This browser is not fully supported by Historic England. Please update your browser to the latest version so that you get the best from our website.

Wheal Trewavas copper mine 310m south of Trewavas

List Entry Summary

This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Culture, Media and Sport.

Name: Wheal Trewavas copper mine 310m south of Trewavas

List entry Number: 1021324

Location

The monument may lie within the boundary of more than one authority.

County:

District: Cornwall

District Type: Unitary Authority

Parish: Breage

National Park: Not applicable to this List entry.

Grade: Not applicable to this List entry.

Date first scheduled: 26-Nov-2004

Date of most recent amendment: Not applicable to this List entry.

Legacy System Information

The contents of this record have been generated from a legacy data system.

Legacy System: RSM

UID: 32989

Asset Groupings

This list entry does not comprise part of an Asset Grouping. Asset Groupings are not part of the official record but are added later for information.

List entry Description

Summary of Monument

Legacy Record - This information may be included in the List Entry Details.

Reasons for Designation

For several millennia the western part of the South West Peninsula, namely Cornwall and West Devon, has been one of the major areas of non-ferrous metal mining in England. It is defined here as prospecting, extraction, ore processing and primary smelting/refining, and its more important and prolific products include copper, tin and arsenic, along with a range of other materials which occur in the same ore bodies. Throughout much of the medieval period most of the tin was extracted from streamworks, whilst the other minerals were derived from relatively shallow openworks or shafts. Geographically, Dartmoor was at the peak of its importance in this early period. During the post-medieval period, with the depletion of surface deposits, streamworking gradually gave way to shaft mining as the companion to openworking methods. Whilst mining technology itself altered little, there were major advances in ore processing and smelting technologies. The 18th century saw technological advances turning to the mining operations themselves. During this period, Cornish-mined copper dominated the market, although it was by then sent out of the region for smelting. The development of steam power for pumping, winding and ore processing in the earlier 19th century saw a rapid increase in scale and depth of mine shafts. As the shallower copper-bearing ores became exhausted, so the mid to late 19th century saw the flourish of tin mining operations, resulting in the characteristic West Cornish mining complex of engine houses and associated structures which is so clearly identifiable around the world. Correspondingly, ore processing increased in scale, resulting in extensive dressing floors and mills by late in the 19th century. Technological innovation is especially characteristic of both mining and processing towards the end of the century. In West Cornwall, these innovations relate chiefly to tin production, in East Cornwall and West Devon to copper. Arsenic extraction also evolved rapidly during the 19th century, adding a further range of distinctive processing and refining components at some mines; the South West became the world's main producer in the late 19th century. From the 1860s, the South West mining industries began to decline due to competition with cheaper sources of copper and tin ore from overseas, leading to a major economic collapse and widespread mine closures in the 1880s, although limited ore-extraction and spoil reprocessing continued into the 20th century. A sample of the better preserved sites, illustrating the technological and chronological range, as well as regional variations, of non-ferrous metal mining and processing sites, together with rare individual component features, are considered to merit protection.



Despite partial reduction of the buildings and limited modification for use as rough pasture, Wheal Trewavas copper mine 310m south of Trewavas survives very well. The survival of the western manual capstan platform is exceptional. The dressing and dumping area is largely undisturbed and has potential for analysis of the waste, and for the survival of buried features. Early 19th century methods and technology for copper extraction, transportation, and primary processing are well represented. The remains form a fairly complete and well-integrated complex, with evidence for development at the site over time. The whole illustrates vividly how copper mines, often situated on the coast because of the visibility of the mineral in cliffs, could be adapted to exploit such locations with their natural hazards and limited accessibility.

History

Legacy Record - This information may be included in the List Entry Details.

