AMATEUR CAVERS have sunk a 45m deep concrete shaft to gain access to Britain's largest cave in the Peak District.
The enthusiastic team of potholers took four years to complete the work, which opens up the way into the top of the 145m deep cave, known as Titan.
Having previously accessed the cave at its base from an old 220m deep lead mine, the team, led by Dave Nixon, set about gaining entry from the surface.
The cavers discovered a big crack at ground level above the cave caused by subsidence. This passage was blocked with glacial mud, boulders and clay which they started to dig out by hand.
The team got permission from the land owner and Peak District National Park to sink a shaft 1.2m in diameter and 45m deep to the top of the cave. After digging out a section with picks and shovels, they installed a pre-cast concrete lining.
'We hired a JCB and a diesel powered hydraulic winch to lower the rings and take out about 850t of spoil, ' said Nixon.
Now that the work is complete cavers can climb down the shaft and abseil to the bottom of the cave. 'We had a guy on the team who used to be involved in sinking shafts in the coal mining industry and a mechanical engineer who was useful for the hydraulic winch, ' explained Nixon.
The team completed four years' work on the shaft from the surface even though they had already spent many years unblocking passages full of boulders from the lead mine deep below.
Nixon's 'obsession' started when he was shown a paper written in 1793 by a scientist, James Plumtree, which described a network of unexplored caves in the area. The journey of discovery started at the mouth of the old lead mine and using the description in the paper, the cavers made their way slowly through the labyrinth of passages to get to where they thought the cave was, way below the surface.
Many of the passages were blocked with limestone boulders and with just a 24V cordless drill for boring holes for rock anchors - and some small explosives to break up the larger boulders that they couldn't remove by hand - the team unblocked each passage.
'Most of it was done by hand because we had very little equipment, ' said Nixon. 'There's no way you can get heavy machinery down there, it's a three hour journey through the lead mine.'
After seven years' work they found the opening to the base of the cave to be blocked by another mass of boulders. 'We started with the boulders we dared to remove, to create a cavity in the boulder choke, and we built up a scaffold frame of galvanised steel. It took about six months to get to the bottom of the cave.'
Finally, after clearing the route in from below, Nixon and his team were able to enjoy their ' nd of a lifetime', created by water erosion of the limestone over millions of years. Its 145m depth makes it more than 60m deeper than Britain's next biggest cave, Gaping Gyhll in the Yorkshire Dales.
'It took six days for me to ascend the cave, ' says Nixon. 'Standing there, knowing you are the rst person in the history of mankind was, well, quite impressive, ' he added.