Funny but serious by all accounts!!

[daltontrees]

I respectfully disagree. In order to ascend one metre, 2 metres of rope passes through the hitch when climbing DdRT. Hence 2:1.

 

The branch/fork/cambium saver in DdRT is the pulley! The friction in it is quite useful in bodythrusting, buying you tiem to advance your friction hitch. But the same friction is the thing that makes it hard work.

[Amelanchier]

I respectfully disagree. In order to ascend one metre, 2 metres of rope passes through the hitch when climbing DdRT. Hence 2:1.

 

Really? Forget about the hitch for a minute - are you saying that if you pull down two metres on one leg of rope running through a cambium saver at the top of a tree you only move the load attached to the other leg one metre...?

 

That is the right criteria for a MA system though - distance of rope pulled through multiplies proportionally with the forces generated.

 

Tony, 2:1 is Ddrt you have 2 legs at the moving block! 1:1 is a straight pull bearing no moving blocks..

 

I should have been clearer - for a 2:1 MA system the pulley moves with the load. A static pulley just redirects force without multiplying it.

[Adam Bourne]

I ment know malice by that at all mate, tony clearly knows where he stands with me. Having met before and myself thinking he was a middle aged man turns!! out he's a young brad Pitt.

 

Look at if from my point of view!! I don't class myself no differently from any other climber on this forum, I climb SRTWP 100% of the time, for me it's natural now!! Climbing is not a religion and I'm not out to convert anyone I just want to see it being classed as a safe working practice that it is!!

[Adam Bourne]

Really? Forget about the hitch for a minute - are you saying that if you pull down two metres on one leg of rope running through a cambium saver at the top of a tree you only move the load attached to the other leg one metre...?

 

That is the right criteria for a MA system though - distance of rope pulled through multiplies proportionally with the forces generated.

 

 

 

I should have been clearer - for a 2:1 MA system the pulley moves with the load. A static pulley just redirects force without multiplying it.

 

RADS tony!! 1:1 you pull 1m of line you get 1m of line, 2:1 (Ddrt) you pull 1m you get 50cm of movement, ect ect

[Amelanchier]

Having met before and myself thinking he was a middle aged man turns!! out he's a young brad Pitt.

 

Now now - no need for rhyming slang... You'll upset my inner middle aged man

[Amelanchier]

I think we need another Dolly experiment With rulers instead of scissors!

[Adam Bourne]

I think we need another Dolly experiment With rulers instead of scissors!

 

Your on watch this space haaaa!

[daltontrees]

DdRT is definitely a 2:1 system. Again it's one of teh advantages of it because when bodythrusting you shove yourself up a foot and pull 2 foot of rope through. You gain a foot for 2 foot of rope pulled through.

[Adam Bourne]

 

[Amelanchier]

Hmmm The distance thing is clearly right. The amount pulled must be divided between the number of legs. Anyone able to confirm the forces?