Setting a pit prop in a Welsh coalmine – Pwll Mawr, Gwent
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The scene is deep underground in a Welsh coal mine, Pwll Mawr, Gwent. A miner is at the coalface, ‘setting’ a wooden pit prop to hold up the roof, whilst he works to extract the coal. This is a temporary solution to hold back the millions of tons of rock above him. You can see the modern steel frames (with the spaces between them filled by wooden beams) further down the ‘roadway’.
Wood has been a vital part of mining since the Middle Ages. Indeed, a laboratory at Nottingham University used dendrochronology to establish that oak timbers found in a pit at Coleorton, Leicestershire dated from 1450.
During the First World War, the German Navy threatened the importation by sea from Sweden and Russia of the huge quantities of softwood pit props needed to keep the Scottish coalfields of Lanarkshire and Stirlingshire in production. Britain did not grow enough suitable wood of its own to keep the coal supply flowing. Indeed, in the 1960s UK forestry interests were still planting the rapid-growing Sitka spruce for use as pit-props, and large quantities of pit-props and pit-bars were being imported from France!
A wooden prop needs to be replaced after two or three years, as the rate of failure increases markedly after this time. The death-knell for the large scale use of the pip prop was the introduction of steel prop and roof arches from the 1920s, onwards. The modern ‘mechanised’ pit, with it’s self-advancing roof supports (as installed at Ormonde Colliery, Loscoe, Derbyshire, before it’s unfortunate closure due to geological problems) was the future.