Event/Activity EPM96 - Archaeological Watching Brief at Boathouse No. 6 and the Recording of Boathouse No. 4 Locks, Portsmouth Dockyard, Hampshire

An archaeological watching brief was carried out during refurbishment work in and around Boathouse No. 6 in Portsmouth Dockyard in 1999. The work revealed construction trenches for the boathouse, and a tunnel and lock chambers to a channel connecting the mast pond to the harbour. Excavations for piles using a small 360 back-actor and piling rig were carried out inside the boathouse. This work consisted of localised level reductions up to 0.45m deep around iron pillars supporting the building. Concrete-filled construction trenches relating to original building were revealed along the lines of the pillars, resulting in further level reductions taking place to enable the construction works to proceed. Outside, level reduction associated with the construction of a new staircase around the southeast corner of the building revealed the construction trench for the boathouse. A number of features which appeared to be associated with the control of water flow and ealy 18th century boat-building were also observed. This evidence suggests the area had been used for boat-building for a considerable period of time. The work extended to replacing lock gates in a channel connecting the Mast Pond to the Harbour, which ran partly through a tunnel under Boathouse No. 4. The channel included lock gates. Although there was no formal requirement for work to be undertaken in this area, a programme of basic recording was carried out. This revealed the tunnel and lock chambers to be of different construction. Evidence suggested a period of reconstruction had taken place in the Modern period, in order to alter the channel's shape and insert or modify the lock system. This probably reflected the pond's change in use from a mast pond to boat repair. A more detailed survey of this feature may reveal more information. It was thought that the 17th century defences designed by De Gomme may have extended across the area of the site. As no evidence of the city defences was encountered, it is probable they were not located in this area, or all trace had been removed by the construction of the boathouse or the 'mast making' building previously on the site. Accession number: 2013/679