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Dowlais Ironworks
Dowlais, Merthyr Tydfil, Wales, UK
Dowlais Ironworks
associated engineer
Thomas Lewis
George Thomas Clark
date  1759
UK era  Georgian  |  category  Factory/Industrial Plant  |  reference  SO068077
photo  site c1865 courtesy www.alangeorge.co.uk
Dowlais Ironworks was the earliest of five major ironworks in the Merthyr Tydfil area. The others were Plymouth (est. 1763), Cyfarthfa (1765), Ynysfach (1769) and Penydarren (1784). Dowlais manufactured iron — and later steel — for more than two centuries and was at one time the largest ironworks in the world. Little remains of this once mighty enterprise, though the ruins of the original blast furnaces and the former Guest Memorial Library are Grade II* listed buildings.
In 1747, Llanishen ironmaster Thomas Lewis (1699-1764) leased the land for Dowlais Ironworks from Herbert Hickman-Windsor (1703-58, 2nd Viscount Windsor) at a rent of £26 per year. Lewis already owned a blast furnace at Pentyrch in west Cardiff, some small forges and works at Caerphilly.
On 19th September 1759, the ironworks was established and nine partners signed the "Articles of Co-Partnership in Myrthir Furnace" for making pig iron. They contributed share capital of £4,000 in the following proportions: Thomas Lewis and Thomas Harris £750 each; Thomas Price, John Curtis and Nathaniel Webb (d.1771) £500 each; Richard Jenkins, John Jones, Edward Blakeway (1718-1811) and Isaac Wilkinson (1695-1784) £250 each.
A blast furnace was erected in 1759, and 508 tonnes of pig iron were produced in its first year of operation. Air to blow the furnace came from a system of cylinders and pistons worked by a waterwheel.
In 1763, the original lease was renegotiated with Dowager Viscountess Alice Windsor (d.1776). A further 8.9 hectares was added to the site and the annual lease increased to £31. At this time, Dowlais had an annual output of 1,524 tonnes of pig iron.
Between December 1765 and January 1767, Price and Webb managed Dowlais. In 1767, John Guest (1722-87) from Broseley in Shropshire was appointed works manager, becoming a partner in 1782. He had good track record, having worked with Wilkinson to set up Plymouth Ironworks in 1763, and was the first of his family to be associated with the Dowlais site. In 1768, Blakeway was discharged from his 1760 bankruptcy, and Harris bought his £250 share.
Under Guest's management Dowlais began to produce bar and wrought iron as well as pig iron. In 1780, the ironworks first exported iron bars to America and, in 1781, a second blast furnace was erected. In 1783, Dowlais began using the patented puddling process for refining pig iron into wrought iron invented by Peter Onions (1724-98), who was Guest's brother-in-law.
Guest died in 1787, and the Dowlais Iron Company was formed, run by his son Thomas Guest (c.1745-1807) and son-in-law William Taitt (1748-1815). By this time, the Guest family had a 10/16 share of the business.
A third blast furnace was erected in 1793, and in 1798, a Boulton & Watt steam engine — the first of its kind in Wales — was installed to blow the furnaces. It had a 1m diameter 2.4m long steam cylinder and a 2.3m diameter 2.1m long blowing cylinder.
By 1801, Dowlais had only three partners: Taitt with 8/16 shares, William Lewis (d.1810) holding 6/16 shares and Thomas Guest with the remaining 2/16 shares. The works was now using Henry Cort's (c.1741-1800) patented puddling furnace to make wrought iron. In 1803, another Boulton & Watt steam engine, with a 930mm by 2.4m beam, was installed to power wrought iron rolling mills.
The combination of the new engines and the improved puddling technique increased productivity to 6,909 tonnes of iron in 1805 and 8,278 tonnes in 1806, and yields continued to rise. In 1808, a second engine for the rolling mills was built with an 800mm by 2.1m beam and a fourth blast furnace was constructed. A Boulton & Watt beam engine with an 2.1m diameter 2.4m long blowing cylinder arrived in 1810, with a fifth blast furnace in 1815, boosting production to 15,850 tonnes of iron per year.
The growth in output correlates with a change in management. In 1807, John Josiah Guest (1785-1852), Thomas Guest’s son and John Guest’s grandson, had succeeded his father as a partner. In 1815, he became sole manager of Dowlais Ironworks, which was by then the largest iron and steel producer in the world. After a depression in trade following the end of the Napoleonic Wars (1803-15), Dowlais bounced back in 1817, building three more blast furnaces and a beam blowing engine.
