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Building a rescue haul system kit

PostPosted: Aug 11, 2013 6:27 pm
by OpenTrackRacer
After completing the recent NCRC Cave Rescue course, I want to build up my own rescue haul system kit to keep with us on trips. I have some equipment already but need more to make a complete system. This has brought up some questions I'm hoping to answer.

To make a z-rig 3:1 haul system the NCRC way, I'll need two pulleys (one prusik minding), a Petzl Rescuescender and one prusik (plus carabiners). I already have a Petzl Rescue pulley (the blue and purple model) and some Sterling 7mm accessory cord for making prusiks. So, it seems that I need a prusik minding pulley (PMP) and a Rescuescender. Petzl only makes a mini PMP and I'd rather have something with a larger sheave diameter. Can anyone recommend a PMP for this application? Also, for the prusik, can anyone recommend what cord length to use for 11mm rope?

I was also wondering about something like the Petzl Pro Traxion. Could that be used instead of a PMP and prusik for progress capture?

Thanks!

Mike

Re: Building a rescue haul system kit

PostPosted: Aug 11, 2013 6:39 pm
by Caver John
I carry two cmc prussic minding pulleys which will handle 11mm fine and are very light and compact. Also two or three prussiks, 2 Daisey chains of 1"x 20' webbing. And some lockers. And a wildcountry ropeman. This all fits nicely in a 7x11 molle pouch on the bottom of my pack.

Re: Building a rescue haul system kit

PostPosted: Aug 11, 2013 7:27 pm
by chh
I realize that you may want a kit that is easily deployed and ready to go, but I wonder how long it will be before you prune that dead weight out of your pack?
If you're going into a vertical cave system, here's what I suggest: Every person on the team carries a micro pulley and a prussic. (You should have a prussic in any case) I use cordage for my footloops and handlines, which I also suggest because I feel they interface better into other improvised systems. Right there you've already got more than you need to set up a haul system of several varieties. And what's better, you don't have to carry it! :grin:

Re: Building a rescue haul system kit

PostPosted: Aug 11, 2013 8:33 pm
by Scott McCrea
What Caleb said. I made a jigger, but it stays in the truck, just in case. The chance you'll need it is slim. Carrying tools in your brain is usually more efficient than carrying them on your back.

Re: Building a rescue haul system kit

PostPosted: Aug 11, 2013 9:32 pm
by Stridergdm
Minor rant: it's prusik (after Karl Prusik).

Anyway, I wouldn't go with the rescucender. I've got two, but keep them in my car.

Use a prusik in place of the rescucender. It's lighter and gives you more options in usage.

Keep in mind too, that you can build a 3:1 with a couple of rope grabs and carabiners.

Pulleys are certainly more efficient which is nice, but not necessary.

And to answer your other question, yes, a Traxion (or micro-traxion as I used to have before it got lost) can be used. They're useful, but have their own quirks.

And Petzl does make larger sheeved PMPs. I have one.

In any case, glad you're taking your NCRC skills and trying to put them to use.

(oh one more tip I'll add just in general, "Rig with only as much rope as you need to the bottom of the pit, leave the extra at the top. It's more useful there."

Re: Building a rescue haul system kit

PostPosted: Aug 11, 2013 9:35 pm
by Caver John
chh wrote:I realize that you may want a kit that is easily deployed and ready to go, but I wonder how long it will be before you prune that dead weight out of your pack?
If you're going into a vertical cave system, here's what I suggest: Every person on the team carries a micro pulley and a prussic. (You should have a prussic in any case) I use cordage for my footloops and handlines, which I also suggest because I feel they interface better into other improvised systems. Right there you've already got more than you need to set up a haul system of several varieties. And what's better, you don't have to carry it! :grin:



I should mention I don't carry this setup caving. I carry it in my SAR ready pack and when doing any hiking in or around crevasses. For caving I agree to improvise with what's available or keep a kit outside the cave.

Re: Building a rescue haul system kit

PostPosted: Aug 11, 2013 10:55 pm
by OpenTrackRacer
Thanks for all the feedback. Thanks also for the Petzl PMP tip... I should have looked in professional rather than just sport!

I understand completely about saving weight and keeping extra rope at the top of a pitch but our situations when mine exploring are usually different than what you encounter in caves. Typically, we have one big drop to start and we usually don't know the depth either so all the rope has to go down. We're going to be working on a new project soon where we know the depth (900' total) and we want to have a haul system on standby at the surface. Weight is not an issue but efficiency and ease of operation are.

A Petzl PMP and Rescucender is cheaper than a Pro Traxion so I'd rather go that route. I'll still have a bunch of standard pulleys and prusiks around if needed and to distribute as needed for pitches further into the mine.

So, one remaining question... how long should I make my prusik loops?

Thanks again!

Mike

Re: Building a rescue haul system kit

PostPosted: Aug 11, 2013 11:05 pm
by OpenTrackRacer
One other thing I just came across. Has anyone ever used one of these?

http://www.karstsports.com/siropaprknto.html#.Ughc8NL1fwk

It seems like an incredibly handy piece of kit, especially since I already have several Petzl Fixe pulleys.

Mike

Re: Building a rescue haul system kit

PostPosted: Aug 12, 2013 1:29 am
by snoboy
If using 8mm cord on 11mm rope, a cut length of 135cm will give you a prusik that will work well with a "standard" 2 inch PMP.

In theory anyway.

