Darby, A
Full Name: Abraham Darby
Achievements: Successfully used coke to smelt iron ore
Born: April 14, 1678; Dudley, Worcestershire, England
Died: March 8, 1717; Madeley Court, Worcestershire, England (Aged 39)
Field & Discipline: Industry; Manufacturing; Iron Manufacture
Language: English
Father: John Darby
Mother: Ann Baylies
Siblings: Unknown
Spouse: Mary Sargeant
Children: 4 sons; 4 daughters
Education: Unknown
Life & Times:
Darby was the son of a peasant farmer who worked as a locksmith. He was a Quaker and Darby was apprenticed to a Quaker manufacturer of malt mills in Birmingham. At the conclusion of his apprenticeship he married and moved to Bristol where he began manufacturing malt mills on his own account. Through his involvement in the malt trade Darby would have been aware that coked coal was used for drying the malt. Most coal contained a large amount of sulfur and other volatile constituents which could be removed by coking (heating) the coal.
By 1702-3 he had joined with a number of Quakers to found a brass mills outside the city at Baptist Mills. Coke may also have been used in the brass foundries. Around 1705 Darby visited Holland and returned with several Dutch brass-founders and their families who went to work at Baptist Mills.
Darby bought a small iron family nearby where some of his Dutch workers began to make cast iron pots in moulds of sand instead of the traditional earth. They failed in this project until they were joined by a Quaker ironworker called John Thomas from Montgomeryshire. Thomas used fine dry sand and a mold that was constructed in several sections which allowed the pots to be removed without breaking.
In 1707 Darby patented Thomas’s process. The new method of molding in sand enabled them to produce pots that were much cheaper than others on the market and the three-legged pot they made became a staple of the poorer classes.
Darby wanted to expand into iron making but despite his success in pot-making his partners in the brass foundry were not willing to risk their capital in a new venture. Around 1708 he took the lease on a small run-down ironworks in Coalbrookdale, Shropshire.
Although metal items had long been made by pouring cast iron into molds, by the beginning of the eighteenth century most of the cast iron produced in the blast furnaces was converted into the more malleable wrought iron. Wrought iron could be heated and then shaped by being hammered, or rolled into thin sheets which were used by craftsmen to make domestic and commercial objects. There was a growing demand for both types of iron but the industry was being held back by a lack of charcoal for fuel. Charcoal was obtained from wood and the supply of trees could only be renewed over time.
Coal, however, was abundant. During the seventeenth century many people had tried to smelt iron ore using raw coal as a fuel but no one had succeeded. Darby rebuilt the blast furnace at Coalbrookdale and from the start used coke in his furnaces as well as charcoal. The local coal had a low sulfur content which made it more suitable for coking than coals from any other area, although whether or not this influenced Darby’s decision to move there is not known.
The area was also well supplied with swift running water for power, it was an establishing iron-making center, and local waterways provided a good transport system to ports and large manufacturing areas such as Birmingham. Coalbrookdale was in a valley where the highest ground round the edge of the valley produced coal and ironstone and provided good drainage for the pits. From the high ground there was a downhill run to the top of the furnaces.
Darby organized the Coalbrookdale works in a more efficient way than his competitors, siting his furnaces and forges side by side on a stream where falling water was made to service one building and then another. Iron castings were made at the foot of the furnaces and another downhill run took them to the wharves on the river Severn.
During the first years of production in the Darby foundry at Coalbrookdale the iron produced by coke smelting was unsuitable for converting into wrought iron, so pots, kettles and other hollow wares were cast direct from the smelting furnace. Darby continued to experiment and probably by 1713 was using coke as his sole fuel. This was the first time that iron had been successfully obtained using mineral fuel instead of charcoal.
In 1715 he built a second blast surface which he was able to do because the availability of coking coal was so much greater than that of charcoal. Darby’s success enabled him to move to a Tudor mansion outside the coalfields where he died in 1717. The coke smelting process gradually spread and eventually revolutionized the English coal industry.
Darby’s son Abraham Darby II, was only six when Darby died and he and did not take over the works until 1718, by which time cast iron from the Darby foundry was being used all over England for steam engine parts. The first iron railway wheels were cast at Coalbrookdale during the 1720’s.
Grandson Abraham Darby III supplied the iron for the first railway locomotive with a high-pressure boiler built by [supplied] Trevithick* at the beginning of the nineteenth century.
Extra Connections: He was a benefactor of [benefactor of] Dalton*
He visited [visited] Huntsman*’s works
Assessment: Darby’s successful use of coke for smelting iron revolutionized the English iron industry.
Oneliner: Abraham Darby, the first great ironmaster
Bibliography:
- Raistrick, Arthur, Dynasty of Iron Founders, David & Charles, Newton Abbot, 1970.
- Thomas, Emyr, Coalbrookdale and the Darbys, Ironbrige George Museum Trust, York, 1999.
- Trinder, Barrie, The Darbys of Coalbrookdale, Phillimore & Co. Ltd., Chichester, 1974.