North-East Alum Industry

The alum industry is widely regarded as Britain's earliest chemical industry. By  the end of the 16th century, England's wool industry was booming, but 'alum', the crucial chemical for making dye fixative for use in the cloth industry, still had to be imported from the Middle East and the Papal estates in northern Italy. As the value of the dye fixative soared, a few Italian specialists who knew the secret of the chemical's manufacture were smuggled to Britain in barrels (according to folklore) and set to work. Production was largely confined to the North-East and some of the largest and most long-lived workings developed where the raw material - alum shale - is exposed in coastal cliffs. The production process was not very efficient: 20 tonnes of alum shale produced only 1 tonne of alum. So quarrying on an epic scale was required, creating vast hollows, terraces and mounds along the coastal cliffs, so large that many visitors assume they are natural. The industry reached a climax in the 18th and 19th centuries, but, eventually, towards the end of the 19th century, the discovery of a new process for producing the necessary chemical put an end to production almost overnight.

 The cliff-edge sites are now under imminent threat of destruction from severe coastal erosion. They are of particular interest because the remains illustrate many aspects of the industry: quarrying, processing, and transport. Quays and rutways (routes for wagons) - all still visible at low tide on the foreshore below the old workings. English Heritage's Monuments Protection Programme team, which works throughout England to identify historic sites of all kinds that may need protection, recommended that the complexes at Kettleness in North Yorkshire and at Loftus, in Redcar, Cleveland, should be recorded before the remains deteriorate further. The site at Loftus, like much of this spectacularly beautiful coastline, is owned and looked after by the National Trust, while the North York Moors National Park Authority has an interest in several others. Although the site at Kettleness is protected as a Scheduled Ancient Monument, the force of the sea cannot be withstood, so the only way of protecting these alum workings in the long-term is to record and understand what still survives, initially through analysis and survey by English Heritage's Landscape Investigation Team.

The Landscape Investigation team has now begun to examine  these two  sites. The sea cliffs are steep and unstable, so the team has received specialist training in the use of ropes and harnesses. Even so, both sites are potentially very dangerous to work on, and even more risky for the unwary visitor. The Aerial Survey and Metric Survey Teams have assisted us by accurately mapping as much as possible from the air. Digitised vertical aerial photographs have been transcribed using photogrammetric techniques to provide contour data and a depiction of the more prominent archaeological features. However, a number of features are not visible from the air, including some eroded remains that now protrude from the face of the cliffs.

The full reports on both Kettleness and Loftus can be ordered on-line. To find out more about this project, contact Marcus Jecock or Abby Hunt in English Heritage's York office on 01904 601 901 or e-mail marcus.jecock@english-heritage.org.uk or abby.hunt@english-heritage.org.uk