The workings of Wheal Sidney are located in Fernhill Wood and the adjacent fields to the west. The mine is just south of the Dartmoor Park Boundary, to the north of the Stannary town of Plympton and three quarters of mile west of the isolated granite boss at Crownhill Down and Hemerdon Ball. The name is derived from the mine owner, Sidney Strode of Newnham Park. The sett boundary is from the Tory Brook in the east, to near the road running from Plympton to Cadover Bridge in the west and comprises three west-east direction lodes which are part of a series that make up the Plympton Mining District. The location of the mine yielded lode deposits which are unlike those in the main Dartmoor granite mass, insofar as they had significant contents of sulphide minerals, in particularly arsenopyrite or mundic. As a result of these deposits the mine infrastructure was very different to other mines on the higher moor, due to the processing of arsenic, which was often an important by-product of tin production.
The ‘modern’ mine operations started around 1850 in earnest but it was said that the area had been worked “300 years since” (ref: Hamilton-Jenkin). Prior to 1850, there is some surviving evidence of tin mining at Fernhill, with two large excavations or ‘openworks’ dug on the ‘backs’ of lodes where they outcrop at surface. Documentary evidence dating from 1527 to 1660 name workings as Fernehyll, Fernhyllewoode, Vernhill Beame, Heath Beme and Furse Parke adwyninge unto Ffernhill Woode at Heath Downe (ref: Shorten). By the mid to late 17th century much of this early ‘ancient’ phase of mining had ceased, with underground workings having reached a depth of 12 fms (72 ft) below surface (90 fathoms on the underlie), this depth having been obtained by the construction of a Shallow Adit brought up from Elfordleigh Valley by the old men (ref: Mining Journal, December 1859). The first evidence of the name Wheal Sidney, was in 1795 (ref: Lyson’s Magna Britannia). After 1795 some interest was shown in the mine, but there was no lease taken up until 1836, granted to Capt. Hitchens of the nearby Bottle Hill Mining Company, albeit ‘no mining of any consequence was undertaken’ by this company.
The ‘modern’ restarting of mine in 1850 commenced after the sett was leased to Eddy and Croker (later Eddy, Croker and Wood) who formed a cost book company, the shares of which were held by a number of investors from Plymouth, Salisbury and London. Initially, work commenced in sinking an Engine Shaft (later known as Old Engine Shaft) and by December 1851 a 44ft waterwheel had been erected and associated stamps completed. However, due to the mundic content the ore required calcination and a revolving calciner (Brunton type) was erected in June 1852. By 1854, the Engine Shaft had reached 45fms, at which time new 45ft waterwheel (built by Messrs Mare & Co, Plymouth) was erected which took over pumping duties, while the old 44ft waterwheel operated 24 head of stamps (ref: Murchison). A tramway was built between the Dressing Floors and the Old Engine Shaft. Between 1852 and 1854, 100 tons of Black Tin had been sold with prices varying between £65 to £82 per ton. By 1855, the mine had just about broken even with sales amounting to £8,459 on a called-up capital of £8,832.
In July 1858 a new shaft was commenced 100fms north of Old Engine Shaft, which became known as ‘New Engine Shaft’. This shaft was sunk, with a view to taking a lode there near its northerly tip. Presumably the tramway was extended at this point. The pumping of both Old and New Engine shafts was provided by the (1854) 45ft wheel which worked, with a bridle, two lines of wooden flat-rods. One line of flat-rods were 260fms (1560ft) long to the Old Engine Shaft and the other line was 270fms (1620ft) long to the New Engine Shaft (ref: Mining Journal). On reaching a depth of 65fms (390ft), a stream was cut into at the shaft bottom, which flooded the mine with the pumps being unable to cope. The set back was overcome with the shaft being re-equipped with new plungers (15in and 16in) and the old wooden flat-rods being replaced by new 2.5 in rods with hammered iron joints.
By April 1860, the New Engine Shaft was 54fms (324ft) deep and 10 months later (in February 1861) it was recorded as being 60fms (360ft) deep and a crosscut was being driven south towards Main Lode. The mine was working with a major disadvantage though as it only had a crab winch to hoist the ore. Also, at that time it would appear that pumping two shafts from one wheel was proving too much and the line of flat rods was fixed to the (old 44ft) wheel pumping water out of the Old Engine Shaft (ref: Western Morning News). According to the Mining Journal, in early 1862, a water turbine was erected to assist the stamping but it is assumed that this unsuccessful as no further reference to it can be found. Maybe there was no further reference to the water turbine as in 1862 the company relinquished its lease, which effectively ended the most productive period of mining at Wheal Sidney, during which time it provided employment for anything from 40 to 80 persons and produced approximately 360 tons of tin, to the value of £25,000. Work, however, did continue as a new lease was granted to Messrs Ewer, Woodlands (both of Salisbury) and Linden (from Plymouth) in March of that year. By the July engineers were constructing an engine house (for 56″ pump), which was completed by October 1862, while the foundations for a winding house were also well underway (Western Daily Mercury).
In November 1864 the sett was signed over to a C. N. Norton of Salisbury and despite initial promise and some good early returns, by 1865 mining had ceased and the lease was revoked. In 1870, the sett appears to have been taken up by Wheal Mary Hutchings and a licence acquired to use the calciner. A Deep Adit was driven 100 fms (600 ft) from the Tory Brook Valley, near the Dressing Floors, which is assumed to have been comply with the terms of the lease; ie Use of the Calciner was under the condition of tin ore prospecting being carried out. Further leases were granted (Pocock, Vosper and Manley) in 1888, but little, if any work was undertaken The last documentation regarding the mine is dated 1920, when a mineral licence was granted to W. S. Spens-Stuart, who was interested in the westward extension of the lodes, within Cann Woods.
The author is grateful to the Dartmoor Tinworking Research Group (DTRG) for a guided walk around the mine (March 2025) and the land owners for access, which provided the opportunity to take the photographs shown here. Much of the information contained in this post was collated from notes created for the walk by Stephen Holley of DTRG, which have been edited and added to for this post.
Bibliography
- Stephen Holley, DTRG (March 2025) – Guided walk notes for Wheal Sidney and Wheal Julian
- A.K. Hamilton Jenkin (2005) – Mines of Devon – Pages 65 and 66
- Bert Shorten (1985) – Metal Mines of Plympton
- Plymouth and Devonport Weekly Journal (various)
- Mining Journals (various)
- J H Murchison (1854) – British Mines Considered as a Means of Investment
- Western Morning News (various)
- Western Daily Mercury (various)
- Barclay & Toll (manuscript) from 1919
- H.G. Dines (1956) – The Metalliferous Mining Region of South-West England
