main line failures
I'm thinking about ways to re-establish the main line after a main line failure (assumption is that the belay engaged properly). If your team has experienced an unplanned main line failure, please relate what happened and how you re-established the main line.
If your team has an established procedure for re-establishing the main line, please share it.
Also, please address the following rather extreme case: You have an attendant with a patient in the basket stretcher in a high angle situation. The main line fails and the attendant is incapacitated as a result. It is assumed the belay engaged properly. How would you deal with this situation?
Have not had it happen, but I would think the next step would depend on how and why the main line failed.is the belay still a secure line? Did an anchor blow? if so, can it be easily replaced and continue to use the same line? Did you comletely lose the main line? How far of the deck is the load? If speed is now more important than redundancy, it is simple to convert the belay line to something that can continue the rescue. May decide to do this and go either up or down, whichever is best for the situation at hand.
Kind of hard to say exactly what would be done without knowing all the variables. But this defenitely something you need to do some fast thinking about and have a sloution ASAP.
We train for this, but have not experienced it (rig for success, right?) real world.
1,000 ways to do it, main point is that you need a load releasing hitch (mariner's, radium, 4:1 jigger) intergrated in your belay system to make it go smooth. Anytime we rig a TTRP (tandum tripple rap prusick, for the visitors) belay we will put a Radium Release Hitch between the belay and anchor.
Reestablishing the main line is done by solving whatever problem existed, then reloading the main line using the load release hitch.
I know there pricey but If you were using a MPD for the belay you could simply lower the rescuer/victim to the ground or raise them back topside. If I was going to reestablish the main line why not lower the new mainline down to the rescuer and see if the bridle attachment is within reach to connect the new mainline onto. If they can't reach and their closer to the topside then the ground why not haul them up and attach the new mainline yourself. The MPD converts to a MAS rather easily so that's a plus.
If I didn't have a MPD I would have already had a pre-rigged 4/5:1 MAS topside that I could piggy back onto the belay line to either off load the belay in the event the on rope rescuer could attach the new main line or to be used to raise the vic/rescuer to a point where we the topside rescuers could make the connection. You could always lower someone down to re-establish the mainline but that seems like a waste of time to me. Tensions will be high and injuries could have occurred or been complicated. I think getting them to a safe area topside or on the ground quickly is the way to go.
My sloppy post did not address my actual concern:
Since the vast majority of main line failures are due to operational errors, all the rigging should be intact after the belay engages; the operation can continue once the load is transferred from the belay line back onto the main line. This is not what I wanted to address.
I'm actually concerned with the very remote case where something (rope, equipment, anchor) other than people fail, the main line is lost, and a new main line needs to be lowered to the attendant for connection to the litter spider. Suppose the attendant, for whatever reason, is not able to connect the new rope to the litter spider mid-face. Sure, this is unlikely, but it could still happen.
Do we declare this an emergency, dispense with two rope technique, and just raise/lower with the belay line only? Are there alternatives?
I like where this is going now. Most rope is rated 9000 lbs or more, take out ~30% for a knot or look at the weakest link in the SSF. You are still going to be over 10:1 SSF in most cases hanging on the belay line. If that belay is rigged to lower, not just catch (a friction device vs. a TTRP for example), then it is the call of the rescuer... Which is more benificial; getting back to a two rope standard or completing the rescue with the least ammount of time on rope? It might be a better outcome for a critical patient to finish the lower with the remaining part of the system.
Originally Posted by servantleader
This speaks to the level of training of the team members and the ammount of risk that the rescuers are willing to assume.
We utilize parallel systems so other than reducing the overall redundancy or SSF of the system we can generally complete a raise or lower. Of course the nature of failure is always a factor that may limit simply continuing w/the op as an SRT evolution.
An incapacitate attendant is always a challenge and usually necessitates getting additional personnel over the side to manage the litter and/or deal with a "second patient". Use of a second system or climbing/rappeling to assist may be warranted based on the situation.
A physical failure of a main line in the system would generally seem to warrant getting anyone in a high angle environment out of the area or to a ledge/stable location. Rockfall, a jam or a line cutting over an edge seem to be the drivers of this type of failure in what I'd likely encounter. Evaluating if continuing will complicate the problem (e.g., sever the remaining mainline) is critical, but getting out of the "hot zone" seems like a priority in most cases.
Having a LRH in the system to provide flexibility re: stuck ropes, etc. is always useful.
Two tension with the MPD is flippin great...
Gotta love two tension system with the MPD...
Originally Posted by ProgressiveRescue