100 foot vs. 300 foot

[Scott Card]

Shane's post of Red Hollow reminded me of a comment I make to those with shaky knees, including myself, at the tippy top of a 300 foot rap. "There is no difference in a 100 foot rap and a 300 foot rap. Its all in your mind." Am I full of it? Ok techies, educate me. :popcorn:

[rockgremlin]

Dunno. The longest rap I've ever done is ~170 feet. But I would imagine that on a 300 footer my knuckles would be a little whiter than usual. :haha:

[Iceaxe]

You're full of it!!!!

There is a big difference between a 100' and 300' rappel. The problem is when you begin a 300' rappel you have nearly 25 pounds of weight being applied as a brake from the weight of the rope. If rappelling double strand you have nearly 50 pounds of brake being applied. Rigging the proper friction is very important when attempting a long rappel, the biggest mistake is not having enough friction when you are 2/3's of the way down.

Also.... a 300' rappel is extremely fatiguing, at least for me, particularly if it is free hanging. I'd say the danger in a rappel rises exponentially in relation to the height of the rappel.

I hate big rappels.... YMMV

[rockgremlin]

I hate em at the top, but LOVE them at the bottom! :haha:

[jumar]

I personally think the difference, besides the extra weight of the rope, is psychological. If you're getting more tired (I'm assuming you mean your hand is getting tired from gripping the rope?) probably don't have enough friction. IMHO

[Iceaxe]

My hand gets tired, my arms get tired, my back gets tired....... my butt gets tired from clenching so tight :lol8:

[Ryebrye]

There is a big difference between a 100' and 300' rappel. The problem is when you begin a 300' rappel you have nearly 25 pounds of weight being applied as a brake from the weight of the rope. If rappelling double strand you have nearly 50 pounds of brake being applied. Rigging the proper friction is very important when attempting a long rappel, the biggest mistake is not having enough friction when you are 2/3's of the way down.

A Petzl Pirana is great for long raps. I set it up in the lowest-friction mode possible and then have at it on single strand... When I get toward the bottom if I need more friction I just run the rope over one of the friction do-hickeys on the Pirana and I'm all set...

Of course, when going single on a 300 foot overhanging rappel - you want to make EXTRA sure that you are not on the same side as your biner block... :nod:

[Scott Card]

You're full of it!!!!

Ya well.


There is a big difference between a 100' and 300' rappel. The problem is when you begin a 300' rappel you have nearly 25 pounds of weight being applied as a brake from the weight of the rope. If rappelling double strand you have nearly 50 pounds of brake being applied. Rigging the proper friction is very important when attempting a long rappel, the biggest mistake is not having enough friction when you are 2/3's of the way down.

Also.... a 300' rappel is extremely fatiguing, at least for me, particularly if it is free hanging. I'd say the danger in a rappel rises exponentially in relation to the height of the rappel.

I hate big rappels.... YMMV

Ok I have to agree. Maybe I am thinking that the only difference in massively screwing up a 100 foot rap and a 300 foot rap is the size of the divot you leave when you hit earth. Yes there are differences and skills need to be sharp on the big boys but the result of screwing up either seems to be the same. So if you hate big rappels, who is going to take me through Heaps? Dang it Shane. Do your Kegels or what ever the male equivalent is and strengthen that sphincter :haha:

[Iceaxe]

Do your Kegels or what ever the male equivalent is and strengthen that sphincter :haha:

I believe the male equivalent is referred to as PRISON. :roflol:

.

[Scott Card]

Do your Kegels or what ever the male equivalent is and strengthen that sphincter :haha:

I believe the male equivalent is referred to as PRISON. :roflol:

.

:shock: :roflol: :roflol: :roflol:

[slim]

A Petzl Pirana is great for long raps. I set it up in the lowest-friction mode possible and then have at it on single strand... When I get toward the bottom if I need more friction I just run the rope over one of the friction do-hickeys on the Pirana and I'm all set...

Of course, when going single on a 300 foot overhanging rappel - you want to make EXTRA sure that you are not on the same side as your biner block...

Hi Ryebrye. Could you explain what you mean about being "not on the same side as your biner block"?

Thanks,

Mike

[Ryebrye]

Hi Ryebrye. Could you explain what you mean about being "not on the same side as your biner block"?

Sure. First, a very concise definition of a 'biner block: When you use a 'biner block - you let out the correct length of rope for the rappel, and then block the rest of the rope from passing through the anchors by tying a clove hitch around the spine of a 'biner.

