Incident Report

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Incident Report 2020-05-01T16:26:00+00:00

Nightmare in Elm Hole

Incident Date


Incident Description

A dive was undertaken to reline the passage from Elm Hole to the major trunk route from Pwll-y-Cwm to Daren Cilau. In order to make the tags go in the right direction and to mainain the best vis. the diver elcted to carry into Elm Hole and lay a new line out to Pwll-y-Cwm. Vis. was good the exit was known to be open but the shaft up to surface in Pwll-y-Cwm was not lined. The diver entered the cave at 7.30 pm and conducted an arduous solo carry to base. Entering the water at 9.15 pm all went well until the diver reached the vicinity of The Window (where the passage enters the main drain). At this point the divers fins became seriously entanged (he was reversing down the passage belaying the line). After becoming untangled the diver literally fell out into the main tunnel loosing the exisiting line. The diver located the left wall of the passage (believing this to be the downstream end of the passage) and continued laying his own line until he met a line (red) confirming that the diver was in fact heading upstream. At the junction of the main line (orange) and the loop line (red) the diver dumped his reel and exited via the main line through the choke to surface in Pwll-y-Cwm. The diver had used up 1/2 of his air supply but was very cold (in a wetsuit) and quite shaken. A clean up dive the next day found _both_ lines that lead into The Window broken. The red line (upstream to The Corner) was broken between the junction and the nearby spike belay. The green line (downstream to The Choke) was broken at the same point but had been washed downstream for 5 m. The new line was re-belayed at the spike and the junction made here rather than in the tight confines of the entrance to Elm Hole. It now runs from here to The Choke. On reflection the diver had followed the left wall of the oxbow pasage between The Choke and The Corner.

Lessons Learned

This was a potentially problematic dive from the outset. Ideally it should have been undertaken with a modicum of support - not after spending all day doing DIY - with greater air reserves (not two part filled 7s ofsomething) and better thermal protection. The diver was also overweighted - not a problem in Elm Hole but it did cause problems surfacing. A fixed line should have been installed from Pwll-y-cwm to provide acomfort. Line junctions in tight spaces are best avoided. The line placement here still could be improved. Possibly fins should not have been used. Never underestimate your familiarity with a cave. The divers knowledge of the system was both a benefit and an enticement.
Line Management Major
Gas Management Minor
Equipment Management Minor
Equipment Failure Negligible
Training Negligible
Medical Negligible
Planning Major
Procedural Error Minor
Cave Environment Major
Weather Negligible
Other Factor Unknown