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Mining investigator warns of underground "ticking timebomb" in Camborne and Redruth area
By
wbchris | Posted: April 08, 2016
MINESHAFTS as deep as San Francisco's Golden Gate Bridge is long are opening up all over the Camborne and Redruth area, according to experts, and could lead to some roads being closed to traffic.
Stuart Dann and his business partner Tom Thomson run Portreath-based Mining Eye Ltd and are employed by mortgage lenders, developers and utility companies to carry out mining searches and investigations to assess the risk of mining subsidence.
Mr Dann, a former teacher, says holes in Scorrier and St Day which have recently made the local news are nothing compared to some of the other shafts he has inspected in the area – which go down literally for miles.
"Things are definitely moving down there," he said.
"Certain parts of Cornwall are particularly problematic, and recently things appear to be more on the move than usual.
"There's also an ongoing problem in the former mining area and the ground radar results are frightening. I think Cormac will eventually be advising people not to park their cars on or drive over certain bits of the road.
"I was up at a former mine near Scorrier and one of the deepest shafts I've seen has opened up.
"I think we're getting to a point where the original timber baulks used to cap the shafts are coming to the end of their lives and we're going to see more of this.
"When we have a lot of rain, and then things dry out, the stuff above loses its integrity and the timbers fail. It's all very interesting and exciting."
Most of the shafts having been capped at around the same time – between 1865 and 1870 – the timber used would rot to a similar timescale, he said, perhaps explaining the series of shafts opening up in the area at the moment.
"The timbers are backfilled above the shaft and the backfill is turning into a weight that eventually drops through the rotting timber, opening up the shaft," he said.
A trip down a mine near Chacewater revealed a depth greater than the height of the Tamar Bridge's pillars, Mr Dann said, and he had uncovered some fascinating artefacts at these extraordinary depths: "Abseiling down is physically exhausting, but we've found all sorts including footprints and mining apparatus such as wheelbarrows that had been left abandoned once mines shut."
Mr Dann, who has 60,000 detailed images of local maps and plans, says his business is at its busiest since it started three years ago.
Though its findings were spectacular, Mining Eye Ltd had identified some real problem areas around Camborne, Redruth and the surrounding villages, he said.
"There are so many local houses built on massive mine shafts. We've heard of landlords buying homes at auction for knock-down prices which they're aware have shafts underneath, and then totally neglecting their duty of care and renting them out regardless.
"My teaching background makes me want to communicate this ticking time bomb – and we really are dealing with holes with the depth of the Grand Canyon and even the length of the Golden Gate Bridge."
Tony Bennett, a mining engineer at Redruth firm Cornwall Consultants, agreed: "Holes have been opening up around the area for years and there's always the possibility that more could open at any time.
"Reasons can be the rotting of timber framing which causes the mine to collapse, a heavy load passing over the top or possibly the weather."
http://www.westbriton.co.uk/Local-m...g-timebomb/story-29075024-detail/story.html#1