APM - Auto-lock Pass-through Munter

doesn't one think that it is easier to rap in than being lowered?

Don't be insulted, just my honest assessment.

Your system says:
I am not comfortable lowering on an Autoblock.
I am not comfortable belaying on a Munter.

So, you have combined the two and needlessly complicated the system.

Why not become proficient at lowering on the Autoblock.
or
Use the Munter for lower and belay.
or
Have your partner tie in, then rap the climber side of the Autoblock while you hold the brake strand.

No switching. No need to unweight the rope. One system. Keep it simple. No need to complicate.

A typical response:

bwalt822 wrote:The only thing it doesn't do well is lower. None of the (good) workarounds are complicated. OMG! I have to redirect the brake strand through a munter, how can I climb when my mind is being taxed so much.

A typical unanticipated problem:

buttonheadspinner wrote:One thing we noticed is that it can be easy to miss-thread the auto-lock device ending up with the break strand on top. Not in and of its self a fatal error but if the belayer treats the miss-threaded device as if in auto-lock mode and lets go of the break strand the climber could be dropped.

My comments stand.

I do not think anyone has mentioned this MAJOR detail yet. If the rope does not contact the locking biner in the center of the device it will not lock off(auto block). By pulling the rope strand up and munting hitching it to another biner you now eliminated the all functions of the auto block and atc. Its like having two belay/lowering devices in the system. Now thats redundant new age technology.

NIVEK wrote:I do not think anyone has mentioned this MAJOR detail yet. If the rope does not contact the locking biner in the center of the device it will not lock off(auto block). By pulling the rope strand up and munting hitching it to another biner you now eliminated the all functions of the auto block and atc. Its like having two belay/lowering devices in the system. Now thats redundant new age technology.

The idea of this system is to temporarily take the autoblock out of the picture when lowering someone onto a single pitch climb where you belay from above. It seems like it is very useful in situation where the climber doesn't have a safe place to rap down to and wait for the top climbers to set up a belay. It also saves the time of not having to set up a rap and then pull the rope up to set up the belay. Its annoying (but not necessarily difficult) to set up a autoblock to lower and this avoids the problem.

Greg D wrote:Don't be insulted, just my honest assessment. Your system says: I am not comfortable lowering on an Autoblock. I am not comfortable belaying on a Munter. So, you have combined the two and needlessly complicated the system. Why not become proficient at lowering on the Autoblock. or Use the Munter for lower and belay. or Have your partner tie in, then rap the climber side of the Autoblock while you hold the brake strand. No switching. No need to unweight the rope. One system. Keep it simple. No need to complicate.

^^^Yes.

To the OP: thoughts on this?

DannyUncanny wrote:Why not add one of those new smaller Grigris to the brakestrand so that if the reverso gets jammed up against a rock so that it's open and your hands are busy making pb&j sandwiches it will still hold the second.

If you have a gri gri then none of this system needs to be implemented. Clip the gri gri into your master point, lower off of it (heck, add a friction redirect if you want to) and then belay with it. No changeover, no twisting of the rope, no complications...

"To the OP: thoughts on this?"

Certainly, glad to respond. So long as autolock belay devices are in use, some sort of release is required. The AMP pre-releases the autolock and adds a Munter. My experience (belaying, being belayed and watching others) with releasing the autolock the conventional way is that the result is a pulley with no friction assist. By including the Munter, we introduce friction.

I guess I see it as using the best of both rather than the avoidance of either.

I enjoy the discussion but don't want my remarks misconstrued as advocacy. It works for me, that's all I’m saying.

There is another post that gets at this topic, “Lower Me, Baby,” where the OP offers alternatives.

AMP set up to lower last Friday.

when releasing the autoblock ... you can put the "brake" strand into a munter on yr harness ... that should produce more than enough friction to lower a released autoblock

i believe this would be easier to setup and superior as you can set up a lower should the climber be unable to unweight the rope ...

bearbreeder wrote:when releasing the autoblock ... you can put the "brake" strand into a munter on yr harness ... that should produce more than enough friction to lower a released autoblock i believe this would be easier to setup and superior as you can set up a lower should the climber be unable to unweight the rope ...

True.

It is possible to mis-reeve the AMP. A quick "dry run" will reveal mis-reeves before anyone is at risk.

Mis-reeved AMP

Bryan Ferguson wrote:It is possible to mis-reeve the AMP. A quick "dry run" will reveal mis-reeves before anyone is at risk.

"Mis-reeves" = mis-weaved?

Is this a typo or is my googlefu lacking?

"Reeving" means to pass a rope through a hole, ring, pulley or block, so the usage could be appropriate, although the picture indicates things so bollixed up I don't think threading is the only problem.

My take is that lowering, and especially long lowering, with a plate in guide mode is dangerous, because most if not all of the plates go from an immovable level of friction to virtually no friction over a very small amount of travel. The load release is sudden, hard to predict, and very hard to recover from once it has happened. There is no way around this, it is a design flaw built into the device, which of course was never intended to be used in such a way. (Perhaps the DMM Pivot eliminates or mitigates this design flaw; I guess we'll find out soon...)

Folks who think this system is "simple" are in fact the ones most likely to have an accident with it, after which everyone clucks and says it works fine if you do it right, which of course is a tautology with no reality content, the point being that it is really easy not to do it right.

Of course you can lower with guide plates, but you are tempting fate if you haven't backed them up in some way that will provide resistance when the plate suddenly releases. There are many ways to do this, some of them like AMP very specialized and only appropriate in certain restricted situations. Actually, AMP isn't even a plate backup system, it altogether removes the plate from the business of lowering and then makes it safe and simple to engage the plate for climbing when the moment comes. But it is only for lowering from a place where the rope is unweighted to a place where the rope is unweighted and so is of little general-purpose relevance.

As bearbreeder points out, you can obtain similar back-up resistance by just putting the Munter on your harness, and this is more universally applicable. But the advent of guide plates seems to have made it extremely unfashionable to apply a belay load to the harness, to the extent that folks will opt for all kinds of more complicated and less useful rigging just to keep the dreaded brake strand away their bodies.