In July 1819, the famous scientist who made groundbreaking discoveries concerning electricity, Michael Faraday (1791-1867), visited Dowlais.
In 1821, Dowlais produced iron rails for the Stockton & Darlington Railway, the world’s first passenger railway. By 1823, the ironworks had 10 furnaces and annual production had increased to 22,644 tonnes of iron. Profit for the year was £34,869.
A fourth blowing engine was constructed in 1824 and, four years later, the 11th blast furnace and fifth blowing engine were built. The 1828 machine was a non-condensing high-pressure beam blowing engine with a 1.4m diameter 2.8m long steam cylinder, a 3.65m diameter blowing cylinder and a 4.6m diameter flywheel — the first of the Dowlais engines to have one. In the 1840s, it worked at 13 strokes per minute and blew 778 cu m of air per minute.
By 1828 shares in the Dowlais Iron Company were in the hands of only two families: John Josiah Guest had an 8/16 stake, his brother Thomas Revel Guest (1790-1837) had a 2/16 share, and brothers Wyndham Lewis (1780-1838) and Rev. William Price Lewis (c.1783-1848) held 3/16 each.
During 1830, Dowlais had 12 furnaces in blast producing 33,133 tonnes of iron, and had become the largest ironworks in south Wales. It also opened Big Mill, for rolling wrought iron rails, and the site's annual output of rails rose to 20,320 tonnes by 1835.
In 1832, John Josiah Guest was elected as Merthyr's first Member of Parliament. Dowlais purchased its first two steam locomotives, Success and Perseverance, from the Neath Abbey Iron Company. They ran along a 1.27m (4ft 2in) gauge plateway.
In 1837, Thomas Revel Guest died and his brother and his nephew Edward John Hutchins (1809-76) each inherited one of the company shares.
Expansion at Dowlais continued, with two more blast furnaces and, in 1838, another high-pressure beam blowing engine. It was built by Neath Abbey Iron Company at a cost of £3,894 and had a 1m diameter 2.4m long steam cylinder, a 3.1m diameter blowing cylinder and a 3m diameter flywheel. In the 1840s, it made 16 strokes per minute and discharged 585 cu m of air per minute. The works' railway was widened to a 1.435m (4ft 8.5in) gauge edge rail.
Profits for 1838 rose to £77,413, and John Josiah Guest was created a baronet in Queen Victoria's coronation honours list.
In 1839, the Ivor Ironworks (SO066082), named after Sir John's eldest son Ivor Bertie Guest (1835-1914), was built at the north of the site as a servicing and maintenance works for Dowlais, which by then had become the largest ironworks in the world. Little Mill was constructed in 1840 to produce rails.
Exports were an important element of Dowlais' trade and, in 1844, it won a contract to supply 50,800 tonnes of rails to Russia. In June 1847, Grand Duke Constantine Nicholaievich (1827-92) of Russia visited Dowlais to see the rails being rolled.
In 1845, the site covered an area of 16.2 hectares, employed 7,300 people and consumed 1,524 tonnes of coal every week. Its 18 blast furnaces produced 76,078 tonnes of forge iron. Monthly output from the mills totalled 2,032 tonnes of wrought iron rails and 2,032 tonnes of iron bars. Expansion led to a reduction in profits, which were £59,038 for the year.
During the late 1840s, the Dowlais lease was renewed. In 1848, following William Price Lewis's death, the Guest family bought the Lewis family's share of the ironworks for £200,000. From 1848 to 1860, £306,712 was spent modernising the business.
In 1849, two of the older beam blowing engines were sold to make way for a new, larger blowing engine installed in 1850. Works’ engineer Samuel Truran (1800-78) designed the non-condensing engine, which had a 3.65m diameter blowing cylinder working a 3.65m stroke and cost £8,839.
Every minute the engine made 20 strokes and blew 1,245 cu m of air at a pressure of 22.4kPa into a 128m long 1.5m diameter regulator pipe. The engine worked at 485kW with a steam pressure of 413.7kPa at one third cut off. Its 12.2m long beam had to be cast in two parts, each weighing 16.8 tonnes, and its 6.7m diameter flywheel weighed 35.6 tonnes. At first it supplied the air blast to eight furnaces but later it was used with three other blowing engines to blast 12 furnaces.
In 1851, John Josiah Guest bought Hutchins' remaining share for £58,000 and so gained complete control of Dowlais. The company made a loss of £32,036. On Guest's death just a year later, the works were managed by his widow Lady Charlotte Elizabeth Guest (1812-95) and sustained losses of £19,720.
