What did I just read?

Discuss vertical caving, equipment, & techniques. Also visit the NSS Vertical Section.

Moderator: Tim White

Re: What did I just read?

Postby Stan Allison » Apr 5, 2013 3:54 pm

I'll consult The Book to see what the one true rebelay crossing technique is. I may have to do some resto as a penance.


I just checked THE BOOK to see what the one true rebelay crossing technique is and unfortunately it seems as if I will be spending eternity with Derek doing restoration. Neither of us is in compliance with Alpine Caving Techniques Chapter J verse 3.5 Passing a Rebelay. ACT does not discuss using either a long cowstail to clip the to the long loop the Stan/right way or using an ascender to attach below the knot on the rebelay anchor the Derek/wrong way. :big grin:
I do know that many of my European caving friends pass rebelays this way and that most of them are still alive. Meanwhile I will continue clipping my long cowstail into the loop when I pass rebelays.
Stan Allison
Occasional Poster
 
Posts: 45
Joined: Jun 6, 2007 5:08 pm
  

Re: What did I just read?

Postby jharman2 » Apr 8, 2013 12:14 pm

I also pass rebelays on descent by using an ascender just below the knot of the "down" rope. I think a FF greater than or equal to 1 on the ascender is VERY unlikely. I can only see two reasons why the ascender would see a shockload:

1. The short cows tail fails while statically loaded causing the load to be transferred to the ascender. This scenairo is very unlikely as it would require the failure of the 'biner or the cowstail. It might produce a FF1 but that would depend on the length of the cowstails and ascender attachment.

2. The descender attachment fails while loading the descender. This is EXACTLY the situation that the safety is intended to prevent. In this situation you have unclipped the short cowstail from the rebelay anchor and are weighting the descender in a controlled fashion. The primary attachment point (d-ring) is all ready well below the ascender when this failure would occur. In this scenario the FF would be quite negligible.

I don't see a problem with either of the previously mentioned methods of passing a rebelay.
John Harman (Pantin apologist)
http://www.wvunderground.net/
User avatar
jharman2
Prolific Poster
 
Posts: 197
Joined: Nov 23, 2006 11:40 pm
Location: West Virginia
Name: John Harman
NSS #: 58082
Primary Grotto Affiliation: WVUSG
  

Re: What did I just read?

Postby Scott McCrea » Apr 8, 2013 12:42 pm

Fantasizing about gear failure is futile. Human failure is inevitable. Prepare accordingly.
Scott McCrea
SWAYGO
User avatar
Scott McCrea
Global Moderator
 
Posts: 3198
Joined: Sep 5, 2005 3:07 pm
Location: Asheville, NC USA
NSS #: 40839RL
Primary Grotto Affiliation: Flittermouse Grotto
  

Re: What did I just read?

Postby Stridergdm » Apr 8, 2013 12:46 pm

Scott McCrea wrote:Fantasizing about gear failure is futile. Human failure is inevitable. Prepare accordingly.


I may have to steal that quote. I like that.
Cavers rescue cavers!
User avatar
Stridergdm
NSS Hall Of Fame Poster
 
Posts: 926
Joined: Nov 1, 2005 10:08 am
Location: Capital District NY and Northern Virginia
Name: Greg Moore
Primary Grotto Affiliation: RPI Grotto
  

Re: What did I just read?

Postby potholer » Apr 17, 2013 3:47 pm

Scott McCrea wrote:Fantasizing about gear failure is futile. Human failure is inevitable. Prepare accordingly.

That's basically what governs my rebelay-on-descent technique.

As with various people above, short cowstail into the knot, long cowstail into the loop below the descender, and remove long cowstail last thing before descent (after checking descender performing OK).

Compared to the slim chance of anchor failure, I think there's a greater probability that I could get distracted in the middle of a changeover and end up removing the short cowstail with the descender not attached to the rope - I've had the odd occasion where I'd started on that path but not got to the point of removing the short cowstail.

Speed-wise it seems to take little extra time, and since I use a Stop, as long as I'm not being observed by any novices I don't want to risk miseducating, it means that locking off is essentially unnecessary for normal-thickness ropes even for situations where both hands are definitely busy taking off the short cowstail - the Stop doesn't seem to meaningfully slide even when not locked off, but even in some scenario of slipping while lowering onto it and the lock not engaging, I could only move a short distance before the cowstail held me.
Compared to locking off and unlocking, placing and removing the long cowstail seems likely to be significantly quicker.
potholer
NSS Hall Of Fame Poster
 
Posts: 381
Joined: Nov 9, 2005 7:29 am
Location: UK
  

Re: What did I just read?

