Testing the strength of heavy duty caving belts

A Method of Testing the Strength of Heavy Duty Caving Belts

The aim of this little test was to establish a method to test the strength of heavy duty caving belts that did not rely on having access to a load cell. I hoped to produce a simple system that needed very little equipment and that would deliver a test load to a belt that exceeded the minimum strength requirement for its use.

What strength does a belt need to be?

Well, this one is a potential can of worms…. Let’s be clear, the manufacturers do not condone the use of their heavy duty belts for taking any load at all. There is a historical use in cave and mine exploration that involves using the belt for the purpose of slip prevention and security on steep ground. If you were intending to use it for this purpose, you’d need to be sure that the belt was strong enough for that, something that the manufacturers will not say.
We take the figure for a heavy person with kit that is used for some load ratings on PPE equipment: 120kg.
If a caver has a short lanyard which they climb above, ignoring all stretch or slack in a system, we will assume a possible fall of 1 metre onto the belt. The person will then be travelling 9.81 m/s (acceleration due to gravity).

velocity = √ (distance x gravity x 2)

v = √ (1 x 9.81 x 2)
v = 4.43 m/s

Kinetic energy = (v²m)/2

Ke =  (4.43² x 120)/2
Ke = 117.72 J

Impact force = Kinetic energy / Impact distance

iF = 117.72 / 0.1 (arbitrary minimum for complete stop)
iF = 1177.2 N

Impact Force = 1.177 kN

Confirmation:

Force = Mass x Acceleration

F = 120 x 9.81
F = 1177.2 N / 1.177kN

So a 1m drop of a 120kg caver onto a belt, not taking into account any stretch or bounce, produces a force of nearly 1.2kN.

Apply to this any safety factor you wish. Worse case? Twice the force falling onto half the strength of kit due to wear and age: 2 x 1.2kN = 2.4kN force will need to be held for a worst case fall and we halve the strength for old, worn or wet kit so 2 x 2.4kN = 4.8kN.

So as long as we can apply a test force of 4.8kN or more to the belt, we can be assured that the item can hold the greatest possible force we can apply to it even if not in new condition. The only remaining factor of concern is that would applying this force in test render the belt unsafe to use again, in essence, are these tests destructive? Only 1 way find out…..

You could easily argue that this figure is seriously overkill for a belt so you should undertake your own discussion as to the correct safety factor to apply and then make sure you test to that, e.g. 2.4kN using 2 or 3 people on the 3:1 MA system.

Testing

Using 1 very large Corsican Pine and a good sized Birch tree, we set up a pull testing rig with a simple 3:1 theoretical configuration. I used a Rock Exotica load cell to get live feedback on the testing here but if you copy the method, you would not need to use one.

For the estimation of test force we regarded each person capable of pulling 50kg (see Gethin Thomas’ work on tyroleans). Through a theoretical 3:1 MA system that would be 150kg per person. With 5 undertaking the pull reaching 750kg and 6 equalling 900kg or approximately 7.5kn and 9kN respectively.

Kit used (minus load cell): Petzl rescue pulley, Petzl Basic jammer, Petzl Partner pulley, Lyon wire sling for tree, assorted karabiners, 20m rope.

Due to the force expected to be placed on the rope, I did not anticipate that I would be able to untie the end knot (fig 8 loop). This was accurate and the knot had to be cut from the rope end. Bare this in mind with your own rope!

We also used a Petzl Rollclip to redirect the angle of pull to make it easier to stand on the tarmac of the road alongside the trees.

Initially we had 5 people pulling the first test on a Lyon roller-buckle belt (brand new).
This produced a force of 5.9kN with no damage or slippage. This is lower than expected but there was a lot of tightening in the knot and stretch in the rope coupled with a general timidness of the pulling team.

The remaining tests used 6 people to pull. This one was conducted on my 10 year old Caving Supplies square buckle belt (already retired). This belt has nicks, fluff and rust  and comfortably took a force of 7.74kN showing no damage or slippage. Next came my current AV belt, with it’s central maillon removed and directly attached to the pull line. This belt held 7.7kN without failure or slippage.Finally, the pulling team seemed at their most confident that nothing was going to break and send shards of metal and wood at them so they really gave the last belt some pain. This Warmbac square buckle belt was subjected to 8.64kN with no damage or slippage noted at the time.It is not surprising that the force exerted by the pulling team was less than the theoretical 3:1 system implied. In practice with the loss of friction due to bearings and turns in the rope a 2.5:1 is a more real world figure and so our 5 x 50kg pulling average adults could be expected to make 500kg/5kN using this system. Add a 6th person if the ground is poor or your team are small!

