World Heritage

Development of Steam Power in Cornwall

Cornwall's World Heritage Bid

Based at Cornwall Archaeological Unit, the project is being undertaken on behalf of a Cornish Mining World Heritage Site Bid Partnership made up of over 60 organisations and more than 100 individuals who are experts in mining history and in managing the sites today. Remarkable advances in hard rock mining and engineering technologies during the 18th and 19th centuries transformed the landscape, economy and society of Cornwall and West Devon and placed the region at the forefront of the Industrial Revolution. These technologies quickly spread to every corner of the globe as the international migration of Cornwall and West Devon's highly skilled workforce forged distinctive cultural links between mining communities worldwide.

Cornwall and West Devon's World Heritage Site Bid has been officially endorsed and signed by Culture Secretary, Tessa Jowell, before being sent off to UNESCO's (United Nations Educational, Scientific and Cultural Organisation) headquarters in Paris to be assessed. The Bid, consisting of the Nomination Document - stating why certain areas should get World Heritage Site Status - and the Management Plan - detailing how such sites would be managed - will be assessed by expert advisers to the World Heritage Committee over the next 12 months. The final decision will be made by the Committee at its annual meeting in the summer of 2006. To find out more about the Bid, visit http://www.cornish-mining.org.uk

Unusually the bid area is broken down into a number of districts of which the Wendron Mining District is one. With a lack of development pressure and a peak of activity predating other districts the Wendron District is the least researched and understood mining district in Cornwall. The final boundary drawn up by the 'expert panel' advising the Bid Team has placed significant mining remains, associated with mines within the boundary, outside it.

For further information contact Deborah Boden, World Heritage Site Bid Project Manager, Historic Environment Service, Percuil Building, Old County Hall, Station Road Truro, Cornwall TR1 3AY

Our WHS Team inspecting a heritage mine in Italy ... and a working lunch discussing European mining heritage

Tel: +44 (0) 1872 322585 Fax: +44 (0) 1872 323811 Email: hes@cornwall.gov.uk

If you have any information on or are interested in the Wendron Mining District contact Richard Williams at Poldark Mine

email: info@poldarkmine.co.uk Telephone +44 (0)1326 573 173

The Development of Steam Power in the Mines of Cornwall

Cornwall became the mining worlds most technilogically advanced district in the early 19th century as a direct result of the development of steam power and mining techniques. This paper was presented by the author to the Joint conference of the Mining and Geological Institute of Portugal and Associação Portuguesa de Arqueologia Industrial. Lisboa, Portugal, 1998. The paper has been published in the journal of Associação Portuguesa de Arqueologia Industrial and in Spanish in the Boletin, Comite Mexicano Para la Conservacion del Patrimonio Industrial, Mexico D.F. Mexico.

A brief account of the development and application of steam power in the mines of Cornwall, UK

''That most useful, powerful, and noble machine, the fire engine, of which we have several (in Cornwall) that are perhaps the largest in the kingdom'' W. Pryce 1778.

Archaeological evidence indicates that tin was worked in Cornwall three thousand eight hundred years ago(1), by the 'Dark Ages' there appears to have been a well established industry1 with trade links to Europe. These early workings exploited alluvial deposits in the old river valleys and lode exposures where these were rich and easy to break from the rock by the methods then available. By today's standards mining methods were very primitive and little is known of the power used. As lode mining was developed various methods were employed both to raise ore and to keep the mines free of water. The power used was manual labour, the horse, and water. Great and expensive efforts were made to keep the mines dry, the most powerful being the water wheel which was developed to a high degree of efficiency.

Pryce writing in 1778 (2) gives an account of the water wheel at the Cook's Kitchen Mine, now part of the South Crofty Mine, which was forty eight feet (14.6 metres) in diameter, working tiers of pumps of nine inch diameter divided into four lifts drawing water from eighty fathoms (146 metres) below the adit and capable of drawing from 120 fathoms (220 metres), he goes on to state that Mr. Newcomen and Cawley contrived another way of raising water, by fire engine the most powerful machine of his day and which was of 'about seventy years standing' (invented seventy years before).

The properties of steam were known to the Greeks, in the sixteenth century, Porta carried out laboratory experiments in Naples as did Caus in England (3) however it was not until 1698 that a patent for a working engine for 'raising water by the impellant force of fire' was granted to Thomas Savery, a military engineer. Savery's engines worked by introducing steam into a piston and then cooling the piston with cold water thus creating a vacuum, whilst his 'fire engines' were a breakthrough they were not capable of raising water from the depths of the Cornish mines. According to Farey (5) Savory visited Cornwall on several occasions in unsuccessful attempts to introduce his engines to the mines. It was no doubt during these visits that he met Thomas Newcomen of Dartmouth, described as an ironmonger.

