Author Topic: New Rope  (Read 11505 times)

Offline Mr Cosmic

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New Rope
« on: January 14, 2008, 12:45:25 pm »
Hi

As a belated Xmas pressie to myself, I've purchased 100m of Edelrid's finest 10mm Static rope  ;D 

The question is what do I need to do with it before I cut it into the lengths I require?

I'm aware that new ropes can shrink by as much as 10% once they are "used".  So how do I get most the "shrinkage" to happen?  My plan was to leave the rope to soak in the bath overnight and then hang it in the garage to dry.  Will this be enough?

PS. I'm retiring about 60m of rope if anyone wants it for non-safety critical work and they are willing to collect it from the Wessex HQ or Cambridge.
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Offline paul

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Re: New Rope
« Reply #1 on: January 14, 2008, 12:47:38 pm »
I'm aware that new ropes can shrink by as much as 10% once they are "used".  So how do I get most the "shrinkage" to happen?  My plan was to leave the rope to soak in the bath overnight and then hang it in the garage to dry.  Will this be enough?

It should be.
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Online Bob Mehew

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Re: New Rope
« Reply #2 on: January 14, 2008, 01:00:59 pm »
Although I suspect this will not be very helpful, what did the instructions say on the leaflet that comes with the reel of rope?

Bob

PS Out of curiosity, what manufacturing date did the tape within the rope state?

Offline smollett

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Re: New Rope
« Reply #3 on: January 14, 2008, 01:03:26 pm »
I usually soak it then pull it through a descender in both directions whilst it's wet. Not entirely sure why though. Just what I have been taught ( i should probably find out why!). I don't think it's too important, something to do with shrinking the sheath to the core. I supose this would happen on it's first use anyway.
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Offline Mr Cosmic

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Re: New Rope
« Reply #4 on: January 14, 2008, 01:14:16 pm »
what did the instructions say on the leaflet that comes with the reel of rope?

PS Out of curiosity, what manufacturing date did the tape within the rope state?

I didn't get a leaflet  :(  The tape inside the rope (a clear plastic tape about 3mm wide) doesn't have anything printed on it, at least not on the first 6 inches.  The rope does have a green thread mixed in with core, which IIRC indicates the year of manufacture.
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darkplaces

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Re: New Rope
« Reply #5 on: January 14, 2008, 02:15:02 pm »
Soaking for 24hrs allow to dry, re-measure, use, re-measure again and mark actual lengths.  :thumbsup:
er but I am no expert so dont take my advice  ;)

Offline Charlie

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Re: New Rope
« Reply #6 on: January 14, 2008, 02:26:15 pm »
I usually soak it then pull it through a descender in both directions whilst it's wet. Not entirely sure why though. Just what I have been taught ( i should probably find out why!). I don't think it's too important, something to do with shrinking the sheath to the core. I supose this would happen on it's first use anyway.

the point of running it through a descender is to bunch up any sheath slippage, as such you should only do it in one direction then trim any excess sheath that has come away from the end of the rope and re-seal. shouldnt be a problem on any decent caving rope (and especially not edelrid)

personally what i do with club ropes is
soak the rope in several changes of water until the water stops turning white
run the rope through a descender
coil
store
cut
mark
use
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Offline potholer

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Re: New Rope
« Reply #7 on: January 14, 2008, 02:34:31 pm »
I tend to soak rope and then hang to drip dry, and repeat doing that along with water changes until the detergent has worked its way out of the rope (the water no longer looks milky or feels soapy between the fingers).

The impression I get regarding lengths is that of the 10% shrinkage, about half happens in initial soaking/drying cycles, and another half in use. Though I never bothered measuring rope straight from the reel, a 200m reel would often measure a little over 190m after initial rinsing and drying, but would shrink further with use.

Even leaving aside the shrinkage issues and the binding of the sheath onto the core, if the rope still has significant detergent in it, it can be very quick on descent when it's wet.

Offline Cave_Troll

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Re: New Rope
« Reply #8 on: January 14, 2008, 02:37:39 pm »
its silicone not detergent

darkplaces

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Re: New Rope
« Reply #9 on: January 14, 2008, 03:02:56 pm »
If you guys dont mind I am trying to sum up the answers with more of an explanation as to why here;
http://www.c**tplaces.co.uk/Wikka/Rope

Offline potholer

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Re: New Rope
« Reply #10 on: January 14, 2008, 03:09:14 pm »
Whatever the treatment is (silicone/detergent/whetever), it certainly feels soapy, and can make the ropes very slippy if not rinsed out.