Re: Building a rescue haul system kit

PostPosted: Aug 12, 2013 4:05 am
by NZcaver
Each time you go back and do another level of NCRC, I guarantee you will reevaluate your options and end up buying even more gear. Welcome to the club. :big grin:

The answer to your Prusik question is approximately 18 inches, AFTER being tied in a loop and measured tight end-to-end (between 2 points). So you'll need to start with a minimum total length of 36 inches plus the Double Fishermans bend plus short tails. Snoboy's 135cm length sounds about right. This should allow you to tie a 3-wrap Prusik to fit snug under a 2-inch PMP, but you might want to go a little longer for larger PMPs or a little shorter for smaller ones. A flexible 8mm cord is recommended for Prusiks on 11mm rope, but 7mm should work OK for what you need. Best plan is to get your PMP and rope and Prusik cord together, and tie, test and adjust the Prusik before cutting it to length.

For the mine application you described, are you talking about pre-rigging a 3:1 haul system using your main rappel rope, or piggybacking a 3:1 onto the rope later if you need it? Either way, lifting 1 person plus the weight of the rope plus edge protection and/or redirect pulley friction will require a lot of work from at least 4-5 people. Or you could go with what Scott suggested and pre-rig a piggyback 4:1/ 5:1 jigger with a pair of 1 inch twin sheave pulleys using 7mm or 8mm cord. Less force and people required to operate, but this will take longer to haul and more resets. Keep your jigger kit in reserve for if you need it, or carry the components spread between several people on a trip. Or pay the big money and get yourself a tiny commercial jigger system.

An alternate option at the top of the shaft is to use a counterbalance system, especially if your help is limited. Let your body weight and/or climbing efforts do the work, providing you have enough equipment and expertise to manage it. But that's a whole other can o' worms. If you do stick with a haul system, consider using a Pro/Mini/Micro Traxion for the PCD in place of a PMP and Prusik. The advantage with the Traxions is that an integral cam is much easier to tension and release and generally adds less friction than a Prusik in this configuration. Just be aware that the rope feeding through any device with a toothed cam should not be allowed to sustain a shock load or there could be disastrous consequences!

I also agree with Greg about the rescucender - probably not the best value for money in your application. However I also think certain mechanical cams have a definite advantage in handling and efficiency over a 3-wrap Prusik hitch for applications like a haul cam. Have you considered the Microcender instead of the Rescucender? Similar design and performance, but about half the size and slightly cheaper. I have several of each, but I keep the smaller ones on my pre-rigged kits because they are just a little more compact.

Have fun with your rescue pre-plan!

Re: Building a rescue haul system kit

PostPosted: Aug 12, 2013 5:47 am
by Stridergdm
I'm going to echo what NZCaver said about a counter-balance. As soon as I read your application it occurred to me that a properly rigged counter-balance may be ideal.

If you're not familiar with how to rig and use one, well all that more reason to come out to Week-long in Colorado next year and take Level 2!

Or get your regional coordinator to arrange for a Small Party Rescue class (in fact that may be ideal for your situation.)

Re: Building a rescue haul system kit

PostPosted: Aug 12, 2013 9:37 am
by Anonymous_Coward
The new Petzl Mini PMPs are 91% efficient, so I do not think there is any efficiency advantage in going to a full size 2" pulley instead.

Re: Building a rescue haul system kit

PostPosted: Aug 12, 2013 11:26 am
by Carl Amundson
My emergency haul system kit consists of a Micro-traxion, a CMI Micro Rescue pulley and a couple of prusik loops.
With that I can build anything I would need for a single person load. It is with me anytime I'm underground.
Also, don't just focus on 3:1 haul systems. A 2:1 haul system with a redirect is a great haul system for a single person load.

Re: Building a rescue haul system kit

PostPosted: Aug 12, 2013 1:29 pm
by NZcaver
Anonymous_Coward wrote:The new Petzl Mini PMPs are 91% efficient, so I do not think there is any efficiency advantage in going to a full size 2" pulley instead.

Good point. I revised my earlier comment.

Pulley efficiency aside, I suspect the tighter bend required to pull stiff caving rope through a 1 inch pulley versus a 2 inch pulley may affect the efficiency of the system too. But it's probably not significant enough to worry about.

Re: Building a rescue haul system kit

PostPosted: Aug 12, 2013 1:51 pm
by cavedoc
snoboy wrote:If using 8mm cord on 11mm rope, a cut length of 135cm will give you a prusik that will work well with a "standard" 2 inch PMP.

In theory anyway.


Yep. The canonical lengths for a tandem prusik belay are 1.35 and 1.65 meters for 8mm cord. Once you take level 2 in CO next year (you're going, right?) then you'll want the set so you might as well cut them that length to start.

Agree+++ on the counterbalance idea for a 900 foot mine shaft. It's been posted before but the rescue in Ellison's used a counterbalance to raise someone up Fantastic Pit, and they had the man power to brute force it, unlike your smaller trips into the desert.

http://www.firefighternation.com/articl ... e-24-hours

Since weight and volume is not an issue for you, why not just rig your shaft in haul configuration to start with? The rope would hang off of the prusik but would be backed up by the other gear in your Z-rig. I'd try it first before settling on it but if you used a rescucender, it might be enough weight to go back down the shaft and reset itself (on a taut rope). With a redirect pulley at the top you could just pull and let go muliple times and accumulate a pile of rope at the top. This is likely the configuration you would end up with anyway if you converted your hanging rope into a haul system.