On the topic of new tricks to learn: as I mentioned earlier in the thread, I am wondering if there are any significant disadvantages to rigging an unrebelayed drop with a fixed brake lower (i.e. with a securely tied off rack or other descender at the top), leaving half the rope above the drop. This seems like a real good idea to me, as if it becomes necessary to lower someone, it is already set up. I wouldn't always rig this way, but given the serious consequences associated with being stuck on rope for a significant time, and the serious consequences of being stuck on rope where there is flowing water, I think there are many situations where it would make a whole lot of sense to rig like this.
Even in cases where rope for lowering is not available, rigging near the end of the rope with a fixed brake lower and *not* tying a knot at the end of the rope would provide for untying the anchor under load once a separate lowering line is attached to the load, or a prusik or rope clamp is attached to the rope.
The additional gear needed for this would be minimal--just an HMS carabiner, if a Munter hitch is used as the descender. When it comes down to it, rigging with this method might not end up using more carabiners. Consider the following three cases.
Case 1:
When one rigs with webbing and attaches the rope with a knot, a carabiner is used. If an HMS carabiner is brought along instead of whatever other kind, a fixed brake lower with a Munter hitch can be rigged with the same amount of gear.
Case 2:
Where one rigs with a tensionless hitch in the middle of the rope in the usual way with a carabiner, one could instead rig with the *end* of the rope (e.g. with a carabinerless tensionless hitch or bowline or rethreaded figure-eight on a coil to keep the anchor from slipping down), and then tie a figure-eight on the line as it comes out from this anchor, attach the HMS carabiner to this figure-eight, and tie a Munter hitch on the HMS carabiner in the middle of the rope. This would also use the same amount of gear, and would automatically brake once all the rope is out, should a mistake have been made and the rope not be long enough. In cases where one expects to give out all the rope and have it still be taught, one could tie an inline figure-eight or alpine butterfly instead of the figure-eight on a bight.
Case 3:
Where one rigs in any other way (e.g. with an endline loop around an anchor point, with a endline double loop knot clipped into two bolts), one could tie the figure-eight (or other midline loop knot) below the anchor on the rope and attach the HMS carabiner to it, with the Munter hitch tied on it in the middle of the rope, just as in the previous case. Here, this would use more gear--exactly one more carabiner.
Drawbacks:
(1) Some complexity is added. Tying the Munter hitch wrong, or locking it off incorrectly, could result in death. Many cavers are not familiar with the Munter hitch, and many more don't know how to lock if off correctly. At best, incorrectly locking off a Munter hitch makes it impossible to unlock. Furthermore, many cavers don't know how to correctly use a Munter hitch. Recently I was teaching a friend of mine who has belayed with belay plates for years how to belay with a Munter hitch. He caught my fall fine but when he went to lower me he ended up dropping me to the floor.
(2) You have to bring HMS carabiners, which tend not to invert easily in most bolt hangers. HMS carabiners are often weaker than D and offset-D carabiners too, but those types also tend not to invert easily in bolt hangers and oval carabiners, which tend also to be weaker but which invert easily in bolt hangers, are often used. Anyway, you have to bring at least two kinds of carabiner, and ultimately that translates into bringing more gear.
But wait...do you really need to tie your Munter hitches on Munter-compatible (HMS) carabiners? Typically the Munter hitch is used to belay, and when belaying the load is expected to be able to change direction. Thus the Munter must be able to invert and the carabiner must be big enough on top to allow this to happen. But when using a Munter for emergency lowering only, one could simply tie it on any old (locking!) carabiner and make sure it is tied in the lowering form.
(3) The Munter hitch, once tied off, is (like) a knot and reduces the strength of the rope...but this rarely, if ever, really matters in cases where you'd be wanting to rig like this.
(4) To be useful for lowering, lots of extra rope must be brought--but if you're bringing it anyway, why not rig like this?
(5) Putting the Munter hitch on a figure-eight tied in the rope itself may not always position it in a safe or usable way.
(6) If you are forced to tie two ropes together in mid-pitch for the drop (EDIT: and therefore are forced to attach at least a third rope to make sure there is twice as much rope as the length of the drop?), this could not be used to lower all the way (though it could still be used to get the load off the anchor and onto something else), because the knot would have to pass the Munter hitch (which can happen if the HMS carabiner is large enough, but never when the Munter hitch is actually loaded). But then if you're tying ropes together, you probably don't have enough rope to want to use this method anyway.
(7) The tensionless hitch is already available, and in cases where the environment permits its use, it has some advantages over the method I propose. A tensionless hitch around a round object has no problem passing knots and preserves 100% of the rope's strength. It also is more widely recognized than the method I propose, and fundamentally simpler. If tied correctly then *usually* it can be used to lower a load. If tied incorrectly, a safe anchor usually still results. While it is rare to practice lowering loads on tensionless hitches, and common to practice use of the Munter hitch, one could remedy this situation by practicing lowering loads on tensionless hitches. Lowering loads on tensionless hitches does not twist the rope and with most anchor points doesn't abrade it significantly. A tensionless hitch takes less rope than a tensionless hitch holding up a Munter hitch.
On the other hand, the Munter hitch has the distinct advantage in lowering that its operation is *way* more predictable, does not abrade the anchor point, and does not require unwrapping the rope from the anchor point. A belay on the same rope, if desired, can more easily be applied to a Munter hitch.
(8) If you're using quicklinks or non-locking carabiners to rig then replacing them with locking carabiners of any kind (HMS or not) is going to add significant weight and bulk to your kit. But then, if you care so much about weight and bulk, you're not doing this anyway because you're not bringing twice as much rope as you need.
NZ or anybody...what do you think of this?