Offline potholer

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Re: New Rope
« Reply #11 on: January 14, 2008, 03:12:28 pm »
If you guys dont mind I am trying to sum up the answers with more of an explanation as to why here;
http://www.c**tplaces.co.uk/Wikka/Rope
Dave Elliot's page
http://web.ukonline.co.uk/members/andy.mccarron/cncc/cor.htm
reckons single-ended descender pulling is the thing to do, and that does make sense from a sheath slippage point of view. As he points out, it'd also be a good way of squeezing out liquid, quite possibly better than hanging to drain under gravity.

Online Bob Mehew

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Re: New Rope
« Reply #12 on: January 14, 2008, 03:23:44 pm »
First, time and rope has changed over the years, so what was accepted practice ages ago may well be superseded now.


I didn't get a leaflet 


This is often the case, but if you remember to ask next time, then they will say "Oh yes one came with the reel, we usually through it away".  These will give you essential instructions in care of the rope. 


The tape inside the rope (a clear plastic tape about 3mm wide) doesn't have anything printed on it, at least not on the first 6 inches.  The rope does have a green thread mixed in with core, which IIRC indicates the year of manufacture.


Forget the threads, your recollection is long out of date (pre 1998).  The tape will have at every 1 metre or less (often around 0.3 m), a set of data printed on it which will include name of manufacture (hopefully Edelrig), date of manufacture (hopefully 2007), the Standard it is manufactured to meet (hopefully BS EN 1891:1998 but it might not have the initials), the type of rope (you should have A not B since A is stronger) and name of material it made of (should be polyamide).

Sorry to expose you like this, but I hope others will learn from your experience.  The date is important - I was sold by some one a rope which was 5 years old!  As some manufacturers only recommend a life time of 5 years, always check this date!  The date should also be on the reel but you are then reliant on the shop not having reused a reel.

But to answer your question.

First, the standard does require the shrinkage to be specified though it gives no maximum value which the rope is required to meet.  Of more value, the standard says the test to determine shrinkage is to to submerge the rope in clean water within a temperature range of 15 +/- 5 degrees C and pH range of 5.5 to 8 for a period of 24 +/- 0.2 hours.  So that gives you a guide to soaking times and conditions.

Second, from a 5 year old Edelrig leaflet, it gives no info on pre washing.  Shrinkage for uncoloured 10 mm superstatic was cited at 2.3%. 

The leaflet also says "wash dirt ropes in hand warm water with neutral soap, rinse thoroughly, dry at room temperature in a shady place.  Halogen free disinfectants are not harmful."

I have not done any work on how water is absorbed by rope, so 24 hours seems as good as any thing.  I soak samples for testing for 2 or more hours, but that was based on what Owen Clark told me.  As you may be aware, most ropes are made with the aid of a lubricant.  I recall some people claim the lubricant does make the rope more slippery to use, so getting rid of it has some benefit.  Running a wet rope under tension through a pulley has possible value in "washing" this lubricant out where as simple soaking may not.  (There is also the lesser problem of the sheath moving with respect to the core, which the pulley trick might help to settle down; though I have no information either way on this point.  My 5 year old Edelrig leaflet cites 0% slippage however.  But the standard indicates this is likely to mean less than 0.1%  or 10 cm overall in your new rope - hope my maths is correct.)  I know some people put a rope through their washing machine (pre clean the machine free of all washing powder first though).  I have no recommendations, but doing the pulley trick twice under water say 12 hours after starting soaking and leaving it for another 12 hours a fresh water seems to be a suitable compromise if you want to shrink the rope, otherwise the clean washing machine is faster. 

In the first instance I would suggest a phone call to the shop you brought the rope from; they should have the leaflet some where and be able to quote shrinkage.  So the question becomes is shrinkage really an issue? Or put it another way, how accurate do you know the pitch plus rigging length? 

What I can't answer is does rope shrink further after its first wetting and drying cycle or indeed after use.  Oh god, another possible piece of work.  Any one interested in doing a simple experiment?  If so, please PM me.

Lastly to other readers, other manufacturer's rope do shrink more than 2.3%, so read the leaflet!


Offline Charlie

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Re: New Rope
« Reply #13 on: January 14, 2008, 03:35:08 pm »
Lastly to other readers, other manufacturer's rope do shrink more than 2.3%, so read the leaflet!

