Stormsdown is at the head of Owlacombe a tributary valley of the the Langworthy Brook, which itself is a tributary of the River Lemon. The geology consists of shales, grits and chert otherwise known as killas by the miners. The mines are in the metamorphic aurole zone that surrounds the igneous mass and the lodes are all hydrothermal sulphide veins.
There are a number of generally east - west lodes that traverse the valley and seven of them have been productively worked. The four northerly lodes were worked by several mines both singularly and jointly and are collectively known as Owlacombe. Two Tin lodes only 25 yards apart known as North Beam and South Beam, were worked in the Medieval period forming one large openwork. These lodes underlie to the north and were also worked at depth in the 19th century, together with the Great North lode that underlies to the south. To the south of the beam a fourth lode which also produced copper was worked at Wheal Brothers and Wheal Union (Dines).
To the south of Wheal Brothers and Wheal Union there were three other tin lodes that were worked over a period of years, known as South Lode No.1, South Lode No. 2 and South Lode No. 3 and it is these that are generally referred to as Stormsdown.
There were also other lodes in the valley but these were unproductive.
In the Ashburton/Chagford Stannery Court book, the following entry appears:
By virtue of which the said Elize Scoble claymeth all the tynworks in Alston Downe, Caton Downe and Stormes Down haveinge purchassed the same of the said Sir George Sonds and the said William Stowell.
Nothing now survives at Alston Down and Caton Down, but at Stormsdown there is an openwork which still survives, the site of another is known from early maps and a third survives in Hooks Plantation. These are all probably contemporary with Owlacombe Beam, which was probably worked throughout the Medieval period. The Stormsdown openworks are therefore at least sixteenth century and probably earlier.
There is no documentary evidence of mining at Stormsdown during the eighteenth century but some development of the Owlacombe mines did take place.
In the nineteenth century major development took place on the owlacombe lodes with a number of successive mining companies working the lodes at greater depths. These mining ventures required considerable capital for investment in pumping equipment (waterwheels and steam engines) and processing equipment, stamps and burning houses etc. The workings went below deep adit which had been brought up from the valley to unwater the beam as early as the sixteenth century. Branches from deep adit were taken to Union and Wheel Brothers. The lodes were eventually mined to a depth of 78 fms (468ft) below adit on the main beam lodes and 47 fms below adit on the Union Lode (Dines). Sometime before the 1840's some shallow exploratory adits were driven at Stormsdown to trial the lodes previously worked in the medieval period, but no further development seems to have taken place.
On the main Owlacombe lodes the last major workings ceased in 1866, but at this time some interest was being shown in the lodes to the south, with deep adit being extended from Wheel Brothers to South Lode No 1, again to prove the lode (Dines).
At sometime a shaft known as South Shaft was sunk on South Lode No 1. (but at what particular date is uncertain). The only other development work on South Lode was undertaken in 1895 and 1896 when Stormsdown Mining Co Ltd is listed, employing 8 and 19 persons (Burt et al). It is possible at this time that deep adit was driven from South Shaft (which is South East of Owlacombe Farm), eastwards to Stormsdown.
The twentieth century sees the only significant mining on Stormsdown since the earlier medieval works
The mine itself is unusual in that it was totally financed by a private individual - namely a Mr Edward Herbert Bayldon, who had made his fortune as a stockbroker in London. At the age of 36 Mr Bayldon had retired and moved to Dawlish. In 1901 he was a member of a committee affiliated to the London Chamber of Commerce which was tasked with furthering mining interests in West Africa and the Gold Coast (Westaway). With a late nineteenth century boom in arsenic and a doubling of tin prices mining again became attractive. This early twentieth resurgence in mining was known as the The Great Electric boom, as new plant and machinery was being tried and developed.
The purchase on the lease or land took place in 1899, but it was not until 1905 that work started on sinking Main Shaft (Terrell). By 1906 work was progressing with the construction of the processing plant and dressing floors. The plant at Stormsdown was influenced by the highly successful modern plant that had been in operation in the Gunnislake Clitters re-working a few years earlier. The Stormdown plant however was even more sophisticated and was a highly efficient plant.
By 1906 the shaft had reached a depth of 200ft (WT 3rd Aug 1906). By 1907 the processing plant was nearing completion and in January of that year Ernest Terrell was appointed as Mine Manager (WBCA 24th Jan 1907). Ernest Terrell had previously worked at Gunnislake Clitters as Assistant Mine Engineer and at Stormsdown was charged with installing the new mine machinery and bringing the mine into production. The plant consisted of Holman pneumatic stamps, classifiers, Buss tables, spitkasten, Buss slimers, 3 Brunton revolving calciners, Holman pan grinders and magnetic separators. The plant was powered by electricity which was generated on site by a Campbell suction-gas plant. The processing floors were situated in the valley bottom and were connected to the shaft at Stormsdown by a 1800ft incline (Terrell)
The production of tin concentrate and arsenic commenced in July 1907 (TC 4th July 1907).
The Main shaft was gradually deepened and in 1908 the Evans 7" steam pump was replaced by a 200HP Hathorn Davey compound differential pumping engine - the only one to be installed in a west country mine. At the shaft head apart from the steam pumping engine, there was a Scott Mountain double drum 30HP electric winding engine (the use of electric winders was cutting edge technology) and a Bickle & Co straight line single cylinder 7" by 14" stroke horizontal steam air compressor (Terrell).
The shaft finally reached a depth of 360ft in 1909 with three levels - adit level at 30fms (180ft), No1 level at 42.5 fms (255ft) and No2 level at 57.5 fms (345ft) (Terrell).
In July 1909 work was suspended and the majority of the workforce were laid off. Pumping continued however while attempts were made to sell the mine as a going concern (Westaway).
In 1911 underground development re-commenced (instigated and financed by Mr Bayldon) and the ore extracted was stock-piled at the shaft head. In July 1912 a new company was formed - Sigford Mines Ltd - the directors of which were Edward Herbert Bayldon, Elsey Fradgley, George Higlett and Owen Bayldon. The limited company had 5000 shares half purchased each by Bayldon snr and Fradgley. Bayldon also provided a £10,000 debenture loan to the new company with the total new investment being £15,000 pounds. Unfortunately no future development took place at the mine as Mr Bayldon died in December 1912 (aged 58).
As before pumping continued while attempts were again made to sell the mine as a going concern, without success. In July 1913 the decision was made to re-activate the mill in order to process outstanding stockpiles of ore. Following treatment of the ore, the mine and mill were stripped out and all the materials auctioned in March 1914 (Westaway).
Recorded production for the mine is 21694 tons producing 158 tons of tin concentrate and 750 tons of arsenic (Paull). This gave returns of £13557 and £9888 respectively (Burt et al). Total investment in the mine was in the region of £70,000 the majority of which was financed by Mr Bayldon.
The Metalliferous Mines of South-West England Vol 2
H G Dines 1954
Report on the Stormsdown and Owlacombe Tin and Arsenic Mines, Ashburton, Devon
Ernest Terrell 1909
Stormsdown Mine Production and Manpower
D Westaway (unpublished)
Report on Stormsdowm and Owlacombe Mines
Josiah Paull 1913
Devon and Somerset Mines
Burt et al
The Life of Edward Herbert Bayldon
D Westaway (unpublished)
WT – Western Times
WBCA – West Briton & Cornwall Advertiser
TC - The Cornishman