Expedition training

[Leclused]

From another thread,

"Practicing how to poo in a plastic bag is a vital expedition skill and should form basic training for all cavers."

That is 100% true, We use a sligthly different method

step 1) lay down a square sheet of backing paper (40x40xm)
step 2) do your thing
step 3) fold together
step 4) put the paper and the poo in a dog poo-bag
step 5) dump the collected poo-bags in a wast container after transport or if not possible bury them in a pit. But if you have to bury them then you need to use biodegradable poo-bags.

 

[Badlad]

@HT & SM - if potty training isn't much your thing and you'd just like a bit of general fitness training, we need a few items carrying up to the May Day Hole area of Ingleborough. It's a steady hour and a half walk on an evening and you'd be doing us a big favour.

 

[KBrook]

Mike bottomley's training regime of regular eveining trips to Long Kin West always sounded like a good idea for three peaks residents.

 

[speleokitty3]

step 1) lay down a square sheet of backing paper (40x40xm)

Thats a huge sheet of paper. I'm not sure that I could carry that

 

[LadyMud]

This thread is absolutely fine without pictures, thank you 🤮

 

[thehungrytroglobite]

@HT & SM - if potty training isn't much your thing and you'd just like a bit of general fitness training, we need a few items carrying up to the May Day Hole area of Ingleborough. It's a steady hour and a half walk on an evening and you'd be doing us a big favour.

Interested, do I get a pint?

 

[thehungrytroglobite]

Mike bottomley's training regime of regular eveining trips to Long Kin West always sounded like a good idea for three peaks residents.

Not sure I quite have enough free time for that!

 

[mikem]

I've been pondering designs for rope treadmills. I think it's important to climb, then lower, if you want to accurately simulate how fast you can climb. If you climb and lower at the same time, you're not raising your body weight, just pulling rope round the system. With a belayer, you might manage to lower at the right time, but I can't see it with an autobelay.

That depends if you're suspended or just hanging from your ascenders. The important thing with belayed rope climbing is that they keep you as high as possible without being able to reach the "roof" (or if you want to make it really difficult, keep them just off the floor!)

 

[Loki]

From another thread,

"Practicing how to poo in a plastic bag is a vital expedition skill and should form basic training for all cavers."

Get one of your mates to hold the bag open. Way easier.

 

[paul]

Or poo in your oversuit hood like a friend of mine did once (by mistake)!

 

[Chocolate fireguard]

I've been pondering designs for rope treadmills. I think it's important to climb, then lower, if you want to accurately simulate how fast you can climb. If you climb and lower at the same time, you're not raising your body weight, just pulling rope round the system.

Are you sure?
I think that so long as you maintain your height you are working at the same rate as though you were climbing a fixed rope at the same speed as the one you are on is being lowered.

Perhaps a small winch could be controlled in a way that allowed it to lower a climber on a rope loop at a preset rate so they could dial in the work rate they wanted? If they don't maintain it they finish up on the floor.

 

[mikem]

The NSS example would be holding part of your body weight on the floating pulley. A winch controlled one would be a different matter, but that's not what the other link suggested either.

 

[ChrisB]

Are you sure?
I think that so long as you maintain your height you are working at the same rate as though you were climbing a fixed rope at the same speed as the one you are on is being lowered.

No, I'm not sure, so pick holes if you like. I'm not thinking of climbing speed, however, but work done, in the engineering meaning of work, force times distance (energy). As you stand up when prusiking in a cave, you are moving your own weight upwards against gravity by the amount of your step up, and you're also accelerating your mass to whatever speed you're moving at. If you're stationary on a treadmill, you're pushing rope downwards against the tension in the rope (which must equal your weight, or you wouldn't be stationary), but there's no additional force from your acceleration.

Looked at another way, when you stand still on the floor, your feet are pressing on the floor with your own weight. If you step up, you have to press harder, and the harder you press, the faster you step up (because you're accelerating your mass faster).