Conclusions

Using a system like the one shown here, with 5 people pulling at average strengths, you can apply a force greater than 4.8kN to your test belt.

Once the test is complete you should thoroughly examine the belt to see if any damage or slippage has occurred. Any that do show signs of damage should be retired. Any slippage may be down to the buckle tightening down so consider testing again. If a belt has taken the test load and shows no damage or deformity then you can be comfortably sure that the belt will be fit for its intended use.

Final inspection of belts:
Lyon roller buckle                                5.9kN            No damage, continuing to use.
Caving Supplies square buckle           7.74kN          No damage, already retired.
AV maillon closed harness buckle       7.7kN            No damage, continuing to use.
Warmbac square buckle                      8.64kN          No damage, slight curvature to webbing now when hung vertically which indicates over stretching or broken fibres down one side. Retired from service.

As a side note, I maintain that the Caving Supplies belts are the tanks of the heavy duty caving belt world and, if kept very clean, will ultimately outperform every other type or brand available. I think this test shows that well as the CS belt had at least 5 more years of abuse over the other belts. I will dispose of the Warmbac belt just in case but don’t tend to use these anyway, but that’s another blog post!

Worn Connectors – Pull Testing 11-6-2017

Over the last few months I’ve been collecting a few bits of retired equipment from stores checks and ‘isolation’ bins with a view to looking at loss of strength due to wear. Nothing here constitutes a scientific test and this is purely for my own satisfaction, but I’m writing it up anyway. I used my home made breaking rig with the Hilti HAT-28 anchor tester to provide the pull force. Each item was pulled up to the maximum possible load of the Hilti, 20kN, and the results were recorded.

Petzl Omni SL

Rated to 20kN main axis. Worn inside arc in 2 places after use with large steel pulley for 12 months. Failed PPE inspection due to wear depth being felt by fingernail and visually obvious.

Pulled to 20kN – No breakage, gate / lock working correctly.

I suspect that the wear on this item had not yet reached a sufficient depth to form a significant weak point. The connector was certainly retired at an appropriate time, i.e. with visible wear but before strength loss occurred.

Petzl M33 OK Oval SL

Rated to 24kN main axis. Wear visible at both ends of the connector. Large radius wear from twin cheeks of a steel pulley and small / deep radius wear from a long term connection to a steel 7mm Maillon Rapide.

Pulled to 20kN – No breakage, deformed beyond elastic recovery. Gate no longer closes and shape is visibly distorted. This item deformed at 15% below its rated strength. This shows that wear had already reduced the strength of this connector and it should really have been retired before reaching this level of wear.

Petzl Vertigo Twist Lock

Rated to 25kN on main axis. Worn on inner surface due to repeated contact with steel cable zip wires whist in use as a cowstail. Retired during routine PPE inspection.

Pulled to 20kN – No breakage, deformed heavily under test but recovered almost completely after. Connector permanently deformed and the gate locking mechanism does not function correctly. This item deformed 20% below its rated strength. This shows that wear had already reduced the strength of this connector and it should really have been retired before reaching this level of wear.

Do not take this test as advice to use kit beyond it’s manufacturer stated working life. Get a quailed person to advise you if unsure or go and do a PPE/FPE inspector course. If you have any retired gear you want to send to me to test in this manner then please get in touch.

Removing Sleeve Anchors (SPITS etc…)

I guess this post is a bit of a continuation from the blog post I did about pull testing SPIT type anchors in 2015. Sorry it has taken me so long to get round to doing this!
The original post can be seen here: http://www.peakinstruction.com/blog/pulling-spit-anchors-back-garden-test/.

One of the points of that testing was to ascertain if the sleeve anchors could be removed from the rock in a cave or mine to either de-clutter the wall or allow a resin anchor to be placed in the same location. This is important from a conservation point of view, these sleeve anchors are a bolt rash on the walls of our caves and once stripped of threads, are there forever…. or so I thought.

Jump ahead to now. Simon Wilson has developed the IC Resin Anchor in the Dales and his website has expanded to become a good resource of information relating to the installation and removal of anchors. Most relevant here is the method that he uses to remove old sleeve anchors, one which I am shamelessly copying here in an effort to spread the knowledge and encourage the tidying up of pitch heads. Simon’s site is here: http://www.resinanchor.co.uk/5.html.

