OUCC Proceedings 11 (1983)
A Reappraisal of the Techniques for Descending Pitches by Ladder - a Case for a Safer Method of Belaying
|OUCC Proceedings 11 Contents|
Almost all the caving clubs in the UK use ladders on many occasions to descend vertical pitches. Some of the reasons which are put forward for using them are:
Of these, reason (2) is of most importance to OUCC, where large numbers of novices exist who may try the sport only once or twice and do not want to become involved enough in caving to learn SRT and spend a not inconsiderable sum of money on new equipment. After all, how can you tell if you like caving without trying it? It is therefore likely that ladders will continue to be used in the foreseeable future in caving, especially in University clubs, where a large percentage of British caving novices are trained.
The problem, then, is 'how safe is laddering?'. In my opinion, not very! A quick look at the caving accident statistics shows that the misuse of ladders features significantly. My main complaint is the way in which the lifeliner at the top of the pitch holds the rope. In virtually all situations I have seen or heard of, the 'round the waist' belay is used. This is a technique much criticised in the climbing literature for a variety of well-publicised reasons:
The obvious solution is the friction belay, a Sticht plate, a figure of eight or even a rack. However, the Sticht plate is smaller, easier to feed rope through, and can be used to abseil with if necessary. This has some useful advantages:
However, there are problems in implementing this technique as lifeline rope tends to be hawser laid with a large variation in diameter; it is then difficult to get a belay plate to fit all the different ropes. An answer is to use kernmantle rope which has a roughly constant diameter of 11 mm. The conventional 'wisdom' is that SRT rope should not be used in lifelining; SRT rope is generally a static rope, with low stretch properties, and consequently has lower shock absorption than dynamic lifelining rope. A quantity known as fall factor I is often quoted to assess the performance of equipment in shock load conditions, the determination of the parameter assuming that the rope is fixed at the point of fall. However, as I have pointed out, with a dynamic belay the rope is not firmly attached to the belayer, and the shock is much less severe.
An additional advantage of the Sticht plate is that it transfers the shock directly to the belay rather than through the intermediary of the lifeliner. What is more, the process is much less strenuous for the lifeliner, enabling him to keep up far better with rapid climbers and so avoid the possibility of a long fall. In the event of a larger fall due to rope snagging, the shock can be far better borne by the belays than by the lifeliner, as mentioned above.
The point I have been trying to make is that the fundamental objection to using SRT rope in lifelining can be removed by proper belaying practices. The implications of this are interesting for the tacklemaster as well as the caver. The tacklemaster can now get rid of large quantities of 'tow rope'/lifeline which were previously needed for laddering, but not used for regular caving in the club which is now dominated by SRT, and hence save scarce club resources. Underground, it means that abseiling can be the standard method of descent, which wouldn't be feasible with hawser laid rope, because of its tendency to kink and even melt. Self-lining is easier as ascenders move better on kernmantle rope than hawser laid. Yet lifelining is still possible, and made even safer by use of a belay plate.
More realistically, there are problems in trying to implement this technique. SRT rope is more expensive per metre than conventional lifeline rope. It must also be made clear that there is no excuse for 'good' or 'bad' SRT rope, rope for SRT or rope for lifelining. Laddering rope must be as good as any other rope in the club and be thoroughly checked. Good rope sense must therefore be encouraged more than it is at present. Some types of SRT rope would be more suitable than others for belaying. Polyester (Marlow) ropes have less intrinsic stretch (0.9%) than nylon (PMI 2%). Nylon is also stronger than polyester. All of which suggests PMI would be more suitable than Marlow in this instances (Ed: However, I'd much rather prussik on Marlow).
I was prompted to write this article for two reasons. OUCC is in the position of having to scrap virtually all its lifeline and spend a large sum on replacing it; it is also a club which becomes more and more predominantly SRT-based as time goes on. However, I disliked the attitude of some cavers in high places in the caving establishment who believed SRT to be the only way to go caving (Champion et al., 1983; Eyre, 1983; Ellison et al., 1983). A major problem with SRT is its expense, and I cannot see why people should have to make a large financial commitment to try a new sport. It is totally impractical at University to be able to teach novices on SRT before they have any caving experience.
In climbing there has been a move away from equipment with the realisation that one can 'fix' any climb technically; in other words, it is better 'style' to do without such gear. I feel caving is going through such a 'gear' period, and although the SRT advances have made for safer and easier caving, that this trend will eventually stop. I for one would hold as the epitome of caving style and elegance a solo descent of the world's deepest cave, using one length of SRT rope and a variant of the cordelette technique; using knots to prussik with, and a belay plate to rappel with! Don't laugh! No-one thought Everest could be climbed without oxygen, solo...
Brook, A., 1983. Ladders and lifeline technique. Caves and Caving
Champion, A., Graham, N. and Ryder, P.F., 1983. Ladders or S.R.T. - the choice is yours. Caves and Caving 21, 14.
Ellison, C., Soul, R. and Lyon, M.K., 1983. Letters. Caves and Caving 22, 34.
Eyre, J., 1983. Ladders - a reappraisal. Caves and Caving 21, 15.
Singleton, J., and Naylor, G.A. 1982. Xitu - the cave. Proc. Oxford Univ. Cave Club 10, 8-20.