Newcomen and his assistant Cawley were to develop the Savory engine into a machine capable of being used for the pumping of water from considerable depths. There is some dispute as to whether Savory and Newcomen were working on their engines separately with Savory actually obtaining a patent first and thereby holding the rights to produce the machines or, whether following Savory's invention, Newcomen improved upon it. Whichever is the case there is no doubt that Newcomen and Cawley were responsible for the first successful application of steam as a source of power in the mines of Cornwall. The date of the first engine to operate in Cornwall is unknown, Carne (4) states that the first engine to be erected in the county was at Wheal Vor, a tin mine in the parish of Breage, where it worked from 1710 to 1714. (Wheal is the old Cornish word meaning mine) The discovery of a six-holed spear guide in the mine in 1815 is said to confirm this (7), however Rolt and Allen (3) consider that 'it is inconceivable that an engine installed at such an early date could have coped with such a load of rods and pumps'. Another writer describes the Balcoath mine at Porkellis which is said to have had the first Newcomen engine in the County. Fueled by turf the engine was later moved to Tregonebris Mine and later to Trevenen Mine. Whilst the fact that a Newcomen engine was on this site at some time unless it was an experimental engine, as suggested by Rolt and Allen (3), the actual date of operation was almost certainly later than Carne believed for according to Farey (5) it was not until 1711 that the first Newcomen engine was completed and 1713 before they had perfected the engine.

What is without doubt is that around this period the first Newcomen engine to operate in Cornwall was at work. By 1727 only five of Newcomen's engines are recorded as working in Cornwall (6). This is a surprisingly low number considering the number of mines at work and the need to explore their orebodys in depth and keep the deeper levels free from water. The slow adoption of steam power in Cornwall resulted from three factors; the tax levied by the government on coal, the cost of transporting it to the mines and the high consumption of Newcomen's engines. The only fuel available, other than the limited amounts of peat, was coal and as there is none in Cornwall it had to be transported by sea from the nearest coalfield in South Wales. There is little doubt that the relatively high cost of fuel, even without a tax, coupled with the large number of engines that eventually worked in Cornwall resulted in the refinement of the beam engine in the county into the most efficient engine of its time. In the early days of steam Cornish mines continued with the practice of driving drainage adits (tunnels) and the use of water power to keep the mines drained whilst mines and works near the coal fields readily adopted the new source of power. At Wheal Rose in St.Agnes in 1725 the engine was 'so very chargeable that the adventurers were fain to bring home an adit of a mile and a half in length to save the cost of continuing it' (7). Following petitions from Cornish mine adventurers the tax was finally abolished in 1739 by which time only one steam engine was at work in the county (2).

With the abolition of the coal tax a new period of rapid introduction of steam power in Cornwall, fuelled in part by the rising price of copper, commenced. By 1758 at least twelve engines were at work, this number being increased by a further sixty when Pryce (2) writing in 1778 stated that 'Mr. Newcomen's invention of the fire engine enabled us to sink our mines to twice the depth we could formerly do by any other machinery.' Whilst Newcomen's engines had enabled the mines to reach depths which had been unthinkable seventy years earlier they continued to be very expensive to operate. Still consuming large amounts of coal the engines were inefficient in their application of power, relying on suction on the upstroke of the engine to raise the water from a maximum depth of 80 fathoms (146 metres) below the adit level, although most engines would probably not have been capable of even this depth (7). The first major improvement to the atmospheric engine was James Watt's separate condenser, which resulted in greater economy in the use of steam in the engine by continuously keeping the cylinder hot and the condenser cool, instead of the two operations being carried out in one cylinder which in the Newcomen engine had been alternately exposed to steam and then cooling water. This improvement transformed Newcomen's atmospheric engine into the first true steam powered engine. The result was to have an immense effect upon the Cornish mining industry and the future development of steam engines.

