Half-Round Orientation for Frogging

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Half-Round Orientation for Frogging

Postby ND caver » Mar 2, 2006 5:49 pm

Hi everyone,

In the last (or 2nd to last?) ACA there were two examples of the half-round mallion harness attachement becoming unscrewed during ascending, but unfortunately there was no info on which way it should be facing to prevent this...

Looking down at your harness, should the gate (when going from closed to open) screw 'away' or 'towards' your body?
I tried every orientation I could think of last night, and no amount of flailing on rope could get it to unscrew, even when almost completely open...

Any thoughts?

- Bob
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Postby David_Campen » Mar 2, 2006 6:26 pm

I don't understand how you have your maillon oriented so that the nut moves toward or away from your body. With a half-round maillon on a Petzl caving harness, as you look down on the maillon, the nut should be on the right when the gate is open and move to the left as it is screwed closed.

Oriented in this way, as you climb and the rope rubs against the nut it will tend to screw it closed.
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Postby ND caver » Mar 2, 2006 10:10 pm

Ahh, thats what I was missing. I assumed that it was rubbing against some part of the harness or clothing.

By 'away' and 'towards' I meant the sense of rotation, i.e if the not was rolling on a flat surface parallel to the ground it would roll either towards you or away from you... saying which side the gate closes from is much clearer.

Thanks -

Bob
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Postby paul » Mar 3, 2006 7:49 am

It is common practice, in the UK at least, to attach the safety link from the footloop jammer in a Frog rig to the bottom of the central maillon joining the front of the harness sides, below the harness attachment points through which the central maillon passes, to leave more room at the top of the maillon for cowstails, croll, descender, etc.

Many use a 7mm maillon to attach the safety link to the central maillon as it is also handy to slip over the central maillons threaded sleeve in order to tighten it up that last bit and also makes it easier to disconnect when wanted. Unfortunately, when the central maillon is in the correct position, as described by David_Campen, if the 7mm maillon slips over the central maillon's threaded sleeve, it also loosens it on the upward stroke of the footloop jammer...
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