The most common alternative to a biner block is to just run the entire rope down the anchors - and leave the halfway point up there. This is sometimes easier to pull - but requires you to go double-strand on your rappel.

Since Pirana's are exceptional at single-strand rappelling, you will almost always use a 'biner block or some way of blocking the rope off when you go down.

The main caveat with a biner block is - NEVER attach your rappel device to the same side as the biner. The 'biner only prevents the rope from pulling through in one direction. If you try to rap off of the same side as the biner - you are basically holding onto one end of a completely free rope. This is an easy way to kill yourself.

That's what I meant. Pull on the side of the anchor that the biner is not sticking against...

Ryan

[capn_blasto]

I full of it!!!!

Har har! ya sure are, matey, ya sure arrrrrr. Nothing ta disagree wid'ya there. No sireeeee bob (hee hee). Hey, and thassa awful heavy rope yer totin' 'round thar...I reckon. Seein' as how yer average 7/16" line weighs about 16 lbs per 300 feet, ah 'spec yer rope out at about a 1-incher! Hard to fit in the lunch pail :haha:

[price1869]

So, would you be able to reach terminal velocity before you made a stain on the sandstone on the 100 ft. rappel? I don't think you would. My TV at an altitude would be 210 fps, but I'm not sure how long it would take me to reach that speed.

I seem to remember that objects in a vaccumm accelerate at 32 fps/ps so
100 ft. rappel:
1st second: 32 feet
2nd second: 64 feet/s
3rd: splat!!! but at a maximum of 128 fps.

On a 300 foot rappel:
1st: 32
2nd: 64 (96 total)
3rd: 128 (224 total)
4th: Splat, somewhere in the range of TV.

Someone with better math skills really ought to figure out at what speed you would hit the ground from each of these rappels. This is all considering that you fell from the top of the rappel with no rope drag (biner block fails and the rope slides through)

Besides all of this crap, Shane makes a very good point with the complexity and difficulty of the 300 ft rappel. Truly the best test is to go and do both rappels and then check the concentration of fecal matter in your shorts.

Okay, I'm done.

[slim]

Thanks for the clarification, Ryebrye. Yeah, that makes sense! 8^)

Mike[/quote]

[Caddis]

Sure. First, a very concise definition of a 'biner block: When you use a 'biner block - you let out the correct length of rope for the rappel, and then block the rest of the rope from passing through the anchors by tying a clove hitch around the spine of a 'biner.

Is this a safe knot for this? At what point will a clove hitch slip or roll over?

Just a NOOB with questions! :ne_nau:

[Ryebrye]

Is this a safe knot for this? At what point will a clove hitch slip or roll over?
The clove hitch is definitely safe for the biner block. The rope doesn't budge. When the knot is loaded - it tightens around the spine of the biner. The knot isn't really holding you as much as it is holding the biner against your anchor.

To tie the clove hitch - you don't tie it the boyscout way of making an X and running the rope under it - that would take forever (to get the other end of the rope wrapped aroudn the thign...) Instead you make two identical loops and slide one behind the other and then clip the biner through them.

Here's a page that talks about biner blocks a lot - including how to use them with pull cords... etc.

http://canyonwiki.com/wiki/index.php/%27biner_block

Here's a page with a bigger image of tying the clove hitch. In this example it is showing a mountaineering use - which is on the top of the biner. In a biner block - you want the clove hitch on the spine of the locking biner opposide the gate. (And you want to always lock the biner to prevent it from spinning around and potentially opening. An open biner is a much much weaker biner)

http://canyonwiki.com/wiki/index.php/Clove_Hitch

[slim]

The clove hitch is definitely safe for the biner block. The rope doesn't budge. When the knot is loaded - it tightens around the spine of the biner. The knot isn't really holding you as much as it is holding the biner against your anchor.


I went out to my local crag to play with this. Set up a 100 foot rap on a single 9.5 mm Bluewater Gold rope using the biner block against a rappel ring. When I looked at that clove hitch and looked over the edge, it just didn't seem good enough even though I'm sure you are right that it will not slip. So I made it a triple loop clove hitch and did the rap. Worked great but later I was wondering if this actually made it more bomb-proof or less. Any Ideas on this?

Mike

[slim]

On that rappel I mentioned above, I had a few other questions come up that I figured I'd bounce off you folks. (My purpose is to figure out a technique to allow a beginner to safely do a long free rappel.)