In 1778 Boulton and Watt commissioned their first steam engine in Cornwall at Chasewater Mine, later part of Wheal Busy. This engine heralded a new lease of life for the Cornish mines. Not only were the new engines far more powerful than the old Newcomen engines but their consumption of fuel was less than a third. This is clearly shown by the following account of the Consolidated Mines of Gwennap which in 1779 had been operating seven Newcomen engines to keep the mine workings drained. The costs of the engines was so great that the adventurers stopped the workings which were acquired by another group of adventurers who erected five Boulton and Watt engines a year later in 1780. These engines consumed 2,030 weys of coal (6,090 tons) compared to 6,362 weys of coal (19,086 tons), a saving of £9,0976, a very considerable amount for 1780. By 1783 twenty-one of the new engines were at work in the county with only one Newcomen engine still operating. By 1790 the number of Boulton and Watt engines working in the county had risen to forty five (7). Until 1800 the atmospheric and later the steam engine were covered by patents held by Savory, Newcomen and later Watt. These were jealously guarded with the result that the development of the steam engine was restricted to the patent holders. Watt had however developed his engines to a high standard during the time of his patent. With the expiry of Watt's patent in 1800 a new era commenced of experiment and improvements culminating in the development of the Cornish engine which was to become recognised as the most efficient steam pumping engine in the world.

In 1801 Joel Lean, then manager and engineer at Wheal Crenver and Oatfield, Crowan was the first engineer to replace bucket pumps with plunger pumps except for the bottom lift and to connect the pumps to a single acting engine. In doing so he became the 'father' of the Cornish beam engine as this arrangement became standard for the Cornish pumping engine. Many variations of engine were to be tried some successful others not. Included amongst the variations were double acting engines where the steam acted on both sides of the piston, compound engines which used two cylinders and inverted cylinder engines, however non was to find favour more than the single acting engine for pumping. To operate pumps at depth and under considerable pressure very strong pitwork was required and considerable engineering skill when one considers the shape of most Cornish shafts which may be vertical to the adit level or until the shaft reaches the mineral vein but then were sunk on the vein itself and could alter direction numerous times before reaching the shaft bottom. An example of the size of timber required to transmit the engines power to the pumps is given by Barton's (6) account of the pitwork connected to Davey's 80'' engine working at the Consolidated Mines in the parish of Gwennap. The main rod consisted of 290 fathoms (530 metres) of the best Riga timber 24'' (0.6 metre) square at surface diminishing to 12'' square at the sump, the timbers were in 50' to 70' (15 to 21 metre) lengths strapped together at the ends with iron plates to form one continuous length. As was normal practice in Cornish mines the bottom pump was of the bucket lift type those above were all plunger pumps spaced between 20 and 50 fathoms (36 to 91 metres) apart, the average being thirty fathoms each raising the water to the next pump. To support the enormous weight of the pump rods balance boxes were used which acted as counter weights.

An important development in the early years was the establishment of foundries which were to build most of the engines erected in Cornwall and which were to develop into engine manufacturers and exporters of world standing. The largest and most successful was the Harvey's Foundry of Hayle where the engineer Arthur Woolf became superintendent in 1816. Harvey and Company were renown for the high standard of their workmanship, no doubt an influence of Woolf. The next two largest were the Copperhouse Foundry of Hayle and Perran Foundry of Perran Wharf. Engines from these and other Cornish foundries were to be found operating in all the major mining districts of the world, from North and South America, Africa, Australia and Europe. The oldest know Cornish manufactured engine beams in existence, built in 1836 at the Perran Foundry, are in fact on the island of Virgin Gorda in the British Virgin Islands.

The construction and development of the engines lay in the hands of the engineers responsible for designing and erecting them. One of the leading engineers was Arthur Woolf, born at Pool, Illogan, Cornwall, he served an apprenticeship as a millwright in London, a fact that was to prove of great importance in instilling in him high standards of workmanship. Woolf was an early exponent of high pressure steam, the engines he erected were the finest and largest in Cornwall far exceeding any others of his day in the high quality of their finish and of their fittings bringing a new standard of workmanship to the art of engine construction6. Another respected Cornish engineer was William Sims. His two cylinder engines combined with a plunger pole working alongside a normal Watt engine rivalled the efficiency of Watts better known compound engines6. Richard Trevithick, the celebrated Cornish engineer, was responsible for two major improvements to engine technology, the advocation of the use of high pressure steam and the design of the Cornish boiler. Trevithick's first attempt at the use of high pressure steam was at Wheal Prosper, Gwithian in 1812 where he installed a pumping engine working at 40 lbs per square inch. Unfortunately engineering construction had not reached the level required to manufacture boilers capable of handling the relatively high pressures and the attempt ended in failure. However with the rapid advances being made it was not long before other engineers followed Trevithick's example. Trevithick erected the first plunger pole engine at Wheal Herland, Gwinear in 1816 working on steam at between 60 and 120 lbs per square inch, this engine failed due to the exposure of the piston to the atmosphere accelerating corrosion and also the fact that it wasted steam due to the lack of a cylinder. It should be noted that Trevithick's fame lies in other areas rather than the beam engine,. On Christmas Day 1801 his first steam powered road locomotive was successfully demonstrated in Camborne, Cornwall and in 1804 he built the world's first steam train for the Penydarren Iron Works in South Wales (6). It pulled 70 passengers and a 10 ton load at a speed of 5 miles an hour.

