Rescue Pully Placement

[Gary_Yngve]

Mark, you're correct, my bad.

 

Anyway, I did an unscientific experiment in my apt, and it feels like it's easier to pull with a pulley at the anchor and a carabiner floating, as opposed to vice-versa. This follows the logic of wanting the pulley where the most friction is, but runs against the logic of wanting the best efficiency where if the system gets clogged elsewhere, you have the best ratio.

 

So who the heck knows..

[Wastral]

Try posting actual reasons where you would actually ever use a drop loop system instead of calling names.

 

In your own post you put that they hardly ever use the drop loop system. As I pointed out there is ALWAYS a faster and safer way to do crevasse rescue in all situations than the drop loop system.

 

Once again, you guys never state how, why, or where you would use a Drop loop system. Just claim others teach it and its good. I have run into many tweedle-des and tweedle-dums in the mountaineers etc who were "teachers". Why would anyone take someones word on something just because they say so and happen to "teach" something. Use your brain, don't be lazy, think it through for yourselves.

 

Just because a teacher says something doesn't mean they know anything, just means they can repeat what they have been told.

 

Its a proven fact that women can hold multiconversations at once wheras most men cannot. Thus, once again I stated fact, while you guys turn to name calling.

 

Brian

[genepires]

No one ever said that "they hardly ever use the drop loop system"

 

you want a scenerio where the drop loop makes sense?

 

3 person rope team with a 60m rope, spaced out 40 feet apart which leaves 40 feet of rescue coils on either end. End guy falls in and cuts into the glacier at 20 feet from the middle guy. This leaves 120 feet of rope on surface, anchor to end of surface rope. Since the rope cuts in so far, prussiking and simple 3:1 won't work. A rescue hole must be prepared to the side to either haul or prussik out. The victim has sprained his wrist and is unable to prussik. So you must haul. There is enough rope to send down a loop (80 ft) and still have rope to make the 3:1 to pull on the 2:1 (40 feet). There is less cutting of the snow with the rope because there is less force per strand. Lip still padded anyway. Just one tool for a job.

 

there is a scene where it works. you happy?

 

I agree that men have difficulty with multi conversations. But those teachers you dismiss have done the rescue for real many times and have experience to back up their statements.

 

gotta run.

[Wastral]

60m rope = ~200feet

If 40 feet apart in your scenario you have

 

200

-80

=120

div by 2 = 60feet coils on lead/rear guy

So have 60 feet +40 feet = 100ft of rope

 

84 feet is used as drop loop due to streching of the rope leaves you 16 feet to make z and tie packs and yourselves to ground. Say an 8 foot z(2:1) = 16 feet, anything shorter and you can barely get the rope stretch out of the system before resetting. Can't even make a 3:1(z on a z)for a 6:1 with the drop loop.

 

Leaves you negative feet to pull with and tie yourselves in on a 2:1 on a drop loop making a 3:1. A knot for the anchor takes another 2 feet out leaving you with minus 2 feet to pull with. For a total of minus 4 feet since with using prussics as hand grabs only takes 2 feet of rope to pull with.

 

Of course who goes in 3 man climbing groups??? No one. Not to mention your scenario doesn't work.

 

Takes 1 leg 1 arm to prussic out anyways. So, if we assume he can't prussic out then he can't attach the loop either and you are sending a climber down for first aid and piggy backing him on your back.

 

Brian

PS. Yes, some teachers know what they are talking about, but it still means one must contemplate what they say and take what they say with a grain of salt

PPS. Youtube is a great spot to learn crevasse rescue placement and how to due basic avalanche awareness training.

Edited February 16, 2009 by Wastral

[pinner]

Can't speak as to the physics of it, and haven't had to use it in a real emergency rescue, but have indeed had my 100 lb girlfriend set up a 6:1 on her own with me 10 m down a hole and haul me out. Might be different in real life applications of course, as we had the rope set up with this specific situation in mind.... but I believe we also got a 9:1 rigged out of it, with some help from some firefighters from Calgary who teach rescue systmes to other firefighters... Between the 5 of us there were pulleys out the ying yang, so we didn't need to worry about where to put it, but they DID say if you only have one, make it the one doing the most travelling, i.e. at point 2. These fine gentlemen were extremely well versed in rescue.

[genepires]

who goes with a 3 person rope team? This is the newbie forum. I would hope that any newbie reading this would start out going on a glacier with 3 or 4 people.

 

Actually I would hope that any newbie would go with 2 rope teams of 3 as a minimum for a basic glacier climb. There is another scenerio where an entirely new rope with LOTS of rope can be used to make any kind of rope system.

 

As for my earlier scenerio, a 20 foot fall is fairly severe of a crevasse fall. There are lots of crevasses where a 20 foot fall would wedge the person. A 10 foot fall is reasonable and can easily make the drop loop. There is your new scenerio. So you see, it is usuable for some situations. To beat an old horse, it is just one tool for certain situations. There is no one way to solve any crevasse rescue situation. That kind of thinking will get people in trouble. The only reason why I am spending way too much time on this is because I only don't want newbies to have incorrect assumptions and head out into trouble.

 

I would trust fully certified AMGA instructors over youtube videos anyday. (as well as all most anybody from this website for that matter) Any knucklehead can post on you tube or this site. I mean, like 2 chicks and a cup are on youtube.

 

Yeah, everyone should question the teachers points and should evaluate the credentials as well as the content.

[Wastral]

The youtube videos were posted from the AMGA guys. I forgot to put that in there. Oops. They also have videos demonstrating rope management, abalakov anchors, avalanche preparedness, Pro placement, rack useage, etc.

 

Brian

Edited February 16, 2009 by Wastral

[genepires]

sounds good. Seeing their rope management should be informative for sure. What did you use to search for those? (guess AMGA and rope management?)

 

[Wastral]

I was originally looking for avalanche stuff. How I found the others I dont know. The related window would be my guess. At the time I was watching the after reports of an avalanche where someone had died and they were investigating the snow pack for why, what, where, and how it happened.

 

Brian

[snoboy]

Rock Climbing dot com already had this discussion.

 

So did Cavechat dot org.

 

Petzl also has something to help us out. Click on any of the pulleys to swap it out, see the change in force on the upper right.

 

I have found a great diagram to explain it as well, but it is needing to be scanned...

[spotly]

Thanks for the links. That's an excellent thread on rock climbing .com.