Bridge Day : Saturday

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Re: Bridge Day : Saturday

Postby Chads93GT » Oct 16, 2011 10:03 pm

i take that back, my belayer was a railroad tie.
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Re: Bridge Day : Saturday

Postby DeanWiseman » Oct 17, 2011 8:45 am

Cody JW wrote: We tried at bridge day to use a bottom belay on our best guy going down the rope , the guy on the bottom was well north of 200 clipped in the rope with full weight feet off the ground and the guy on rope did not even slow a bit. Maybe these tricks of running at an angle may work , but keep in mind at that time you have somebody screaming down the rope out of control and time is a factor.


Yeah, forget trying to weigh down for friction--I don't think that's a good technique for anything but relatively short stuff (say... 100 feet). But to do the J-belay, even moving just a couple steps is enough to make a huge difference. Part of it, though, is being in the right spot in the first place.

Another thing I think is lost on most people, a military parachute drops anywhere from 15-20 feet per second. If you were dropping at 20 fps at Bridge Day, you would be down in just over 40 seconds, which is at least twice as fast as I go... and I'm making pretty good smoke. My point is I think people "feel" like they're going faster than they actually are when they panic.

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Re: Bridge Day : Saturday

Postby DeanWiseman » Oct 17, 2011 4:25 pm

By the way, was that a KICK ASS Bridge Day or what?

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Re: Bridge Day : Saturday

Postby Scott McCrea » Oct 17, 2011 4:33 pm

DeanWiseman wrote:Yeah, forget trying to weigh down for friction--I don't think that's a good technique for anything but relatively short stuff (say... 100 feet).

I don't understand this. I get and have used the J-belay. But, when people say that bottom belays don't work on long ropes, I have never seen a good explanation of why.
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Re: Bridge Day : Saturday

Postby Chads93GT » Oct 17, 2011 5:09 pm

Dean, it was pretty awesome. It was a LONG day (started at 4am) and pretty cold up top. Once I rapped to the bottom and felt the temp change i had to strip off 4 layers down to my compression t shirt before climbing back up. once up i was sweating my ass off till i cooled down, had to put all 4 (dry) layers back on finally to warm up, lol. Crazy.
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Re: Bridge Day : Saturday

Postby johnlhickman » Oct 17, 2011 6:10 pm

Chad. Speaking of no belay. Did you find out if someone recovered your phone?

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Re: Bridge Day : Saturday

Postby Chads93GT » Oct 17, 2011 7:07 pm

johnlhickman wrote:Chad. Speaking of no belay. Did you find out if someone recovered your phone?

John


I emailed all of the team it landed bya nd the gal who found it responded and is sending it back to me. The micro card is undamaged and the phone still slides apart to expose the qwerty keyboard, lol.
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Re: Bridge Day : Saturday

Postby Cody JW » Oct 17, 2011 7:23 pm

Scott McCrea wrote:
DeanWiseman wrote:Yeah, forget trying to weigh down for friction--I don't think that's a good technique for anything but relatively short stuff (say... 100 feet).

I don't understand this. I get and have used the J-belay. But, when people say that bottom belays don't work on long ropes, I have never seen a good explanation of why.
I do not know why, all I know is it did not stop our guy. I will say most people who have used bottom belays have tried them on a lot shorter drops than this. I am sure it may be possible, but only when the person is close to the bottom belayer . Like I said before, I am not sure most people will want to hang around and wait until the out of control person who has been falling several hundred feet gets closes enough to stop them on a long drop like this. Maybe I am wrong and I could be but I just think your natural self preservation mode will kick in. Our attempt was where the person on rappel was about five hundred (or maybe more) feet up and the belayer pulled straight down with a QAS. I just would not count on one on a drop like that with all things considered. Maybe if a deviation can be used with some sort of weighted pulley where the belayer was not right at the bottom of the rope will give the belayer more confidence. "On Rope" describes this to protect the belayer from a rockfall in a cave shaft. Not sure how that would work in this situation. 900 feet is a lot of nylon. I just remember how much stretch I had to climb out of the rope there and at Golandrinas before the rope felt tight. At Golondrinas I remember climbing out lots of stretch near the bottom, then it felt kind of tight then all of a sudden I would have to climb more stretch out after I went up about 50 feet where the rope felt like the stretch was gone. Before somebody comes up with the suggestion that maybe we were using dynamic, we were using PMI classic pit rope. I am not saying it will not work at all, at some point it likely will. I am just saying do not expect the same result you would get on a bottom belay at your favorite 150 foot pit. Where is Storrick ?? I figured maybe he had some kind of scientific study on rope stretch on long ropes and how that may create problems with a belay . What we did was not scientific , it was just one attempt out of curiosity . I suspect a more thorough test may prove me wrong. I just would not trust one there.
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Re: Bridge Day : Saturday

Postby self-deleted_user » Oct 17, 2011 7:42 pm

OMG that was YOUR phone that we all heard drop, Chad?? hahahahaha nice (yes, we heard it clang from down below :P we were like "oh someone lost a cell phone...." haha)

