Canyonero Rope - Wear and Tear or ???

Hello Tom,

I hope you are doing well. I wanted to pick your brain about the Canyonero rope. I purchased this rope several years ago and the rope has seen a lot of use all over the world. After going to Costa Rica on a spring trip ( where we ran Mordor Canyon among others) I did a trip 2 months later in Nevada with friends and I noticed "flat spots" at different places along my rope. One of my friends reported he "thought he could hear the core  snapping" as he was on rappel. Since we are conservative as far as safety measures go, I retired the rope due to these symptoms. I had a day off today and decided I to dissect one of these areas of "rope damage" to see what the inside of the rope looks like. Prior to dissection, the spot  on the rope I selected had some visible sheath abrasion, didn't feel "round" anymore and had a specific point that I describe as "hyper mobile" when the rope is bent in your hands. I dissected the sheath back as carefully as possible but still likely cut into the core a little bit in the process. When I exposed the core, I didn't find any obvious damage to the core other than a couple of outer strands that were likely cut by me when I removed the sheath.

The point of this email is:

A) Do you suspect the acidic conditions in Costa Rica could have accelerated the breakdown of my rope?

I understand you have supplied the Toros group a great deal if gear and was wondering if they have had any similar observations. My friend who was also on the trip core shot her BlueWater rope on her next canyon trip after Costa Rica. Both of our ropes were well used prior to Costa Rica so I can't rule out normal wear and tear. Scott of the Toros group mentioned that they change the cord on their anchors frequently in Mordor Canyon due to the acidity of the environment there.

B) In your opinion and with your knowledge of the construction of this rope, did I make the right decision to retire this rope? There is definitely sheath abrasion though no core is visibly exposed. Upon dissection, I can see no obvious sign of core damage though I am also not familiar with the core used in this rope. Most of the ropes I've ever looked at the insides of are more of a classic Kern mantel design with obvious twisted core strands.  

I attached pictures of the process to provide better visualization of the rope. Thanks in advance for any insights into the rope. I'm definitely a big fan of Imlay ropes and would like to understand them better to better gauge their lifespan and safety considerations when using them.

Cheers, D. K.

Hi D.K. -

Thanks for the questions.

 It is quite challenging to damage the core without damaging the sheath.  I believe it can be done with a microwave oven... but that is the only way I have heard of doing it.

 Many ropes have the core made from twisted bundles of fibers. Dynamic climbing ropes almost always do...  and I suspect that Climbing Rope makers who make static ropes use twisted bundles as a matter of habit.  Twisted bundles make the rope more bouncy (less static), but I am told they help ropes maintain their round shape better.  We use straight fibers (aka non-twisted bundles) because it makes the ropes more static (and that is the way the factory I use was making the ropes that I modified into the current models).

Soft spots in a rope can be a result of a section of loose sheath, rather than of a diminished core. How can there be a section of loose sheath? Say you had 10 people rappel down the rope and stop at the same point. As canyoneers, we would call this “Saturday”, as it happens rather often. If the sheath has any tendency to slip, then the sheath will be squeegeed down the rope to the stopping point, and the sheath above the stopping point will be a bit tighter, and all the slipped sheath ends up in the rope at and near the stopping point. 

The mild sulfuric acid found in some of the CR canyons definitely could damage the sheath fibers in a way to make them less durable, less tough, more easily abraded. Given the tight weave of the Imlay ropes, I doubt that the core fibers were damaged by the mild acid. (It seems like if there was mild-acid damage to the rope, it would also change the hand of the rope... maybe the "heard the core snapping" sounds were embrittled sheath fibers breaking.)

 Your rope looks well-used. I can look at a rope almost microscopically using my super closeup lens on my SLR camera => computer screen. When I look at your image #4 on my screen, I see lots and lots of broken sheath fibers, which to me means that the sheath was worn out, and it was time to retire the rope anyway.  It is hard to put a number on it, but to me it looks like of the 16 bundles that are woven into the sheath, it looks like EACH of the 16 bundles only retain about half of their original fibers.  It might be possible to measure this if I had an analytical scale, but my postal scale is not so sensitive.

 This could be just from extended use.  It could also be that the damage from the mild acid made the fibers less tough and therefore wear and tear were accelerated. The Bluewater Canyon Pro ropes have a polyester sheath very similar to mine though less thick - so could have the same problem.

 Or it could just be that this particular section of rope got rubbed up real good at some point.  We usually think of cutting one bundle all the way through (= coreshot) as being the death knell for a rope - but it is also possible to just plain wear out a section of rope by slowly cutting fibers evenly on all 16 bundles without actually cut through one specific bundle.

Hope that answers your questions.

 Tom