With the improvements in engine construction the use of high pressure steam gave greater efficiency and power and eventually became normal. Trevithick's second contribution to the development of the beam engine was the Cornish boiler which he introduced in about 1812. The design of the Cornish boiler was such that it was capable of safely working at much greater pressures than the 5 pounds a square inch or so of its predecessors. Other major improvements to the efficiency of the Cornish engine lay in areas other than physical improvements of the engines. In 1810 Captain John Davy commenced monthly publication of 'The Engine Reporter' in which the 'duty' or efficiency of individual engines was reported. Joel Lean was appointed registrar and reporter. As a direct result of this publication great rivalry ensued between the various mines and engine-men leading to greater care and efficiency of the engines and greater awareness of good practices. The Reporter continued publication for almost one hundred years and remained unique to Cornwall. In 1825 Samuel Grose, the manager of Wheal Hope, Gwinear, built a 60 inch engine to which he paid meticulous detail to its construction and the insulation of its steam supply to prevent the loss of heat. The results, recorded in the 'Engine Reporter', was a duty of 45.2 million. Considering that the average duty of all fifty six engines reported in 1825 was 32 million and that the highest reported duty for a 60 inch engine (working on Oppies Engine Shaft of Poldice Mine) in 1821 was 35.6 million this was indeed an astonishing improvement. Thomas Lean (8) writing in 1839 calculated that improvements to the engines during the twenty one years since 1814 had resulted in an overall financial saving in the county of £84,300.

A natural progression of the steam engine was to apply its power in a rotary motion thus enabling its use as a whim or hoisting engine and eventually for other applications. The first whim engine to operate in Cornwall was erected at Wheal Maid in the parish of Gwennap in 1784. This engine worked without any mechanical means of reversing its movement therefore requiring the engine to be stopped and the motion of the fly-wheel reversed. In later engines an eccentric gear and other reversing gear improvements were made. The financial saving over the horse whims of this engine was said by John Davy to be considerable ' we draw as much for £20 as we had for £150 before we had this steam machine' (6). Such financial savings were obviously of considerable interest to mine owners with the result that by 1834 over 60 steam whim engines were at work in the county, by 1865 Spargo (9) recorded 184.

A veriant of the vertical steam engine for use as a whim engine was the horizontal engine, first erected in Cornwall by Sims and West in 1843 at the Par Consols mine (6) .This arrangement did not at first find favour as it was believed that excessive wear would occur on the lower half of the piston and cylinder, however in practice this did not occur. These horizontal whim engines were to be developed with separate cylinders and other improvements into the steam winding engines which were to operate until the end of the 'steam age'. The whim engines were not only used for raising ore but also were eventually to be used for transporting the miners. A natural application of the rotary engine was to power Cornish stamps which crushed the ore, however the use of steam engines for this purpose was limited as the main application of stamps was in the dressing of tin ores with most tin mines being relatively small scale operations it was therefore only in the larger tin mines that stamp engines were used.

From 1850 it was not unusual for rotary engines on small mines to be equipped to carry out more than one operation, both pumping and winding and or stamping or operating a crusher. Pumping and winding were the most frequent combination of operations. To supply power to small operations or trial mines a semi-portable engine was developed mounted on its own bedplate and using a locomotive type boiler. Smaller engines of this type were also made portable by the addition of wheels to the bedplate. Steam power was also adapted for the operation of lowering and raising pumps and pitwork where good control was required to position equipment. In 1846 the first steam capstan was installed at Par Consols. Designed by West this was a small steam whim (winding engine) geared down with a small winding drum. Steam capstans were not common outside the larger or deeper mines until after the 1870's. The beam engine was also developed for man riding with the introduction of the Man Engine, popularly believed to be a Cornish invention but actually first operated in Germany (6). In 1833 the Royal Cornwall Polytechnic Society promoted a scheme with a prize for the first mine to install a machine to raise and lower miners safely into the mine. However it was not until 1842 that the first trial man engine was installed by Michael Loam at Tresavean Mine, Gwennap, this proved such a success that in the following year the rods were extended from the trial 24 fathoms to the 248 fathom level (454 metres). In total sixteen man engines were installed in Cornish mines, the cost of installation and the advent from 1880 of the gig for man riding were the reasons why such a small number were installed in the county.

