H M Prison Dartmoor: Sewerage Aqueduct


Heritage Category:
Listed Building
List Entry Number:
Date first listed:
Date of most recent amendment:
Statutory Address:
Sewerage aqueduct crossing Blackabrook River to north-west of Dartmoor Prison.


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Statutory Address:
Sewerage aqueduct crossing Blackabrook River to north-west of Dartmoor Prison.

The building or site itself may lie within the boundary of more than one authority.

West Devon (District Authority)
Dartmoor Forest
National Park:
National Grid Reference:


The sewerage aqueduct at H M Prison Dartmoor, constructed in 1900 to the east of the site.

Reasons for Designation

The sewerage aqueduct at HM Dartmoor Prison, constructed in 1900, is listed at Grade II for the following principal reasons: * Historic interest: the sewerage aqueduct forms part of the historic prison complex, representing a 1900 improvement to the sanitation and infrastructure of the site; * Design interest: the dressed granite structure is of elegant as well as practical design, with dressed granite to the segmental arches, making a striking feature in the landscape to the east of the prison; * Group value: the aqueduct forms part of an important and relatively complete group of listed prison buildings, both within and outside the prison walls; there is a particularly direct link with the reservoir to the west of the complex.


Dartmoor Prison was built by the Admiralty in 1806-9 on land leased from the Duchy of Cornwall, to receive prisoners of war. During the Napoleonic Wars of 1803-15 there were 47 prisoner of war hulks moored at Chatham, Portsmouth and Plymouth, and pressure on Plymouth was increased when prisoner of war prisons at Norman Cross, Northamptonshire and Stapleton near Bristol became full. The London architect Daniel Asher Alexander (1768-1846), was employed to design Dartmoor Prison.

The first inmates were received in May 1809, and by June that year the prison housed 5000 prisoners of war. As described in Risdon’s Survey of Devon (1811), and illustrated by two views by Samuel Prout (1809 and 1811), by a drawing in Ackermann’s Repository of 1810, and by a survey drawing of the prison of 1847, Dartmoor Prison originally consisted of five blocks laid out in a radial arrangement around a central market place, in total covering c12ha and surrounded by a double, circular perimeter wall. Internal walls divided the prison into a number of sections. In the central market place prisoners could trade with outside traders. The western part of the prison included an Infirmary and a separate Petty Officer’s Prison. The main entrance of the prison was flanked to the right by the Governor’s House and to the left by the Surgeon’s House. In 1812, following the outbreak of the trade wars with America, two blocks were added to house prisoners, and the Petty Officer’s block was converted into a barrack to supplement the large barracks complex south of the prison. The prison closed in 1816. Despite the opening of a railway from Plymouth to Princetown in 1827, the area saw little economic development following the prison closure.

In 1850 the prison re-opened as a civic prison to address the contraction in the transportation of prisoners to Australia; alterations were made to the convict accommodation, and by 1851 there was room for 1030 inmates. During the 1860s, 1870s and 1880s a number of alterations were made to the prison by the architect Sir Edmund du Cane (1830-1903), appointed Director of Convicts and Inspector of Military Prisons in 1863, and Surveyor-General of Prisons, Chairman of the Board of Convict Prisons and Inspector-General of Military Prisons in 1869. Further rebuilding of the prison took place during the first quarter of the C20, with four new wings built between 1901 and 1915. A detailed description of Dartmoor Prison during this period was published in 1909-10 by RG Alford (Notes on the buildings of English Prisons, vol. 2, pp75-87).

During the First World War Dartmoor Prison housed around 1000 conscientious objectors, who mainly undertook farm labour or worked in quarries on the Moor.

Dartmoor Prison has seen much change in the course of the C20 and early C21. Major prison riots which took place in prisons across the country including Dartmoor in 1990, led to an extensive refurbishment programme to improve the prison’s security. Despite the degree of rebuilding which Dartmoor has undergone over more than two hundred years, the radial plan established by the original design has survived.

The sewerage aqueduct located to the east of the prison represents an improvement to the original system for the supply and circulation of water. Water was carried from higher ground to the west along a leat four miles in length and passed into the reservoir. From the reservoir the water passed under the road and into an open conduit that ran around the site and drained out at the east side of the site; it was then carried in a leat to land at Tor Royal, to the south-west of the prison. The freshest water was therefore supplied to the Infirmary and the Petty Officer’s prison to the west of the site. Water moved both clockwise and anti-clockwise around the prison and passed beneath small privy blocks attached to the outer ends of each wing, a system of sanitation akin to medieval monastic reredorters. A bathing pool, located roughly on the site of the present E Wing, features in the view of 1810, but was apparently removed when new internal walls were built in 1812. In 1900 the sewerage aqueduct was constructed, to carry waste away from the prison across the Blackabrook River to new sewage works.


Prison sewerage aqueduct, constructed in 1900.

MATERIALS: granite rubble and dressed granite.

DESCRIPTION: the aqueduct is approximately 275ft long and has an eleven-arch span, the segmental arches being formed of dressed granite. The low parapets have dressed coping stones.


The contents of this record have been generated from a legacy data system.

Legacy System number:
Legacy System:


Books and journals
Brodie, Croom, Davies, , English Prisons, (2002)
Joy, Ron, Dartmoor Prison, a complete illustrated history (2 volumes), (2002), vol 2, p. 75
Stanbrook, E, Dartmoor's War Prison & Church 1805-1817, (2002)
Historic England Archive Report HMP Dartmoor - Building File No. 92318


This building is listed under the Planning (Listed Buildings and Conservation Areas) Act 1990 as amended for its special architectural or historic interest.

End of official listing

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