Lady Charlotte remarried in 1855, to Charles Schreiber (1826-84), and trustees were appointed to run the works. The trustees were engineer George Thomas Clark (1809-98) and Edward Divett MP (1797-1864), later joined by Henry Austin Bruce (1815-95, 1st Baron Aberdare).
The number of steam engines working on site illustrates the size and power of the Dowlais operation at that time. There were 16 winding engines at the works' coal and iron ore pits, 14 engines working inclined planes, 11 locomotives, 10 forge and mill engines, five blowing engines, four pumping engines to drain the pits and supply the site with surface water, two engines driving clay and pug mills, and two engines driving lathes and shearing cold iron. The combined power output of these 64 engines was 5,450kW.
In 1856, building work began on the Guest Memorial Library and Reading Room (SO069078), which was completed in 1863 at a cost of £7,000. In the same year, Dowlais was the first ironworks to obtain a licence for Henry Bessemer's (1813-98) newly patented process for making malleable iron without using coal or charcoal. Air was blown through molten iron to remove impurities, making it ideal for wrought iron or steel. The works made a loss of £52,907, and William Menelaus (1818-82), who had worked at Dowlais from 1851, was appointed general manager.
In 1857-59, another wrought iron rail mill — Goat Mill — was constructed inside a 73m by 64m building. Its machinery was powered by a pair of coupled high-pressure beam engines with cylinders 1.1m x 3m working at 24 strokes per minute with a one third cut off. Six Cornish boilers 4.3m long and 2.1m in diameter supplied the steam.
By 1859, Dowlais was profitable again, as a result of the combined efforts of Clark's financial and engineering management, and Menelaus' technical expertise and operational control. It recorded a surplus of £17,940 for the year despite purchasing the mineral ground of Penydarren Ironworks (SO055068) for £59,875. One of Menelaus' innovations was to use waste heat from the blast furnaces to fire the boilers in the mills and furnaces. He also used small coal (gravel-sized lumps of coal waste) to fire the puddling and balling furnaces. In 1863, yearly profit had increased to £36,572.
In 1865, weekly iron production at Dowlais was 1,422 tonnes of rails and 610 tonnes of bars, plates, angles and girders. To feed the blast furnaces, ores were sourced from Whitehaven, Barrow, Cornwall, Forest of Dean, Northampton and Spain as well as Wales, and the works operated 70 balling furnaces, 150 puddling furnaces and 14 rolling mills. From 5th June 1865, Dowlais also began manufacturing steel rails and steel headed rails, using two 5.1 tonne Bessemer converters (egg-shaped vessels with a single spout at the top), and its yearly profit rose to £104,843.
In 1869, there were almost 100 steam engines on site and its 9,000 employees worked 16 furnaces in blast and produced 152,400 tonnes of iron. A duplex steam hammer was installed for hammering steel ingots. Dowlais' efficiency was such that it was able to produce 1 tonne of pig iron using 1.25 tonnes of coal, against an industry average of 2.25 tonnes of coal per tonne of pig iron.
In 1871, Dowlais built its first open-hearth furnace for refining pig iron into steel using the Siemens-Martin process, named after its inventors Carl Wilhelm (Charles William) Siemens (1823-83) and Pierre-Emile Martin (1824-1915). A new cogging mill for rolling steel ingots down to sheet steel was opened, and profits for the year totalled £165,840.
In 1873, Dowlais formed the Orconera Iron Ore Company to import quantities of Spanish iron ore, as local sources were becoming depleted. To boost steel production, in 1874, a new blast furnace 16.8m high and 5.5m in diameter was constructed with the capacity to make 305 tonnes of pig iron per week. It had a closed top and was blown with hot air at 649 degrees C. Raw materials were supplied to the top of the furnace by a water balance. Dowlais was now operating six Bessemer converters and four regenerative gas furnaces on the Siemens-Martin steel process.
Steel-making capacity was increased in 1881, when the Bessemer converters were enlarged to give four 8.1 tonne converters and two 6.1 tonne converters. After Menelaus died in 1882, local engineer Edward Pritchard Martin (1844-1910) took over as general manager of the ironworks and brought in further labour-saving machinery. Profit for the year was £192,441.
In 1884, new reversing mill was installed and the following year, 1885, two new foundries were built and a new cogging mill constructed on the Goat Mill site.
In 1888, construction commenced on a new ironworks at East Moors near Cardiff Docks, owned by Dowlais, which facilitated the import of iron ore for its operations. Iron production began here in 1891, with two furnaces in blast. The two sites were to continue working in tandem until 1930.
Clark, the resident Dowlais trustee and works supervisor, retired in 1892. Three years later, in 1895, a new Bessemer steel plant with two 15.2 tonne converters and plate mills opened (construction had begun in 1888) adjacent to Goat Mill.
