I wanted to see the works, Mr. Johnson, or Thomson or some such name, would show them to me ...[10]

This seems to be a non sequitur, and it may be that the carriage was simply a stone wagon equipped with boards as seats for the Engineer to view the works on the line.

The P&DR railway was a horse-worked line with short cast iron rails on stone blocks, using a track gauge of 4 ft 6 in (1,372 mm), built with the intention of improving the moorland areas around Princetown. 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[note 5] 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.[21]

From Princetown, where the terminal was intended for general merchandise servicing the small community there, the line ran west, passing between the Foggintor Quarry (to the north) and Swelltor Quarries (to the south, on the promontory formed by King's Tor); it swept round the north of King's Tor and to the west of Ingra Tor, now heading general south past Peekhill and across the western flank of Yennadon Down. South of Dousland there was a sharp turn to head north again, to maintain the contour, passing west to Yelverton where the line passed through the centre of the common. Close to the Roborough road, the line descended southwards curving past Clearbrook, and now with multiple twists the line descended to the west of the Tavistock Road through wooded terrain, before turning west through Leigham Tunnel. Negotiating more twist the line descended to the west of the River Plym to reach a point a little west of Marsh Mills. Here it turned west and followed close to the north bank of the Plym, eventually reaching Crabtree wharf.

On some similar lines a vehicle was provided for the horses to ride on the downhill journey but there is no evidence of this arrangement on the P&DR. The line was single-track and there were frequent passing sidings to enable opposing "trains" to pass one another.

The line was conceived as a toll line, where any carrier might use the line for his own wagons, but the overwhelming dominance of the Johnson Brothers' quarry traffic meant that the main line was effectively their private railway.

The intermediate land was moorland and agricultural upland but there were few significant settlements. Sidings, apparently for general merchandise, were provided at Yelverton and Roborough. Nearing Plymouth, the line ran to a wharf at Crabtree, and the later extension reached both Sutton Harbour and a wharf on the River Plym at Laira; at the time of construction the city had not been built up in those areas.[2][8]

The extension to Marsh Mills was of similar construction, but in generally flatter terrain, and the further extension to Plympton ran on the north margin of the Exeter turnpike road. There was a two-span cast iron bridge at Marsh Mills. When the line was extended again to Cann Quarry, it was laid on the towpath of the erstwhile canal.

At the crossing of the South Devon Railway main line, boards were laid between the rails of the P&DR for the horses to walk on.

Fishbelly rail from the Cromford and High Peak Railway

The track gauge was 4 ft 6 in (1,372 mm); the rails were of the cast iron fishbelly pattern 3 to 4 feet in length (914 to 1,219 mm). In contrast to later railways the rail spanned only a single space between stone sleeper blocks, being fastened in cast iron chairs. The "later" rails (after Hopkins' redesign) were 46.5 inches (1,181 mm) long with a 2.5 inch (63 mm) lap; the rail head was 1.75 inches (44 mm) wide with a web ¾ inch (19 mm) thick; the depth of the rails was 4 inches (102 mm) at the sleeper block and 6 inches (152 mm) at mid span. In some places wooden sleepers were used, 5 feet long by 6 inches wide by 3 inches thick (1,524 by 152 by 76 mm). The earlier rails were butt ended and 36 inches (914 mm) long with a head width of only ½ inch (12 mm). "These rails do not appear to be fastened so securely and durably as those with overlapping end laps."[note 6][22]

The main line had a generally falling gradient, and it was steep enough to require efficient braking. The wagon structure was founded on two main beams 9 feet (2.743 m) long, with the bed formed of 2½ inch (64 mm) planking armoured with longitudinal iron strips. The wheels were cast iron, 29 inches (737 mm) diameter with 4½ inch (114 mm) treads; the wheel treads were conical "so that the diameter close to the flange is 29¾ inches" (756 mm) . The axles were 41½ inches (1,054 mm) apart. The brakes were cast iron and fixed to a long wooden lever, acting on both wheels on the same side. The couplings were connecting links 15 inches (381 mm) long.

There was a mobile crane, mounted on a wagon body; it was capable of lifting loads of 80 cwt (4 tonnes). It was in addition to the fixed cranes.[23]

For some years the P&DR line was the only significant line in the area: but in 1843 the South Devon Railway (SDR) deposited plans for its proposed line from Exeter to Plymouth. When the Bill was presented in the 1844 Parliamentary session, it contained the statement that "Messrs John and William Johnson are in possession of and claim to be entitled as mortgagees or assignees to the said Plymouth and Dartmoor Railway ... " This was the de facto position, and the P&DR proprietors were unable to have the clause containing the words removed. The section from Plympton to the junction near Marsh Mills was sold to the SDR and closed in 1847 to allow them to construct their main line without the necessity of making a crossing of the P&DR.[8] Lord Morley seems to have acquiesced in this; his china clay traffic from Lee Moor used Plympton as a railhead and he may have considered the SDR a more efficient carrier from there to Plymouth.

The SDR obtained powers in the 1846 session to take over the P&DR line between Crabtree and Sutton Pool, but the terms were subject to negotiation, and this proved difficult and slow.[2] At one stage the SDR attempted to install a crossing of the P&DR without agreement:

The progress of this extension was stopped by a dispute between the South Devon Railway Company and the mortgagee in possession of the Dartmoor Railway, a line 24 miles long, constructed in 1820. This railway was crossed on the level at right angles by the South Devon line. The mortgagee not getting the terms he asked from the South Devon Railway, brought immense blocks of granite from his Dartmoor quarries, and deposited them on the line where the South Devon wished to cross. This effectually prevented the railway from proceeding with the line and they soon arranged a compromise, which had the desired effect, the granite blocks being then removed by the mortgagee of the Dartmoor Railway.[24]

This crossing became "the well-known oblique crossing at Laira",[25] although the location was really Laira Green as opposed to Laira Wharf on the River Plym.

