Ropes

[CaverA]

I'm considering buying a new rope. I've decided to get it from Caving supplies:

http://www.caving-supplies.co.uk/

But I can't decide which rope to get. The choice is between the Mammut Pro-static 11mm which according to the web-site is a heavy duty caving rope suitable for rescue and industrial use.

OR

The Mammut performance static 10mm which is suitable for SRT, abseiling, rescue and industrial applications. I intend to use the rope as a life-line and abseil rope, my current rope is an 11mm and I was advised to get it because I was just starting out and this rope was more hard wearing. I'm looking to get 50m of it. The one aspect that does put me off is the colour of the 10mm!!

Any advice/suggestions would be good

 

[cap n chris]

For your purposes, 10mm.

 

[AndyF]

I've always liked Mammut ropes, and for what you need 10mm is the right one IMHO.

Colour doesn't matter a hoot (is it yellow by any chance?) If so then we have some of it and it is quality gear...

 

[martinr]

The Mammut performance static 10mm which is suitable for SRT, abseiling, rescue and industrial applications. I intend to use the rope as a life-line and abseil rope

Dont even think about using an SRT rope as a lifeline.

SRT ropes are static (low stretch). Lifeline is dynamic (stretches). If you lifeline with SRT rope, you risk serious injury if you have a fall.

 

[darthnoddy]

isn't a lifeline kept tight so you don't fall?

 

[Stu]

The Mammut performance static 10mm which is suitable for SRT, abseiling, rescue and industrial applications. I intend to use the rope as a life-line and abseil rope

Dont even think about using an SRT rope as a lifeline.

SRT ropes are static (low stretch). Lifeline is dynamic (stretches). If you lifeline with SRT rope, you risk serious injury if you have a fall.

Not strictly true.

OP, 10mm.

 

[cap n chris]

11mm is certainly low stretch and hence totally unsuited for lifelining; zero slack in the rope is also required generally for l/lining. 10mm is the better of the two options from the OP - hence the answer to the question. Whether or not other cavers would consider using semi-static instead of dynamic as part of their lifeline is another thread. 11mm is over-engineered for the OP's purposes, is harder to rig with, heavier, crap for l/lining etc..

 

[CaverA]

11mm is certainly low stretch and hence totally unsuited for lifelining; zero slack in the rope is also required generally for l/lining. 10mm is the better of the two options from the OP - hence the answer to the question. Whether or not other cavers would consider using semi-static instead of dynamic as part of their lifeline is another thread. 11mm is over-engineered for the OP's purposes, is harder to rig with, heavier, crap for l/lining etc..

Sorry I'm a tad confused. I was under the impression that all general use caving ropes were static or semi-static and climbing ropes were dynamic. Also if the rope was anchored above the pitch then no fall factor is induced? But the 10mm is a good all rounder for the intended use?

Thanks

 

[Les W]

All caving ropes are semi-static and normally around 10 to 10.5mm diameter. Martin R's comment on lifelining refers to the fact that incorrect or poor life lining technique can result in potential falls on the rope and if this is the case then Dynamic rope is better.  :-\

I think it would be better to correctly train people in the correct techniques and then it would be perfectly OK to use semi-static rope for a lifeline. 

Wessex have both types of rope in our tackle store for several reasons, the main one is that we cannot be sure that people using the rope for lifelining won't use poor technique, so it provides a safety net, also we discourage the taking of SRT rope for ladder and line work, so the fact that they are different means that people tend to use the different types of rope for the different types of vertical caving. This means that the SRT ropes are better looked after and last longer.

 

[CaverA]

I've always liked Mammut ropes, and for what you need 10mm is the right one IMHO.

Colour doesn't matter a hoot (is it yellow by any chance?) If so then we have some of it and it is quality gear...

They describe it as gold which is very nice.

 

[cap n chris]

I was under the impression that all general use caving ropes were static or semi-static and climbing ropes were dynamic.

Correct.

Also if the rope was anchored above the pitch then no fall factor is induced?

