Steam Technology - Beam engines

Of the thousands of beam engines erected only a small number have survived and those still on their original sites are fewer still. It must be noted that the relocation of beam engines from one mine to another was very common practice. An engine may have been moved three or four times during its lifetime and therefore may have had several different but entirely authentic locations.

Levant Mine (A1, 1840, Listed Grade II). The restored engine house contains an all-indoor beam whim that was designed by Francis Michell and made by Harvey & Co., Hayle, in 1840. It worked until 1930 and was the first engine to be preserved by the Cornish Engines Preservation Committee, formed in 1935. It is now under the care of the National Trust. © HES.

Levant Mine. Interior view showing part of the engine, restored to working (steaming) order, but powered by modern oil-fired plant for practical reasons. © The National Trust.

East Pool & Agar Mine (A5, engine house 1924, Listed Grade II*). The 90-inch pumping engine at Taylor’s Shaft was designed by Nicholas Trestrail and manufactured by Harvey & Co., Hayle, in 1892. It was purchased secondhand in 1923 from the nearby Carn Brea & Tincroft Mines and was the last Cornish beam pumping engine to be erected in Cornwall. It was also one of the last to work, being replaced by electric pumps in 1954. © The National Trust.

Within the nominated Site there are four beam engines still in situ on their original metal mines: There is an indoor winding engine at Levant Mine (St Just Mining District); There are two at East Pool & Agar Mine - Taylor’s pump and Michell’s whim - and the Robinson’s pumping engine at South Crofty Mine (Camborne and Redruth Mining District).

Many beam engines were moved from mines to the St Austell china clay district. These include engines at Rostowrack and Parkandillick, the Goonvean engine and the Greensplat engine which has been re-erected at Poldark Mine (Wendron Mining District). The china-clay industry’s adoption of beam engines has contributed to their present-day survival.

Beam engines in the United Kingdom

The Newcomen engine at the Elsecar Colliery in Yorkshire is on its original site. Others are to be found in the Science Museum, London, and in Dartmouth, the Devon birthplace of Thomas Newcomen. Later mine engines are to be found in situ at Hodbarrow Iron Mine, Cumbria (built by the Perran Foundry), Dorothea Slate Quarry, Caernarvon (built by Holman Brothers of Camborne) and Prestongrange Colliery. Kew Steam Museum, near London, was a pumping station that pumped water for public utilities. It contains important Cornish engines. Similar sites such as Crofton (where water was pumped to upper levels of the Kennet and Avon Canal) have other examples of beam engines, some of which were made in Cornish foundries. Beamish and Blist’s Hill at Ironbridge (Shropshire) and the Science Museum in London have important examples of ex situ beam engines.


Newcomen, Watt and Trevithick: The development of the steam engine

Thomas Newcomen and the Atmospheric Beam Engine

The atmospheric engine invented by Devon-born Thomas Newcomen and installed at Dudley Colliery (West Midlands) in 1712 triggered changes in the Cornish mining industry that were to take it from an enterprise limited by what could be achieved using manpower, horse power and water power to a mechanised industry capable of large-scale and increasingly reliable production.

The engine at Great Wheal Vor (Breage), probably installed between 1710 and 1714, was the first such engine on a metal mine and can be taken as the beginning of the industrial revolution in Cornwall. This was not industrialisation in its economic and social sense but rather the establishment of the means to achieve industrialisation.

The engine introduced a radically new method of working. It also created the necessity for skilled workers who became known as engineers. Building upon centuries of mining experience, Cornwall was, over the next seven decades to 1790, poised to change from a region with a growing mining industry, to a fully industrialised economy which was amongst the earliest both in Britain, and the world. However for some time Newcomen engines proved to be something of a false hope for Cornish mine adventurers. Their inherent inefficiencies combined with the crippling burden of coal duty had initially made them far too expensive for all but the largest and most profitable mines to install. By 1727 only five Newcomen engines were working in Cornwall and by 1740 there were still only about 20. This slow adoption of steam power resulted from four factors: the high initial capital cost of constructing the engine; a duty on sea-borne coal (following petitions from Cornish mine adventurers this was finally abolished in 1741); the high cost of coal shipment from the coalfields of Bristol and South Wales and the added cost (often as much again) of mule carriage of landed coal from Cornish ports to the mines.

Added to this was the high consumption of coal necessary to keep the engines running continuously (a large engine might consume as much as 12 tons of coal per day - 80 mule loads - and worked at an incredibly low efficiency of 1%). Even on the larger mines these running costs were often so high that the engines would be taken out of service after only a short period of use, to be replaced with the water-wheel pumps which had preceded them.

Nevertheless by the time of Newcomen's death in 1729, his engines were helping to drain mines in Hungary, Sweden, France, Germany, Belgium and Spain. One had even been delivered to the port of Vera Cruz in Mexico but had never made it to the silver mines for which it was intended. In 1753-55 Josiah Hornblower erected the first beam engine in North America (New Jersey).

Despite work by the Yorkshire engineer John Smeaton which resulted in the doubling of the efficiency of the Newcomen engine, it was proving too fuel-hungry for most Cornish mines.