The South Devon Railway opened its line to Laira Green on 5 May 1848.[26] The station was immediately on the Exeter side of the Laira crossing,[note 7] at the turnpike bridge. The completion to Millbay took place on 2 April 1849.

The South Devon Railway was anxious to get rail access to Sutton Pool, and on 23 April 1851 they finalised an agreement with the Johnson Brothers: it transferred ownership to the SDR; the SDR would lay mixed gauge track (broad gauge and 4 ft 6in) to maintain P&DR access to Sutton Pool while giving themselves access from Laira. The Cattewater section (the stub to the wharf on the Plym) was excluded from the arrangement. The triangular junction between the line to Sutton Pool and that to Cattewater had very short radius curves, but this area (referred to as "the Granite Works"), and wharves at Laira, were horse-operated for the first years. Some improvement to the curve was made, and the broad gauge rails opened in May 1853. The SDR obtained an Act on 3 July 1854 authorising the strengthening of the line for locomotive operation, and a deviation near the Granite Works to further ease the curve there.[2][8][28]

At the time of the South Devon Railway reaching Plymouth, promoters were already proposing a branch line to Tavistock, and after initial uncertainty it was a South Devon and Tavistock Railway (SD&TR) that seized the initiative. On 5 July 1852, the Committee negotiated an agreement with Lord Morley, owner of the china clay extractive works on Lee Moor. The SD&TR agreed to build a branch line to Lee Moor for Morley; in doing so they would acquire the right to take over the P&DR Cann Quarry branch from Marsh Mills, which they needed to build their line. The Lee Moor line "would be at once constructed": presumably entirely on Morley's land no authorising Act was required, but the Company was not yet incorporated.

Work started on building the Lee Moor branch in September 1852: it was to be an intrinsic part of the SD&TR lines, and possibly on the broad gauge. The SD&TR got its authorising Act on 24 July 1854. In August 1854 trial operations on the Lee Moor line were under way, but were suspended following an accident on 4 October 1854. An investigation revealed that the construction of the line was gravely inadequate.

William Phillips (as J & W Phillips) was the lessee of Morley's china clay deposits and had been relying on the completion of the line to get the mineral to Plymouth. After an investigation he undertook, it was plain that the works were unsatisfactory, and an agreement of 5 June 1856 the SD&TR relinquished its interest in the line, and Phillips took over.[2][8]

The SD&TR opened its line to Tavistock on 21 June 1859, but without taking over any of the P&DR line.[29]

The SDR closed the Laira to Sutton Pool line in 1856 so that it could be rebuilt for locomotive working, implementing the authorisation of 3 July 1854. When it reopened in 1857 the 4 ft 6in gauge and broad gauge lines had been separated between Laira, Prince Rock and Cattewater.[30] In 1869 the obligation on the South Devon Railway (by agreement with Phillips) to maintain the 4 ft 6in gauge access to Sutton Pool lapsed, and on 19 April they introduced locomotive operation, having removed the Dartmoor gauge rails.[2]

Map of P&DR after opening of the Princetown Rly

However in November 1877 plans were deposited for the Princetown Railway: a standard gauge branch line from a junction on the Tavistock line at Yelverton. Near Princetown this would serve the town and the quarries on the P&DR line, which it was to replace. Some minor alignment improvements were made to accommodate locomotive working, and a major section of new route to pass east of Yennadon Down and to descend to the Tavistock line at Yelverton.

The transfer took place in 1878: the Princetown Railway paid £22,000 in shares for the necessary part of the line, and it opened on 11 August 1883.[8][28] The activities of the Plymouth and Dartmoor Railway were now confined to the Lee Moor traffic from the point where that line joined; in Plymouth there were interchange arrangements with the Great Western Railway (GWR) at Laira, and a wharf on the Plym, also at Laira.

In the 1870s the GWR and the LSWR were competing for possession of territory around Plymouth, especially in the South Hams, the area east of the Plym. The Plymouth and Dartmoor Railway worked as an ally of the LSWR in promoting a branch lines locally, and they obtained powers in 1875 to construct short branches from the P&DR line at Cattewater. The LSWR took over these powers in 1882 and the branches were from the LSWR Friary line.

On 2 August 1883 the P&DR obtained powers to build a line to Turnchapel; it succeeded in building a bridge over the Plym near Laira road bridge, opened as far as Plymstock (then called Pomphlett) in 1887. The LSWR took over the powers for the branch, and they opened it on 1 January 1897.[2][33]

Towards the end of the nineteenth century the P&DR had lost the quarry traffic from Dartmoor (to the Princetown Railway) and practically all the general merchandise traffic. The Lee Moor line flourished as the trade in the mineral flourished, and the china clay work therefore dominated the residue of the Company. In 1916 the rails on the disused section above Cann Wood were recovered for scrap, and under the Railways Act 1921 the Company was transferred to the new Southern Railway. In practice this referred to the short branches around the Cattewater. The Lee Moor Tramway continued in use, traversing the southern end of the P&DR main line, and the entire section of route from Lee Moor to Laira became colloquially known as the Lee Moor Tramway.[8]