Not true; if the lifeliner isn't any good and a loop of slack rope occurs between the belay device and the climbing caver, then there is shock load possible - usually as the caver is near the pitch head (i.e. when the slack rope may be more than one-third of the distance to the belay device, thus potentially resulting in an injurious fall factor).

But the 10mm is a good all rounder for the intended use?

Yes; certainly better than 11mm. 

 

[CaverA]

I was under the impression that all general use caving ropes were static or semi-static and climbing ropes were dynamic.

Correct.

Also if the rope was anchored above the pitch then no fall factor is induced?

Not true; if the lifeliner isn't any good and a loop of slack rope occurs between the belay device and the climbing caver, then there is shock load possible - usually as the caver is near the pitch head (i.e. when the slack rope may be more than one-third of the distance to the belay device, thus potentially resulting in an injurious fall factor).

But the 10mm is a good all rounder for the intended use?

Yes; certainly better than 11mm. 

Thanks everybody, your information has helped.

 

[Bob Mehew]

Caver A - can I suggest you also read http://ukcaving.com/board/index.php/topic,3569.0.html on fall factors.  You should be aware of the down sides of using semi static ropes for life lining.  It is a gross simplification to divide up semi static and dynamic ropes between caving and climbing.  If you are climbing underground then you definitely should be using a dynamic rope.  But on a ladder, the theory goes that semi statics should be OK.

The British Standard requirement for semi static ropes is to arrest a 100 kg mass from a Fall Factor 0.3 with a peak force of less than 6 kN.  That for a dynamic single rope is to arrest a 80 kg mass from a Fall Factor 1.7 with a peak force of less than 12 kN.  Although at first glance it might seem that semi static is better than dynamic, in fact the behaviour is not linear and one can't simply relate these figures.  Elongation (stretch) figures are less than 5% with 50 kg for semi statics verses 8% for 80 kg for dynamic rope.  (Again you can't relate these figures.)  General experience points to semi static ropes having less capacity to minimise peak forces than dynamic ropes as the Fall Factor increases, as the Paul indicates in the other thread.  There is also a feature of dynamic ropes being better than semi statics when you are in a situation with small lengths of rope and increasing fall factors.  There is also the question on how you attach the rope to yourself.  Transmission of the forces via a harness is obviously better than via a loop of rope, but some harnesses are better than others.

I should also add that neither standard relates diameter with strength; any diameter (between 8.5 and 16 mm) semi static rope has to be capable of sustaining a static strength force of 22kN whilst dynamic ropes have no equivalent requirement for strength!  But be aware that semi statics come in two types "A" and "B".  Type "B" is less "strong" in several parameters.

Lastly, when you go and purchase a rope, ask for a copy of the manufacturer's information sheet and also to see the marker tape inside of semi static ropes.  This marker tape will show manufacturer's name, the British Standard number (EN 1891:1998 which might be prefixed with BS), type of rope (A or B), the name of the material from which the rope is made from (this might be colour coded) and most importantly, the year of manufacture.  (Some of this data might be on the reel.)  Check this date against the manufacturer's recommendation life time as is often stated in their info sheet; you might be alarmed by the results!  I would almost go so far to recommend that don't buy if no info sheet is available and that you pay for a metre or so of rope to do this check if the shop keeper declines or go else where. 

 

[MSD]

Semi-static rope is perfectly OK for lifelining underground (unless you are lead climbing). Obviously if communication broke down badly between lifeliner and the person being lifeined you could reach a dangerous situation, but I'm not sure the situation would be much less dangerous on dynamic rope - you still have equal chance of hitting something regardless of what rope you are being lifelined with.

Dynamic rope has a looser weave and gets knackered by mud and grit (one main reason for changing your cowstails often). Climbers would NEVER treat a rope the way it necessarily gets treated underground. If you need to use a dynamic rope for a lead climb, bag it up in a waterproof bag inside a tacklesack to keep it as clean as possible.

10mm is the better choice. 11mm is just too heavy and bulky uness you want lifeline elephants or the rope is going to be exposed to be heavy loading and/or wear, for example for rescue.

Mark