* Is there any chance, on these long rappels, of heating the rap device so much that it could melt the rope? I went quite slowly and kept feeling my ATC. It definately got warm but never too hot to touch.

* I tried using an autoblock on the brake hand side attached to a biner through my leg loop. This works pretty well but is rather tiring since your hand is up higher than usual to hold on to the autoblock. It also seems kind of touchy getting the right amount of friction since you're basically holding the loops of the autoblock, not the actual rap rope. What's your opinion on a brake-hand autoblock?

*One mystery, using the brake-hand autoblock, when I got to the bottom, the rope below me had received a bunch of twists which were hard to deal with since I had about 50 feet of rope on the ground. Was this the spiral autoblock doing this or some other phenomenon?

*What about a chest harness? I rigged a simple one using a criss-crossed sling with two biners attached to give about 10 or 12 inches to the rope. I liked the extra security it seemed to give . Thoughts on that?

That should be enough for now! :blahblah: :smile:

Mike

[rockgremlin]

That clove hitch is very sound. Its commonly used in the canyoneering community, and I've never had a problem using it, neither have I ever heard of an incident of it slipping or failing on any occasion. As long as it is loaded it is a very safe and effective knot.

I've never heard of a belay device heating up so much that it melted the rope. I don't think that's possible - especially since your BD is moving along the length of the rope -- its never staying in one spot on the rope.

As far as autoblocks go - I've never used one, but there's an alternate method for adding friction that works as well as the autoblock, but doesn't add twists to your rope. Its called the "Z loop," and its the brain child of Mr. Tom Jones. Instead of looping your brake strand through an autoblock, just thread it through a biner on your leg loop, then thread it back up through another biner from the belay loop on your harness. This configuration will stop you cold anywhere during the length of the rappel, and chances are that it might be too much friction, especially if using a large diameter rope, or when double roping.

More tricks/tips here: http://canyoneeringusa.com/utah/tech/

[Ryebrye]

I've never used autoblocks either. I can see them being useful if you somehow let go of the brake rope or if you get conked out while rappelling - but those scenarios both seem very unlikely to me.

If I ever need to lock off mid-rappel, I loop the rope around the lock-off horns of the Petzl Pirana and I'm fine. I can count the number of times I have had to do this on one hand.

As far as burning the rope goes - I have read one some places to avoid doing super-fast raps because it can melt the outside of the sheath. I've never seen this happen - but as a result of reading that, I only go super-fast on my friends ropes :haha:

If you want to be extra-cautious, you can tie a figure 8 in the rope and clip the loop into the anchor with a locking biner. You then also set up a 'biner block that only the last person on the rappel will use. (That person takes can untie the figure 8 when he unclips the biner...) For small groups I don't usually bother with it. Maybe I should.

[rock_ski_cowboy]

I've never used autoblocks either. I can see them being useful if you somehow let go of the brake rope or if you get conked out while rappelling - but those scenarios both seem very unlikely to me.

I've used autoblocks. They're alright. Once a piece of tape on the rope got stuck in my autoblock and I got stuck mid rappel. That was ugly. I prefer adjusting friction using leg-loop carabiners or even a Z . Adding 2 biners instead of 1 on an ATC usually is sufficient to do the trick.


If I ever need to lock off mid-rappel, I loop the rope around the lock-off horns of the Petzl Pirana and I'm fine. I can count the number of times I have had to do this on one hand.

I occasionally lock off by wrapping the rope several times around my leg. I don't know if this is the best way to do it, but its easy and fast. When I do this, I usually still leave a hand on the rope, just in case.


THe triple clove hitch may work, but why use something untested and unknown when a simple, known knot is bombproof. If you don't like the clove hitch, I'd recommend tieing a figure 8 or overhand on a bite and clipping that. Instead.

[Ryebrye]

I occasionally lock off by wrapping the rope several times around my leg. I don't know if this is the best way to do it, but its easy and fast. When I do this, I usually still leave a hand on the rope, just in case.

That's one of the methods that they describe in Mountaineering: The Freedom of The Hills - so it has to be true.

Do autoblocks slow you down? I prefer long rappels to be so fast that I am just short of free-fall... (well... not really - but I do tend to go very fast.)

[snatch]

the problem of the extra braking weight while rapping on a single strand for 300 ft. can easily be solved with 25 lb. juevos. for a double strand, i guess you'd need 50 lb. juevos. either way, additional juevos would come in handy on a 300 ft. rap.

[Iceaxe]

can easily be solved with 25 lb. juevos.

:roflol: