The Callow Rock Lime Co. Ltd. was created in 1919 to manufacture high purity white lime from the Burrington Oolite limestone. It was established by Herman and Francis C.Tiarks, a London banking family whose altruistic aim was to create employment for returning troops from WW1. At the beginning the quarryface and a small vertical kiln were both worked and filled by hand, with the help of a small tramway which carried stone to the kilntop. The lime was of excellent quality and their reputation grew. In 1922, two additional large kilns were added and a larger replacement plant to make hydrated lime. By 1926 it was selling 500 tons of lime a week and a further, more efficient kiln was erected in 1936. In the 1930s the lime was delivered to customers or to Cheddar Station by steam powered lorries. In 1946 the company diversified to produce lime-based coloured textured wall rendering material and by 1951, 110,000 tons of limestone was being extracted annually. The company then expanded their services to include water treatment, gas purification and sand-lime brick-making. They were even exporting as far as the East and West Indies. In 1951, lime from Callow Rock was supplied as plaster for the Royal Festival Hall. In 1961 it was taken over by ECC Quarries who increased aggregate production. By 1969, the high purity stone reserves were diminishing, and the kilns were becoming quite old so lime-burning ceased. A large concrete product plant now occupies the lower part of the quarry which was established from the late 1980s onwards and which consumes much of the quarry output. It has a capacity of 1.3 million tons of carboniferous limestone a year, all of which is transported by road. The quarry operates above the water table and has enough reserves to continue quarrying till 2075. The quarry is owned by Aggregate Industries (previously Bardon Aggregates), a member of the Swiss-based Holcim Group.
Historical notes: The British Geological Survey