twelveheads Archives - Explore Cornwall

Nangiles Mine

Caitlin — Mon, 03 Aug 2020 18:53:12 +0000

The remains of Nangiles mine are a common site for anyone heading along the mineral tramways track between Bissoe and Twelveheads. The most notable left over of this working is the large tailings dump that stretches down from Engine shaft to the pathway that the Redruth to Chacewater Railway would have run along.

In 1808 Nangiles and Bread and Cheese mine were already at work with a steam engine. Large quantities of copper, tin and zinc were being turned out. By 1819 the mine had reached 70 fathoms (128m) in depth, but was starting to struggle to find as much copper as its neighbours.
Prior to 1848 Nangiles was worked alongside its neighbour Wheal Andrew, however they both stopped working in this year. In 1862 work resumed again with a new 80-inch pumping engine being erected on Engine shaft. This was later sold to Wheal Rose United in 1872, where two years later it was moved to Holmbush Mine. Unfortunately, in 1967 when the Wheal Jane group were investigating the site, the engine house and its stack were deemed unsafe, and were significantly reduced in size; only the arch from the bob wall remains.

By 1870, the mine had reached 160 fathoms (m) in depth and was working mostly for pyrite and blende. The main issue was that the water in the mine was incredibly corrosive and the pumps had to be lined with brass, a very expensive outgoing for the company. Between 1905 and 1915 the mine was worked as part of Falmouth Consolidated Mines. Then from 1969-79 and 1980-91 the area was investigated by the Wheal Jane group and mined for tin.

Following the closure of Wheal Jane and the withdrawal of a number of grants that paid for the running of its pumps, a new solution for the removal of mine water had be to made. Following a discharge of contaminated water in late 1991, a decision was made to pump water from a blocked adit up to a higher level where it could be treated. However costs quickly mounted and this was abandoned over the Christmas period until further work could take place in the New Year. By mid January pumping still hadn’t recommenced and on the 16th approximately 50 million litres of toxic mine water was released into the Carnon River through the now burst concrete plug on the Nangiles Adit (or rock-fall, depending on source). While the immediate Carnon River was used to the constant influx of toxic water from the many mines that feed into it, it was downstream in the Restronguet Creek and Fal River that there a greater impact on wildlife.

Pumping was immediately restarted and plans for a passive treatment plant put into place at the Wheal Jane site. This plant was fairly successful (apart from being put in back to front), but there was also the risk further contamination, so a more permanent plant needed to be put in. Between 1992-2000 a temporary plant was installed, with planning for the permanent plant being submitted in 1998.

The mine had at least three engine houses over its life.
The most famous of these is the 80″ pumping engine on Engine shaft. This was erected in 1862, but only worked for ten years when it was sold to Wheal Rose United, then onto Holmbush mine.
Hidden deep in the bushes is the precarious remains of the 36″ stamps engine built in 1871 from the Welsh Gold Mining Co. Now held together only by ivy and luck, this once drove 84 heads of stamps prior to the engine being sold to West Condurrow in 1891. It ended its life at Wheal Grenville.
The other engine on the site was a 70″ pumping engine erected in 1847 and sold three years later to Crane and Bejawsa Mine in Camborne.

Shafts

Lodes

Shafts

Lodes

Access

Parking

References

Access

Parking

References

The post Nangiles Mine appeared first on Explore Cornwall.

Cusvey Mine

Caitlin — Tue, 18 Sep 2018 13:53:14 +0000

Up above Twelveheads stands the two engine houses and single stack of Cusvey mine. The mine was first worked for tin between 1734 and 1764, before becoming a very prominent copper mine alongside its neighbour Wheal Fortune.
Cusvey was forced to close following the global slump in copper prices, but reopened as part of Consolidated mines in 1819. The mine closed again in 1857, where it later became part of Clifford Amalgamated before its final closure in 1870.
The Wheal Jane group did some explorations and digging around in the late 20th century, but apart from that it has been left to overgrow and fall down until it was consolidated in 2009 as part of the cycle/tram route.

Shear’s pumping engine house, built in 1826 (maybe), is potentially one of the oldest engine houses remaining in Cornwall. Originally built for a 70″ engine, this was later replaced with a smaller 65″ engine. It’s boiler house was somewhere to the north. The pumping engine pumped out of Shear’s shaft (150 fathoms/274m) right in front of it.

Remains of the calciner flue can be seen hidden amongst the bushes and brambles. The calciner is likely to have burnt off the arsenic as waste rather than for collection and selling. The chimney just behind the pumping engine house was also built around 1826 and would have served both engine houses on the site and possibly a calciner somewhere further down the hill.

Remains of the winding engine house hidden in the Cornish jungle. This house was actually built before the pumping engine and is a rare find as its beam was houses inside the engine house. The whim worked a separate shaft slightly to the east; this has been left by the council to become overgrown and obscured to restrict public access. East shaft reached 100-fathoms (183m).

Access

Parking

References

Access

Parking

References

The post Cusvey Mine appeared first on Explore Cornwall.

Wheal Henry

Caitlin — Fri, 14 Sep 2018 15:45:21 +0000

The scant remains of Wheal Henry lie to the west of the village of Twelveheads, with little more than the shell of the engine house and a couple of shafts visible on the surface.