I started with the original block of Stoney Dale limestone used for the original testing in 2015.


 

 

 

 

 

Method used:

  1. If required, dress the rock near your anchor sleeve with a chisel to create a flat area for drilling.
  2. Drill a 6 or 7mm hole immediately next to the anchor sleeve.
  3. Drill a second hole parallel to and as close to the first as possible.
  4. Bore out into a slot using an old drill bit and some wiggling.
  5. Tap the anchor sleeve into the slot using a cold chisel or old screwdriver.
  6. Remove the anchor from the hole. This may well need some jiggling about or a bit of extra chiselling. If possible, screw a bolt into the sleeve to aid extraction.
  7. Fill hole with resin or drill out for the installation of a new resin anchor.

Shown with a SPIT 12mm self drilling anchor:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SPIT 12mm self drilling anchor that had sheared off in a previous test:


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Another SPIT 12mm self drilling anchor that had sheared off in a previous test:


 

 

 

 

 

 

 

 

 

 

 

This removal method works well once you’ve had a little practice and was far less destructive or time consuming than pulling the anchors out with the HAT-28. I also used the same method successfully to remove 10mm lipped sleeve anchors as well (HKD / drop-ins etc…) although have no photos.
As I was drilling so close to the sleeves, occasionally hitting them, this was very hard on drill bits. I melted the head off my cheap 7mm half way through and swapped to the 6mm bit. I’ve just ordered some quad tipped bits from Hilti in the hope that they are tougher. I’ve only ever destroyed one of them in the tough welsh rhyolite of Parc mine.

The remaining triangular hole can then be cleaned out and filled in using an expired resin cartridge with some limestone dust thrown on. It won’t disappear 100% but will be a huge improvement over the old rusty sleeve.
If you plan on re-using the hole for a new anchor, try to position your slot to the intended orientation of the head of a ‘P’ style resin anchor. Once the anchor is placed, make sure the whole hole is filled with resin leaving no voids. You can’t use the SPIT resin vials for this job as they have a set quantity of contents, you will need to have a resin cartridge gun to fill the irregular hole properly.

I hope to begin removing some of the decades of old sleeve anchors in sites now resin bolted and potentially earn some karma points back for anchors of this type that I myself have placed in the past prior to my ‘enlightenment’.

Thanks for reading.

Coiling Caving Ladders

Caving ladders are an integral part of the LCMLA Level 2 award. Being practiced with a ladder not only saves time but lots of faff. It can be hard to pack loosely coiled ladders into tackle bags, meaning they get dragged and thrown about the cave, something that no kit really deserves. Practice coiling your ladders and look well polished on your assessment and in front of your clients.

Struggling with ladder coiling? Collar me for a face to face demo or contact me.

Review – Petzl Club, semi-static rope

I had an email about a month ago from Shaun at Hitch n Hike. He’d been sent a 70m sample rope from Petzl to evaluate and once it came out of the box and he saw the colour, he knew who to call.

20151215-0000 Club 10mm pt1This rope was a 70m coil, sold in an un-shrunk condition. Rather uniquely I think, Petzl will be supplying this rope with an additional 10% of length over the advertised sale length. This is to ensure that the shrunk length is not shorter than the labelled length. So if you buy 70m, you receive 77m.
20151215-0000 Club 10mm pt2There are no sold prices advertised as yet but a conversation with Shaun indicates that this rope will come in a little below the similarly spec’d Beal Antipodes 10mm which is so popular as a caving rope.
We opted to reduce the 70m length to a 25m and 45m, both of which were of course 10% longer pre-shrink due to the generous measuring of the manufacturer.
I washed and shrank the rope before allowing it to dry naturally as per usual preparation methods.Petzl Type A rope

The rope is a fierce shade of orange and in the hand feels supple and easily knotable. This characteristic made for pleasant use and did not deteriorate with a month’s heavy use. It was used in SRT rigging and group management with Italian Hitches and was easy to use in all knotting applications.
The feel is quite like a floating rope as seen in throw lines, sort of hollow. Although a normal kern-mantle construction, the rope would compress down flatter as it moved over karabiners and more importantly, through a Petzl Stop. I don’t have a brand new Stop but it could not be described as heavily worn. The rope crept through the Stop in most applications, including haul and belay. I did have the opportunity to abseil using a Petzl Pirana canyoning descender and found it was a really nice abseil. I suspect this rope has been designed more with those type of descenders in mind.
The rope gets pretty heavy when wet but the water does not adversely affect the handling, certainly no more than any other. It’s been dragged through mud, slate dust and water and still cleans up well.
The rope packs into tackle bags well due to its suppleness but it this does cause a problem for SRT. It does not push well through ascenders and requires some manual feeding at times when a stiffer rope would be pulling through on it’s own.
It does feel quite heavy for it’s size. I’m sure on paper it won’t be much different from Beal or Mammut equivalents but to me it felt heavier than most of my other ropes of similar lengths.

