Rope Testing - Hand Lines Experiment


Are you responsible for a fixed line in a cave or mine? If so, BCA may be prepared to give you a free replacement unused rope for your fixed line. In the debate over whether rope is an acceptable fixed aide within a cave or mine environment, some evidence has just been acquired which points to larger diameter ropes left in situ potentially having quite reasonable life times (in excess of 10 years), though it is emphasised that smaller diameter ropes (under 11mm) probably do not. A proposal has just been accepted by BCA to fund an experiment to acquire more data to help this debate. The objective of the work is to replace a small number of existing hand lines, leave them for a reasonable period of time and then take them out and test them. The work will be under the guidance of Bob Mehew, BCA’s Rope Test Officer.

The work is aimed at fixed ropes used as a hand line for ascending, descending or traversing in a cave or mine. We are specifically looking for existing fixed aides which are used either as a security system in a traverse or as a hand aide to climb up or down a pitch. So this proposal will cover situations where people use Cows Tails for achieving their security. But this work is not intended to cover rope on pitches where ascenders or descenders are intended to be used. We will also consider proposals which involve replacing existing wire rope fixed aides with rope.

In order to side step several potentially thorny issues, the rope will only be supplied to locations which already have rope installed as a fixed aide. Any application must be supported by the local Regional Caving Council, NAMHO or another National Body, though preliminary enquiries are welcomed. It should be noted that this support does not commit the body to endorsing rope as fixed aides; rather it is to ensure the applicant is a reliable person or group. As the funding is limited, it is anticipated that there should be around 200m of rope available and requests will be dealt with on a first come first served basis subject to agreement of details. In addition, the applicant shall be required to undertake an inspection regime and maintain a dialogue with BCA’s Rope Test Officer. It is likely that the ropes shall be left in place for a 5 year period or longer, depending upon data, subject to the results of the inspection program, of course.

Because the testing of rope requires a minimum length of rope, a range of information is required to enable consideration of the application. A reasonably accurate estimate of the overall length of rope, lengths between anchors and lengths required for each anchor is required to help assess whether the installed rope can provide sufficient lengths of rope to make the samples for testing. The BCA test rig uses a total of about 2.25m of rope with tying the knots at either end to make up the appropriate length sample. So each section of installed rope between anchors should have a minimum length of around 2.25m between fixing knots. Given we wish to test a number of samples we are therefore looking at rope section lengths between anchor sections which are a number of times the minimum length of 2.25m. The use of knots in the rope to aid a person to hold onto the rope is acceptable, but details of the locations of such knots will also be required. In order to facilitate the inspection, it is anticipated that the ropes will be connected by stainless steel shackles to the anchors. (Stainless steel is being considered to avoid rust marks.) So details of the anchors to which the rope will be attached area also required. This does not rule out the use of natural belay points or other anchors but given the rope will be tied around the point, there is a need for an estimate of the length required for each loop including tying the knot itself. These details are open to discussion.

The inspection process is also being developed but will be based on the processes of a visual inspection, a tactile inspection plus probably a “rolling loop” inspection. (One makes a full turn in the rope and see's if the curve is smooth; one then rolls the loop along the length of the rope looking for any points where the curve shows an angle indicating a defect in the core.) Unless the location is naturally clean, it is anticipated that the rope will be disconnected from the anchors and washed before inspection.

If you are interested, then please contact Bob Mehew either via rope[at]british-caving.org.uk or by phone on 01704 569107.