UKC

One of my mates uses an alpine bod harness. To belay, he clips the krab through the leg loops and the waist loop, but this creates three way loading. Is it best to use a maillon or a short piece of rope to join the leg and waist loops and then clip into that? What do other people do and has anyone any better ideas?
Cheers

In reply to Philip M:

I use a Bod and I've never had a problem. Some time ago Tome Jones, the BD harness designer, posted on rec.climbing indicating that the forces required to pull everything into line are well below any load that'll cause cross-loading problems.

Try a search on google, you may be able to find it.

Mike

In reply to Philip M: A quick check with the online search facility reveals the following:

http://www.ukclimbing.com/caff/forums/t.php?t=18443
http://www.ukclimbing.com/caff/forums/t.php?t=17894
http://www.ukclimbing.com/caff/forums/t.php?t=11320
http://www.ukclimbing.com/caff/forums/t.php?t=7011

There seems to be more than enough there to keep you confused.

My Alpine Bod has a label on the inside of the wasitbelt which clearly shows the belay device attached to a krab clipped in to both the waistbelt and what they call the "crotch loop". Given that BD is a US company which needs to be paranoid in protecting itself against liability claims, I can't imagine they would knowingly publish dangerous advice about their product. I ask myself which I would rather trust to hold my fall: BD's product being used unmodified in the way BD recommend, or BD's product being used with an unsanctioned and untested modification contrary to BD's advice?

In reply to Martin W:
however, if you're tied on to the rope yourself, you could always belay off your rope loop if you're concerned about 3 way loading...

In reply to Jem: If I'm tied on to the rope then I do always belay off the rope loop. You could argue that this is contrary to BD's recommendations, but it's what I've been taught to do, and it's what I do with every other harness I have. I don't imagine most people would be in any confusion about that practice. It's when they aren't tied-in, eg belaying indoors, and they discover that there's no belay loop that additional guidance is needed from the manufacturer.

In reply to Philip M: Use of a mailloon is handy so when you are not tied in to the climbing rope you haven't got a load of dangly bits!

In reply to Peter:
Are you seriously advocating clipping a alloy krab to a steel maillon? Are you a caver?

In reply to Philip M:
Has anyone seen the latest bod harnesses in the shops?
they have a fabric belay loop, like a more normal harness which is permanantly connected to the leg loop. you have to thread thro this when putting on the harness.

In reply to Philip M:
You could tie a piece of static line like you tie on to the harness just for belaying off.

Just tieing on doesn't seem to much hassel to me, if your leading then just don't untie, if your top roping then tie on when your partner does and remain that way for belaying and climbing.

In reply to Woker:

....and when you do untie (at the top of the climb or to rig up a rappel/abseil) don't drop your krab and belay plate down the crag!

In reply to Philip M:
this is an explanantion i was given from a bd rep. "the alpine bod is a mountaineering harness (quick on /off with crampons etc) & as such when starting a mountain route one would tie in at the start of a route and untie at the end of a route. the tie in loop would be used for belaying from (similiar to the old wild country plj). the newer bods have a belay loop because they are more likely to be used for cragging type routes."

bd always advocated clipping a 'biner thru the loops but its quite telling that they have introduced a belay loop - to alleviate potential maybe? belaying with a 'biner thru the loops "has" the potential for a 3way load but unlikely in this set up (much more so with conventional harness). tie in if your not happy and belay from the loop. use of a maillon isnt a problem either (metal on metal isnt an issue).

In reply to stu:
For a long time now I've had a very short tape sling (1" tape) tied around the crotch loop & when I put the harness on I thread the waist strap through that. For belaying I use the bight formed by the rope but the short sling is useful for quickly attaching a rope when not climbing as such (glacier travel, ski touring, etc) or for attaching a prussik to protect an abseil.

Sounds like the newer models have such a sling already there.

In reply to stu:

So has this been a climber's 'urban' myth or just disproved by more recent research. I can understand how metal to metal contact can compromise the strength, but this raises the questions about clipping bolt-hangers and pegs.
I can find no definitive statements from the UIAA.

In the SRT world, cavers have always clipped into Maillon Rapides on their chest harness with a krab. However on pitches, the maillons are never directly clipped.

In reply to John I:

Okay, I'll bite.....explain why "metal to metal" contact compromises strength?......This is a new one for me.

I don't generally clip carabiners together to get an extension, but that's because they most often are non-locking and two non-lockers clipped together can "un-clip" one or the other.

Cheers,
D

In reply to Dave Noake:


I think you'll find that this is true of the Bod, but not the Alpine Bod which is what the original question was about.