Over the last month the rope has been used as an SRT line, Level 1 handline and belay rope, a ladder lifeline and as a hauling line for rescue. It has been used by me, friends, other instructors and course students.

I like this rope. It is nice to handle, bright and has a good feel. I won’t be purchasing this line for SRT, it is not the right rope for that. I think this is a rope designed for canyoning, where descents are done on figure eights and not generally assisted breaking descenders like Stops. I’d own a few lengths for group work through. It’s nice handling and tough feel would make it a pleasant Level 1 rope. In summary, this is nice stuff but perhaps not as an SRT caver’s rope.

Pulling SPIT anchors – Back garden test

This week I thought I’d embark on a little back garden test of some brand new SPIT self driving anchors and some SPIT Grip 10mm sleeve anchors. Both take a normal M8 bolt and hanger and can be found in caves and mines across the UK. The Grip sleeves are placed with a drill and only require a 10mm hole, the caving SPIT sleeves can be placed with a hand driver or drill/driver combination in a 12mm hole. Recently there have been discussions about potentially removing superfluous spits in some committees. The idea being that any old ones could now be removed where resin bolts are installed nearby.

I made a quick trip to the Hitch N Hike emporium of shiny things and located a lump of suitably good limestone to transport to the back garden. I set a number of each SPIT anchors into the limestone using the standard installation method for each. For testing I used my freshly calibrated Hilti HAT-28 unit attached directly into the sleeves via a hardened M8 bolt.

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Bolt 1, 12mm:
This didn’t make it as far as the testing. Unknown weaknesses in the boulder cracked open as I was hammering the bolt home and the placement failed. Annoying but it does serve to highlight the issues of using any expansion anchor, especially shallow ones like these. Another tick in the ‘for’ column for resin bolts.

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Bolt 2, 12mm:
A normal placement in a better part of the rock. I tested this by adding force in 4kN increments until 15kN was reached and the bolt started to slowly extract from the hole. Every time the force increased beyond 15kN the bolt pulled a little further out until it ultimately was removed intact from the rock at a little over 15kN.

Bolt 3, 12mm:
A normal placement as with Bolt 2 in good rock. Force was applied in the same way as before up until about 18kN when a small cracking noise was heard. I very gently increased the load expecting the cracking might be the limestone surface under the metal legs of the puller. At 19kN the bolt let out a loud crack and the tester jumped free of the block. “Great” I thought, it pulled out. Nope. The SPIT sleeve sheared about 15mm from the top, the remainder remaining set in the limestone block.

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This was a first for me and I came to a couple of possible conclusions.
1: The sleeve was defective and the break was a freak occurrence.
2: The bolt I used was not screwed far enough into the sleeve and as such mainly applied force to the top section of the sleeve.

Bolt 4, 10mm:
This anchor came out very quickly. The bolt was extracted intact at 5kN. On later inspection the internal cone had not been driven to the full depth, perhaps 6mm short of the end of the sleeve. I suspect this made for a poor expansion in the hole and hence low removal force was required.

Bolt 5, 12mm:
As for Bolt 3, this sheared in the hole, leaving over half its length still in the placement. It sheared at 20kN. I suspect that a longer bolt would give a different result for this type of test. The bolt used was tightened to the same depth as a standard hanger plate attachment would have been when in normal use. The next test would use a longer bolt.

Bolt 6, 12mm:
A longer bolt was used to test this placement. The bolt was screwed in until fully inside the sleeve but not tightened as I did not want to begin to force the cone out the back.
This test did not result in bolt failure. The sleeve was extracted 1mm from the rock as the force reached 18kN and at 20kN was still holding strong at that position. This is the maximum force the HAT-28 can apply.

Bolt 7, 10mm:
This sleeve had it’s cone driven harder when setting, to the point that the sleeve began to push into the drill hole slightly. The tester removed this bolt from the rock at 9kN and it came out intact. The cone was found to be 4mm from the end of the sleeve.