As for belaying...I don't understand why it doesn't work 'cause uh...it was working fine for me. I was catching Mark on the practice bluff just fine when he was going out of control (on purpose). In fact I heard stories this weekend of belaying at Bridge Day saving people - I think it was Tiny saying that peeps were along your path of thinking, Dean, until he explained long rope belaying and situations it *had* saved people. I dont remember the stories exactly but I know VBats are uber safety conscious and I'd trust all the experienced peeps on the team. My understanding is if you do it right, it works, basically. Just like a lot of things ;) Gotta keep pulling slack through to keep tension equal and I guess hmmm isn't static rope by definition <6% stretch? So wouldn't that be for a 900ft rope about 50ft of stretch so if you were to have to weight the bottom if they went out of control at the very top you would need to get downhill enough to account for 50ft max. And if pulling slack out as they com down that gets to be less and less. Hence why pull=slack-out-like-mad-shove-qas-up-high-rundown-jump yeah? And that would go down as they come down, loosing control halfway down only need 25 ft, so on so forth. I could see how long rope could be *harder* as there is more stretch to account for but I don't think that means it doesn't work, just that have to pay attention and plan for it, yeah? Of course, what do I know :P

For me the hardest bit about belaying was when the wind got gusty. I tried really hard to give people good rides (and was told I did yayyyyy!) but when it was gusty...not much I can do if I let out more slack the wind would just take it anyway. I felt bad though, a couple probably had some jerky rides from that. At least when the wind was solid the person on rope could adjust for that tension I was told which made me feel better for that - I was trying to figure out if there was anything I could do to make rides better in such situations but I guess the answer is basically...nope whoever is on rope has to deal with it.

LOL there was one gust that lifted me off the ground :yikes: I just had my qas on it holding 'cause we had no one up top and the wind was being particularly gusty and I didn't want it running into straight-peoples-rope (there was a group near us that had soooo much tension i rarely saw any natural wind-arc in it and the ropes got close a few times because of that especially if there was no one on our rope), and all of a sudden *bam* I was like a bunny hopping on the ground forced to by the wind. It was rather funny xD I'm not that lightweight either!
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Re: Bridge Day : Saturday

Postby Carl Amundson » Oct 17, 2011 7:45 pm

Chads93GT wrote:
johnlhickman wrote:Chad. Speaking of no belay. Did you find out if someone recovered your phone?

John


I emailed all of the team it landed bya nd the gal who found it responded and is sending it back to me. The micro card is undamaged and the phone still slides apart to expose the qwerty keyboard, lol.

We actually found 2 phones that had come off the Bridge.
I'm glad we could get it back to you.

Oh and yeah that was a GREAT Bridge Day. :banana:
Last edited by Carl Amundson on Oct 17, 2011 8:11 pm, edited 2 times in total.
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Re: Bridge Day : Saturday

Postby Chads93GT » Oct 17, 2011 7:47 pm

J belay didnt work on Mt. Thor when the park ranger rappelled out of control for over 3200 feet to his final destination of 4250. ONe of the safety team guys was on that trip and told me about it, it didnt slow him down at all.
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Re: Bridge Day : Saturday

Postby Chads93GT » Oct 17, 2011 7:49 pm

and i prefer no belay :P
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Re: Bridge Day : Saturday

Postby Cody JW » Oct 17, 2011 8:31 pm

I did it many years ago, I do not remember anyone positioned as belays. Back then we were all told at the safety meeting that EVERYONE had to have 6 bars engaged when they left the catwalk, after that you could do what you wanted. I said " No problem here" . The only bottom people I remember was for radio communication from top to bottom.
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Re: Bridge Day : Saturday

Postby johnlhickman » Oct 17, 2011 10:36 pm

Before I started going to Bridge Day, I think Wm Shrewsbury did some belay tests and also some test on just how hot a rappel brake bar gets while traveling down the rope.

The challenge of an effective bottom belay for long distances is the rope stretch and the increased need for friction as the rappeller approaches the ground due to lower rope weight and heat build up on rack bars. There might be an article on this in an old issue of The Nylon Highway, which is published by the NSS Vertical Section, or an old TAG-Net posting.

I do believe the J belay, where the rappeller descends into a loop, can be effective as it is easier for the bottom belayer to control and doesn't depend on increasing friction. A perfect spot for this is Surprise Pit in Fern Cave, AL where there is a 50 foot rise from the rappel landing zone.

While the stopping effect of a bottom belayer may be questionable, they do serve an important function at Bridge Day by helping manuever the rappeller away from trees, thorns, mud and water. They can also help move the rope away from the bridge structure to prevent wear points.

Glad everyone had a great time at Bridge Day. Even on the Safety Team, I managed to get in three rappels on our safety team rope and one climb on the ascent ropes. I had only gotten one rappel and climb in the previous two years, so I was glad to get more rope time in. Will be in nursing school next year, so I don't know when I will be back.

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Re: Bridge Day : Saturday

Postby jharman2 » Oct 18, 2011 9:29 am

johnlhickman wrote:There might be an article on this in an old issue of The Nylon Highway, which is published by the NSS Vertical Section, or an old TAG-Net posting.


http://www.caves.org/section/vertical/n ... tblay.html
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