/ BMC Live....Q+A on Gear: Ask Dan.......NOW LIVE
BMC LIve....Q+A on Gear: TODAY
Dan Middleton works part time for the BMC as their Technical Officer. Part of his job is to provide technical advice on all types of safety related equipment for walkers, climbers, and mountaineers.
As part one of the BMC Live! series of online Q&A sessions, Dan will be available at UKClimbing.com on today to answer any questions you may have about equipment for walking, climbing and mountaineering.
• Just starting out?
• Does kit ever break, and why?
• Want to know how to check axes and crampons for damage?
• Wondering whether to retire your rope or not?
Ask Dan a question!
Dan will be monitoring this thread until 10 pm tonight and answering your questions as quickly as he can. If he can’t give you an immediate reply (because you’ve got him stymied) he’ll admit it and get back to you when he can. After today, he’ll answer any further questions but can’t promise to make it snappy.
Dan Middleton UKC Profile: http://www.ukclimbing.com/forums/profile.php?id=69129
THREAD OPEN NOW FOR YOUR QUESTIONS
Sorry about that, thread now open for questions.
Actually I have a question.
If you put a force of around 450 kg on a pair of jumars on a dynamic rope, the sheath of the rope will be ripped to shreads. I witnessed this last week under test conditions at Plas y Brenin.
Are there any climbing situations where that could happen?
Hi Mick, you're absolutely right, most toothed ascenders will strip the sheath at about 450 kg. If ascending a rope using jammers, good technique maintains a position below or level the ascender at all times - never above. SRT cavers know more about this, through plenty of experience. So, avoid being clipped into a jammer with a sling and climbing up above it.
Of course, with a damaged sheath already present, say on a fixed rope, the sheath might break much more easily. An old trick here is to have a knot tied in the bottom of the rope, so if the sheath breaks it slides down until it bunches up rather than sliding off the end of the rope. It's pretty scary looking, but at least the rope is functional enough to enable you to escape.
Finally, any kind of hauling system which uses mechanical advantage to help hoist a heavy load might end up loading a jammer enough to strip the rope sheath - especially if the load gets stuck and you try to free it by cranking as hard as you can.
A recent death in Zion here.
I have asked this question to a few people, but never had a accurate/reasonable response. If a cam had 100kg hanging on it, what force is being pushed outwards by the cams to counteract that 100kg.
I have had answers from 100kg to 300kg. My guess is that more force has to push out, to prevent it slipping.
Basically the argument is not to use cams behind flakes that might be levered off by the force being multiplied in the event of a fall.
There's been the recent BMC request for info on helmets/head injuries and I also seem to remember some talk about shortcomings of the CE test programme etc. Are there any updates on the subject of helmets?
... and to add to that, my harness is about 4 yrs old too and the retainihg loops which hold the doubled back bit of the buckle strap have come undone so I have to use a gear loop to return the strap around. I guess because they don't hold any load it should be ok to just sow them up again?
Good question this one. The outward or "normal" force depends on the camming angle of the device. For Friends this is 13.75 degrees. If you have all 4 cams in contact and a perfectly parallel crack, and the force pulling on the stem is 100kg (call it 1000N), the force on each cam will be 1000/4/tan13.75. This works out roughly as 1000N outward force on each cam, or 2000N in each direction. A good explanation on cam physics can be found here http://www.duke.edu/~mak25/Forces.html
I'd say that more relevant to most situations is the fact that whether the cams slip or not is almost independent of the load (as long as the rock doesn't break). So, if a cam doesn't move when you give it a good tug when placing it, there's a good chance it'll stay put if you take a whipper on it.
We're in the process of putting together a report based on our head injury survey now. We have to be careful how we present the info, because the survey was self selecting so it wasn't an unbiased test. That said, some of the comments were pretty hair-raising - there are some very lucky people out there!
We're probably going to go from a famine to a feast as far as information regarding helmets goes. I've just recieved the latest independent BMC helmet test results, to be published soon, and the final draft of a new booklet on helmets is ready. Watch this space!
Second question, I like using guide style belaying for seconds with my ATC guide (and on my old Petzl Reverso). I normally do this off a hefty tree of which there are plenty at Finnish crags. But how much extra strain does this put on the anchor that is eliminated by belaying in the 'normal' way, i.e. off your harness?
What are your thoughts on a technique ive seen people using multy pictch climibng (abroad). When block leading the leader belays with a guide plate (reverso etc) on a direct belay and instead of moving the second off it onto a screw gate into the powerpoint anquor they leave them on it and tie a back up overhand knot in the dead side of the rope. Then the leader sorts the rope and goes on again.