Bolt 8, 10mm:
This bolt was set very hard indeed. The cone was pushed completely into the back of the sleeve with some serious hammering force. The cone was 3mm from the back of the sleeve. This bolt was extracted at 13.5kN and came out intact. The rock around the placement failed as the bolt was nearing full extraction.

Summary:

Bolt 1 12mm no result
Bolt 2 12mm extracted at 15kN
Bolt 3 12mm sheared at 19kN
Bolt 4 10mm extracted at 5kN
Bolt 5 12mm sheared at 20kN
Bolt 6 12mm no failure at 20kN, 1mm of extraction
Bolt 7 10mm extracted at 9kN
Bolt 8 10mm extracted at 13.5kN

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Conclusion
Nothing can really be drawn from that info as it is such a small sample. The main learning points I have taken from this are:

  • 12mm sleeves may shear when a bolt is not inserted fully.
  • 10mm sleeves extract at lower forces than 12mm sleeves.
  • 10mm sleeves must be driven home very well to make their higher strengths. This is not always possible as the sleeve can be pushed into the drill hole if not drilled to exact depth*.
  • All shallow expansion anchors can cause the rock to crack near the surface and no placement at this depth can be 100% guaranteed until the cone is set.
  • There are big variations in the extraction forces which depend on many variables during the installation..
  • No sleeve anchor can be removed with 100% certainty meaning that they will likely remain in the walls of the cave or mine forever.

*One of the selling points for this type of anchor sleeve is that they have a lip to prevent them slipping into over drilled holes.

I’ll be doing some further testing soon and will be taking the rig to some corroded anchors already in situ for a more real world test.
Finally, please consider not using SPIT sleeves or any other brand in places that get high traffic or will likely be resin bolted in the future. They will litter the cave wall forever (as can be seen in places like Garlands Pot and P8). A resin bolt can be removed and the hole reused. A 12mm through-bolt can be over drilled and hit into the hole and covered with resin. SPIT sleeves are likely visible forever.

Can you cut rope with a household jet washer?

After the last blog post where I tried to compare washing a caving rope in a washing machine to jet washing I thought I’d try to see how much damage I could do to a rope with a jet washer.

This photo was from the previous test where I exposed the rope to a full power, fine jet for approximately 30 seconds.OLYMPUS DIGITAL CAMERAI could not see any evidence to say that the rope had been damaged by the jet wash exclusively. The longer fibres shown here could have been the result of the already cut fibres in the sheath (short cut sections showing) being forced out from under another braid. Of course, the damage may be down to the jet wash alone. I think the only real way to progress with this test is to take a piece of brand new rope and jet wash it. I don’t have any laying about right now so I did some more testing with the leftover Beal Antipodes 9mm from the previous testing.

I split the rope down into various grades, from single bundles to cotton size filaments.Anatomy of a ropeI hypothesis that the worst case scenario is a rope being jet washed up against a solid surface whilst under moderate tension. The tension would keep the rope in the jet longer and the solid backing would provide a surface for the fibres to be crushed against or even abraded. It had occurred to me the damage could come from the power of the jet rubbing the rope against a course material.
The backing for this test was a piece of porcelain tile, almost completely smooth to the touch. The tile sat between the rope fibre and the wood in the test device I knocked up.Test assembly v1I tested each size of bundle on both full power and the normal setting that I use for washing. Both jet setting were fired at point blank range into the fibres for 60 seconds. This test was repeated at least twice for each sample after it was checked close up.
This sample had been washed on high power/very tight jet for 120 seconds. The jet was directed at the same area of the sample for all the test time. For scale, the fibre here is about size of that very tough cotton used for stitching canvas and kit bags together.One strand

The fibre bundles became so small that I could easily break them in my hands. This one was no bigger than a piece of cotton.Cotton thinkI figured that if my jet wash could not cut through a piece of sample that was thin enough to break easily with my hands then I did not need to progress onto smaller samples.

Conclusion?

As before, I need to state that this back garden test does not give a statistically sound result and as such only serves to show what occurred in this one instance of testing.

I could not get my jet washer to cut any size of sample on this test. In both high power/confined and low power/wide spread modes, I saw no damage to the rope fibres. No doubt individual filaments of the fibres may well cut very easily but they break with the slightest of effort in the hands anyway so I doubt the value of that observation. The cotton size sample was the smallest test size and even that could be broken by hand with little effort.
It is also worth noting that this experiment was done on a 7 year old rope that had seen high use in very abrasive environments over its life.

