The deadly croll

[David Rose]

SOME Petzl gear - probably almost all - is almost certainly fine. It would take a lot to persuade me to dump my Simple descender, for example.

But as a firm, they have not handled the Ecrin Roc or Croll issues well.

 

[Simon Wilson]

If you search for Petzl Croll on Amazon you will find that there are plenty of shops selling them for ?32.

 

[ZombieCake]

Maybe there'll be a new product line? Instead of a Croll you could have the "Psycho Rope Slasher", a Basic ascender might be "The Sphincter Tightener", the Fractio "The Brown Trouser Harness", and the Stop "the Strawberry Jam Splatter"

 

[Pegasus]

Maybe there'll be a new product line? Instead of a Croll you could have the "Psycho Rope Slasher", a Basic ascender might be "The Sphincter Tightener", the Fractio "The Brown Trouser Harness", and the Stop "the Strawberry Jam Splatter"

....and they'll all be really, really tiny   

 

[ZombieCake]

Yes, it's an integrated system:  As you push the ascender up the rope there's the almost imperceptible click, click as the teeth ride over the rope strands.... will it work or turn to PlayDoh?  Then you stand up and wonder if the rope will get sliced - that's where the harness comes in.  Then there's looking down when you feel some resistance in the jammer and might want to change over....
Think I might get into the ladder business 

 

[ian.p]

Does anyone know how we could raise this issue at the next bca committee meeting it occur s that this would be a worthwhile issue for the equipment and techniques comite to investigate and engage with petzl over a national representative body will have some clout one would hope

 

[Mark Wright]

Before we think about making another BCA official statement, can I offer my two penneth.

There is no doubt that the new style Croll wears out a lot quicker than the previous models and Petzl are fully aware that some are not happy with it.

But how long should we expect them to last? This thread prompted me to do a thorough examination of my gear, the Croll in particular. Not that I don?t regularly examine my gear, I do, usually after every trip.

My croll was manufactured on the 25th January 2013 and it?s done about 4,000m of ascent on generally dry 10.5mm and 11mm rope. I use the traditional ?Frog? technique with both feet in a single foot loop with the rope running between my feet. I don?t use a Pantin. I tried but just didn?t get on with it.

About 1,000m ago my Croll started slipping, occasioanlly quite worryingly. If I were doing a PPE examination in the workplace, it should be carried out in accordance with the recommendations of the manufacturer. Under that criteria I should have retired my Croll from service after +/- 3000m, about 3 years in this case.

Anyway, I decided to ignore the inspection recommendations of the manufacturer and carried on using it for another 1,000m and as a result I had some very worrying moments coming out of the Berger a couple of weeks ago. On one occasion it slipped about 0.8m before engaging, frightened me half to death. I could probably eke out another 500m but who know?s what might happen.

It has now been removed from service.

The stainless steel wear plate has only a very slight groove near the top and there is a 0.5mm groove in the lower part of the alloy body and on the bottom of the lower attachment hole there is about 2mm loss of material (burred over). I use an Omni Triact.

The wearing down to 4mm of material mentioned earlier is really taking it to the extreme. Testing carried out in industry demonstrated that if the chest harness was particularly tight and there was a falling backwards, whiplash type incident onto a cow?s tail, the top hole of the old, old (pre-plastic) type Croll could break. That had about +/- 7mm of material.

We probably all take our gear way beyond the manufacturers recommendations in terms of being safe for use. I bet we?ve all seen the old, old style Crolls with their top and bottom edges worn to a razor sharp edge. How many Stop top bobbins have you seen worn to a razor sharp edge and how many rack top bars have you seen that are worn more than half way through. Most of the time we get away with it but sometimes not.

The expedition cavers who had the rope cutting incident very clearly took their equipment well beyond the manufacturers recommendations relating to removal from service.

They might not like how quickly they wear out, I don?t, but if they are embarking on a major summer expedition on 9mm ropes then I think taking a Croll that has already done 4,000m of ascent and is already slipping is probably not the best idea, some might say irresponsible. The writer of the article mentions his Croll had started slipping some time before the 4,000m. He still carried on using it though. They mention being able to get 3 or 4 times more life out of the old style, I wonder what the top and bottom adges of those Crolls looked like after 16,000m of ascent.
 