The first official mention of the mine dates to 1734, but like all the other mines in the area, it was probably around for much longer. In 1837, Wheal Henry amalgamated with Killicor mine across the valley, another ancient sett where practically nothing remains, however this was short lived as both had poor tin resources.

From 1841, the mine started paying for access to the Great County Adit, although it isn’t clear when it actually reached the mine. The mine was described as very poor at this time and stopped paying for the County Adit in the 1860’s.
When the mine actually closed isn’t recorded (that I can find), but since there are no recorded outputs from 1847, its likely to have closed for the final time during the 1860’s, having reached a final depth of 90-fathoms (164m).

There is a small adit below the engine house, however its unclear what it’s connected to.

Shafts

Lodes

Output

Shafts

Lodes

Output

The engine house of unknown size (although not bigger than 24-inch), a Watt type rotative engine which would have probably worked from the shaft below via flat rods. This house is very unusual, actually sitting the wrong way around facing away from the shaft, probably due to the steepness of the hill it sits on. The house itself is built of killas without any other materials, such as wood, being used to strengthen it.
The history of the engine house is a bit of a mystery, with no actual records of its erection existing. It was likely built between 1800-20 (maybe 1819?), with surveys of the site classing it as probably one of the oldest standing engine house in Cornwall.

Access

Parking

References

Access

Parking

References

The post Wheal Henry appeared first on Explore Cornwall.

Poldice Mine

Caitlin — Fri, 14 Sep 2018 14:33:54 +0000

In the Poldice Valley on the outskirts of St Day and Carharrack are the remains of a once very significant mine in Cornish history.

First officially mentioned in 1512 during a legal dispute, the site itself is ancient with permission for stamping water courses being granted as far back as the reign of Queen Elizabeth. By 1702 the mine had already reached 100 fathoms and used ‘engines’ to help dewater the mine, although these were probably water wheels. Two Newcomen engines were added to the mine to aid dewatering in 1941, with work then starting on the Great County Adit in 1748.

On the 8th of July 1786, Boulton and Watt sent the mine manager of Poldice, expressing concern over their state of affairs and whether or not they could pay the money owed for the engines they had just erected. The 11th of July saw another letter sent, this time giving some discount on the monthly payments for the engines (£110 rather than £166)

The base of the overhead cable from Parc-an-Chy

In 1800, Poldice amalgamated with its neighbour Wheal Unity, raising 41,196 tons of copper worth £41,441 before closing. It reopened a couple of years later. 1821 saw the erection of a 90-inch Woolf pumping engine on Bissa Pool shaft. This engine came from Wales in the middle of a storm, with the boat having to land in Padstow rather than Hayle, while some other components were left in Wales only days before it was due to start working.

In 1852, Poldice amalgamated with Wheal Unity, Wheal Maiden, Wheal Gorland and Carharrack Mine to form St Day United. One record shows that nine engines of different varieties were working during this period, with work started on a man engine in 1865, however, this was never finished before the mine closed again in 1866/67.

The mine reopened in 1870 as Poldice Mine, but only worked for a couple of years before closing and selling the engines. 1873 saw another reworking as St Day United with the purchase of another large 85-inch engine, but this only lasted six months before it folded. By 1880 only West Poldice (Unity Wood) was still in action, although one of the calciners is dated 1883 and another 1897. All of the remaining engines were all bought for £12,000 in the early 1900’s by J. C. Lanyon & Son and scrapped along with those from Clifford Amalgamated. Between 1924 and 1929, the dumps were reworked for tin, copper and arsenic but with little success.

From 1926-29 another mine, Park-an-Chy, about a mile to the NE started to transfer its ore to Poldice for dressing as it was unable to rustle up enough water for dressing on its own site. It did this via an overhead cable that landed just above the dressing floor remains. Park-an-Chy was attempting to mine both tin and wolfram, which require different processing methods (fine and coarse crushing respectively) and eventually this proved too difficult and the venture stopped.

During the 1970’s, the dumps of Poldice were reworked again for the last time, this time by Mount Wellington, along with the rest of the Consol’s area.

The remains around Bissa Pool shaft, the 90″ pumping engine installed in 1821 and the 20th century horizontal engine.

Shafts

Lodes

Output

Shafts

Lodes

Output

Concrete remains from the overgrown Bissa Pool stamps

Over it’s life Poldice had a large number of engine houses, although not at the same time. Prior to 1741 it utilised waterwheels to unwater the mine until the installation of two Newcomen engines in that year. By 1777 there were four of these engines, two of which were sized at 66″ and 60″. Three 63″ Boulton & Watt pumping engines were erected in 1780, 1782 and 1785, one of which was replaced in 1787 by a 58″ double acting engine. In 1821 the enormous 90″ pumping engine was installed on Bissa Pool shaft, with two smaller engines elsewhere. A whim was added in 1843 along with a man engine on Paynter’s shaft in 1865. The final installation was a 85″ pumping engine from Perran Foundry in 1873.

On the left is the house for ore crusher, then some buddles and finally the remaining wall of a calciner.

Access

Parking

References

Access

Parking

References

The post Poldice Mine appeared first on Explore Cornwall.