Any burning issues (we'll assume the aquors are all fine and equalised)?
> I have asked this question to a few people, but never had a accurate/reasonable response. If a cam had 100kg hanging on it, what force is being pushed outwards by the cams to counteract that 100kg.
Being an engineering type, my answer for a Friend in a parallel placement would be – half the load divided by the tangent of the camming angle: 50/ tan(13.75) = 204.3 kg.
However, placements and cams vary and fall factors add up as already stated. Apply the same formula to 5 kN (Typical Fall, Figure 6.6, MLT Handbooks vol. 2) and you get 10.2 kN (1040 kg)!
Mines more of a question for beginners wanting to get into winter mountaineering. I have a small amount of experience in Scottish Winter but all was done with rented gear and now I would like to purchase my own. I have crampons already and will soon be getting some 4 Season leather boots as they fit my feet really well.
My query is regarding Ice Axes. There are plenty on the market, ideally i would like something that can tackle alpine routes but would also like to have something that could be used on more technical ice climbs in Scotland etc. I've had the DMM flys recommended to me, would this be a good starting point?
I played with some wire gates of a particular brand this weekend. They were about a year old.
On three of them, the wire gate stuck open, once when I was on the lead! I had to close it myself.
Someone suggested putting a spot of lubricant on them to make them close by themselves and springy again.
Now excuse my ignorance, but I thought the design of these wire gates was so that were actually a spring themselves.
Would a lubricant make a difference do you think - or is there some fault here with the wire gates?
I have a climbing rope 60metres, which i have had for 10 years for the first 5 years the rope was very rarely used but over the last 2 years the rope has been used outside most weekends. The rope is showing no signs of abuse. Should I retire the rope?
A 4 year old harness may be totally fine, or it may not. I've seen one harness which was dangerously worn after 1 climb: the climber had come off second best against a rough granite chimney!
For piece of mind, follow the manufacturers advice on lifetime. This varies between manufacturers, but as an example Petzl advise a maximum of 10 years from the date of purchase. This means that even if the harness looks totally fine, and has never been used, it is recommended to scrap it.
In addition, you should regularly check your harness for dangerous wear and tear. Check the webbing, load bearing stitching and the buckles. Belay loop and tie-in points take the most hammer, check these carefully. If you don't know how to check your gear, Petzl have some useful videos on their site which can give you some advice. You can also download the free BMC Care & Maintenance booklet here: https://www.thebmc.co.uk/Download.aspx?id=77
Dangerous chemicals, such as acids will damage your harness and may not cause visible damage. Keep your harness away from them - what did you have thrown in the boot of your car last week?
Lex, if your sewing is up to it, then resewing a non load bearing part such as a retaining loop should be OK. It won't damage the webbing. Bear in mind that any kind of home repair will invalidate any warranty though.
Ice picks first: Modern heat treatment has brought noticeable improvements to the quality of ice picks. They tend to bend rather than break, which is a good thing! If the pick has bent, it has deformed plastically, so it may have work hardened and become brittle (like the old bending a spoon until it snaps trick) Whether the alloy used is susceptible to this I don't know to be honest. I expect BD would tell you to replace it though! For 30 notes, personally I'd replace it and sleep easy.
Guide plates: normal belay devices are effective load limiters - the rope slips through if the force becomes too great. Guide plates lock and pinch the rope - I haven't seen any published tests on what happens if you take a decent fall factor onto one, but I can't imagine it doing the rope any good! If the leader was to fall off just above the belay and the belayer was anchored using a tied off guide plate, you could be in serious trouble. I've personally used this method in the Alps, but clipped into the powerpoint with a sling to my harness - it takes 30 seconds.
Again, as far as forces on the anchor go when belaying seconds, there are two factors. The lack of a dynamic belay or slippage will increase any forces, but also not being part of the belay has a big effect. If the belay is dodgy, the human body can act as a very effective force damper - think old school winter belaying. By belaying direct you remove this from the system. It's hard to put figures into systems which have so many variables, but the basic rule is, only belay direct if the anchor is unquestionable.
Just a quick bit of advice r.e boots and crampons: always try to buy your boots first then your crampons. Otherwise you may end up having to compromise on the fit of the boots in order to get boots which are compatible with your existing crampons - it often comes as a shock that crampons don't always fit boots which on paper they should.