Postby Anonymous_Coward » Apr 17, 2013 5:27 pm

Stan Allison wrote: Both you and Derek will probably spend eternity in ACT hell for your acts of sacrilige. This will involve mopping up nasty leads for eternity on one of my cartography projects.


Hmm, it seems that I may in fact already be in hell. :big grin:
Andy Armstrong
American Carbide Council
User avatar
Anonymous_Coward
NSS Hall Of Fame Poster
 
Posts: 893
Joined: Feb 3, 2006 1:40 pm
Location: Inside the Beehive
NSS #: 45993RL FE
Primary Grotto Affiliation: Paha Sapa Grotto
  

Re: What did I just read?

Postby hunter » Apr 19, 2013 6:10 pm

Andy, I'm pretty sure you are!

I should note that I am very, very happy to discover I don't usually cross rebelay's in the same fashion as either Stan or Derek! I always clip my long cowstail in as backup but I almost always clip into either the bolt hanger, maillon/locking biner or knot depending on which one I can reach. On rare occasions I mix this up with a backup on the loop if the previously mentioned points are hard to access for some reason. Somehow a short fall onto the bolt/knot strikes me as nicer than a longer fall onto the loop but I'm only moderately thrill seeking.

I am reluctant to mention it but I have popped my croll off a couple of times on J hang change overs that were rigged short. No surprise that when you load a croll this way it can come off.

James
hunter
NSS Hall Of Fame Poster
 
Posts: 395
Joined: Sep 9, 2005 9:47 am
Location: New Mexico
  

Re: What did I just read?

Postby Extremeophile » Apr 20, 2013 6:07 pm

Stan Allison wrote:
I'll consult The Book to see what the one true rebelay crossing technique is. I may have to do some resto as a penance.


I just checked THE BOOK to see what the one true rebelay crossing technique is and unfortunately it seems as if I will be spending eternity with Derek doing restoration. Neither of us is in compliance with Alpine Caving Techniques Chapter J verse 3.5 Passing a Rebelay. ACT does not discuss using either a long cowstail to clip the to the long loop the Stan/right way or using an ascender to attach below the knot on the rebelay anchor the Derek/wrong way. :big grin:
I do know that many of my European caving friends pass rebelays this way and that most of them are still alive. Meanwhile I will continue clipping my long cowstail into the loop when I pass rebelays.

It took me a while to consult The Book, but there is a footnote on a later page that describes your long cowstail into the rebelay loop method:

Marbach and Tourte wrote:It may be due to the graver consequences of user error with a rack that in the US, standard practice is to use both cowstails for safety when beginning a descent and passing a rebelay. The short cowstail is placed in the anchor or its connector, the long one is clipped into the rope loop as a backup. When the descender is installed on the lower rope, the short cowstail is removed to load the descender (long cowstail is still hanging slack in the loop). The long cowstail is only removed once the user has unlocked the descender and verified that it is loaded correctly. The long cowstail is removed and the descent continues.
After some accidents involving the use of two cowstails in these circumstances, many European cavers consider this technique to be more dangerous than the use of one cowstail, given the use of a spool descender (which does not detach from the rope when loaded incorrectly). However, the French Caving School does consider the use of two cowstails a viable choice when teaching beginners.

Call me a heretic, but I don't see how the use of a backup has led to "some accidents", and how it could be considered "more dangerous".

Although they state that the descender may not detach from the rope when loaded incorrectly, in Chris's case this wasn't the problem. Besides, I have heard anecdotes that suggest it is possible to load a spool descender incorrectly leading to the rope becoming detached, e.g. when the front plate doesn't latch properly. There are other possible problems with spool descenders such as cross-loading the main attachment biner that will keep me using a backup even at the risk of being labeled a "beginner".
User avatar
Extremeophile
NSS Hall Of Fame Poster
 
Posts: 761
Joined: Dec 7, 2009 7:37 pm
Location: Littleton, CO
Name: Derek Bristol
NSS #: 34941
Primary Grotto Affiliation: Colorado Grotto
  

Re: What did I just read?

Postby potholer » Apr 20, 2013 6:56 pm

I'd wonder how 'many' European cavers would consider the both-cowstail-technique to be dangerous rather than (in the eyes of some) just unnecessary?

Indeed, I'd wonder how many cavers were actually aware of the 'some accidents' mentioned?

It's not immediately easy to imagine what such accidents could involve, short of someone losing control of descent while removing the cowstail, or something odder.
potholer
NSS Hall Of Fame Poster
 
Posts: 381
Joined: Nov 9, 2005 7:29 am
Location: UK
  

Re: What did I just read?

