|Iron Bridge, Shropshire. The parts of this dramatic bridge were cast at the nearby foundry |
of the Darbys at Coalbrookdale and erected in 1777.
A most significant change began in the iron industry in 1709 when Abraham Darby succeeded in using coke instead of charcoal as the fuel in his blast furnace at Coalbrookdale in Shropshire. This particular furnace has survived, although much modified, and has been carefully preserved after having been lost for several generations under a mound of industrial waste.
The trouble with using coal fuels previously had been that they contaminated the iron in the furnace with undesirable impurities. Darby was fortunate in discovering locally coal with excellent coking properties which, together with the increased blast which he put in his furnaces, overcame this problem and allowed the industry to begin the movement from the backwoods to the coalfields. The movement was a slow one in its initial stages, partly because of the remoteness of Coalbrookdale and the conservatism of other iron founders about following the initiative of Darby and his family, and partly because of the continuing dependence upon water power until the steam engine had developed sufficiently to provide a reliable alternative.
These restrictions were gradually overcome in the eighteenth century, so that in the following century there was a concentration of blast furnaces on the coalfields to make the 'Black Country' landscape of the Midlands and its counterparts in South Yorkshire and elsewhere.
Industrial Archaeology in Britain / R.A. Buchanan / Pelican 1972, page 98