Event/Activity EPM195 - An Archaeological Evaluation at Gunwharf Quays

The Conservation Practice Ltd carried out a series of excavations at Gunwharf Quays in August and September 1997 ahead of the redevelopment of the site by the Berkeley Festival Waterfront Company. The excavations were undertaken following a desk-top study of the site compiled in July 1997, which assessed the likely effect of the redevelopment on the archaeology and historic buildings. Trenches were excavated by mechanical digger under the supervision of an archaeologist. Due to restrictions imposed by the Ministry of Defence, each trench was excavated, recorded and backfilled on the same day. As the deposits included loose fills e.g. moats, the trenches were excavated to a depth of 1.2m, any structures and fills recorded, and then excavated up to a further 4 metres if necessary. Approximate measurements were taken for features exposed at lower levels. Moat Wall & Beeston's Bastion Three trenches were excavated within the area of the inner post-medieval defences of Portsmouth town in order to determine the condition of any surviving remains of Beeston's Bastion and the moat wall. Two trenches approximately 16m long by 1m wide were excavated across the site of the north and west walls of the Bastion, and were extended to investigate the inner side of the adjacent moat wall. No remains of the north wall of Beeston's Bastion were encountered. What appeared to be a robbed out trench may have represented the removal of the foundations to the west wall of the bastion in the 1870s. The moat wall was revealed between 91cms and 95cms below the present ground level. The remains of two brick walls, probably associated with Ordnance House (built 1870s) and surrounding structures, were observed 20cms below the present ground level within the area of the north wall of the bastion. The fill of the moat was revealed to a depth of 3m below ground level. A third trench was excavated in order to examine the condition of the wall on the outer side of the moat. The east face was revealed approximately 2.1m below the present ground surface, the wall having been demolished above this level. It was concluded that as no remains relating to Beeston's Bastion were encountered on the site, it would appear that the foundations of this structure were completely removed when it was levelled in the 1870s and Ordnance House was constructed. The foundations of Ordnance House may survive. The moat walls were partially demolished and robbed of their facing stones when the moat was infilled in the 1870s. The facing stones may have been reused elsewhere on the site, some possibly in the late-19th century wall on the south-west side of St George's Road. Sea Line Wall & Mill Redoubt Eight trenches were excavated within the area of the outer post-medieval defences of Portsmouth town in order to determine the condition of the Sea Line defensive wall and the wall around Mill Redoubt. The work concluded that the Sea Line wall probably survives in some places but not in others. It is likely that the wall may be intact underneath the Royal Marine Infirmary building and the original perimeter wall. It may also survive about 10m north of Nelson's Gate. At least part of the section of wall on the west side of Scott Road appeared to have been partially demolished and robbed of its facing stones, but it was found to be intact where it joined the wall and abutments on the west side of King's Mill. The wall around Mill Redoubt remained intact with its facing stones 56cms below the modern ground surface. It is possible that sections of the wall which had been crossed by late-19th century water and foul sewers, thought to have been laid to a depth of 4m, had been destroyed, although these areas were not investigated. King's Mill Three trenches were excavated across the site of King's Mill in order to locate any remains that had survived. One of the trenches (Trench 8B) was situated to the east of the mill to locate any remains of the mill sluices, which were thought to have been damaged by a surface water sewer constructed in the 1890s to a depth of 4m below ground level. The east ends of the three sluices associated with the mill were found to have survived to within 45cms of the present ground level. Iron refuse guards were attached to at least two of them. However, the work concluded that the mill and sluices located under and immediately to the east of it had probably been destroyed during the demolition of the town defences in the 1870s and the construction of a surface water sewer in the 1890s. Quay Walls Two trenches were excavated in order to locate any surviving remains of the quay walls to the Old Gunwharf. One of the trenches (Trench 9) was situated within an abandoned garden in front of the Vernon Wardroom (Ariadne block). The trench measured 6m long by 1m wide, and was excavated to a depth of 2.15m at its southern end. A second trench (Trench 10) was situated on a grass verge on the south side of the Main Road opposite the west end of Hecla block. The trench was 5.1m long by 1m wide. Sections of wall remaining above ground were also examined to determine whether they had formed part of the quay wall to both the Old and New Gunwharf. The work concluded that the quay wall on the north side of the Gunwharf site was probably the original wall to Old Gunwharf built 1709-1715. Sections of the original may also have survived behind a sheet-piled concrete face present in the west and south-west sides of the site in 1997, and where it formed the north side of the Basin, except where it had suffered bomb damage and been cut by service trenches. The New Gunwharf wall, built 1797-1809, survived as part of the present quay wall on the west side of the site, and around steps on the south-west side of the Pool. It was also thought likely to survive in several places either behind the current quay wall or below later structures. The wall had been partly demolished where it formed the south side of the basin, and the facing blocks removed. Drawings dated to 1798 show the construction of the original quay wall to the New Gunwharf. This had been altered by the removal and replacement of wooden fender piles, land ties and capsill with granite blocks. Accession No: 2013/112