 

[JoshW]

No, I'm not sure, so pick holes if you like. I'm not thinking of climbing speed, however, but work done, in the engineering meaning of work, force times distance (energy). As you stand up when prusiking in a cave, you are moving your own weight upwards against gravity by the amount of your step up, and you're also accelerating your mass to whatever speed you're moving at. If you're stationary on a treadmill, you're pushing rope downwards against the tension in the rope (which must equal your weight, or you wouldn't be stationary), but there's no additional force from your acceleration.

Looked at another way, when you stand still on the floor, your feet are pressing on the floor with your own weight. If you step up, you have to press harder, and the harder you press, the faster you step up (because you're accelerating your mass faster).

not a physicist, but would the friction through the system to force the rope through (just to “hold” position) not go some way to adding effort required even if not in the technical definition of ‘work’

 

[mikem]

But, as the rope moves down you are being taken down by it, so still have to step up to counteract it. The problem is creating an effective balancing system. (You need to consider relativity & that the acceleration is gravity...)

 

[ChrisB]

would the friction through the system to force the rope through (just to “hold” position) not go some way to adding effort required

If it was a auto-belay system, then depending how it was done, there are various extra forces that might add effort. But what I'm asking is whether a system in which the caver is stationary does accurately replicate real prusiking.

But, as the rope moves down you are being taken down by it, so still have to step up to counteract it.

Yes, that part of the force is the same.

The problem is creating an effective balancing system.

That's the problem if you're designing an auto-belay system, which isn't what I'm asking about.

(You need to consider relativity & that the acceleration is gravity...)

I don't think many cavers move at a sufficient percentage of the speed of light that relativity makes a difference. Gravitational acceleration is there all the time, it's the additional acceleration required to move that's the question. Think of a large rocket at launch; the thrust is greater than the weight, but it still has to accelerate the mass of the rocket. A massive rocket like Saturn V leaves the pad very slowly, less massive rockets like surface to air missiles have much more energy and accelerate faster.

 

[mikem]

Yes, I jokingly meant relative motion rather than the special or general theories - the difference in gravity is negligible whether you are 5m or 80m up that rope, so you are doing the same work (it's analogous to running the opposite way on a moving train - you are doing 5mph, the train is also doing 5, so you appear to stay still relative to the scenery)

 

[Chocolate fireguard]

As you stand up when prusiking in a cave, you are moving your own weight upwards against gravity by the amount of your step up, and you're also accelerating your mass to whatever speed you're moving at. If you're stationary on a treadmill, you're pushing rope downwards against the tension in the rope (which must equal your weight, or you wouldn't be stationary), but there's no additional force from your acceleration.

Looked at another way, when you stand still on the floor, your feet are pressing on the floor with your own weight. If you step up, you have to press harder, and the harder you press, the faster you step up (because you're accelerating your mass faster).

What you say about acceleration is true, but I think you are forgetting that at the later stage in stepping up on a step, you must accelerate downwards (let's not talk about deceleration) so you come to rest. So in that later stage the force you are applying to the step - and therefore the force the step applies to you - is less than your weight.
The Principle of Conservation of Momentum says that if a body starts and finishes at rest the (vector) sum of the impulses of all the forces that have acted must be zero.
This means that over the course of taking a step the average force you have applied is equal in size to your weight. Just as if you had remained still.

But of course you have done work in stepping up. That is equal to the force times the distance moved (by the point of action of the force in the direction of the force). On a rope that point of action is your foot jammer, and you have lifted your weight by the same distance relative to that, whether the rope is stationary or moving downwards (or upwards) at a steady speed.

 

[alanw]

A simple solution. How hot is the braking device getting? If it's as hot as it would be descending a pitch over the same distance, then you are doing the same amount of work. (Of course, compensation needs to be made for ambient temperature and water in the air and on the rope).

 

[aricooperdavis]

I briefly fiddled with a design where the "pitch" rope goes up through a rig with a cord on the release handle. When you get up to the top you just pull the cord to descend. The problem with this is that it's unbelievably scary - if you want to slow down you have to release the cord, which is very counter intuitive. A better solution might be to have the rig on a ground anchor and the pitch rope running through a pulley. Then you can clip the release cord to your harness so it's pulled as you move up, which lowers you, so you effectively stay relatively stationary. I haven't tried this yet though!