Event/Activity EPM108 - Archaeological Watching Brief at The Institute of Marine Sciences Phase 2a, Ferry Road, Eastney

Southampton Archaeology Unit carried out a watching brief at The Institute of Marine Sciences, Ferry Road, Eastney, in 2010. The work involved observing groundworks relating to the demolition of an existing building dating to c. 1970, and the construction of a new two-storey building on the site. Observations were made during the removal of footings belonging to the demolished building, and the excavation of the foundations for it's replacement. All of the trenches, with the exception of those used to remove the existing footings, were excavated by mechanical excavator, nearly all to a nominal depth of 900mm. The external wall footings were nominally 800mm wide, and the internal footings 450mm. Larger pad bases were distributed around the footings. A lift base trench was excavated to a depth of 1500mm. Due to the lack of archaeologically significant remains in the footings, it was not considered necessary to observe the associated drain runs, as these were only expected to be 300mm deep. The work was carried out on behalf of the University of Portsmouth. The site is located on the west shore of the shingle spit across the entrance to Langstone Harbour, to the west of Ferry Road. The spit is thought to have been dry land since the prehistoric period. At the time of the development it was occupied by a complex of mid-20th century buildings in use by the University of Portsmouth Institute of Marine Sciences, although these were originally built for the Ministry of Defence. Cartographic evidence showed that the first buildings to occupy the site belonged to a 19th century Coastguard Station which had been built by 1870, and consisted of a main building and small out-house. By 1910 both buildings had been demolished, the Coastguard Watch House having re-located to the south-east near the flagstaff, and the site was unoccupied. The natural deposits exposed during the work consisted of gravel overlying gravelly sand - the drift deposits that formed the site. The base of the spit deposits was not exposed, nor any deposits associated with the pre-spit ground surface. No certain evidence of pre-19th century human evidence was found. The only archaeology comprised a buried soil horizon of unknown date, overlain by a dump of clay of uncertain date, and a brick-lined pit in disturbed ground, probably associated with the 19th century coastguard station. Two features filled with clean sand were thought to be modern service trenches. The whole site was covered with a 200mm thick concrete raft which formed the floor of the late 20th century building. Observations made during the removal of the footings of the existing building showed they consisted of a very shallow reinforced concrete ring below it's external walls, which did not penetrate below the modern make-up layer. Accession No: 2010/567