Summary
An 1850s/60s military bastion, including the main bastion wall, and part of the counterscarp wall. Excluded from the listing are the mid-C20 set of stone steps leading from the top of the bastion down part of the east wall to the ditch below, the mid-C20 metal vehicular entrance gates in the counterscarp, and the C20 brick buildings built within the bastion ditch. The truncated and partially rebuilt part of the southern counterscarp wall is also excluded.
Reasons for Designation
The mid-C19 New Bastion, including part of the counterscarp wall, is listed at Grade II for the following principal reasons:
* Historic interest: as part of the final phase of improvements to the Devonport Dock Lines;
* Architectural interest: using high-quality ashlar stone, the impressive main bastion wall contrasts well with the rubble-stone of the counterscarp;
* Level of intactness: despite the loss of half of the counterscarp wall, overall the bastion survives well, including the magazine and embrasures that clearly illustrate its former defensive function;
* Group value: as part of the Mount Wise defensive site it has strong group value, particularly through its association with Admiralty House, Hamoaze House, and the Old Gun Wharf Wall (all listed Grade II).
History
Mount Wise occupies a commanding strategic position by Plymouth Sound, overlooking the approaches to the River Tamar and Stonehouse Creek. The site has a long history of military occupation and use. The first defensive structure on the site was a gun wharf, part of which was enclosed by a bastion to the east. It was abandoned after 1724 when the Morice Yard to the north of the Dockyard was completed. The first defensive lines to guard the landward approaches to the naval yards at Plymouth Dock were begun following the outbreak of the Seven Years War in 1756. Known as `the Lines' or the Dock Lines, the defences consisted of a bank and ditch and included a likely realignment of the Old Gun Wharf’s eastern bastion. Between 1778 and 1780 the Dock Lines were rebuilt in a permanent form. The Old Gun Wharf, running to the south, became a subordinate part of this defence line. To complement these land defences, Mount Wise Redoubt and five batteries were established in the late-C18 to defend the dockyard from naval attacks to the west. Mount Wise continued to gain in military and strategic significance. Residences were built here in the late-C18 for the Governor (Government House) and the early-C19 for the Port Admiral (Admiralty House).
The Dock Lines continued to be improved at various times, the last major phase of which was between 1853 and 1868 when they were moved to the east and an earthen rampart with a firing step was established on the top of Richmond Walk Quarries. A small portion of the original course of the Lines was retained to the east of Government House, which was incorporated within the New Lines, and was adjoined by a New Bastion. The New Bastion was established at the south end of the line, and is likely to be amongst the last bastions to be newly built in England, completed just before the publication of the Royal Commission on the Defence of the United Kingdom (1860). By the early-C19 a large part of the area to the south of Government House had become part of the buildings formal gardens, enclosing a sunken rose garden. In 1934 Government House and its grounds were transferred from the General Office Commanding Western District, a senior military department that had taken control of the house since the early C19, to the Admiralty. Government House became known as Admiralty House (listed at Grade II), and former Admiralty House became known as Hamoaze House (listed at Grade II). In June 1937 proposals had been drawn up to establish a combined services headquarters near to Hamoaze House within the C19 Plymouth Dock Line ditch to the south of Admiralty House and into the western end of the New Bastion. Further brick buildings were placed within the ditch and beside the bastion walls. The counterscarp wall has been subject to the greatest amount of alteration in the C20, including the insertion of a vehicle entrance for the combined headquarters and the lowering and re-building of the portion flanking the car park to the south.
Details
An 1850s/60s military bastion, including the main bastion wall, and part of the counterscarp wall. Excluded from the listing are the mid-C20 set of stone steps leading from the top of the bastion down part of the east wall to the ditch below, the mid-C20 metal vehicular entrance gates in the counterscarp, and the C20 brick buildings built within the bastion ditch. The truncated and partially rebuilt part of the southern counterscarp wall is also excluded.
MATERIALS: Plymouth-limestone ashlar scarp wall with a rubble-limestone counterscarp wall.
PLAN: an angular bastion wall, facing toward the east and south, with a parallel counterscarp wall.
DESCRIPTION: an ashlar-faced scarp wall topped by a rolled cordon. The wall is abutted and overlain to the north-west by the rubble-stone wall of the new lines. The southern side of the rampart includes a set of musket loops overlooking the approaches to the Old Gun Wharf. The rampart is topped by an earth bank that is partially lined on the interior of the bastion by a low stone rampart. A rectangular expense magazine projects to the south-west from the centre of the eastern bastion wall. It is entered via a brick-arched entrance on the north side of the magazine, leading into a brick-vaulted chamber.
The bastion became part of the gardens to Admiralty House which has led to minor adaptations to the internal bastion wall.
On the exterior of the bastion is part of the counterscarp wall which survives around the south-east corner of the bastion. It is constructed of rubble stone. Its western flank was truncated and largely rebuilt due to the construction of the mid-C20 Maritime Headquarters Bunker.
