Abraham Darby

Abraham Darby (1678-1717), English ironmaster who made the first successful use of coke in smelting iron.

Born near Dudley, in Worcestershire, Darby was to dedicate his life to iron-making. In the early 18th century, iron production was primitive, limited, and expensive. Smelting iron ore requires high temperatures, which for over 3,000 years had been provided by burning charcoal. In England, however, the price of charcoal was climbing as forests dwindled. An alternative fuel was coke, the solid carbonaceous residue remaining when volatile materials have been distilled from coal. Coke had been produced for half a century or more, but its use in iron-smelting had not been mastered. Darby made the first successful use of coke in iron-smelting in 1709. He found that lumps of coke were stronger than lumps of charcoal and could support a larger charge of iron ore, so that iron could actually be produced not only more cheaply than with charcoal but at a faster rate. The only disadvantage of using coke instead of charcoal for the smelting of iron was that the resultant product (pig iron) was not very malleable and had a high carbon content. In 1760, John Smeaton invented a blast furnace that could smelt iron both quickly and cheaply. Smeaton’s device was based on the principle of an air-blast produced by a fan run by a waterwheel. A larger furnace meant a stronger draught and a hotter fire, so that iron production was improved still further.

With these innovations, Britain was producing the world’s best iron, in the highest quantities, by the late 18th century. The ability to produce this cheap, strong, versatile building material contributed significantly to the nation’s military and industrial rise.

Darby’s son, Abraham Darby II, improved his father’s iron-smelting process using coke, and effectively established the technique. Darby’s grandson, Abraham Darby III, collaborated with John Wilkinson to build the first cast-iron bridge, which spans the Severn River at Ironbridge in Coalbrookdale, Shropshire, and is still in service today.