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Post by dougsanders on Sept 7, 2013 7:23:46 GMT -8
Can we develop consensus as to the Best Practice for lowering a 2-person load as might occur during a small party self-rescue?
Historically, the linked carabiner brakes were a wonderful method for lowering a 2-person load. However, as the carabiner evolves away from large ovals toward smaller non-ovals it becomes increasingly harder and time consuming, to build them. This has lead, at least the Everett Basic Course, to stop teaching the carabiner brake as a back up for a missing rappel device, teaching the Munter instead.
The Double (Monster, Super) Munter appears to be the new Best Practice.
For a mid-wall 'pick-off' the rescuer can be lowered on a Munter. To transition to a Double Munter, the para-biner gate is opened, additional rope is routed to make the Double Munter, the gate closed and locked.
When lowering a 2 person load from the start, the Double Munter is used from the start.
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Post by jasonmartin on Sept 8, 2013 16:20:21 GMT -8
Doug,
The super munter works very well in this application. Other options to consider are:
1) Stacking belay devices:
In other words, the line from a redirected tube style device on the anchor is redirected a second time...
2) Using Two Carabiners in a Lower Off a Device:
If you add two carabiners to a rappel device (tube style) it creates more friction. This is also true with a redirected tube style device...
Jason
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Post by gregggagliardi on Sept 11, 2013 9:56:10 GMT -8
Another good lowering method uses an autoblocking belay device in guide mode. I tried to send a photo of the setup on an earlier post but it didn't work. Here are the steps in setting it up. I assume that there are three climbers; 1 victim, 1 attendant who will lower with the victim and the rescuer. I am also assuming that a secure, multi-piece anchor has been built (e.g., with a cordelette). Finally I assume that everyone is safely tied into the anchor with a lanyard.
1. Tie the end of the rope to victim and attendant (long tail bowline will work, but other systems may be preferred due to the victim's injuries and the terrain. A yoke attachment or rescue spider may be preferred over the long tail bowline). 2. Setup the rope on an autoblocking belay device in guide mode. The live (to be loaded) end of the rope goes to the attendant and victim. 3. Place a friction hitch on the live end of the rope and clip it to the master point with a locker 4. Clip the shelf with a locker and redirect the belay side of the rope through this biner, thus creating the ability to lock off the belay device from behind the device (as if it were on your harness). Keep your hand on the belay side of the rope under moderate tension 5. Now clip the autolocking biner on the belay device to the master point, thereby unlocking the device. 6. Place your hand on the friction hitch and slowly release it while keeping your hand on the belay side of the rope. Slowly release allowing the weight of the attendant and climber to load the system. As this occurs the attendant unties the victim and him/her self from the anchor just as you would do in a rappel. 7. Slowly lower. If there is not enough friction, then redirect the brake strand thru another locking biner clipped to your harness belay loop. If that is still not enough friction (unlikely) then clip the harness redirect biner with a Munter.
Advantages:
Though this appears complicated in a written explanation it is actually quite easy to learn and can be set up quickly. It provides a safe, well-regulated lower. The system is easily converted to a raise. If the lower will be longer than a rope length, two ropes can be tied together and the knot can be readily passed by setting the friction hitch up in advance clipped to the master point with a Munter Mule Over Hand knot or other load releasing hitch. If need be, the system can be re-locked off by unclipping the locking biner from the master point (back the system up first before doing this). Once locked off the attendant and victim are belayed in guide mode. They can rest, reposition themselves, monitor and re-treat injuries or even ascend the rope with the assistance of the rescuer who will no doubt have to create a high mechanical advantage raising system.
I would be happy to send a series of photos that show how this system is built. Email me at gagaliardi@nventure.com and I will send them. (file is too large to attach on this post)
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Post by gregggagliardi on Sept 12, 2013 8:29:15 GMT -8
correct email address: gagliardi@nventure.com.
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Post by gregggagliardi on Sept 13, 2013 13:04:31 GMT -8
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