Details

The scheduling includes remains of an early 19th century copper mine, Wheal Trewavas, situated on the south coast of Cornwall, east of Mount's Bay. The location comprises moderate to steep south and south east slopes, and sheer cliffs. The two standing engine houses with their detached chimneys, and the capstan platform at Old Engine Shaft, are Listed Buildings Grade II. The scheduling also includes later cliff-top pasture boundaries, and remains of a World War II radar station. Wheal Prosper pumping engine house lies 770m north west, and is the subject of a separate scheduling. Wheal Trewavas was a short-lived, though productive, mine documented as beginning production in or just before 1834 and ceasing by mid-1846 when the workings beneath the sea were flooded. The most westerly of the two main shafts, Old Engine Shaft, was active by 1834; the other, New Engine, in 1836. (In 1879 limited exploration of the east part of the area took place). The mine exploited four copper lodes and one bearing tin, trending south east-north west across the coastline. Its underground levels extend beneath the sea, beyondthe scheduling, where rich copper ore was found. On the land are earthworks and structures for obtaining ore through shafts and adits (sloping tunnels), and dressing or preparing it for smelting. Old maps provide complementary evidence for the complex. The core of the mine contains a possible openwork or pit to exploit a lode from the surface, and at least two adits and five shafts. Six or seven more shafts are known beyond the scheduling, and steam engines draining and raising ore from shafts within it may have been supplied with water by launder from a spring to its west. The Old Engine Shaft is spectacularly sited on a ledge on the cliff top, some 40m below the plateau and 20m above sea level. The ledge is cut into the very steep rocky slope by up to 4m, and extends to the brink of the cliff, where walling up to 8m high revets the sites of the capstan, boiler house, and shaft head. An adit opens from the back of the platform. The Old Engine Shaft is in fact a pair of adjoining shafts on Trewavas Old Lode. That to the north is sub-rectangular. Its relationship with the standing engine house to its south west, which supported a steam driven pumping engine for draining the mine, suggests that the northern shaft is earlier. Masonry on its northern side could be the remains of a contemporary engine house. A platform further north, with a truncated granite chimney on its western side, is considered to represent a boiler house, and this could have served an earlier steam engine. The standing engine house is a gabled structure with three storeys above the part sunken basement. The walls are of granite, mostly large, roughly coursed rubble, with massive squared and dressed pieces at corners and openings and other stress points. Doors and windows are flat-topped. The WNW doorway is exceptionally tall to ease the movement of machinery around the precipitous and confined site. The SSW wall of the engine house bears traces of the roof of the boiler house, also visible as a platform with rubble walling surviving up to 3m high. This house extends 8.5m NNE-SSW and an estimated 16m WNW-ESE. Its rubble stone chimney is sited on the slope above. The connecting flue has rubble walling, and was roofed with stone slabs, some remaining in situ. Above the chimney is a rock-cut sub-rectangular yard, perhaps for coal, with evidence for a structure on its northern side. The yard contains the concrete footprints of structures associated with the World War II radar station. The station itself, situated on a prominent spot to the south west, survives as a concrete base, with traces of walls, openings, and wooden flooring. To the SSW of the boiler house is the site of a capstan for moving machinery in the shaft. It has a rock-cut pit for the winding drum and slot for a rope to the shaft head. There is also a levelled area surrounding the pit where people circled the drum, turning it by pushing radiating handles. Quarries west and north west of Old Engine Shaft provided building material for structures at the mine, and contain evidence of stone splitting methods. The installation of the Old Engine Shaft and subsequent plant was facilitated by a levelled and metalled access way. This approaches from the north west, where it was carried over a hollow on a causeway, the width of which (around 4m) reflects that of the boilers and other loads. The count house where workers were paid is by the track, on the site of the possible openwork; parts of its walls are standing. Miners going to and from work, via the adits, would also have used this route. Ore brought to the surface at New Engine Shaft for dressing was hauled up the coastal slope by inclined tramway. Three are visible, each a straight cutting, with a platform of the type used for a horse whim above it. The easternmost cuts that on its west; it may have been replaced by the third following reuse for flat rods. The floors and dumps west of the inclines, extend south to the sea. Here ore was hand broken and sorted in the open or under sheds. This area would also have processed ore from other shafts, such as that to the north on Way Sowan Lode with low walling of an engine house, as well as New Engine Shaft, thought to be on North Lode. It contains waste (with variations in size reflecting its treatment); trackways; a tram or barrow way; and is considered to incorporate other buried remains. The New Engine Shaft in the eastern part of the mine is also sunk from the top of the cliffs, though set slightly back from the edge. The ground is higher and less steep than at the early shaft, but is still cut down some 2m to accommodate the works. The rectangular shaft here has a slot for a balance bob to counteract the weight of the pump rods below. The adjoining pumping engine house is similar to that standing at the Old Shaft. Unusually, it has no large opening to admit machinery at the rear, due to the proximity of the cut bedrock there. The opening at the front is round-headed, and the driving floor retains its cylinder bedstone. The boiler house to the east, visible as an earthwork, is offset to follow the contour. It is 9.5m long by 2.4m wide and has a detached granite chimney with string course and collar. Both this house and a further building platform beyond have retaining walls up to 5m high on the seaward side. West of the shaft are horse whim and capstan platforms. By 1844 power was taken from the New Engine by flat rods. These are thought to have run plant at the Old Shaft, via a cutting through the mine road, and the eastern tram incline. All modern fencing, stiles, and notices are excluded from the scheduling, although the ground beneath these features is included.

MAP EXTRACT The site of the monument is shown on the attached map extract.

Selected Sources

Books and journals
Hamilton Jenkin, A K, Mines and Miners of Cornwall, (1962), 43-46
Brown, K, Acton, B, 'Exploring Cornish Mines' in Exploring Cornish Mines, , Vol. 2, (1995), 143-159
Holmes, L, 'Proceedings of the International NAMHO 2000 Conference' in Trewavas Head Mine, (2001), 120
Holmes, L, 'Proceedings of the International NAMHO 2000 Conference' in Trewavas Head Mine, (2001), 118-121
Other
Made on MPP visit, Parkes, C and Herring, P, Sketch on 1877 Ordnance Survey Map base, (2003)
Title: Ordnance Survey 1:2500 Map Source Date: 1877 Author: Publisher: Surveyor:
Title: Ordnance Survey 1:2500 Map Source Date: 1908 Author: Publisher: Surveyor:

National Grid Reference: SW 59936 26551

Map

Map
© Crown Copyright and database right 2018. All rights reserved. Ordnance Survey Licence number 100024900.
© British Crown and SeaZone Solutions Limited 2018. All rights reserved. Licence number 102006.006.
Use of this data is subject to Terms and Conditions.

The above map is for quick reference purposes only and may not be to scale. For a copy of the full scale map, please see the attached PDF - 1021324 .pdf

The PDF will be generated from our live systems and may take a few minutes to download depending on how busy our servers are. We apologise for this delay.

This copy shows the entry on 18-Jan-2018 at 07:43:15.

End of official listing