Lifeline

[Christian_Chourot]

Following a committee meeting tonight, it falls to me to ask this question for our interest (but not decision making!):

What type/specification of rope is the lifeline of choice for people nowadays?

I eagerly await the disagreements...

 

[Hammy]

Having recently observed the antics of several different caving 'teams' on the 5m ladder climb from Kingsdale Master Cave to the Roof Tunnel it would seem that for some the lifeline of choice is no lifeline at all!

Some folks seemed glad to be able to use my SRT rope as a handhold to pull themselves onto the safe haven at the top though - which was a good thing since one of them in particular appeared to be 'in extremis' and it would certainally have ruined his day (and probably ours and many other peoples too) if he had parted company....  He was so out of breath and shaking that he didn't even have time to ask politely if I minded, which of course I didn't!

(my rope incidently was 10mm Mammut Performance Static which serves well for both SRT and lifeline, along with several other brands and rope types/diameters)

 

[cap n chris]

See these threads for more ropey agreementing:

http://ukcaving.com/board/index.php/topic,3625.0.html
http://ukcaving.com/board/index.php/topic,537.0.html

 

[paul]

We usually use SRT (Semi-static 10 or 10.5 mm diam.) for lifelining ladders rather than have separate ropes for the job. No problem providing you take care not to let too much slack develop.

 

[Bob Mehew]

No problem providing you take care not to let too much slack develop.

How much length of rope might that be?  And following on the logic, how much slack would you permit in a metal chain lifeline? 

You might wish to read BS EN 1891:1998 & 892 : 1997 for what shock load the rope might give and http://www.hse.gov.uk/research/hsl_pdf/2003/hsl03-09.pdf for what shock loads might do to you, before you answer.

 

[Rob]

You might wish to read BS EN 1891:1998 & 892 : 1997 for what shock load the rope might give and http://www.hse.gov.uk/research/hsl_pdf/2003/hsl03-09.pdf for what shock loads might do to you, before you answer.

Tis indeed a fascinating read...

...too many arrows...  ​

 

[andysnook]

I must admit this is a subject I have given great thought, but rarely entered into any debate on.

Bob - your post there is very interesting indeed, but substantially technical - I'll save that for when I can properly digest it.

I have heard so many arguments either way.

The likes of Andy Sparrow will tell you that the shock load of even a small fall factor on SRT rope would injure you or at best be most unpleasant.

I mostly see people lifelining using climbing rope (10.5mm on average I would guess) as I mostly do myself.  This is mostly down to the overall influences of those around me.  Our club's tackle store has plenty of climbing rope for lifeline, and whether it's deliberate or not, that is what inevitably gets used for lifeline.

But - I know of people within our club who will say (as posted above), that SRT rope is the correct rope to use, and that correct technique means that there wont be any slack in the line in the first place.

I've not fallen on either, but if I had to choose - well I'd go for a fall on climbing rope.  I might be wrong, but right here right now - and considering all the conflicting opinions I've heard on this subject I'd go for the "more shock absorbing" option.

I've allowed myself to come off a ladder so others can practice lowering me off - or just to feel the weight.  Now, I like most others (well, on the mendips anyway) are going to be dangling by a belt at this point.  Once I've been doing this for a short period i'm not comfortable.  Now, I try to imagine what it would feel like actually falling with even a small amount of slack onto a belt around my waist - I'm not optimistic that it would be fun in any way shape or form.

The main arguments against dynamic rope that I have heard would go along the lines of :-

(a) Dynamic climbing rope doesnt wear anywhere near as well as SRT rope  (easy to avoid, just replace the rope more often!)
(b) A fall near the bottom of a long pitch will simply dump you into the floor due to rope stretch (especially if the lifeliner is at the bottom of the pitch, so double the rope length!)

Perhaps some thoughts from people who have actually taken falls on either type of rope ?

 

[andysnook]

 

[Robert Scott]

Our Tackle Keeper is talking to Steve Round (Bernie's Cafe, Ingleton) about some rope for lifelining. If I remember the explanation correctly the rope changes from dynamic to static after a fall on it (could be the other way round - but let's not waste computer power discussing that). The rope is also orange (?) so it will not get mixed in with our standard SRT rope.
Contact Steve (015242 41802) for a chat.

 

[paul]

No problem providing you take care not to let too much slack develop.

How much length of rope might that be?

It is almost impossible to maintain the lifleline absolutely tight when taking in hence "not let too much slack develop". Maybe that should be re-worded "no slack at all" meaning absolute minimum practicable.

