Taking the wider view.....

[epik]

Technically speaking, you're right about the Fall Factor 1 of course. However, all dynamic ropes have a limit of maximum stretch. If you take a fall while doing a regular climb, you might reach a velocity of 20 or 30 metres per second before the rope (and belayer) catches you. Now if you jump off El Cap, it would be quite feasible (not to mention crazy) to reach terminal velocity of 100m/s. Climbing ropes are designed to stretch "normally" up to about 8 or 10%, so despite having a massive long rope with what appears to be a lot of stretch distance - I'd imagine the resulting impact force on the anchor, rope, and body must be hideous.

This could be the reason that rope manufacturers generally don't produce climbing ropes longer than about 50 metres.

You are right you would reach terminal velocity (pretty sure you reach this in 80ft so anything above this doesnt make any difference) but your still only taking a fall factor 1 so it doesnt really matter how long it is! You'd apply pretty much the same impact on yourself dropping 6m on a FF1 as you would falling 60m on a FF1 (being that you only have 0.6m stretch to take the load as apposed to 6m in the long fall). As you can check from the below website from petzl. Just put in anchor 3 at half your fall distance and you will see it doesn't really make any difference if you times those numbers by ten!

http://en.petzl.com/petzl/ProConseils?Langue=en&Conseil=56

Also rope manufacturers make 60m and 75m ropes in europe and you can happilly buy 250m on a drum if you wanted to! Imagine that a 250m fall

 

[Frog]

As someone once said...
"Life should not be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, bacon bap in one hand, beer in the other, body thoroughly used up, totally worn out and screaming "WOO HOO what a ride!" "

I like that quote but can I have a cider in my hand as I dont like beer!

 

[AndyF]

As someone once said...
"Life should not be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, bacon bap in one hand, beer in the other, body thoroughly used up, totally worn out and screaming "WOO HOO what a ride!" "

I like that quote but can I have a cider in my hand as I dont like beer!

I like the quote too... but I guess I just want to avoid being unfashionably early....

 

[SamT]

Reminds me of the mountain unicyclists; google for Kriss Holm. There's a video of him riding on the handrail of a similarly high bridge. After a bit you notice he's playing safe he's riding right on the inside edge so if he slips he'll land on the bridge not fall off. That's when you get impressed with his skill of course. But in my experience unicycling is far more likely to injure you than caving.

Kris Holm even

I love www.video.google.com

http://video.google.com/videoplay?docid=6247678297142977088&q=Kris+Holm

Awesome.

 

[SamT]

Awesome.

But a bit crap at the same time

 

[emgee]

As someone once said...
"Life should not be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, bacon bap in one hand, beer in the other, body thoroughly used up, totally worn out and screaming "WOO HOO what a ride!" "

I like that quote but can I have a cider in my hand as I dont like beer!

I like the quote too... but I guess I just want to avoid being unfashionably early....

The version I know didn't have either the bacon bap or the beer which suits me. I kind of like the idea of adding turning up late though it's spmething I'm good at.

 

[emgee]

Reminds me of the mountain unicyclists; google for Kriss Holm. There's a video of him riding on the handrail of a similarly high bridge. After a bit you notice he's playing safe he's riding right on the inside edge so if he slips he'll land on the bridge not fall off. That's when you get impressed with his skill of course. But in my experience unicycling is far more likely to injure you than caving.

Kris Holm even

I love www.video.google.com

http://video.google.com/videoplay?docid=6247678297142977088&q=Kris+Holm


Awesome.

That's the equivalent of doing the Giants round trip with a few novices try

http://www.krisholm.com/multimedia/

The clip from One Tired Guy has the bridge bit I was talking about.

Me the best I could manage was a hundred yards on a flat surface.

And getting to that stage was a lot more painful than caving.

 

[NZcaver]

You are right you would reach terminal velocity (pretty sure you reach this in 80ft so anything above this doesnt make any difference) but your still only taking a fall factor 1 so it doesnt really matter how long it is! You'd apply pretty much the same impact on yourself dropping 6m on a FF1 as you would falling 60m on a FF1 (being that you only have 0.6m stretch to take the load as apposed to 6m in the long fall). As you can check from the below website from petzl. Just put in anchor 3 at half your fall distance and you will see it doesn't really make any difference if you times those numbers by ten!Also rope manufacturers make 60m and 75m ropes in europe and you can happilly buy 250m on a drum if you wanted to! Imagine that a 250m fall

If I remember my physics from school correctly, a falling object (aka human body) accelerates at 10m/s per second. After about 10 seconds you have already fallen 450 metres and reached terminal velocity of 100m/s. Petzl's neat little fall factor calculator is not designed for the non-belayed type of FF1 we're talking about, and it doesn't seem to accept a value of 450m.

Again yes - the percentage of rope stretch and (theoretically the impact force) is about the same for a 6m fall as a 60m fall. I'm just thinking the force exerted by an 80kg body after a really long fall (like say, 600m) would be way out of a climbing rope's tolerance - akin to having a bunch of climbers tied together take a 10m fall on one piece of rope at the same time. But maybe I'm wrong? :?

So rope manufacturers in Europe sell 250m drums of dynamic rope? We can't even buy dynamic rope off the roll easily in the US - finding cowstails can be a real pain! Do they INTEND those 250m ones to be climbed on in one piece (rather than cut up)? I'd be interested if you could post a link... 8)

 

[epik]

Petzl's neat little fall factor calculator is not designed for the non-belayed type of FF1 we're talking about, and it doesn't seem to accept a value of 450m.

So rope manufacturers in Europe sell 250m drums of dynamic rope? We can't even buy dynamic rope off the roll easily in the US - finding cowstails can be a real pain! Do they INTEND those 250m ones to be climbed on in one piece (rather than cut up)? I'd be interested if you could post a link... 8)

Maybe Petzl work on the basis of you having died of old age before you hit the end of the 450m?

As for ropes yes they sell them on 250m drums though not many shops buy them so in general not much call though if you asked they would do it! Most drums are sold to shops to be cut up but nothing stopping you buying the whole 250m. The link below is the first rope i came accross but there are many more,

http://www.theoutdoorshop.com/Outdoor/ProductDetails.aspx?language=en-GB&product=505101

The biggest reason for not wanting people to use 200m ropes isn't the fall force created but the stretch. Imagine telling your second he has to climb 20m before he is actually on top rope

 

[NZcaver]

Maybe Petzl work on the basis of you having died of old age before you hit the end of the 450m?

Thanks for the info... 8)