I would imagine the majority of cavers around the world do not do anything like the 4km / year and certainly not the 10km / year of ascent as posted earlier. I would hazard a guess that the average caver around the world would be doing less than 1km / year and if that meant it would last about 3 years, I  would say that?s pretty good considering how much we drag them about.

Personally I really like them and I will be replacing the old one with another. I will probably get rid of the new one as soon as it starts slipping this time though.

I don?t think it?s fair to say the Petzl Croll is potentially deadly, its fairer to say it is us who are potentially deadly when we choose to think we know better and ignore what the manufacturer recommends.

As has been mentioned, Petzl will certainly lose a bit of business in chest ascender sales, just as they did with the Torse chest harness and the Ecrin Roc helmet as people try the oppositions products. You never know, when those products wear out Petzl might have come up with something new. 

I really don?t see what any intervention from the BCA might achieve, other than possibly making us all look a bit stupid. It is the cam that wears out first and when it does it should be removed from service. If we choose to ignore the wear on the cam then there is plenty of evidence to suggest an accident might result.

Yes, lets tell Petzl that we are not happy how quickly they wear out but lets not complain about what happens to the Croll when we decide to ignore what the manufacturer says and keep on using them when they are no longer fit and safe for use.

Perhaps the BCA Equipment & Techniques Committee could look at educating people on what is an acceptable level of equipment wear and what isn't. The inspection criteria already provided by Petzl is pretty easy to follow and if the expedition cavers who experienced rope damage had read it we probably wouldn't be having this particular discussion.

Mark 

 

[Pitlamp]

To a large extent I agree with Mark, for a different reason. I just can't forget all the superb innovation and excellent products which Petzl has made for us over many years. A lot of cavers take such items for granted but those of us who remember how dreadful abseiling & prussiking gear once used to be are pretty grateful to what has generally been a reliable company (in the greater scheme of things).

Anyone remember the original "Cloggers" - which had to be completely detached from everything to be clipped on or off the rope? Or the early descenders which made the rope turn into a Nagasaki tramdriver's nightmare knot? Petzl transformed vertical caving and made it much safer.

The new style Croll is clearly very unsatisfactory but I'd be very surprised if Petzl doesn't resolve the issues and make improvements. For now, at least, this Croll problem should be kept in perspective.

 

[Smiley Alan]

mark is wright  - cavers  complane alot but  never seem to complane about themselfs .. . its like they reckon kit shood  last for ever and never need replasing .

 

[NewStuff]

mark is wright  - cavers  complane alot but  never seem to complane about themselfs .. . its like they reckon kit shood  last for ever and never need replasing .

I don't, and neither does anyone I go underground with.

Maybe some of the old boys will run razor edge bobbins etc, but we're young enough to like living (we'd all like to be 20 years younger, physically), if something needs replacing, it get's replaced, or you don't do a trip that requires it.

 

[bograt]

I tend to agree with Mark, maybe cavers are expecting too much for their money, I personally have never ascended more than a Kilometre (cumulative) in a year on a rope, so would expect the Croll to last a bit longer than someone further 'oop north' who scales GG every weekend, I consider it to be 'Horses For Courses', if you think you are going to wear it out too quickly, consider paying a bit more for something a bit heavier duty (two at ?35 each for 2x2 years is more expensive than one at ?60 for 5years).
This also illustrates the importance of keeping a good record of the 'mileage' of your hardware--.

 

[Simon Wilson]

Everybody wears Crolls differently. Two people have reported wearing out the bottom attachment which I think is very unusual.  A caver who doesn't use a Pantin will probably wear the cam out first. Using a Pantin tends to make the frame wear more and hauling loads might also contribute to this.

Petzl have always been rather vague about exactly how much wear of a cam is acceptable and in my experience most cavers in the past would use a chest or hand jammer until it started to slip. To cavers who have worn out a few jammers, slipping causes no great alarm; it just tells them it's time to get a new one.

If the bottom attachment was wearing it would be very easy to see and most people would retire the Croll in good time long before it became dangerous. If the cam wore and started to slip it would also be very obvious and most people would retire a Croll at the first sign of slippage. With earlier Crolls if the frame wore and started to look thin at the top edge you would easily spot it and a very great number of cavers will have retired a Croll for that reason long before the Croll was dangerous.