In reply to Diligence:

I presumed that it caused stress concentrations.
In additions to implications for bolt-hangers and pegs what does this say about wires? This is why I was querying its veracity.

Are their any metalurgists out there?

In reply to Philip M:


I’ve used alpine bods for years, for cragging and on big things and have always tied in, through the belt and lower loop. Had some falls and never had any problems. One of best harnesses you can get as long as you remember to 'dress yourself' properly when you put it on. Otherwise you may as well get yourself a whillans nut cruncher!

I’m also curious to hear more about the metal on metal thing, surely if there are any adverse factors they would apply when clipping and extender into a wire, or when using pulleys, ascenders etc.

In reply to John I:

I'm not a metalurgist either, but my instinct tells me that it's not true.

I also don't see a large issue with three way loading of a crab used on the Alpine bod harness. I don't see how the loads could get large enough to be of any concern, but I guess each to their own and all that.

It's interesting for me to listen to the thoughts from climbers in the vicinity of the UK and Europe, definately different in some instances than the views of climbers I know here in Canada.

D

In reply to Philip M: What is the problem, as stated earlier, obviously the forces required to pull everything in to line are like bugger all. BD also say this is fine and that comes from litigation central (something BD know a thing about, hence the Chouinard/BD name change last time they got stitched up). Just use a HMS krab for single pitch, and stop being silly.

In reply to Diligence:
This has been a fascinating thread.
Following up all the references has led me to review my own practices, particularly on multi-pitch climbs.
Over the last 15 years, I have used a Chouinard Bod and later a BD one (both without belay/rap loops). I always have TWO HMS krabs through my 'belt & leg loops', belay off one and clip the other to a single anchor. The other anchor(s) clipped directly to my tie-in loops OR a larks-footed sling at the back of my harness.
It is very convenient for skiing, mountaineering and cragging but hanging belays are a bit uncomfortable.

The most useful contributions were:
Tom Jones on Tradgirl Climbing when he posted the official view as BD harness designer and a personal one as an experienced climber.

Pit Schubert(UIAA Safety Commission) on catastrophic harness failure. Apparently a possibility when the harness becomes a direct link in the belay chain. (This would explain the demise of rear anchor loops on harnesses).

Dr Gear here...

The problem with three way loading dosn't seem to be that you could break the HMS will holding a fall - as this would be impossible as the rope would slip before it could generate anough KN. It's more liklly to cause a figure of eight to pop open the gate of the HMS if everythging is missaligned (this is how they recon Patey died.)
Instructors like Delta Maillons becouse they need a belay loop - leaving me wondering why they didn't buy a harness with a belay loop in the first place? If you go down that track then you'll find it very fiddly, or impossible, to drop the leg loops/crutch strap, unless you undue the belt or uncrew the mailon. Having a mailon that can be unscrewd is a bad idea as it could do just that, so if you use one you're probably best sticking some Locktite on it and tightening it with a spanner.
Tying spectre or tape in lew of a belay loop is a BAD idea, as you could suffer the consiquenses of the loop coming undone, or the loop melting through in certain curcumstances like a violent sideways pull(a big danger with dyneema against nylon).
Like the other threads say clip into the rope loop (that way it's bomber and you can escape the system, or if you trust your own judjement clip straight in with a chunky HMS and use a normal belay tube device (ie don't ever use a Fig 8 unless you're in the army or are doimg something for charity).
The BOD is a great harness, but there are some other harness that are lighter, more compact and fully ajustable and with belay loops you can use while having a dump! The main advantage is that they are dead robust.
Cut the belay loop off it if your into wintery stuff, and if you're clipping in instead of tying in then use two HMS back to back.

Don't always go by what the safety Nazis say - their 'safety' advice can often be far from it when your using gear for real and not hypothetically.

Dr Gear

Some climbing centres are funny about the three way pull problem with Bods and wont allow you to do it. I always belay off the rope loop as I mainly only use them in winter but our club uses them as general purpose harnessess as they are cheap, light, work for winter and summer and are less likely to get nicked. You need to watch beginners carefully when belaying off a rope loop as if they dont watch what they are doing the belay karabiner can move into a cross load position, or allow the belay rope to run over the gate, both of which are dodgy. These new karabiners with a clip to fix the rope loop, to prevent movement, are good but perhaps encourage climbers to rely less on checking. We always emphasise to beginners to always check their belayer's harness and belay set up before climbing, always pay attention, always expect a fall ..etc. I guess we need to be careful about getting blase and moving away from the 'climbing is dangerous' mantra.

