Old Ing to Dismal Hill – half the free dive
Saturday, 6 October 2007
After our fairly successful fresher meet at Birkwith I got roped into trying the free dive connection between Old Ing and Dismal Hill, whilst Chris and Steve who didn’t have wetsuits came along to bypass the sump in the bypass crawl.
The sumps are described as fairly technical as the second of them is through a window at 2m depth, and should only be attempted by competent people etc. This description however failed to take into account what the dive would be like if the part of the dive line that re-belays into the air bell had broken off, and so started another epic adventure…
First Matty dived through with his hi-tech tinted goggles. After a while we felt no tugs on the line as was agreed and so after a little while of wondering what happened Dan set off. He soon returned spluttering for air claiming that the line ended quite deep at a blank wall with a roof above his head. This prompted a little concern especially after Simon tried next and also returned claiming the Sam
So whilst those guys got their breath back I dived in. The line appeared to lead through a tight section but I moved to the right and it felt like I came through a slot into a large area. The rope appeared to be leading downwards here which was rather worrying and not at all like the description. But before I got to the end of the line I felt a large void above my head, so I swam up into it trying to bring the line with me. Unfortunately I didn’t have enough buoyancy (with lead weights attached) to swim up whilst pulling the now tight line, and get my head out of the water, and as Matty saw me he pulled me up, but the line pulled out of my hand.
So now two of us were in the air bell with no idea where the line had gone and so no way to let the others know what had happened. Further more, there was a bolt on the wall for the re-belay of the line, but no line attached to it. Finally I had to dive to about 3m depth to retrieve the line, where I had to flail around blindly to try and catch it as there was no visibility, and again it was again hard to pull up as it was taught and Matty had to help me back up, my head only just out of the water whilst being able to keep a grip. So now I managed the three tugs after quite a while.
All we could now do was wait for the others as there was no way of telling them what had happened and soon Dan came through, this time I stuck my foot where he could grab it and find the way up to us. No sooner had Dan appeared through the surface, we asked him if he still had the line but again the tension had pulled it out of his grip, so another dive was needed to find it. Then Si joined us in a similar way.
We were now getting more than just a little worried as the air bell didn’t seem nearly so big as it originally was and we couldn’t regain the dive line without a few attempts at diving down in the zero-vis water. Eventually we managed to find the line and decided to head back out as we were concerned about the description of a 60 odd meter sump in the floor and the obvious confusion of the lines etc. Also the air was getting stale and our constant attempts at taking deep breaths to dive to regain the line probably accelerated the process.
The return dive was much easier, with the most awkward bits seemingly at the air bell end. The air was much fresher on the Old Ing side and I think we made the right choice of action. The trip was then completed via the dry crawl.
Hopefully no-one else will try this trip with the line in this condition as it is very dangerous, and impossible to return to the surface in the air bell with the line, without help. Hopefully the line will be replaced soon and with a rebelay into the air bell to avoid confusion. We checked out the sump on the Dismal Hill side and concluded that the thing which appeared to be a re-belay on a blank wall with a roof above everyone seemed to encounter was actually in the 2m depth sump and we had nearly done both dives in one, if only we could have found the way through. Very confusing but I hope to complete it with better lines.
This account has ominous similarity to the 1976 account of the fatal free diving incident in Langstroth Cave. Try reading CDG NL40:24 which starts ?The leader of the party dived first and had some trouble losing the line in this airbell???
I?m all in favour of free diving and believe that training is a good thing. The current best estimate is that you are 25 times more likely to survive a cave dive if you are qualified than if you are not.
Monday, 08 October 2007
The research and stats behind this figure are here for any one that wants to know more about how it was calculated.
Monday, 08 October 2007
There has been a number of incidents and near misses recently when cavers have been passing sumps by holding their breath. ?Free diving? is a legitimate and exhilarating aspect of caving and it can be done in relative safety with the right approach. This list of things to consider (below) was originally put together for submission to the CPC Record in September 2007 (for the October issue) but I was asked if it could also be put onto the ULSA website. It?s not necessarily an exhaustive list of all safety points (and others may well be able to add useful ideas) but it may be helpful to some cavers.
? Find out as much recent information as possible beforehand.
? Always expect prior information to be misleading or wrong.
? In longer free dives it is safest if a fully equipped diver checks the sump first.
? Anyone who is unduly apprehensive should not proceed.
? Unexpected underwater obstacles commonly occur; look ahead for these and abort if in any doubt. An underwater tangle can kill.
? Be prepared to turn back long before the breath hold comfort zone is exceeded; you should never go further than the point from which you can easily return on the Sam Allshorne lungful of air.
? Consider thermal protection (wetsuit, neoprene hood & gloves etc), buoyancy difficulties (the possible need for lead weights) and vision (a diving mask and multiple waterproof lamps).
? A diving line is essential in most cases, preferably a thick rope giving good feel with cold hands. It is best to use a separate rope for pulling other equipment through the sump, with some sort of simple fail safe signalling system agreed previously to indicate that the sump is clear, bag jammed underwater, etc.
? Be aware that small airbells are quickly contaminated, for example with carbon dioxide. This has resulted in fatalities in the past.
? Always try to do the free dive in optimum conditions. Good visibility helps; low winter temperatures do not. Some flow may keep the water clear but excessive current is dangerous.
John Cordingley (BCRC Diving Officer)
Tuesday, 09 October 2007
Two divers have gone to have a look at this and were unable to sort out the line due to there being no visibility.
Monday, 15 October 2007
Have relined the two sumps with WHITE SRT rope for freedivers, belayed to the bolt in the airbell. Have removed the underwater line junction which leads down into the floor rift (to Red Moss Pot I think) and have belayed it to a spike in the airbell with a conection to the bolt above water, to keep the freedive line totally seperate from the Red Moss line. The Red Moss line is RED climbing rope. Removed all old tat from the cave. Still a fairly commiting freedive in my humble opinion…
As from the CDG notice board posted by Dave Ryal
Monday, 22 October 2007
Posted by: Noel Snape
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Posted: 07 October 2007