In rare cases steam engines were erected underground, the first was at Wheal Towan, St.Agnes in 1785 and one of the last in 1876 at Levant Mine, St.Just where it was installed on the 210 fathom level about a quarter of a mile seaward and was used for hoisting from the 250 fathom level (457 metres) to the 230. As can be appreciated the use of steam engines underground was not popular with the miners, creating greater heat and smoke in already hot, and in many cases poorly ventilated, tunnels.

With the demise of copper and the slump of the tin price in the 1870's an era of decline set in with mines now hardly profitable little if any money was expended on preventative maintenance with a resultant falling off of engine efficiency and an increase in the number of boiler explosions resulting from corrosion due to the age of many of the boilers still in use. The relative poverty of this period is also the reason why the improved Lancashire boiler found few purchasers in Cornwall. It is true that several engines were built after this time but the heyday of the steam engine had passed and with it slowly went the large engineering works and foundries which at one time rivalled the best in the world. The last steam engine to work on a mine in Cornwall was the steam winder at Robinson's Shaft of the South Crofty Mine, Illogan which stopped in about 1960. The last engine to work commercially was the Greensplat pumping engine, now preserved at Poldark Mine, bringing to a close the age of steam in the county which had lasted some two hundred and fifty years. A number of beam engines are preserved in Cornwall, the oldest is the 27 inch Skip Shaft Whim Engine at the Levant Mine sited on the cliff edge near St. Just. Built in 1840 the engine is still worked by steam. The largest is the Taylor's Shaft 90 inch pumping engine of the East Pool and Agar Mine with its 52 ton beam, on the same mine site is the Mitchell's Whim Engine which stands beside the main road from Redruth to Camborne on the site of the new Cornwall Heritage Centre.

© Richard Williams BA., MCSM., MSc.

References: 1. Penhallurick. R.D. (1986) Tin in Antiquity. The Institute of Metals. London; 2. Pryce W. (1778) Mineralogia Cornubiensis. James Phillips London. reprinted 1972 D.B.Barton, Truro; 3 Rolt. L.T.C. and Allen. J.S. (1977) The Steam Engine of Thomas Newcomen. Moorland Publishing Company, Hartington; 4 Carne J. (1827) On the Period of the Commencement of Copper Mining in Cornwall. Transactions of the Royal Geological Society of Cornwall vol.3. p35-85; 5 Farey J. (1827) A Treatise on the Steam Engine, Historical, Practical and Descriptive. Volume 1.Longman & Rees London 1827. reprinted David & Charles Newton Abbott Devon 1971; 6 Barton D.B. (1965) The Cornish Beam Engine. Pitman Press, Bath; 7 Hamilton-Jenkin A.K. (1927) The Cornish Miner. Reprinted 1972 David and Charles, Newton Abbot; 8 Lean T. (1839) The Steam Engines in Cornwall. Simpkin Marshall and Co. London. Reprinted 1969 D. Bradford Barton, Truro; 9 Spargo T. (1865) The Mines of Cornwall and Devon, Statistics and Observations. London. Cornish section reprinted D.Bradford Barton, Truro 1959-61.

Other useful references Barton D.B. (1967) A History of Tin Mining and Smelting in Cornwall. D. Bradford Barton, Truro. Collins J.H. (1912) Observations of the West of England Mining Region. Transactions of the Royal Geological Society of Cornwall. vol. 14. Crowley T.E. (undated) Beam Engines. Shire Publications, Buckinghamshire. Dickenson H.W. et.al. (undated) Thomas Newcomen - Engineer. Newcomen Society, London. Hodge J. (1973) Richard Trevithick. Shire Publications, Buckinghamshire. Martin T.H. (1869) On an Improved Piston for Steam and Other Engines. Report of the Miners Association of Cornwall and Devon. Rolt L.T.C. (1963) Thomas Newcomen. David and Charles, Dawlish. Russell A. (1949) The Wherry Mine, Penzance, its history and its mineral productions. Mineralogical Magazine. vol. 28, p517-533. Savery T. (1702) The Miners Friend. S.Crouch, London. Reprinted 1979 by Antiquuarian Facsimiles, Edinburough. Seymour G. (1977) The Man-Machine. Mining Journal, London. Woodall F.D. (1975) Steam Engines and Waterwheels. Moorland Publishing Company, Derbyshire.

Back to Top of Page