With the new Croll, if it wears at either the bottom attachment or the cam it will become obvious while the Croll is still safe. However, if your new Croll wears at the frame you can't tell how thin the wear plate is. The cavers who have worn through the wear plate and have reported it publicly have expressed alarm at the fact that they had no warning before the Croll jammed and left them 'hung up' on a damaged rope. The new Croll can fail in a highly dangerous way that no other design has ever done.

There are two very important points that some people appear to not have understood. One point is that the users cannot tell how thin a worn wear plate is because it wears in the middle of a complex curve and you can only see the front side. The other point is that when it gets very thin the 'blister effect' occurs which means that a wear plate that looks OK can wear to a knife edge extremely quickly.

The issue is nothing to do with ignoring the manufacturer's advise. The complaint to Petzl is nothing to do with the shorter life of the new Croll, although that does contribute to the problem. The complaint to Petzl is that they have produced a very dangerous design, they have failed to test it to see what will happen when the wear plate wears through and they have not recalled it when it has become apparent that their designers have made a serious mistake which has put several intelligent and experienced cavers in grave danger.

 

[ian.p]

I am not convinced by the idea of using other defects like a worn cam as a proxy for a potentially dangerous defect as simon says theres a lot of variety in the ways people wear out their crolls I've always hammered through the attachment loop at the bottom of my old style crolls before the teeth go. I also have reservations about using millage as a marker partly because its quite hard to keep track off and partly because there is such a variety of conditions that the croll could be exposed too. Given that the standard method of assessing the safety of a piece of equipment before use is a visual pre use check i think its reasonable to expect that the manufacturer designs equipment so that all of the critical elements can be adequately visually examined.
Designing for expected failure after around 3000m of prusicking means that it is very possible for a croll to go from new to failing in one expedition the user will not be considering retiring on age grounds and whilst they might have been keeping track of their mileage its unlikley therefore being able to visually examine the jammer is critical. 

 

[pwhole]

To be fair to Petzl, all their technical leaflets do state that equipment may have to be retired after a single use, if necessary, even though their metal pieces are defined as having an indefinite lifespan. Obviously that will never be the case in normal use, and most of my caving is digging-oriented, so filthy gritty ropes and heavy loads are a given really, and I would expect the gear to wear faster than a recreation-only caver, but I was just surprised how fast they wore out compared to the previous models. As I mentioned, I never saw the stainless plate wear out, but I'm glad I wore out the visible parts early enough that I didn't get that far.
And I definitely won't let the frame attachment hole get down to 4mm ever again. :chair:

 

[Simon Wilson]

I can't imagine what you're doing to wear out the attachment hole. You are using an Omni, aren't you?

 

[pwhole]

I was mostly using a steel D-maillon, which was the source of the problem, no doubt, but I was using that with the old-style Croll too, and it wore far less. I've gone back to using a Moka for the ally-to-ally contact now, but I do find it a bit cramped as a central connector. I think I may have to switch to an Omni, and keep the Moka for my Garma chest harness, for which it is perfect.

 

[Simon Wilson]

I'd say definitely get an Omni.

I just looked at the photos you posted and I notice that the top attachment is also very worn. Do you think it's grit that's acting as abrasive?

 

[pwhole]

I think so - we were digging in JH, and it was mainly mining fines and gravelly mud in both - several times we ended up suspended mid-pitch as one of our devices seized up. They always got thoroughly washed after every trip, but I just don't think they're up to that kind of treatment for long. The SRT techniques were also very rough and ready, so the frame probably got loaded more heavily more often than on normal trips. I think a larger, more heavy-duty device is more suitable, now I've had the chance to try a smaller one. I'm not sure the TurboChest would have coped with that any better, to be honest.

 

[Simon Wilson]

I'm sure you would trash a Turbochest in no time. They are beautifully engineered but can't take mud and grit.

 

[nickwilliams]

I can't issue any 'official' statement on behalf of the BCA Equipment and Techniques Committee without consulting the other members, but I can say we are watching this subject with interest.

Having said that, I think it is fair to say that we have been asked for guidance on equipment care and inspection occasionally in the past and in practice there is usually very little we can say other than 'follow the manufacturer's instructions'.

Nick Williams

BCA E+T Committee Convenor