Monument MPM2033 - Remains of post-medieval town defences, University of Portsmouth Sports Building, Ravelin Park

The remains of the former post-medieval defences comprising Town Mount Bastion, the counterscarp, moat and East Ravelin, observed during an excavation and watching brief by AOC Archaeology ahead of the construction of the University of Portsmouth Sports Building in Ravelin Park in 2018-2019. Foundations and demolition layers relating to the Second World War NAFFI building (later used as the Students Union) were also observed. See MPM378 (Town Mount Bastion) and MPM34 (East Ravelin) for more details relating to these monuments. See records MPM387 and MPM1877 and MPM1878 for further information and remains recorded during previous investigations for Town Mount Bastion and records MPM34 and MPM1879 - MPM1882 for the East Ravelin. Town Mount Bastion The bastion wall supported the scarp (inner side) to the moat and had been constructed from limestone blocks. Gun embrasures, seen as a series of short regularly spaces limestones walls, had been added to the scarp at a later date. A wide construction cut for both the moat and bastion was observed. Deposits excavated from the moat had probably been used to form the mount base of the bastion which appeared to have been reworked at a later date. Evidence of the demolition and robbing out of the walls, and infilling of the moat during the mid-19th century was also recorded. See record MPM387 Town Mount Bastion for further details. East Ravelin The northern and inner walls of the East Ravelin together with part of the moat were observed during the investigations. The northern wall was constructed of faced limestone blocks which survived to a height of 3.33m and was observed for a length of 25m. Four gun embrasures for cannon were identified on the inner side of the wall along the line of the scarp. They were the same size as the embrasures added to Town Mount Bastion (see above) indicating that the embrasures on the bastion were also added by de Gomme. The moat around the ravelin was 16.48m wide, it's base was not observed during the excavations. The moat cut was effectively also the construction cut for the ravelin wall on the north side. The inner wall of the ravelin was constructed of limestone and yellow sandstone. It measured 1.50m wide and survived to a maximum height of 3.56m OD. The remains of the wall consisted of four courses of foundation. The wall was recorded for a length of 26m. An integral brick drain fed into a ditch-like channel cut into the glacis of the ravelin which was filled with deposits of domestic origin. A layer of silt at the base of the moat was thought to have accumulated when the moat was in use. This deposit was overlain by a series of layers of backfill. See record MPM34 East Ravelin for further details. Counterscarp The counterscarp (outer moat wall) was situated 24m east of the bastion wall (which formed the inner moat/scarp wall). The counterscarp wall had been constructed using limestone blocks 0.55m x 0.32m x 0.24m bonded with lime mortar. It ran on a north-south alignment parallel with the bastion/scarp wall. The wall measured 0.90m wide and was supported by five slightly irregularly spaced buttresses 0.90m by 0.90m positioned approximately 2.90m apart. The facing stones had been robbed from the western face of the counterscarp wall (that facing the moat) but the eastern side of the wall had survived undamaged below the level at which it had been demolished. The wall survived for a length of 27m within the area covered by the watching brief. When the defences were demolished in the late-19th century the wall had been reduced to 2.92mOD. The counterscarp turned east for 49m and beyond the area covered by the watching brief. This section of wall was constructed from squared limestone blocks 0.50m x 0.42m x 0.30m and was well coursed and bonded with sandy lime mortar. Buttresses had not been used to support this section of wall. The wall had been reduced to 2.92mOD when it was demolished. It has been suggested this section of the counterscarp may have been a secondary part of the defences after de Gomme's redun had been remodelled to form the East Ravelin. 19th - 21st Century Apossible robber cut A small elongated pit 1.8m long by 0.51m wide by 0.17m deep against the internal face of the counterscarp wall may have been a robber cut to remove stone from the fortifications for re-use during the 19th century demolition works, or it may date to slightly after. Two intercutting pits found within the construction cut of the counterscarp wall post-dated the walls construction. The features may have been associated with the demolition of the defences or be slightly earlier in date. The counterscarp wall had been used as a base for a concrete foundation to the Second World War NAAFI (Navy, Army and Forces Institute) building that previously stood in the south-west corner of Ravelin Park. The foundation was 0.30m deep with bricks manufactured by Southwater. The NAAFI building was later used as a Student's Union and was demolished in 2004, after which the site became a university car park. Other features associated with the NAFFI included a salt-glazed sewer pipe within a trench, and a drain with a rubble fill. A demolition deposit was found over the inner/western wall of the ravelin. The demolition of the NAFFI building was represented by a widespread layer of rubble which included bricks manufactured by Warnham SB Co of Sussex. This deposit had been cut by modern services. Services had also cut through the ravelin embrasures and a small section of the western ravelin wall (0.5m by 0.3m and 0.5m deep) had been taken out and tipped over when the services were constructed. A layer relating to the sites former use as a car park during the early 21st century overlay the demolition deposits. This included mixed hardcore overlain by tarmac painted with car-parking spaces. Accession No: 2018/36