Monument MPM1208 - Timber structures, Broad Street

17th century timber structures, possibly freshwater containers (cisterns), recorded during a watching brief in 2007. A small number of finds were recovered from reclamation deposits in the same trench, which included post-medieval pottery and clay pipes.

The remains of two timber structures were revealed during an archaeological evaluation on the site of the former Wightlink workshops in Broad Street in 2007. Fragments of clay pipe found within the fill of both structures suggested they dated to the 17th century. Their exact function is not known, but it has been suggested that they may have acted as freshwater containers (cisterns), supplying boats in the nearby Camber. A small number of finds were recovered from reclamation infill deposits on the same site. These included clay pipe and residual pottery.

The first timber structure was contained within an east -west aligned rectangular feature (62), the base of which was 3m below the present ground surface. The cut for the feature contained a 0.3m thick yellowish brown clay fill at its base, which formed the foundation for a rectangular oak timber structure (66). The structure had been constructed using planks butted together in a north-south alignment laid onto clay and surrounded by plinth timbers along the edges. A further row of butted timbers positioned at right angles to the underlying timbers, overlaid the base timbers. The sides of the structure were constructed from planks laid east-west. At the visible western end, the side had been cut to overlap the base timbers. The sides were supported by uprights on each corner, which had been tenoned into mortices in the plinth timbers and pegged. The uprights had been secured to the sides using oak dowels. A 0.2m thick yellowish brown clay lined the sides of the structure. The cut for the feature had been backfilled by two different fills (63 and 68). These comprised a very dark greyish brown stoney loamy sand to the north of the structure (63), which contained 3 fragments of pre-1850 clay pipe, and a loose shingle along its southern and western sides (68). A further fill (75) overlay fill 68, and contained a mid-late 17th century clay pipe fragment. The timber structure had rotted away at a height of 1.10m from its base. The backfill for its foundation (67) contained fragments of 17th century clay pipe and a sherd of tin-glazed pottery dating to post 1620. An environmental sample taken from the same backfill contained slag, coal and hammerscale. Provided the deposits that made up the backfill were from the local area and had not been brought in from elsewhere, this would indicate that industrial activities such as ship building would have been taking place in the area around the camber at this time.

A single oak plank from a second clay-lined timber structure (70) was recorded 2.4m to the south of feature 62. This was also aligned east-west. It's filled contained early-mid 17th century clay pipe fragments.

The stratigraphy of the two timber structures suggests they were in use at the same time, the clay pipe fragments from the fill of feature 70 giving an early-mid 17th century date. It was not possible to identify their exact function, although it has been suggested they may have been freshwater containers, with the clay-lining forming a barrier to prevent sea water from entering the structure.

Reclamation infill deposits in the same trench contained Post-Medieval urban ware pottery, mid-late 17th century clay pipe fragments, a residual Roman samian and Medieval (13th/14th century) coarseware sherd and pre-1850 clay pipe fragments. A probable levelling layer which overlaid the deposits contained fragments of early 18th century clay pipe.

Accession number 2007/4

Molloy, Tony, 2007, Report on an Archaeological Evaluation at the Former Wightlink Workshops, The Camber, Broad Street, Old Portsmouth (Unpublished document). SPM183.