Challenge

I’d really like for other cavers to go out and try this experiment for themselves. Take a small piece of old or new semi-static caving rope and split it down to various sample sizes. Use a domestic jet washer / pressure washer on it’s highest setting and see if you can cut or damage the sample. For consistency, do it in 60 second, point blank range bursts.
Let me know via the contact address on my website or via the thread on UKCaving what happens. Failures to cut are just as important as actual cuts, so let me know either way.

Thoughts on jet washing caving ropes

I thought I’d ponder a little bit about the ‘myth’ of jet washers and caving ropes. I say myth because it appears that there is no real test data out there in the caving community. Recent caving forum discussions about jet washing happened to coincide with an associate company requesting we don’t use jet washers on their kit earlier this week and the two events spurred me to type something up.

Disclaimer – This is not a scientific, empirical experiment and you should always follow the care instructions of the equipment manufacturer.

I have used all sorts of methods for washing ropes over the years and most of my older ropes have been subjected to each at one time or another. Some times a rope may simply get dunked in the stream by the cave, other times I see fit to pull it through my home made rope washer but, more often than not, I get the jet wash on them.
The jet wash is always set to its lowest power and widest spray pattern. I’ve caused real damage to wood and clothing before by using the jet wash on full power so I am cautious. Some site this as the reason you should never use a jet wash on ropes. I agree. If you don’t know how to wash with a jet wash don’t do it. That, and if you don’t know how to operate your washing machine and it ends up on a boil wash, you probably shouldn’t put your ropes in there either.
This Beal 9mm got a super fine jet of water for about 30 seconds at point blank range in a test today. Damaged Rope

Apart from being incredibly clean for a 7 year old rope, you can clearly see the elongated sheath fibres. I’m not convinced the jet wash cut any fibres, more that it simply forced the already cut and abraded fibres out from under the other braids. The core was not exposed. I’d not want to do this to my ropes ever but I would call it far from ‘cut’ or ‘shredded’ as some anecdotal tales from the web recall.

Moving on. The rope I chose to retire was a Beal Antipodes 9mm semi-static that I purchased in 2007. The rope was one of my main users for 3 years as a 40m before being cut into 2 shorter lengths for cave leading handlines and general Italian Hitch duties. For the last 2 years it has languished unloved in the shed and has been the subject of much abuse in non life-critical applications. It’s probably not been washed for a year but before that it saw regular jet washing and stream dunking.

I cut the length in half and removed a control sample from either piece. The two 1m control sections came from the very end of the rope, where it was marked, and roughly half way along the 20m length respectively. I single daisy-chained one 10m length and double daisy-chained the other.

Test rope setup

The 2 longer lengths were soaked in cold water for 10 minutes as a pre-treatment.

As this was happening I cut open the 2 control lengths for a comparison.

End of rope section:Mid rope inner sheathEnd reel control Mid rope section: OLYMPUS DIGITAL CAMERAMid rope inner

The 2 samples looked very similar and I’m happy to say, despite years of being jet washed, were relatively clean and un-abraded inside. The fluffing you see was caused by the cut into the rope.

I dropped one of the test lengths in the washing machine. I set it to ‘delicate’ on a cold wash with no spin after first running a rinse cycle to clear any detergent. It had a 62 minute wash time.
While this was going on I jet washed the other test length in the same manner I do all my ropes. The process took approximately 5 minutes and once complete the rope was allowed to drip dry until the washing machine had completed it’s cycle.

After washing After washing

In both photos the washing machine cleaned rope is at the top and the jet washed one at the bottom.
I think it’s clear to see from the photos, and certainly was in real life, that the jet washed rope was far cleaner than the machine washed rope. It also had a much suppler feel and was more knotable over all. Remember the ropes have been identically treated until this very last wash in this test.ComparissonThe rope on the left is the machine washed and the one on the right has been jet washed.

It is hard to draw conclusions from the comparison here as this is only one wash cycle. The jet wash seemed to get the better results in terms of appearance and suppleness but the internals of the ropes looked very similar.
The one thing that I do take from this test is that despite the differences in the test washing, all the samples from this rope did not show any appreciable abrading of internal fibres from grit ingress. The anti jet wash argument is that the force of the water pushes grit into the core, causing damage. What I observe here is that this is an incorrect assumption as the 4 sections of visible inner on this very old, well used and heavily jet washed rope show no signs of damage by internal abrasion.

My theory is that the jet washing forces the grit and mud through the core and out the other side of the rope, as opposed to moving it into the core and it magically stopping there. I always clean my ropes after each trip. Perhaps they simply do not stay dirty long enough for the grit that does enter the core to be damaging. The outer sheath shows far more wear and damage than any of the internal structures of the rope.

