block and strop

[Adam Bourne]

That seems a very good piece of advice to me Maj , well communicated also imo

 

 

Thanks mate, just don't like the fact that there are a lot of beginners on here reading things like this and go out dismantling and lowering of big lumps like that and not thinking about all the factors first......it takes a lot of skill and time to pull of rigging like that, and would honestly say there are only a hand full of climbers and groundys on here that could........

[Marc]

why would anyone want to be thinking of lowering that amount of weight?

 

Think your wasting your money, putting yourself and others at risk! and for WHAT? just to get home 5 minutes early!

 

One day some one will Go big........TOO Big and they won't make it home????

 

working within the SWL and making sure you know all your SWL and where the weakest link is, in your gear and the tree is imperative.........They are there for a reason......

 

Say you had all your gear down to a T. block, strop, rope, LD, blocking down timber lets say 1ton each section, so 4000kg on a 1 metre free fall, now think of what might happen if say......the line got snagged on the floor that the groundy did not see...i would not like to find out what happens after that! would you?...and i think people forget that us humans do make mistkes, its a lot to ask from your groundstaff to nail everytime...your not only putting your equipment to is limits. But to pull it of every time without something going wrong would take countless calculations, equipment checks rope checks more checks than it would take to just go that little bit more smaller get the job done safe and efficiently without destroying gear and still get home in time for coronation street......

 

Save the big weights for the Cranes lads..........If your that bothered about going home Early stick some extra money on the job so it pays to nip back in the morning.........

 

 

Adam

 

Nicely put, small and smooth is often faster, not sure on why you want a 60ton strop to secure the block as you do not want to generate that kind of force, and in my opinion blocks being so strong is to give more reliability and good service life not to actually go to those limits!

 

I,d also like to point out, that the moment of stupidity in my previous post was the lowering of one wind blown limb on an emergency call out, it was top roped and pre tensioned, but pushed the entire system to limit.

In 5 years in this job it's the only time I,ve seen rigging maxed out like that, and the only time I want to.

[J.Bailey]

[ame=http://www.youtube.com/watch?v=oa1SAkP0wx0&feature=share&list=UU2TSFy9wbZLR5jfeW6gWrGg]big rigging gone wrong - YouTube[/ame]

 

thought i might share this video if it helps..

[MOG]

@ paul smith.......

 

why not just times original weight by 4.

 

i.e 80kg log x4 = 320

 

instead of....

 

80kg log x 3 = 240 + original weight = 320

 

Or am i missing something here?

 

Mog

[Paul Smith]

@ paul smith.......

 

why not just times original weight by 4.

 

i.e 80kg log x4 = 320

 

instead of....

 

80kg log x 3 = 240 + original weight = 320

 

Or am i missing something here?

 

Mog

 

Mog, how you work it out is up to you as long as its the right answer. The reason I do it like that is you always have the log weight in your head, or at least I do!

[Jamie M]

"For each meter of free fall multiply its original weight by 3+1.

 

1m Free fall with 4ft 12" diameter Beech, shock load of 80kg X 3=240kg +80Kg=320kg

 

2m Free fall X6 +original 80kg = 560Kg

 

So for the original post,- 1000kg X3 +1000= 4000kg"

 

 

Mog, looking at Paul's post above, I think his calculation uses multiples of 3 then the original log weight added on after, as opposed to a straight log weight times four.

 

Have a look at the below to see if I am making sense

 

 

Pauls way 2m Free fall X6 +original 80kg = 560Kg

 

Your way 8 X 80kg = 640Kg

 

This leads to a difference in your calc of + 80Kg. Whilst this is a fault in the right direction i.e. overestimating the load, I think you may have missed a trick with Paul's original calculation.

 

Hope I've got this right or I'll look a complete tit!

[Jamie M]

Paul,

Your calcs seem to tie in with my previous thoughts on load factors but I can't recall where I first heard it from. Do you have a ref or citation? Cheers.

[Paul Smith]

I will dig it out, sure I've got it somewhere!

[Jamie M]

Cheers chap appreciated!

[MOG]

@ jaime and Paul,

 

yeah i get it now. its only +1 original weight rather than 2, when you keep times it.

 

so for 0.5m free fall

 

it be 1.5x original weight + 1 original weight.

 

0.5m freefall x1.5 original weight 80kgs = 120kgs + original weight = 200kgs

 

??

 

cheers fellas think it makes sense to me now, now i am the tit