Monument MPM1148 - Timber Structure, Oyster Island, Langstone Harbour Langstone Harbour

Timber structures on Oyster Island, Langstone Harbour. The Island consists of a small mound with a shingle bar connecting it to the southern most tip of Farlington Marshes. The latter is covered by most tides.

The structures form three distinct groups. The two groups at the mainland end of the shingle bar may have performed a coastal protection function for a small brick and flint built house which once stood on the site. The house is marked on the 1947 Admiralty Chart as 'red roof conspic.'

The third structure is more substantial, and surrounds the southern side of Oyster Island itself. The timbers form three concentric semicircles about 22.5m in diameter, with 'cells' created by further posts placed radially. Most of these posts were reused ships timbers, about 150mm square, many with treenails. They appear to have been half carlings (beams supporting the deck of a ship). The timbers in this area are surrounded by blocks of dressed stone, possibly placed there to reinforce the structure. The presence of a substantial midden of oyster shells 25m to the south west of the island would suggest that it may have been used for oyster farming, and the structure was certainly used as an oyster bed during the latter part of its life in the post-medieval period. Due to similarities with a timber structure in Caernarfon Bay, Wales, it has been suggested that the Oyster Island structure may have started life as a fish trap. However, this is purely speculative.

Further posts were found on the northern side of the island, but these did not form the same pattern.

Langstone Harbour Project No. OI.108

[1] p. 107

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Oyster Island is at least in part artificial, and the bar is highly likely to be an artificial causeway, probably constructed by the Russell family in the early 19th century in connection with their oyster farming operations.

The timber structures are thought most likely to be 18th or 19th century in origin.

[2] Data supplied by Hampshire AHBR 2014. Ref: 56158

<1> Allen, M J & Gardiner, J et al, 2000, Our Changing Coast 'A Survey of the Intertidal Archaeology of Langstone Harbour, Hampshire' (Bibliographic reference). SPM81.

<2> Hampshire County Council, 2014, Hampshire Archaeology and Historic Buildings Record (AHBR) (Index). SPM171.