On marshes, South of river wall. Seven rectangular storage buildings. (represented by multiple polygons) (1) Photographs (2-7). Site identified during 2002 survey. Monument consists of seven concrete built structures. Each structure is at least partially surrounded by a bund and a door lintel only surviving in one structure. All structures seem to be contemporary with no evidence of earlier structures (8).

This feature is recorded in the English Heritage Historic Area Assessment for the St Mary Hoo Parish. The report states: "Little other industrial activity was occurring in the parish until the Thames Storage (Explosives) Company negotiated the lease of some land on St Mary's Marshes in 1891-92 for a gunpowder repacking station at St Mary's Marshes. The explosives were transported by river and the benefits of an isolated location were demonstrated when one of the seven magazines was destroyed in an explosion on the 29th July 1905. The site seems to have ceased operation soon after…Non agricultural sites on the marshes include the remains of the short-lived Thames Storage (Explosives) Company site built in 1890s and 1900s. This was located east of St Mary's Bay and served by its own landing stage. Seven roofless mass-concrete magazines sill stand, possibly including the replacement of the magazine destroyed by an explosion in 1905". (9)

This feature was the subject of English Heritage Research Report 52-2013, when it was studied as part of the wider Hoo Peninsula Historic Landscape Project (10). From the report: "Magazines were constructed on the marshes around 1892 by the Thames Storage (Explosives) Company for the packing, repacking and storage of explosives, as a commercial venture on land leased from the Dean and Chapter of Rochester Cathedral… Documentary evidence suggests that the Thames Storage (Explosives) Company went into liquidation in 1907 but the magazines possibly had a second life as a 'Government magazine', eventually going out of use in 1913, when the lease on the land also expired. Seven magazines survive in a ruinous state, some with protective earth bunds, and appear to be an unusual use of mass concrete in an explosives storage context".

<1> Victor Smith and Ron Crowdy, Thames Gateway Assesment: Gazetteer of Defence Sites (Index). SKE6445.

<2> 1946, Photograph (Photograph (Print)). SWX9477.

<3> 1946, Photograph (Photograph (Print)). SWX9629.

<4> 1947, Photograph (Photograph (Print)). SWX9822.

<5> 1947, Photograph (Photograph (Print)). SWX9852.

<6> 2000, Photograph (Photograph (Print)). SWX10252.

<7> 2000, Photograph (Photograph (Print)). SWX10265.

<8> Wessex Archaeology, 2002, North Kent Coast Rapid Coastal Zone Assessment Survey Phase II: Field Assessment (Pilot) (Bibliographic reference). SWX11840.

<9> historic england, 2014, Hoo Peninsula Outline Historic Area Assessment: St Mary Hoo Parish. Research Report 2014-52 (Bibliographic reference). SKE31593.

<10> English Heritage, 2013, St Mary's Marshes, Hoo St Mary, Medway, Kent: An assessment of the late 19th century explosives magazines (Monograph). SKE29387.