Ice axes: it really depends on what you plan to do. The ideal axe for alpine mountaineering and winter travel will be comfortable in the hand, and have a curved pick for optimum self arrest. For technical climbing, you want a reverse curve pick and perhaps a bent shaft etc. If you want one pair of axes to do everything, prepare to compromise! A trend which seems to have passed is curved picks for modular technical tools; a shame in my opinion. To get to the point, if choosing a technical tool to use as a classical mountain axe, something without a massive grip or trigger rest will plunge more easily into snow, so a simple light axe like the Fly would be a decent choice.
Well Mick, don't cry - I bet a climbing superstar like you got them as "review samples" anyway!
I'd try a spot of lube anyway, but it does sound as though there is a problem here. Any krab, wiregate or standard, should be retired if the gate spring doesn't close the gate. If a bit of cleaning and tlc doesn't fix it, bin it. Gate open strengths of krabs are only around 1/3 of closed gate strengths: a sticky-open gate is a recipe for disater.
So is that Double the force (pauls figures) or quadruple (Dan's).
Either way thanks for your time, and detailed answer.
The manufacturer will probably tell you to retire the rope after 10 years maximum, assuming minimal use and despite the rope looking fine. As the rope is such a critical part of the safety system , why go against this advice? After 10 years you've probably had your moneys worth! Chances are your rope is fine, and might last for a while longer, but why take the additional risk when climbing is exciting enough as it is?
There was a UIAA sponsored investigation into ropes, slings and tat taken from belay points in the alps and tested. The results were very interesting as i remember and seemed to go against some commonly held beliefs about uv radiation and kit. It might have been material specific (slings, webbing and ropes can be made out of different materials), i can't remeber do you have a link to an online version?
Also i remeber reading a study done into ropes that had been soaked in various liquids that they could come accross, surprisingly if i remeber rightly the rope soaked in petrol was unharmed from a strengh point of view but the rope soaked in pee (body temp was worse than room temp pee) was allarmingly weakened. Again, do you have a web link for the report?
Hi Dan just wondering what you think of the fairly common practice (in euroland) of using the reverso etc. in autoblock mode using a snap gate for the rope (but of course screw gate for attaching the belay plate to the anchor).
i guess the reasoning is that the rope biner is not load bearing so you could get away with it.
personally i don't see the problem with 2 screw gates from a weight point of view, plus it makes it easier to change over to a waist belay once the second is up.
One important point to consider: don't think that just because ropes seem to be fairly indestructible that this applies to everything else. I'd trust rope tat much more than tape, because with tape all the load carrying fibres are exposed to the surface. I'd still not trust anything, rope or tape, if it was badly worn or faded.
Not sure how relevant this question is, but it appears to me from videos that gear is generally tested on rigs that apply an increasing load until failure, rather than a sudden shock load. Would a shock load introduce any other methods of failure etc? Is it a fair test?
Also, does age reduce the strength of metal work significantly
Obviously I'm not worried too much about failure as there seems to be plenty of spare strength in krabs etc.
Next year I'm going to be the Gear Sec fo my uni mountaineering club (Kings College London). I had a look in the gear locker last week and there is LOADS of what looks like antique gear! Old school crampons that look like they're made of mechano. 60s/70s scottish axes, old school quick draws, ropes, tents etc. That leaflet (https://www.thebmc.co.uk/Download.aspx?id=77) looks brilliant, I'll read that.
But main question is: any gear that we decide to get rid of, can it be recycled in any way? Scrap metal/Museum antiques?! Or just bin it?
If there is anything that might be of historical interest, get in touch with http://www.mountain-heritage.org/ as they would love to hear from you. For more tips on recycling and green climbing, there are articles in Summit 52 and the soon to be published Summit 53 on this.
I'm sure that Dan won't mind me stealing his thunder by chipping in...
One tip is that the crab you put on the back should be a crab with an I beam profile rather than a pure round cross section crab for two reasons.
1. if you want to lower a second who is weighting the rope and locking it you can 'pump' out slack far easier with a crab that is not a smooth round profile.
2. a round crab at the back was thought to be a factor in a failure to hold a fall on icy ropes when used in direct mode by a brit guide guiding an ice fall.
hope this helps
There are some factors which are affected by the speed of testing, but these are generally not significant. For materials which are noticeably rate sensitive such as webbing, a loading rate is specified so that there is a level playing field when testing.
Sometimes the engineers do get caught out; a good example is the discovery of gate flutter during dynamic loading. No amount of static strength testing would have helped discover this. The solution, however, still involved static testing: the gate open strength requirement was simply raised.
Age in itself isn't too much of an issue for metal items - aluminuim alloy krabs will probably get stronger but more brittle over time. Some manufacturers now give an indefinite lifespan for metal components; this means that wear, corrosion and loss of functionality (gate loses its springiness etc) become the main reasons for retirement.