Let's also remember that we're talking about a lifeline and not a rope which has a fixed attachment to an anchor. A lifeline is being fed through a friction device (such as a Stop or Italian Hitch). Should the person being lifelined fall of the ladder (and I have done this accidentally a couple of times over the years) and the lifeliner has not let any slack develop, which is hopefully the case, then the fall should be very small in distance and some of the shock load will be absorbed in slippage through the belay device.

And following on the logic, how much slack would you permit in a metal chain lifeline? 

I wouldn't consider using a metal chain lifeline - too difficult to use in a belay device.

You might wish to read BS EN 1891:1998 & 892 : 1997 for what shock load the rope might give and http://www.hse.gov.uk/research/hsl_pdf/2003/hsl03-09.pdf for what shock loads might do to you, before you answer.

Yes - well worth a read.

The point is that many cavers do not often use ladders and are more likely to have SRT rope. It is better to have some sort of lifeline rather than none at all.

 

[cap n chris]

I was recently reminded of the amusing quote attributed to Roy Davis of the Oxford Uni CC, which neatly summarises an alternative approach to descents:

"There are many ways of getting down a pitch the easiest, of course, being to simply jump. This practice is to be discouraged, however, because the jumper might injure someone below."

 

[Cave_Troll]

sadly you're also going to have to consider attachment to the caver.
If you wear a harness you'll be a lot more comfortable than if you've jsut tied the rope around your waist or are wearing a belt. Even if you use bungee cord rather than caving rope

 

[biffa]

As I understand SRT rope is designed to take a factor 1 fall and deliver less than 8kN force where as climbing rope is designed to take a factor 2 fall and deliver less than 8kN force.  So for lifelining (unless you belayer doesn't take in and you climb above them - which is unlikely) you will never get more than a factor one fall (fall same length as the rope from climber to belay) - so SRT rope would be OK.  In reality you are unlikely to get anywhere near this force due to the much reduced fall factors.

However even in a proper climbing harness 8kN hurts!  Maybe the question ought be what sort of harness/belt arrangement you use?

 

[damian]

As I understand SRT rope is designed to take a factor 1 fall and deliver less than 8kN force where as climbing rope is designed to take a factor 2 fall and deliver less than 8kN force. 

I think you'll find it's actually slightly more complicated than that. For Static ropes it's a FF0.3 with less than a 6Kn force for a 100Kg load with Type A ropes (10mm+) or 80Kg with Type B ropes (less than 10mm). For dynamic ropes it's a FF2 fall with less than 12Kn for an 80Kg load.

 

[theFerret]

I may be corrected but a viewpoint from the CIC bunch, me being one, is that a lifeline should always be kept tight and there is no reason not to be able to when using a mini/pro traxion, this also allows for quick and efficient rescues as opposed to italian hitch. The shock load from a tight semi-static rope falling off a ladder belayed on a mini traxion is very minimal. Also semi-static ropes were designed for use underground, they were brought from caving into industry, originally desiged by cavers for cavers. Dynamic ropes provide no rescue use for tired cavers unable to finish the ladder climb and are not designed to be underground in the first place.

 

[damian]

I may be corrected but a viewpoint from the CIC bunch, me being one, is that a lifeline should always be kept tight and there is no reason not to be able to when using a mini/pro traxion, this also allows for quick and efficient rescues as opposed to italian hitch.

I think it is probably wise to add a big health warning with Traxions or Pulley-jammers that you MUST know how to release it under load and that, if like me, you're pretty light, this can be very difficult with someone twice your weight. I am aware of at least one incident recently involving a mini-traxion being used where the climber couldn't be released when needed.

Also anyone being lifelined with a traxion or pulley-jammer MUST be wearing a harness, as it is not possible to instantly lower them to the ground. While this is common practice in instructed caving, it is definitely not common practice on smaller pitches on Mendip in particular.

In short, they're a great piece of kit but need a much higher standard of training prior to safe use than an Italian Hitch.

 

[cap n chris]

Good addition, Damian.

 

[whitelackington]

I agree with an earlier poster that it is probably more important to be wearing a well fitting harness than which type of rope you use,
likewise for the person doing the lifelining.

Problem is,
who is going to supply these well fitting harnesses for beginners?

 

[cap n chris]

Beginners won't be climbing ladders.

But, if they were, they would be the most obvious candidates to be wearing a harness since they are far more likely to experience difficulties. The moral responsibility to ensure they were equipped with a harness would rest with the trip leader.

 

[graham]

Beginners won't be climbing ladders.

Define beginners. I think you are wrong here, Chris.