Mallions

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wormster

Guest
A quick question:

When rigging for srt off P anchors I was taught to rig my mallions so that they screw up.

Now its mystifying me, why this way??...

I can see several answers but I thought I'd throw it out to the rest of you.
 
R

rsch

Member
Because if you don't screw them up the rope might fall out, or they might come off the P hanger?  :eek:
 
cap n chris

cap n chris

Well-known member
I think he means screw up(wards) i.e. the twisting collar; karabiners are always screwed downwards with gravity so they don't undo from vibration. Also, it's maillon, not mallion. Me being picky.
 
D

dunc

New member
Because if you don't screw them up the rope might fall out, or they might come off the P hanger?
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lol
When rigging for srt off P anchors I was taught to rig my mallions so that they screw up.
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I assume you mean screwing the gate/collar/whatever its called upwards as opposed to downwards? If so then not sure why that way is preferable, I was told when rigging that having the gate screwing downwards was best, gravity and all that?
 
mak

mak

Member
nah you can screw in any position you like - as long as it ends with it hanging downwards after you've finished screwing  ;)
 
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darkplaces

Guest
mak said:
nah you can screw in any position you like - as long as it ends with it hanging downwards after you've finished screwing  ;)
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He's clever  :sneaky:
 
whitelackington

whitelackington

New member
wormster said:
A quick question:

When rigging for srt off P anchors I was taught to rig my mallions so that they screw up.

Now its mystifying me, why this way??...

I can see several answers but I thought I'd throw it out to the rest of you.
Click to expand...

It is not really a quick question.
If your s.r.t. skills are this lacking you should stick to armchair caving
 
D

damian

Active member
whitelackington said:
It is not really a quick question.
If your s.r.t. skills are this lacking you should stick to armchair caving
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A little harsh ... at least wormster has seen fit to question it .. and it sounds to me like he can see the problems himself too. Much better than the people who don't think about what they are doing.
 
graham

graham

New member
I find it hard to believe that, for most krabs and all maillons, that gravity would come anywhere near to overcoming the frictional forces involved in screwgates.

A more logical consideration is to have the rope, when the setup is loaded, at the end of the jangly metal thing furthest from anywhere that it might fall out of. In terms of this argument, therefore, gates should be positioned such that they have, effectively, screwed upwards.
 
Ship-badger

Ship-badger

Member
graham said:
I find it hard to believe that, for most krabs and all maillons, that gravity would come anywhere near to overcoming the frictional forces involved in screwgates.

A more logical consideration is to have the rope, when the setup is loaded, at the end of the jangly metal thing furthest from anywhere that it might fall out of. In terms of this argument, therefore, gates should be positioned such that they have, effectively, screwed upwards.
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Not so for a maillon surely, which will bend if the gate is not screwed up; especially the long ovals that most of us use for rigging. Wormster says he was "taught", I wonder who by. Anyone who has taught me has always insisted on "screwed-down".

I regularly use oval krabs with a pulley for lowering and lifelining systems, and these regularly unscrew themselves if they are placed "screwed-upwards".
 
graham

graham

New member
Sure, but an unscrewed Maillon will bend under load whichever way up it is. i was thinking in terms of disaster management rather than anything else, there.

As far as your experience of pulley wheels is concerned, that simply confirms my thought that gravity is not the major factor controlling whether a gate unscrews or not and that if it does unscrew then you want your rope & pulley wheel to be as far from the opening end of the gate as possible.
 
cap n chris

cap n chris

Well-known member
graham said:
I find it hard to believe that, for most krabs and all maillons, that gravity would come anywhere near to overcoming the frictional forces involved in screwgates.
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Maybe not for maillons, but with karabiners you can often (and I mean often) watch the gates twisting themselves open, especially when someone is prusiking up a rope (the vibrations from the jammers on a tight rope make the collar on the krab spin), if the karabiner is so arranged that the collar isn't facing downwards with gravity; if you do witness it as a result of the karabiners being in the wrong alignment, it's quite simple to screw them up again by keeping an eye on things - obviously, overtightening a krab while it is under load is great fun when it comes to derigging! 
 
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Peter Burgess

New member
Perhaps the position of the nut relative to the rope, in terms of ease of rigging and derigging is more important for maillons, and this would determine the best way to hang the device. i.e. does the nut move away from or towards the rope when you undo it. Just a thought. More relevant perhaps for smaller maillons where there is little room for movement.
 
graham

graham

New member
cap 'n chris said:
graham said:
I find it hard to believe that, for most krabs and all maillons, that gravity would come anywhere near to overcoming the frictional forces involved in screwgates.
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Maybe not for maillons, but with karabiners you can often (and I mean often) watch the gates twisting themselves open, especially when someone is prusiking up a rope (the vibrations from the jammers on a tight rope make the collar on the krab spin), if the karabiner is so arranged that the collar isn't facing downwards with gravity; if you do witness it as a result of the karabiners being in the wrong alignment, it's quite simple to screw them up again by keeping an eye on things - obviously, overtightening a krab while it is under load is great fun when it comes to derigging! 
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Don't think I've ever seen 'em do that. maybe I just do 'em up properly in the first place. ;)
 
whitelackington

whitelackington

New member
Maillions should always be tightened by screwing the nut down.
You do not need to do them up with a spanner, just finger tight
but you do need a spanner with you because they sometimes tighten themselves.
 
Brains

Brains

Well-known member
Krabs can and do stretch very noticeably under a load - watch one next time even a medium size caver is climbing up to you. To tighten the gate during this will mean, as CnC says, some really good fun derigging. Maillons will be subject to the same stretch which will effectively ease the threads, allowing them to self undo if rigged "screw up." I agree this is unlikely but is a possibility. Also, do not over tighten a maillon - if it is stiff it is because it is bent / stretched / compressed. Using a spanner on the hex to tighten can cause them to shatter (seen it happen), so only finger tight. If they do tighten up another maillon or the end of your stop can be used as an improvised spanner...
 
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