In reply to stu:
"(metal on metal isnt an issue)"

I suppose you've read about the deaths caused by abbing on normal fig 8's attached to normal locking screw gater biners have you ? Sometimes they get a funny angle between the two and this preasure can break the screw gate, this can not happen when useing material to metal.

In reply to Woker:

Not so sound "challenging", but surely there must have been some other extenuating circumstance for the abb situation you mention. What's the basic capacity of a screw-gate? Around 23KN Lengthwise, and cross-wise about 15kN minimum, with and open gate it's near 7 or 9KN....surely the force from a "funny angle" during an abb wouldn't generate enough force to break a screw gate?

Was there some sort of dynamic load, say, an out of control abb then a rapid deceleration?

It's common for me during multi-pitch climbs with multiple climbers to build a belay anchor with a master point (ie a crab) that we all clip into for convenience.....this intrigues me.

D

In reply to Diligence:

From memory in certain circumstances its possible for a figure of 8 to apply a dangerous static lever force to the gate of a locking crab which causes it to break. Contact the BMC if you are really interested, I'm sure there is a technical report on it somewhere.

In reply to Offwidth:
Thanks...

D

In reply to Diligence:

As a bod owner I belay with the krap clipped into the rope loop I've tied on with. Easier to do and easier to escape from.

Now as a metallurgist I can't think of a good reason not to use metal on metal. I suspect the figure of 8 problem, which was reported in Summit I think, had as much if not more to do with the shape of the 8 and the loading this caused on the krab in a particular situation.

The only sort of reason I can think of for not using using metal on metal is that if the two components were used like this in combination for a lengthy period of time one could wear the surface of the other. This would be a particular problem with a soft metal (aluminium) on a harder metal (steel), as opposed to metals of the same hardness. But you would have to be pretty stupid not to notice the wear happening long before it was a real problem.

In reply to Woker:
its called malconfigured 'biner alignment or something and not only have i heard about it i was present at a bmc investigation test (after the army bridge incident some yrs ago) and they managed to bust open the biner with the fig of 8 just by standing in a sling!! very very difficult to do the same with biner on biner and similiarly difficult if your fig of 8 descendeur has a very small bootom "o". metal on metal isnt so much the issue as to how they interact.

In reply to Horse:


Ha ha, you say that, but a couple of mates have worn half through a krab on a single rap descent of somut in Pakistan. That was rope (or rather grit) on ali.

I know that's got nothing to do with your point.

In reply to Horse:
Agreed it was specific to the figure of eights hole size and the crab. the way the biner broke is by levering the gate out the way it isn't supposed to bend, this way they are actually quite weak and the screw gate just got cut through.... Still I can' see how this would happen as easily not using metal on metal, chaining biners together is not best practice for these reasons.

In reply to Woker: 100% agree with you. One of the points about metal on metal is that it is possible to exert a significant twisting force on the krab with another krab, figure 8, maillon or whatever. It is not practically possible to exert similar twisting forces with a sling or a rope (or the wire on a nut, in most instances). If you examine your krabs, you should find strength ratings for longitudinal pull, cross loading and gate open. You will not find a twisting strength rating and that's because they aren't designed to sustain such loads.

Admittedly if there is fabric elsewhere in the system (eg in the harness) then some of the twisting forces will be absorbed, but since we don't know what the failure load is anyway then that isn't much comfort. If the weight of one person hanging from a harness on the end of a rope is sufficient to cause a figure 8 to break open a screwgate krab by twisting then the twisting failure load would seem to be quite low.

By the way, this is different from the reason why you are not supposed to clip anything other than rope or a slings in to non-locking krabs. We all know (I hope) that an incorrectly clipped rope can open the gate on a krab in a fall. It is very much easier for two krabs to intertwine and unclip in even low load situations. That's why, if you need to chain quickdraws together, you should clip both slings in to one (or even both) krabs in the middle, rather than clipping the two krabs together.

I also remember seeing a sequence of photos showing how a krab can unclip itself from a bolt hanger. This was on a web page somewhere - anyone know if it's still around?

In reply to John I:


Forgive me if I've misunderstood your description, but this sounds to me like exactly the kind of setup which Tom Jones of BD said harnesses are not designed for? To quote from his posting on TradGirl:

"Your belay biner should connect directly to the rope tie in loop so that the forces of the belay can link directly to the anchor. Otherwise, the forces from a severe fall would run from your belay biner to the belay loop, to the harness, to the rope loop to the anchor. This would tend to rip the harness apart and the results are very unpredictable. It is much better to have the forces transfer as directly as possible to the strong point in the system"

In reply to Martin W: It's not the web page I remember seeing before, but this one does illustrate a couple of self-unclipping mechanisms involving bolt hangers:

http://www.putzl.com/~klew/unclip.shtml

In reply to Martin W:
Precisely, my post admitted that....