And they dont always give a true value, I had a 200m reel of Mammut 10mm [shrinkage 5.5%] drop to 178m.
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Offline Mr Cosmic

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Re: New Rope
« Reply #14 on: January 14, 2008, 03:46:06 pm »
Following Bob's comments, I've cut open a longer length of the rope and the tape does have some printing on it.  Unfortunately this is smudged beyond all recognition :(  Looks like the ink wasn't dry when the rope was assembled.

Following on from everyone's advice I think I'll go through a few rinse - 12 hour soak - descender pull-though - dry cycles before cutting and labelling the rope. 

Out of interest, I'll measure it before and after and see how many metres are lost through shrinkage and sheath slip.
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Online Bob Mehew

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Re: New Rope
« Reply #15 on: January 14, 2008, 04:06:43 pm »
I should have said that the smudging of the tape often occurs, though not until the rope has been used in my albeit limited experience. 

As for measuring, this is tricky as strictly you should do it under a 10 kg load since there is some stretch in the rope.  But I doubt if you have access to a 100m drop to do this simply.  Not sure if you can get it accurate enough on say a 2m length.  I use small 15 mm long pins for work on the rope test rig which I push through the rope so the 1 mm diameter head marks the point.  Unfortunately with a 10 mm diameter rope this means you have up to 5mm of sharp end exposed, which does not sound sensible when washing a new rope.  Possibly a waterproof pen mark might do, but the mark is likely to be several mm in size, so you are going to be possibly up to 0.5% in just measurement errors in a 1m length of rope.  I guess you could rig up a double length with your rope held on the ground, run up to a pulley rigged way up on a ladder or the top of house wall and then back down to the ground where it is loaded under a weight of something larger than 10 kg to cope with friction in the pulley.  Then you can measure the distance between the marker points with a tape.  Hmm, good luck.  Could you PM me with the results?  Many thanks

Bob

Online Bob Mehew

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Re: New Rope
« Reply #16 on: January 14, 2008, 04:30:50 pm »
 :-[ Sorry I should have clearly stated that having marked your rope, then you should not use that bit of the rope. 

See http://theuiaa.org/upload_area/files/1/Notification_about_the_marking_of_ropes_by_climbers.pdf

darkplaces

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Re: New Rope
« Reply #17 on: January 14, 2008, 06:41:58 pm »
Blimy that reads like a giant cop-out.

They should have said, marker pens have been found to degrade rope strength. best not use it. try tags or heatshrink...

Plus if your marker is on the last 5cm of rope... What the hell are you doing on that bit anyway!!! Other then falling off the end because you forgot the knot.

Offline damian

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Re: New Rope
« Reply #18 on: January 14, 2008, 07:06:44 pm »
Agree with most things people have said above, but would point out that whatever the initial shrinkage you get (which I always find is a little higher than the manufacturers suggest) over the first few months' of usage, it will shrink substantially more. Therefore, if I want a 30m rope, I pre-shrink the rope (soaking in a bath or black plastic bin through at least 4 changes of water) then cut it to 34m. By th end of the first year it will almost certainly be 31m.

Finally I would say Edelrid shrinks less than Mammut.

Offline Cap'n Chris

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Re: New Rope
« Reply #19 on: January 14, 2008, 07:10:43 pm »
Er, just don't mark the length of your rope. Simple.

I've never needed to (so far), since all my bundles of rope are obvious, i.e. 12m, 25m, 50m, 100m.

Offline potholer

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Re: New Rope
« Reply #20 on: January 14, 2008, 07:17:30 pm »
Are they obvious when they're in a bag?

Offline Cap'n Chris

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Re: New Rope
« Reply #21 on: January 14, 2008, 07:41:54 pm »
Yep, `cos they're in the right order of use for the trip.

Offline Christian_Chourot

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Re: New Rope
« Reply #22 on: January 14, 2008, 07:47:29 pm »
They are if you've packed them in the right order.

Offline Cap'n Chris

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Re: New Rope
« Reply #23 on: January 14, 2008, 07:56:11 pm »
Yes; yes, they are. Why would anyone pack ropes in the wrong order?

Offline Christian_Chourot

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Re: New Rope
« Reply #24 on: January 14, 2008, 08:00:35 pm »
I had the page open before you'd added your reply... I was making the same point!