In this one, we scramble down, then up, 660 feet cliffs to explore the abandoned coastal alum mine tunnels of Loftus in the UK, dating back to the 1650s! We also look at a near by tram tunnel.
Alum is a chemical used principally in the textile industry for fixing dyes. It is not found in a natural state in Britain but can be manufactured from some types of shale. During the medieval period in Britain alum was imported, mostly from Italy. Domestic production began in the north of England in the early 17th century. The industry flourished in the north for 200 years until the mid-19th century when it was overtaken by new techniques using shale from coal mining, whilst after 1880 aluminium sulphate replaced alum for most industrial purposes. The last English aluminium works (at Goole) closed in 1950. Approximately 50 alum sites have been identified in England. Most were along the Cleveland and Yorkshire coast. Other early sites are known on the south coast, particularly in Dorset and Hampshire. Alum works comprise two main monument types: the quarry where extraction and initial processing took place, and the alum house where final processing took place. Alum shale was extracted from quarries sited on steep inland hillsides or coastal cliffs. Initial processing on the quarry floor consisted of calcination by burning shale in clamps, and the production in settling pits of alum liquor. The liquor was transported to processing works in sealed casks or through wooden channels known as liquor troughs. Larger quarries possessed inclines and haulage gear and sometimes harbour facilities. Stores, workshops and laboratories can also survive. Evidence of secondary industries such as epsom salts and iron silicates production is also preserved at alum works. The alum industry was the first chemical industry in Britain. Its quarries and works illustrate the early stages of the industry and the technological advances through the period known as the Industrial Revolution. The alum industry also offers important information about wider changes in social and economic conditions during this period. The large scale of the industry's workings also mean that its remains are today a major component of coastal landscapes.