In 1778 however there were still over 70 Newcomen engines at work when Pryce stated 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. A

Newcomen Engine. From Farey, A treatise on the steam engine,1827. © The Cornwall Centre.

depth of around 200m (below adit) approached the limit of the capability of these engines and, though they opened up important new ore-ground at such depths, technology remained at this level until the introduction of the Boulton & Watt engine into Cornwall in 1778.

James Watt and the Separate Condenser

James Watt (1736-1819) invented the separate condenser in 1769 and in doing so created the first economic steam-powered engine. Not only were the new engines far more powerful than the old Newcomen engines but also their consumption of fuel was less than a third of the atmospheric engines.

In a region without its own coal, the invention was a breakthrough of immeasurable consequence. Boulton & Watt’s first engine in Cornwall was at the Chacewater Mine (later part of Wheal Busy, Chacewater) in 1778. Over the next four years 40% of the Boulton & Watt engines built were destined for Cornish mines.

What later became Consolidated Mines in Gwennap operated seven Newcomen engines in 1779 to keep the mine workings drained but had to cease working due to the crippling cost of firing them. The mines were subsequently acquired by another group of adventurers who erected five Boulton & Watt engines in 1780. These operated at a full third of the pumping cost in coal.

By 1783, 21 of the new engines were at work in the county with only one Newcomen engine still operating. By 1790 the number of Boulton & Watt engines working in the county had increased to 45 and by 1800 mines were able to attain depths of around 300m below adit. The era of the Newcomen engine was over. James Watt and Matthew Boulton were not slow to recognise that Cornwall in particular stood to benefit enormously from these efficient pumping engines.

Protected by Watt’s patent from 1776 they could profit from a market in engines that they controlled and encouraged. Boulton & Watt invested in a number of Cornish mines to encourage the adoption of their engines. Under the terms of the licensing agreement with the owner, mines could only use this new technology under an arrangement which returned to Boulton & Watt one third of the saving in coal gained by using their engine rather than an atmospheric of equivalent power – an equation which was prone to dispute and interpretation.

The patent was strictly enforced, as Hornblower and Winwood were to discover in the 1790s (in relation to their compound engines). Edward Bull Junior, with his inverted engine termed it a manifest piracy... Watt continued to improve his engine designs: the steam jacket in 1778; an improved rotative winding engine in 1781 (the first Cornish whim engine was erected three years later); the idea of expansive steam in 1782; the double acting engine and, in 1784, the parallel motion which kept the piston rod in line with the beam. By the last years of the century, however, the Cornish mines’ market was becoming far less important to Boulton & Watt than the developing factories of the Midlands and North of England. Nevertheless their engines had laid the foundation for the most significant phase in Cornish mining.

Richard Trevithick and the Cornish engine

Richard Trevithick (1771-1833) of Camborne, is Cornwall’s most famous engineer. He is accredited with the introduction of high-pressure steam and a series of historic innovations. James Watt distrusted high-pressure steam. He recognised the potential both for wear and tear due to harder working, and for catastrophic explosions in poorly-maintained boilers and engines. Trevithick, by contrast, recognised it as the way ahead; the key to the development of much faster, more powerful, and portable engines.

The end of the Watt Patent in 1800 ushered in an era of experimentation with alternative engine designs that flourished during the first three decades of the nineteenth century. The publication in Cornwall (from 1811) of Lean’s Engine Reporter recorded the power produced by engines per unit of coal. It helped to promote competition amongst engineers and mine owners to develop efficient and powerful engines.

The Cornish engine was adopted not only by Cornish and overseas mines but, from 1837, by the new waterworks being constructed to service Britain’s rapidly-growing towns and cities. Cornwall and West Devon foundries expanded to meet the growing demand. They benefited from being in close contact with their market and rapidly became leaders in engine-building technology, supply and the erection on site wherever in the world the topography and depth of workings required them.

Trevithick’s first high-pressure engine was erected at Stray Park (latterly a section of Dolcoath Mine) in 1800 and incorporated a series of radical improvements. It worked perfectly from the beginning, clearly implying that the engine had been under development for some time. Trevithick’s influence on mine engines was considerable, particularly following the introduction of his high-pressure ‘Cornish’ boiler which allowed safe, high working pressures. An important legacy however lay in the potential for small, powerful, self-contained engines, particularly in the field of self-propelled transport.

Trevithick’s work laid the foundation for the development of the steam locomotive, the steam ship, the portable engine, the traction engine and the steam car and lorry, for many of which he built prototypes. The development of efficient

The Cornish Beam Engine that became standard pumping equipment in the nominated Site and at many mines throughout the world. From Davies, Machinery for Metalliferous Mining, 1894. © The Cornwall Centre.

high-pressure steam engines with multi-tube boilers effectively freed industry and communications from the limitations of water power, horse power and wind power. Equally significant, the more economical use of fuel meant freedom of location. It was now possible to take and use steam power anywhere.
Mining applications for the new steam technology

The first steam stamps were installed at Wheal Fanny (Carn Brea) in 1813; the first steam capstan, by William West, at South Hooe in 1835; and the first British man-engine by Michael Loam at Tresavean in 1842. But it was the Cornish pumping engine and the rotative winding engine which were to be the mainstay of Cornish and West Devon foundries. They were produced in their thousands for mines and works the world over. On overseas mines however, the rotative winding engine was quickly superceded by more efficient methods.