Hole size of Nelson's Column opens in back garden
A mine-shaft as deep as Nelson's Column opened in the garden of a £250,000 Edwardian cottage
Last Updated: 7:57PM GMT 21 Dec 2008
Mark and Susan Gilbert watched in horror as the ground caved in and a "vast crater" appeared just steps away from their back door.
The couple heard a "loud creaking" moments before their patio collapsed into the pitch-black chasm.
When the smoke and debris finally cleared, they were left with a giant hole measuring 15ft in diameter - and 165ft (50m) deep. :shock:
Experts say the disused shaft would have been used by teams of miners up until the late 19th century to bring underground coal to the surface.
The couple said the ordeal at their home in Huddersfield, West Yorkshire, left them "shaking for hours".
Mr Gilbert, 54, said: "The whole patio literally disappeared and fell into a vast crater.
"The ground in that area just fell away to expose a massive mine shaft 50 metres deep.
"It was a scary sight and although no one was injured, we were both shaking for hours afterwards."
Mr Gilbert, a delivery manager for Royal Mail, added: "There are some things that you just don't expect to happen - and that was certainly one of them."
The couple bought the three-bedroom end-of-terrace cottage nine years ago but had no idea its grounds contained the openings of a mine.
The property is on the outskirts of what was once a thriving coal mining region, and they carried out extensive land surveys before moving in.
But the searches failed to spot the shaft, which experts believe was never officially registered.
Since 1999, they have used the 18ft by 12ft patio on a daily basis to hang out the washing, enjoy BBQs with friends, and relax in the evenings.
But earlier this year, it began to "sag" in the middle and Mr Gilbert was forced to hire a builder to flatten it out.
The workman filled the depression with two tonnes of concrete before re-laying the slabs at the correct angle.
But within weeks it had dropped "significantly' - and Mr Gilbert finally realised what could lie below.
He said: "We'd undertaken lots of surveys when we bought the place, but they never revealed anything.
"We knew the area was once a mining area, so when the ground started to sag again, we knew something could be amiss."
Last month, experts from the Coal Authority, the Government agency which deals with abandoned coal mines, visited the property and confirmed the presence of a mine.
They erected fences around the patio and advised the Gilberts against walking over it until it could be filled after Christmas.
But at around 8am last Thursday, the ground gave in completely - swallowing the patio whole and leaving a vertical shaft in its place.
Mr Gilbert said: "It beggars belief to think that there's such a large hole in our back garden.
"When it caved in, the earth around it covered it up a bit so it's difficult to appreciate exactly how deep it is.
"But you really wouldn't want to walk on it - there's a drop of 50 metres below that which I've been told would open up under the weight of just a gram or two.
"It was just a miracle that neither of us weren't in the garden at the time, or we would surely have been killed."
The Coal Authority (CA) believes the shaft was part of the Quarry Pit Mine network, which was last worked in 1836.
It is among an estimated 170,000 unregistered mines, which are frequently discovered by homeowners across the UK.
Luckily, residents who find mines on their property are protected financially by the Coal Mining Subsidence Act, which ensures that holes - and any damage they cause - are repaired free of charge.
The Gilbert's shaft will now be filled in by CA workmen using tens of thousands of gallons of liquid concrete.
A spokesman for the CA said: "A shaft measuring 50 metres is certainly unusual and was clearly dangerous to the homeowners.
"The Coal Authority visited the property and made the area safe, and we will now be carrying out a filling operation to return their back garden to how it once was."
http://www.telegraph.co.uk/news/newstop ... arden.html
and investigation was on-going.
