Unlocking Our Coastal Heritage Project Retaining Wall and Spalling Floor Consolidation and Interpretation, Porthmeor Tin Stamps

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1 Unlocking Our Coastal Heritage Project Retaining Wall and Spalling Floor Consolidation and Interpretation, Porthmeor Tin Stamps As part of a wider project funded by the Rural Development Programme for England (RDPE) and administered through DEFRA, the South West Coast Path team (SWCP) and the National Trust (NT), a number of archaeological sites have been selected in order to better conserve, enhance and manage them. The sites were chosen on the basis that they were on or adjacent to the South West Coast Path and that they are currently at risk of being irreparably damaged or lost, or could be made more accessible for wider audiences. This strand of the project (Strand 1) is entitled Unlocking our coastal heritage protecting the cultural corridor. The site of Porthmeor Stamps in West Penwith comprises the structural remains of a 19th century water powered tin processing mill. It was selected on the basis that sections of its former spalling floor and large retaining wall are in danger of collapse which would subsequently result in the loss of an integral part of the site and potentially block Porthmeor stream and potentially destroy an historic clapper bridge. In relation to the South West Coast Path it is highly significant as it is the first site encountered by visitors when they enter the World Heritage Site designated zone for West Penwith s mining heritage. The scheme of works proposed comprises the consolidation of the spalling floor and its retaining wall. This will consist of dismantling the existing granite-faced retaining; re-profiling of the underlying earth and stone bank which forms the feature, and the deposition of material in the slumped area on top of the spalling floor; and the reconstruction of the granite facing to consolidate the feature. This will enable safe future public access and use of the site. In order to understand the built form and to be able to make informed management and conservation recommendations in relation to the historic structure, a detailed archaeological building survey should be undertaken along with a watching brief on any work requiring ground disturbance.

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6 Surveying the site Archaeological Project Summary As part of the Unlocking Our Coastal Heritage project delivered through the Rural Development Agency, the South West Coast Path and the National Trust, a number of archaeological sites were selected for conservation, enhanced management and interpretation. One such site consists of the remains of a mid-19th century waterpowered stamping mill and associated dressing floors adjacent to the Porthmeor Stream in Zennor, the easternmost industrial site in the St. Just Area of the Cornwall and West Devon Mining Landscapes World Heritage Site. Sections of the granite revetment work enclosing the spalling floor adjacent to the stream are in danger of collapse, which would not only degrade this exceptionally well-preserved and accessible site, but also risk damaging an adjacent ancient clapper bridge carrying the Zennor Church Path across the stream.

7 A scheme of works was implemented to dismantle and re-build the failing sections of walling to safeguard the site and enable continued access to it. Historic Environment Projects were asked to provide a suitably detailed pre-works record of this part of the Porthmeor Stamps site. The survey used a combination of direct measurement coupled with photography to record the affected stretches of walling making up the spalling floor revetment wall and the adjacent wheelpit. The survey revealed that the majority of the walling to the spalling floor which fronts onto the nearby stream is in fair to good condition, the principal exception being the area forming the return from that flanking the Church Path and extending to roughly 2.5m downstream, the problems being most evident in the section of walling above the level of the clapper bridge carrying the path. Much of this section of walling required rebuilding. However, a close inspection of the area at the base of the wall showed that the flash flood which swept down this stream a few years ago scoured out the stream bed and has to an extent undermined the basal courses of the wall. Underpinning of this section of the wall was also be required. The clearance and consolidation work now allows for much greater visibility and access of the site for the public. The project has also given us a renewed understanding of the complexity of the site and will help inform its management and conservation into the future. WORK IN PROGRESS

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12 WORK COMPLETE

13 Other comments The work has safeguarded the archaeological features of the site and surrounding important features. The archaeological survey has provided valuable information to include in future interpretation of the site to enhance visitor enjoyment and the works has secured safe future public access and use of the site. On site signage has informed passing visitors of both the importance of the buildings and the partnership within the project. This is a complex site, grade 2 listed which involved gaining license from English heritage and potential disturbance of the stream involved licensing from the environment agency, both through county planning. Access was through farmland and some work was necessary to harden surfaces and temporarily widen access points. The complexity of the work necessitated the employment of CDM associates to ensure a safe working environment. With all this in place the project ran smoothly and efficiently. We have managed to extend the project programme through the commercial partnership programme to include a project for designing discreet interpretation on the site and to sign it from the Coast path.