In 1897, Dowlais had 11 furnaces in blast, six Bessemer converters in use, and operated four rolling mills and three cogging mills. Annual coal production had reached 1.524 million tonnes.
After Clark’s death in 1898, Ivor Guest (now 1st Baron Wimborne) was more active in the management of Dowlais. On 27th September 1899, the company was renamed the Dowlais Iron, Steel & Coal Company Limited. On 9th July 1900, Guest merged or sold his company to engineering entrepreneur Arthur Keen (1835-1915), apparently for £1.5 million, forming Guest Keen & Co.
In 1902, Guest Keen & Co amalgamated with Birmingham business Nettlefolds Limited, becoming Guest, Keen & Nettlefolds or GKN. The new company bought the share capital of Crawshay Brothers, the company running Cyfarthfa Ironworks (SO038068), Martin retired and William Evans (1843-1915) of Cyfarthfa assumed control of both Cyfarthfa and Dowlais.
A new blast furnace plant was constructed in 1905-09, with automatic mechanically charged furnaces — the first in Britain of their kind. In 1906, Dowlais built its first complete locomotive, the 0-6-0 tank engine Arthur Keen. On 27th June 1912, King George V and Queen Mary visited Dowlais as part of their official tour of south Wales.
In 1920, the Ivor Ironworks built its last complete locomotive, an 0-4-0 tank engine (No.46) and the ninth locomotive to be designed and constructed at Dowlais. A new power station was constructed at Ivor in 1920-1, together with new coke ovens and by-product plant.
The economic downturn of the late 1920s affected the industrial heartland of south Wales. In 1930, most iron and steel making at Dowlais ceased and production was transferred to the company's works at Cardiff and Port Talbot, though Big Mill remained in operation. GKN amalgamated with Baldwins of Swansea, to form the British (Guest, Keen, Baldwins) Iron & Steel Company.
In 1936, Dowlais Ironworks closed, except for the general castings foundry and fitting shop on the Ivor site. The company name also changed, to Guest Keen Baldwins Iron & Steel Company Limited. In 1937, one blast furnace at Dowlais was brought back into operation to manufacture pig iron. Some production continued after World War II (post 1945), using the name Dowlais Foundry & Engineering Company.
In 1951, Guest Keen Baldwins Iron & Steel Company Limited was nationalised under the Iron & Steel Act 1949 and became part of the Iron & Steel Corporation of Great Britain. However, in 1954, the company was re-acquired by GKN as the Guest Keen Iron & Steel Company.
A new ingot mould foundry costing £2m was erected in 1957-8, and Dowlais celebrated its bicentenary in 1959. In 1967, new automated iron-making plant was bought from Germany in a comprehensive refit, and Dowlais also became part of British Steel.
In August 1971, the general castings foundry was refitted for making castings in liquid sand. Production continued at the Ivor site until 1987, after which the works was closed and the buildings demolished (1988). The last ingot mould made here — for an iron ingot of 18.8 tonnes — is displayed on a plinth (SO067077) near Dowlais High Street.
Remains of the original 1759 Dowlais blast engine houses (SO069077) and the former Guest Memorial Library are Grade II* listed buildings.
Steel plant machinery: Hick & Son, Bolton
Steel mill engines: Kitson & Company
RCAHMW_NPRN 34084, 33697, 34085, 34093, 88063
Research: ECPK
"Economic History of the British Iron and Steel Industry" by Alan Birch, first published 1967, reprinted by Routledge, Abingdon, 2006
"Clark, George Thomas (1809–1898)" by B. Ll. James, in Oxford Dictionary of National Biography, Oxford University Press, 2004
"Menelaus, William (1818–1882)" by John Williams, in Oxford Dictionary of National Biography, Oxford University Press, 2004
"An Inventory of the Ancient Monuments in Glamorgan", Royal Commission on the Ancient and Historical Monuments of Wales, 1981
"Chronological Date Sequence for Events for the Dowlais Ironworks" by John A. Owen, in The Merthyr Historian, Vol.1, Merthyr Tydfil Historical Society, 1976
"The Dowlais Iron Works, 1759-93" by J. England, Morgannwg transactions of the Glamorgan Local History Society, Vol.3, pp.41-60, 1959
"The History of Merthyr Tydfil" by Charles Wilkins FGS, Joseph Williams & Sons, Merthyr Tydfil, 1908
Cardiff and Merthyr Guardian, 26th June 1847
reference sources   CEH WalesBDCE1

Dowlais Ironworks