"Following up all the references has led me to review my own practices, particularly on multi-pitch climbs"

I had developed techniques for managing a Bod which are now considered to be bad practice and Ii had not updated procedures taught to me more than 20 years ago.

I also remarked on a common practice which used to be taught of attaching a sling to the rear of a harness, Some manufacturers actually provided a read tie-in.

"(This would explain the demise of rear anchor loops on harnesses)"

The old thinking was to avoid a belayer being spun round when taking a fall. In the same way as the 'live rope' on a body belay should be on the same side as your anchor.
Of course, removing the harness from the belay chain removes this risk.

In reply to Martin W: Except on a dodgy belay (esp winter) thats exactly what you do want.

In reply to Offwidth: I agree that it's a good idea to protect a poor belay in some way. I'm not sure that doing so by introducing an element in the system whose behaviour could, according to the manufacturer, be "unpredictable" is the best way to do this, however.

Mind you, my experience in this area is limited. What are the recommended practises? What do people think about using a screamer (whose behaviour is at least supposed to be predictable) to attach to a suspect anchor?

In reply to John I: Fair enough, I misread your original post. I thought it seemed a bit odd, since you usually seem to offer well-considered advice. Apologies for the misunderstanding.

In reply to Martin W:

"I agree that it's a good idea to protect a poor belay in some way. I'm not sure that doing so by introducing an element in the system whose behaviour could, according to the manufacturer, be "unpredictable" is the best way to do this, however. "

Waist belays are still recommended practice in certain circumstances: Mountaineering is not completely predictable.

In reply to Offwidth:


Of course they are. I knew that. Why didn't I remember it before I posted? I must have been focusing too much on the idea that this is a gear forum. Silly me.


Also true. However, but we can still take steps to avoid areas of known unpredictability. I pretty much know how my waist belay will perform. I don't have much idea how a belay directed through my harness will behave - it might be OK, it might not. If I was the one being belayed, I think I'd prefer my partner to use the tried and tested method, rather than test the untried method on me!

In reply to Martin W:


"I don't have much idea how a belay directed through my harness will behave - it might be OK, it might not"

A harness is really a sling connected by a safe attachment. Stressing across a harness may not be as predictable but I doubt very much if it is dangerous. Even if I also nearly always use the 'tried and tested method'.

In reply to Martin W:

Okay guys, I must still be missing the point here. If I correctly read what Tom Jones from BD wrote, then he is saying that using the belay loop will unacceptably stress the harness (ie "rip the harness apart"). I must be unclear about something.....you see, I view the harness waist belt as a closed loop of webbing....rated to 15KN (CE Standard). I see the belay loop as a closed loop of webbing rated to at least 15KN (CE Standard). In effect, this is two pieces of webbing connected together.

How is the use of a belay loop as an integral part of a harness different from extending two slings with a screwgate crab? (neglect the friction effects of webbing on webbing concerns). In both cases, the "closed loops" of webbing are stressed in exactly the same way. If leading, the rope from the leader to the pro will act dynamically. If belaying a leader, the rope (from the belayer, through his belay device, to his harness, to the tied in rope loop) to the anchor will act dynamically.

In both cases, there is a static conection (ie webbing) to an anchor system, but the link is also composed of the dynamic rope - without the dynamic link, the system would be subjected to severe loads - and would probably fail quickly.

An additional dynamic link is the belayer himself. Consider that if you have a questionable anchor system which you are forced to use. What is a good way of absorbing energy and protecting the anchor? In ice climbing we often use a screamer as an additional energy absorber, BUT we always use our body( via the belay from the belay device connected to my harness wrapped about my body.) - unless we are belaying directly off an anchor, such as when using a Munter on a crab attached to an anchor - in which case we are relying solely on the rope to be the dynamic link in the system.

My point is, how is a harness with it's associated webbing connections, different from any other webbing system we build? In particular, does the dynamic nature of the body's response to load not decrease the total effects on the system?

D

In reply to Diligence:
Apologies to PhilipM for hijacking his thread. Should we be starting a new thread on this?

In reply to Diligence:
see this for info on how biners can fail

http://www.cogeq.com/8_article.pdf