I continue to believe that regular low-power jet washing does no harm to my ropes. I do know that some manufactures do not suggest using a jet wash on ropes and you should make your own choice with reference to the manufacturer’s guidelines. I will continue to cut open ropes as they are retired and will update this blog should my opinions or observations change. Meanwhile, if there is anyone out there prepared to take this subject up for a dissertation or just for interest then get in touch!

Gleistein GeoStatic NE 9mm rope – 18 months use

It’s now March 2014, about a year and a half after I bought my first length of the Gleistein Geostatic 9mm rope.
The 31m length I bought was soaked at home and measured to 32m, no doubt down to Shaun at Hitch N Hike’s generous measuring style!
I labelled it up as a 30m and went about using it.
I re-measured it today and it came in just over 29m, a shrink of 3m since initial cutting, approx. 9%. So it seems, just like any other rope, once it’s cut you still need to factor in about 10% for shrinkage over the life of the rope. I’m still happy because there was no noticeable shrinkage after cutting and soaking when first purchased in Sept 2012.

I have a 21m length bought about a year ago that has just re-measured to 19m. This length has had a hard life already, it is my traveling rope on cave leading work and has been dragged through numerous Italian hitches whist being covered in grit and the particularly abrasive mud in Peak Cavern’s trade routes. It has done a good job at sawing through my alloy krabs but the rope itself is still in excellent condition. There is some light fluffing on the sheath comparable with some of my far less used ropes and the colour, like the 29m length, has faded into a more pastel orange. It still handles extremely well, clearly not as supple as when new but a massive improvement over the 2-3 yr old Mammut 9mm I have, which is more akin to wire cable now.

My cleaning regime for all my semi-static ropes is simple and it gets done after every trip. For clean trips it is just a spray with the hose or a dunk in clean water to remove particles from the surface. More often than not it gets a low power jet wash (controversial I know!). Never force dried, only hung in a spare room or over the bath.

I’ve got 3 lengths now, each bought about 6 months apart and will continue to purchase this rope as my current ones approach retirement.
In another year and a half, when this rope is no longer in service I’ll do a final post mortem report. I’d also like to send a few samples to be tested by the BCA and Bob Mehew to see what toll the hard life has taken on it.

Gleistein is still available at Hitch N Hike as cut lengths or entire reels: http://www.hitchnhike.co.uk/acatalog/gleistein-9mm-geostatic-ne.html

The initial blog post is here: http://www.peakinstruction.com/blog/first-look-at-gleistein-geostatic-ne-9mm-semi-static-rope/

2013 Petzl Croll & Basic review

I’m a self confessed gear junky. I love to play with shiny things and we all love a rope trick or two. I also like looking good when I work, image is important as a first impression can be the difference between a days work and no work. All vanities aside, I think that a professional instructor should be equipped with the most up to date equipment available and of course the knowledge of how to use it! You can imagine how excited I was to read that Petzl were planning a re-release of the Croll and Basic early 2013. I was also mildly worried as historically there had been little change to the design of what was arguably an already excellently functional pair of products.
I managed to get my hands on one of the new Croll ascenders as they hit the shelves and have just acquired a new Basic literally as Hitch N Hike unpacked their shipment from Lyon.
I’ll start with a look at the Croll.

2013 Petzl Croll

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Like the Basic, the last major design change in the Croll was when they went over to plastic safety catches from the metal ones. Since then we’ve only seen some small cosmetic tweaks. As you can see above the the 2013 Croll (right) is a complete redesign on the previous model. It looks as though Petzl have done a ground up redesign with a completely new set of parts and with an eye on size and weight.

The previous versions of the Croll weighed in at 130g, the 2013 is a featherweight 90g.
Usefully, the 2013 Croll is small enough to stir your coffee with if you are unable to find a spoon nearby.

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The safety catch although small is easy to operate, one handed installation and removal from the rope is just as easy and smooth as prior versions. With the cam being smaller a shorter action is required to disengage the safety catch making the process faster but in no way less secure.
The attachment holes are well sited and allow the Croll to sit flat. I have used mine with a Torse chest harness and found they make a perfect combination, as I’d expect from 2 products from the same manufacturer. I’d recently had issues with an Anthron AC-30 chest ascender as the use of a Torse interfered with the clean running of the rope.
The main change apart from size is the addition of a stainless steel plate inside the rope groove. Although it does not cover the entire rope contact surface it shields the frontal portion where most heavy wear is generated as the user leans back on ascent. The stainless steel insert should improve the lifetime of the 2013 Croll, especially for cavers operating in digs or where there are a lot of fixed, gritty ropes.

