A high-pressure steam rock-boring engine, which also lifted and loaded the stone for transport, was designed by Richard Trevithick and built by Henry Harvey at his foundry in Hayle. Mining rock drills, however, were not adopted in the region until the last quarter of the 19th century – well after Joseph Fowle of Boston, USA, invented his machine in 1851.
Rock drills increased the rate of boring shot holes dramatically. Their operation by compressed air also greatly improved ventilation and reduced working temperatures in deep mines. But these did have a sinister downside: deadly sharp dust produced by the high speed drilling caused thousands of miners to die a painful death from ‘miner’s phthisis’ (silicosis – a form of lung disease).
The Cornish Rock Drill
Cornish manufacturers eventually pioneered dust suppression by delivering a water spray to the drill tip which also had the benefit of providing lubrication. One of the major manufacturers was Camborne-based Holman Brothers which, with James McCulloch, developed what became known as the Cornish Rock Drill. It was to see use in South Wheal Crofty, Dolcoath, Tincroft, East Pool, Kit Hill, and also mines in Wales by 1882.
Rock drilling all over the world
By 1896 more than 1,000 Cornish rock drills were in use on the Rand gold mines in South Africa.
Whilst the decline in Cornish mining closed much of the home market, trade in the Camborne engineering heartland soared with the opening up of huge markets overseas. By the late 1880s rock drills had found a ready market in Australia, New Zealand and Spain.
In 1889 Holmans began trading in South Africa and interests were concentrated on the Rand Goldfields in what became their greatest market for over half a century. By 1896 there were more than 1,000 Cornish rock drills in use on the Rand gold mines. Their impact on the development of these deep mines was crucial and by the turn of the 20th century their number had doubled. Both Holmans and Climax established experimental drill test sites – near Camborne and Carn Marth Quarry respectively.