Ooh! Send me some pics, I might recognise some from my time at Kings! (Geology, 1985!)
Just a quick one, I'm aware of the damage that bolts can do to gear-end karabiners and thus to keep them well away from ropes. Does the same apply for slung gear such as cams and hexes? Can slings be damaged significantly enough to fail by bolt-damaged karabiners?
I just had my first eperience climbing sea cliffs this weekend. Amazing! Most of are gear got at least a bit of spray on in and I was wondering is this going to cause any damage and should I take any precausions or wash all my gear now im home. Esp. the rope. Also if you or anyone reading this has any advise on weather to wash a tent that has been exposed to sea water please give me some feedback. Thanks so much for your time.
I hope you enjoyed climbing on seacliffs - the UK is probably the best place in the world for this type of climbing! To keep your gear in good shape, chuck it in the bath full of cold water or rinse it under a tap, then hang it all up to dry naturally. Moving parts might need a little oil - follow the manufacturers advice and wipe off any excess oil. Sea water on its own won't damage your rope, but often contains sand etc, which can abrade the rope from the inside.
It's a good idea to clean your rope any time it gets dirty, sandy etc. One of those rope brushes is a worthwhile investment - use the bath again and some rope cleaner (Ecover works well too!) and run the rope through the brush a few times. You'll be amazed how much crud comes out after a few months of climbing time.
A couple of my cams have bits of grit and general muck in the workings and arent running as freely as they once did. I have brushed away the loose stuff but some is still in there. Is it ok to use WD40 or similar on them?
Also I have one cam where the cable seems to be twisted or kinked in some way. The end result is that when the cam is not being used the heads arent lined up properly, one head is a bit higher than the others. Is this likely to be a dangerous thing or just an annoyance?
For an upcoming Nepal trip, I have picked up a pair of HA Vegas. I already have Grivel G12 crampons, but due to the "roll" on the sole of the Vegas, the front of the boot doesn't sit flush on to the crampons - there is a small gap. Is this likely to cause any problems in use?
I have a female friend who wants to climb with me. She says she'll bring her own rope, its about 100ft long and made from 'natural' materials (apparently it is plaited). She says that a fella called Prince scaled it up the side of a building...... am i right to be wary of her rope or should i just go with it?
...that's funny, nice one
A good soaking in warm water and detergent should help. Operate the trigger mechanism and try to get as much dirt as possible free - on old toothbrush can be useful. Then rinse in cold clean water and let it dry. You can apply some WD40 or GT85 around the axle, make sure you wipe away any excess oil to avoid contaminating the textile sling. This should do the trick.
You may find that one of your trigger wires has slipped and is a little misaligned. Feeding a liitle through the trigger bar and straightening any kinks so each side is evened out may help. Badly kinked wires do tend to break eventually though - take care when stuffing your rack into your pack as you race to catch last orders! It's not dangerous though - as long as you place your cam properly it will just mean that the trigger bar will sit unevenly. There's more comprehensive info on looking after cams and the rest of your gear in the free Care & Maintainence booklet https://www.thebmc.co.uk/Download.aspx?id=77
I have a 60m 10.5mm Beal rope which I have had for about 6 years. It is used all year round from the indoor wall, to UK crags and alpine crags. However, it has only ever taken one big fall and even that was less that Factor 1. Also, I have only ever washed it once in Tech-wash but having read this thread, I will invest in a rope brush!
How do I assess the rope for unacceptable wear and tear so that I know if/when to retire it?
I also have a pair of 8.5mm Mammut Genesis Super-dry half ropes. These only get used a few times per year on big multi-pitch rock routes and on ice routes. One of the ropes suffered a small nick from an ice-axe. My friend who had borrowed the rope got rid of the freyed strands with a lighter and I can't see where the damage was, eventhough I have looked closely.
Is this acceptable management for a rope?
Should I retire it immediately?
What is the best way of keeping the Super-dry coating on the rope healthy?
Thanks for the advice but I have another quick question regarding my 8.5mm Mammut Genesis half ropes - they have a great tendency to twist/coil around themselves. I have run the ropes out several times from one end to the other and from the middle out and over a large balcony to the ground in an attempt to undo the twists. I'm also careful when coiling them to make sure they are coiled properly.
Is there anything I can do to try and stop them twisting?
Any advice would be greatly appreciate.
Many Thanks, Justin
Dan is the man Justin. I'm a gear punter.
