Thread: Breaking the Edge
09-25-2013, 03:50 PM #1
Breaking the Edge
When lowering a rescuer/load, or having the rescuer break and edge/enter a hole while utilizing a high directional such as a tripod, or A frame what is your preferred method of the position the backup line is in during this time? Running through the high point as well, low running over the edge with protection or another method? Also, why do you do what you do?
Personally I prefer having the backup line start out high and then lowering it to the edge via a mini 4:1 or 5:1. Then raising it back up as the load is breaking back over again. Reason for this is so the load is always on two lines with minimal fall factor.
09-29-2013, 12:45 AM #2
- Join Date
- Feb 2006
Used to hear the word "never" a lot when talking about running your belay through the AHD. Now days there's some good talk about running your belay high during edge transition (with some form of MA attached to the AHD head) due the possibility of a big drop on a short rope . Once the transition is complete the belay lives on the ground once more. The same goes for raising. You would raise the belay line off the deck as the person comes up over the edge - with the aztek (or whatever). It just really depends how well your AHD is guyed and what it's rated for in the first place. There are no "rules" about an up or down position. You could get people to testify best practice for either option. The only place I would throw "never" back into conversation would be running a belay through an aerial device used as an AHD. But that usually just gets people mad when I say that.
Last edited by bottrigg; 09-29-2013 at 10:00 AM.
09-29-2013, 01:12 AM #3
I don't see why you would put MA on the Belay? Your main line should be designed not to fail. In the event it does, your belay can be quickly converted to a raise system. I am still on the fence about putting the belay on the AHD.
09-29-2013, 07:55 AM #4
- Join Date
- Sep 2006
- Albany, NY
I think your spot on with the raise / lower setup on the ahd, especially like it to also manage air and com lines in confined space with a kootney. It's great edge protection as well.
The mini 4:1 work great, but can be valuable elsewhere too. I like to use a 2:1 with a Petzl grillion or a GriGri with an appropriate length rope for your need. Terminate the end on the ahd, then the device to the belay line through a biner and the running end back up and through the ahd biner. There isn't need for real ma so this makes adjustment either way quick and easy and don't require a lot of effort on the edge attendants part
09-29-2013, 09:49 AM #5
I personally like the belay/retreival line for vertical entry confined space to be in the high help. If you have to retreive the rescuer on the belay line (say becomes incapacitated) having the belay/retreival line running on the ground screws you on edge transition.
To play my own devils advocate, say you loose the high help in a catostrophic style event... tripod falls into the hole (seen it happen real world in a training scenerio). The belay/retreival line run on the ground will not see a fall factor for a rescuer that is in the hole, now his worry is being struck by a tripod!
In all honesty, I will operate with the belay/retreival line ran either on the high help or on the ground. No worries to me either way.~Drew
USAR TF Rescue Specialist
09-29-2013, 07:32 PM #6
I think I misunderstood what the original poster was describing. I am more a visual person. Does this image describe what was meant? If so, I will have to say I have never tried this method, but it looks useful. The Aztek looks like the tool for this job.
Last edited by MichaelXYZ; 09-29-2013 at 07:35 PM.
09-29-2013, 08:30 PM #7
For a simple vertical edge transition with additional high help, I would run the belay on the ground. The highest dnager of loosing the AHH will be durring the edge transition anyhow, having the belay up in the high help will give you the fall factor. Keep it on the ground.~Drew
USAR TF Rescue Specialist
09-29-2013, 09:21 PM #8
The biggest issue I have seen with the belay not being on the high anchor is twisting, and entanglement of the belay with the main line in a confined space scenario. I had this happen once on a job. I get the arguments for separating the belay from the main line anchor, but planning to prevent entanglement must be considered.
09-30-2013, 11:06 AM #9
- Join Date
- Aug 2007
Edge transitions will always be one of the most challenging components of a rope rescue operation be it in a traditional situation or in a confined space application.
First, we must continue to train and work on proficiency in this segment of our over all operation.
Many times a team will work on all aspect of the operation and when it comes to the final phase "transitioning the edge" they do a grab and go and hurry off to complete the evolution.
The idea of having an adjustable option to raise the belay at the transition point is a very good one. It does come with a cost of having manpower and equipment to accomplish it. If you have both its a great option.
We have utilized another method for the edge transition for a number of years. When the package (traditionally a horizontally rigged transport device) reaches the edge, we slide a folding attic ladder between the face of the edges surface and the basket. Approximately one third of the ladders length is behind the basket. At that point the ladder is levered back to a horizontal position from the vertical angle it was originally in. This provides a smooth transition of the basket up the final inches of its travel and also provides a level of security as the basket can now be safely slid on to the hard deck with minimal impact on the victim.
And lets be honest it is the victim that we are there to assist. I have witnessed both in training and at actual incident the second trauma of the day for the victim being the poor handling they receive by the rescuers during the edge transition.
All of the previous replies to this thread have been great. Our goal at Firehouse is to reenergize the Forums so that responders around the country and beyond have a place for good positive interactions as well as a place to reach out to others in the field for help with questions they have.
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