I had a test of the Croll down Oxlow Mine recently and we used a mix of rope types and diameters, some very supple and some stiff and fat. After the initial bit of step and pull, the rope runs as smoothly through the Croll as it ever did, with no twisting or feeding issues.

In summary then, in producing the 2013 Croll, Petzl has taken a much loved and hugely popular item of equipment and completely redesigned it. A bold step but one that appears to have completely paid off. Petzl’s updated documentation for the Croll can be found here.

2013 Petzl Basic
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The 2013 Basic is the newest piece of kit to hit the shelves from Petzl. Just like the 2013 Croll it has had a complete redesign. I will probably sound a bit like a parrot here repeating lost of stuff from the Croll comparison but I’ll be as brief as possible.

Again the Basic has been on a diet, dropping from 135g to a skinny 90g. If you were to make the switch from the previous jammer versions to the 2013 ones you’d save a total of 85g, that’s the equivalent of a 3rd jammer in your pocket. You could even stop your New Year diet 0.19lbs early or not feel guilty about bringing that extra bag of Haribo underground.

Just like the 2013 Croll, the Basic has shrunk. Perhaps not to the same degree as the Croll but the unit feels noticeably more compact in the hand, not to mention comfortable.

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The upper section of the Basic is now fitted with a gentle curve and a matching section of plastic. These changes fit my hand like a glove, feeling comfortable with a left or right handed grip. I may however find it a little harder now they are so easy to hold to coach efficient technique with out over reliance on arm strength.
Another big change is the loss of the double hole at the top. In the past we have been able to build pulley-jammers or mechanical advantage SRT systems by placing a karabiner through the top holes and capturing the rope. This is no longer possible on the 2013 version but have no fear, Petzl have thought of that and given us the solution.
The new lower attachment point is double size, allowing 2 karabiners to be clipped in.

The previous version of the Basic allowed us to clip into the top attachment holes for use in tyroleans, pulley systems and rescue:

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The 2013 version allows us the same versatility but with a simpler, single attachment point:

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The only use that the Petzl documentation indicates for the top attachment hole is to add weight to help reset a z-rig hauling system. You should probably read Petzl’s documentation if you don’t understand that.

The final big change to the use of the Basic is involving pulley-jammer setups, the kind of hauling and rescue technique that an instructor first learns. The new advised method is arguably simpler to arrange and easier to learn. It does however require an extra krab over the previous method.

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I intend to spend some time hauling weights on this arrangement but I really expect no loss in function over previous techniques.

Although it may take users a little while to adjust to the new method of use, I think that the 2013 Basic is a good addition to the Petzl family and combines nicely with the Croll to shrink both the size and weight of the average SRT kit. I think that I could remove my new Basic and 8mm footloop assembly and put it in my pocket between pitches.

One moan (well it can’t be all singing Petzl’s praises), bring back the bright colours! I love my new Basic but I know that one day I’ll drop it in a puddle or sump whilst I’m sorting my harness out and because of its stealth colour I’ll not be able to find it again. Give us a choice of tactical colour for the bandit runs and military users but lets have some red, purple, orange or lime greens for the people who don’t wish to blend in!

Final Thoughts

Interestingly, neither the 2013 Croll or Basic are listed as having a breaking strength or working load limit. The closest we get is the advice that for industrial users Petzl do not recommend the use by anyone over 100kg.
I think this reflects the attitude where the jammers are not placed in situations that require them to hold more than a person’s weight and high load scenarios like traverses and rescue have specialist rigging kit. The issue we may have with this is in a spare rope rescue scenario where we pick off a caver from one rope and accompany them to the floor on another rope attached via a Basic or Ascension jammer. Petzl has an online tool to advise people over 100kg how to use the equipment and that appears to show that correct use of a Croll (i.e. no fall factors!) will be fine with larger loads. For an Ascension it suggests increasing the shock absorbency of the attachment point, i.e. using a dynamic safety link or a cowstail as is widespread in Europe.
I’d still like to see some figures from Petzl for 9mm and 10mm rope to confirm that we can continue to use the Basic in the above way. I don’t expect any loss of strength but it would be comforting to know for sure.

Finally, with all this lovely new lightweight and compact kit coming to our shores, when can I expect a nice redesigned Stop descender?