> Hi Carl,
> The manufacturer will probably tell you to retire the rope after 10 years maximum, assuming minimal use and despite the rope looking fine. As the rope is such a critical part of the safety system , why go against this advice? After 10 years you've probably had your moneys worth! Chances are your rope is fine, and might last for a while longer, but why take the additional risk when climbing is exciting enough as it is?
I have a similar question, my mate uses a rope that is 15 years old at the local indoor wall. Last week the rope made a funny stretching sound when I was lowered off the top of a 10 meter route.
Even though I've decided to not climb on the rope, is there any chance of it snapping because of its age?
Many Thanks, Justin
If you think about it, retiring gear from front-line trad use to be an old "wall rope" is crazy. I don't know about you, but I'm too much of a scaredy cat to take many whippers on trad, whereas at the wall I fall off all the time!
The name was well chosen over 10 years ago. As for the rope, I'm only guessing that it is at least 15 years old as it may be a couple of years older than that.
My mate is of the belief that modern ropes don't fail but I'm getting worried now about it.
So I will take your sage advice and decline to use it. problem is that my rope is 9 years old. Think its time to buy another one.
another rope damage question. I've got some shots here of a severe rope fray:
As you can see, one of the strands seems to have cut and pulled through, leaving a frayed end, and a few inches up (2nd shot) the sheath has bunched slightly and the core is visible through one small section of the weave.
(Apologies for the poor quality of the pics)
I'm assuming this is worthy of retiring the rope?
If so, given that this happened after 4 days of use, would there be any use in speaking to the shop/manufacturer? Or is this just plain bad luck?
PS the damage is pretty much at the half way mark of the rope.
If the core isn't actually coming out of the sheath then the rope is probably still safe to use; but I wouldn't expect it to last for long as the sheath will start to deteriorate. Check for lumps or discontinuities in the construction and if in any doubt don't use the rope.
Thanks Dan. Although I didn't notice it at the time, this may well have happened pulling the rope on a multipitch abseil. Looks like 2 x 30m ropes for me, then.
Question 1) Clipping 2 half ropes into one crab. This has always been a bit of a no, no in the UK but European climbers seems happy to clip both half ropes into one crab when lead climbing? Is it acceptable to clip both ropes into one crab?
Question 2) I have a tendency to replace all "tat" before abseiling out of some absolute fear that old tat is going to fail. I have heard this rumor that you only need to pull the rope through a piece of tat once (rope direct on tat) for the tat to become damaged, and although the tat may look to be in good order it is actually not. Is this just paranoia or is this based on truth? I have seen some tat after just one abseil rope pull and noticed the tat at the friction point to be significantly melted, and it makes me wonder about what is going on inside the actual cord.
Can you tell me if a prussik loop damages a) prussik line B) rope
when it is used to control an abseil, and when ascending a rope due to the heat/ friction between the two?
If so, how many times would you use a 5mm prussik loop before retiring it?
Hi Jamie, bear in mind that Euro's often use twin rope technique (clipping both ropes into each piece of protection). There is no problem with this, because both strands follow the same path all the way up, so in a fall both ropes will stretch and load at the same time. Problems arise if say you clip both ropes into one piece part way up and then go back to normal UK double rope technique above this. In a fall only one rope will be loaded, and this moving rope will run over the other, causing melting damage to both ropes. This is bad! So, either clip both ropes together all the way, or keep them totally seperate. As far as krabs being strong enough to take both ropes, apparently in a fall both ropes tend to squish down and locate nicely so this has never been seen as a problem. I think if it was then special krabs for twin rope technique would be available?
Pulling your ab rope down directly through tat will melt the tat and weaken it. This will be visible though, you get a glazed surface which then tends to break up and look furry but feel crispy. Cord is always better than tape, because cord has the strong bit (the core) protected by the sheath, and it will be the sheath that gets melted. Best of all though, is to use a cheap and light maillon as an abseil ring through the cord and then the cord will last for much longer. If you want to know more about abseil points stations, have a look at this: www.thebmc.co.uk/Feature.aspx?id=2598
When used correctly there shouldn't really be much heat build up or friction either ascending or used as an asbseil backup. Over time you will probably notice some wear on your prussiks if they get a lot of use. They also work better when the cord is nice and soft, so if they get stiff or start looking a bit glazed or crisy on the surface then its probably time to replace them. I tend to replace mine even if they look OK every few years anyway, the cord only costs a couple of quid so its not going to break the bank.
It's a completely different story if you take a fall onto a prussik. If you're lucky you'll melt it onto the sheath of the rope, if not it'll melt clean through.
Okay thanks Dan.
But in what situation would you take a fall on a prussik?
I'm with you, thanks for the info.
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