Mining Heritage Trail St Austell

A Car Free Day Out around St Austell CL11

Sandy Bottom, Carn Grey tor and Carclaze – an 18th century engineering wonder and St Austell’s mining heritage (about 6km)

Take the service bus (Western Greyhound no.524) to Carlyon Arms, known locally as Sandy Pub on Sandy Hill. Alternatively, if you arrive at St Austell Station, you can walk along Carlyon Road for approximately half a mile, when you reach a crossroads with traffic lights go straight across onto Sandy Hill.Continue down the hill until you reach Sandy Pub.

A play area for children about 100m east of the Pub has many humps and bumps, these are the remains of dumps from Charlestown United tin mine, which in 1836 employed 814 people, including 120 women and 263 children under 14 years, mostly underground.

Take the footpath going up the valley which now forms the Sandy Bottom linear park. The name ‘sandy’ derives from the fact that there was much tin and china clay mining further up the valley, which we will see something of later, which gave rise to large quantities of waste sand which was thrown into the stream and then washed down towards the sea. Several old buildings and chimneys testify to the former industrial activity here.

At the top of the footpath you come out onto Phernyssick Road, turn left and proceed up a step hill to a mini-roundabout at the top, then turn right along the road.

Old photograph of the Drying Kilns near St Austell
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Old photograph of the Drying Kilns near St Austell

The strange building in front of you is a block of apartments ‘Lovering House’ constructed on the site of a former china clay drying kiln. There was a coal-fired furnace at the left hand end, from which the hot gases passed under the kiln floor in ducts to the other end where there was tall chimney to provide a strong draught for the fire. The wet clay was placed on the hot floor to dry. It was very labour intensive hot work.

Continue along the road for 1.5km until you see a small sign on your left for a footpath to Carn Grey. Proceed along this footpath to a splendid example of a granite tor, which is known as Carn Grey. There are magnificent views here. On a clear day it is possible to see Rough Tor and Brown Willy on Bodmin Moor and the whole of St Austell Bay from the Gribbin in the east to Black Head in [[Image:St_Austell_CL11_SandyHill_03.jpg|thumb|right|300px|alt=Carn Grey Tor|Carn Grey Tor]]the west. Below the tor is a disused granite quarry. This quarry is a Site of Special Scientific Interest (S.S.S.I.) because it contains a special type of granite. The local authority has turned it into a rather attractive amenity. This quarry provided much of the stone used in the older buildings in St Austell and, strangely, many of the prehistoric standing stones in this area came from here as well. The Market House in St Austell was built with granite from this quarry.

Take the small footpath westwards from the tor, pass through the style in the hedge, bear right and then follow round to a gate. From there ascend the grassed over sand tip in front of you to a group of stones at the summit of the tip. Note how well the vegetation of grasses, heather, gorse with the occasional rhododendron has colonised the sand tip. A scene from the TV programme ‘The Natural History of Britain’ was shot here. From the top of the tip a view westwards shows Carclaze pit.

From the summit of the tip descend southwards and follow round the perimeter fence, noting the way vegetation is re-establishing itself on both the faces of the china clay pit and the tips to the south.

Follow the footpath around the south side of Carclaze china clay pit until, just before you reach the main road, a trail from the direction of the main road joins the main trail. Continue on the main trail for about 30 yards to where it is possible to look down into the pit. On the right hand side the south face of Carclaze Old Tin Pit can be seen; ahead and to the left all the workings were for china clay. The Old Tin Pit is described in the following extract:

Carclaze Old Pit lies on the southern boundary of the St. Austell granite about 3 km NNE of St Austell. It probably originated from tin stream workings in the Sandy Bottom valley following a rich source of tin to the crest of the hill, where a massive stockwork consisting of a tin-bearing vein swarm, adjacent to the granite margin, was developed by an open pit. This was a ‘must-see’ site for late 18th and early 19th C visitors to Cornwall from the Continent and there are many accounts and illustrations describing the pit and the method of working. The earliest scientific account was by a Frenchman, M. Jars from the Académie Royale des Sciences de Paris, who visited the pit in 1764. This was followed by other Frenchmen: Bonnard in 1803, Dufrénoy and de Beaumont in 1824-7 and Daubrée in 1841. Von Oeynhausen and Von Dechen from Germany provided the first geological map and cross-section of the pit in 1829, showing the layout of the veins. The pit was connected to the processing works by an 500m long underground canal, possibly constructed as early as 1720, which would make it the earliest underground canal in Britain. The canal fell in around 1800, but was rediscovered in the mid 19th century when 16 or 18 of the small barges, all chained together, were found. An ingenious system of leats brought water to the pit to provide power and process water. Waterwheels drove the machines (‘Stamps’) which pulverised the ore so that the tin could be separated. Tin extraction from the Old Pit had practically ceased by the mid 19th C as the tin ore was exhausted and production switched to china clay. These accounts also show how the technology of the early china clay industry evolved from large scale open pit tin operations. Below: Thomas Allom’s lithograph of 1831.

Old illustration of Clay mining
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Old illustration of Clay mining

If 19th century accounts are to be believed, around £100 million worth of tin was extracted from this small pit of 2 hectares; all the workings to the left were later and were for china clay. The south face of the old tin pit can also be seen from the viewpoint on the top of the tip described earlier. The steeply southward dipping veins of the tin stockwork can be seen in the face.

It is possible to continue northwards along the trail to where china clay is seen in a low cliff beside the track. China clay is formed by water breaking down the granite over millions of years to form a soft china clay bearing rock. A book written for the layman gives greater detail:

Bristow, C.M. 2006 China Clay – a geologist’s view: geology, minerals, environment and world kaolins. ISBN 1 900147 459. Published by Cornish Hillside Publications, St. Austell. pp60. Price £7.99, obtainable from all good bookshops and from the Wheal Martyn bookshop (add £1.50 for P. & P.).

Retrace your steps to the trail leading down to the main road (A391), cross the main road with care, as it can be busy, and continue up the trail on the other side to an old road alignment, (now used for parking), where one should turn left and proceed downhill. At the crossroads turn left and then, after about 50m, turn right onto the hill leading down towards Tregonnissey. At the bottom of the hill, at the traffic lights, it is possible to catch a bus (First No 101) back into St Austell. Alternatively you can take Bus 101 in the opposite direction to visit the Eden project.

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