Postby Cody JW » Apr 21, 2013 9:18 am

I was really concerned with removing the upper foot loop Jumar on a frog ( the one that has the safety line running to the seat) for the short time it takes to reconnect it above a tricky lip and leaving yourself hanging by only the croll. It seems I have had to do this many times in the past, just felt better having my QAS attached when doing this. I already had the QAS on my seat anyway so it did not involve anything I did not already have .
It only takes one person to surrender a dog to a kill shelter ,but it takes many to rescue it.
User avatar
Cody JW
NSS Hall Of Fame Poster
 
Posts: 905
Joined: Oct 24, 2007 10:16 am
Location: Indianapolis In. USA
Name: Jeff Cody
NSS #: 23961
  

Re: What did I just read?

Postby caverdan » Apr 21, 2013 9:28 am

While you guys have been out playing with your Cow's Tail's... :off topic: ...Mikie and I have been at Hooters figuring out how to properly weigh a persons Ta Ta's. :banana: The flop and drop method that "might" have been used in the article did not seem practical or accurate. We found....through much expermentation....that by leaning a person forward or back..... changed the scale reading immensely. :down: Our solution was to make a mold using quick setting plaster and a wood box of proper dimension ....to contain the test subjects.....breasts. :woohoo: Make sure to lube them up so they don't stick in the mold. :doh: Vaseline works good for this. Once the plaster has set....remove the subject that is being weighed. Place Saran wrap into the mold and fill it with Tapioca pudding. Now you can remove the Saran wrap and pudding a get a pretty accurate weight measurement. Is it more than a mouthful?? Most women's are....not so much for men. We are still working on a conversion chart for pounds of tapioca pudding per gallon. :big grin: (Maybe we can set up a booth at convention to further our studies)
Member: Colorado Madrats, SoCoMoGro,CWSG.
caverdan
NSS Hall Of Fame Poster
 
Posts: 657
Joined: Nov 24, 2006 9:39 pm
Location: Colorado Springs
NSS #: 40262
  

Re: What did I just read?

Postby mgmills » Apr 21, 2013 10:04 am

caverdan wrote:While you guys have been out playing with your Cow's Tail's... :off topic: ...Mikie and I have been at Hooters figuring out how to properly weigh a persons Ta Ta's. :banana: The flop and drop method that "might" have been used in the article did not seem practical or accurate. We found....through much expermentation....that by leaning a person forward or back..... changed the scale reading immensely. :down: Our solution was to make a mold using quick setting plaster and a wood box of proper dimension ....to contain the test subjects.....breasts. :woohoo: Make sure to lube them up so they don't stick in the mold. :doh: Vaseline works good for this. Once the plaster has set....remove the subject that is being weighed. Place Saran wrap into the mold and fill it with Tapioca pudding. Now you can remove the Saran wrap and pudding a get a pretty accurate weight measurement. Is it more than a mouthful?? Most women's are....not so much for men. We are still working on a conversion chart for pounds of tapioca pudding per gallon. :big grin: (Maybe we can set up a booth at convention to further our studies)


LOL - Only you and Mikie could come up with something like this.
Martha Mills
NSS 39864
User avatar
mgmills
Global Moderator
 
Posts: 1375
Joined: Sep 5, 2005 3:06 pm
Location: Sewanee TN
Name: Martha Mills
NSS #: 39864
Primary Grotto Affiliation: Dogwood City Grotto
  

Re: What did I just read?

Postby Phil Winkler » Apr 21, 2013 6:09 pm

Please ensure you tip the subjects very well, too.
Phil Winkler
13627 FE
User avatar
Phil Winkler
Global Moderator
 
Posts: 2375
Joined: Sep 5, 2005 8:48 am
Location: Wilmington, DE and Dewey Beach
NSS #: 13627FE
  

Re: What did I just read?

Postby Anonymous_Coward » Apr 22, 2013 12:12 pm

Thank you Dan for finally bringing this thread back to its original topic.
Andy Armstrong
American Carbide Council
User avatar
Anonymous_Coward
NSS Hall Of Fame Poster
 
Posts: 893
Joined: Feb 3, 2006 1:40 pm
Location: Inside the Beehive
NSS #: 45993RL FE
Primary Grotto Affiliation: Paha Sapa Grotto
  

Re: What did I just read?

Postby Cody JW » Apr 22, 2013 8:47 pm

Caverdan -Now that you have the Ta Ta's figured out , have you figured out a way to accurately weigh the rear end. I think there was a reference to that in the article also.
It only takes one person to surrender a dog to a kill shelter ,but it takes many to rescue it.
User avatar
Cody JW
NSS Hall Of Fame Poster
 
Posts: 905
Joined: Oct 24, 2007 10:16 am
Location: Indianapolis In. USA
Name: Jeff Cody
NSS #: 23961
  

PreviousNext

Return to On Rope!

Who is online

Users browsing this forum: No registered users