block and strop

[WorcsWuss]

I don't think there is anything in our line of work that j would like to lower 1 ton with. Bearing in mind the rope should be the weakest link!

 

1M free fall would create an horrendous shock load!

 

I've been trying to find the precise formula for this to put into an excel sheet on my phone to calculate this from a green weight chart when on a job... Can someone tell me this, it must be more obvious than I'm making it seem....?! You know, height of drop x weight = load....? I just want to know what load will be imposed on an anchor from a given freefall height....

[Paul Smith]

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

 

What will hold up to that safely?

[avatar tree climber]

thats what I'm saying the rope needs to be the weakest link so the strop that we use to attach the block needs to be stronger and the only one i can find is 9 tonne mbs ! .and well i lowered a 1800 kg log straight on the back of a transit it got weighed at the tip !

[avatar tree climber]

i know all that but sometimes when chogging the log needs to drop a good ft i just want to be able to drop bigger pieces

[Paul Smith]

thats what I'm saying the rope needs to be the weakest link so the strop that we use to attach the block needs to be stronger and the only one i can find is 9 tonne mbs ! .and well i lowered a 1800 kg log straight on the back of a transit it got weighed at the tip !

 

What was your set up to lower 1800kg? I think you may well have exceeded the SWL somewhat!

 

Why on earth would you want to go bigger? I'm all for go big or go home but always within SWL.

[Sirnick2]

Lowering 1800kg? Thats a 3600kg rigging point in the tree

[Martin Nemec]

Maybe here (avalaible to diameter 96mm):

http://www.gleistein.com/assets/download_pdfs_images/Kataloge/Industrie_DE_EN.pdf

 

[Marc]

Maybe here (avalaible to diameter 96mm):

http://www.gleistein.com/assets/download_pdfs_images/Kataloge/Industrie_DE_EN.pdf

 

 

Will that fit in my GPRS ayeeeeeee,

 

16mm or even 19mm dead eye sling is good for most things and if you pop that you deserve the Darwin award.

 

And lowering an 1800kg log is no biggie when top roped from a nice hefty anchor, I,ve/we lowered far heavier trashing a bollard and 16mm rope well it went to 12 under load in one moment of hell why not.

That was on the Painshill park cedar of Lebanon for those of you who may know it.

 

The weak link is usually the way you undertake the task not the equipment, I want a tough block for greater ability to handle repeated heavy loading, it's an relatively expensive part of a lowering kit so it's good to have a higher failure cycle by it being tougher than needed, a strop is high wear and cheaper to replace.

[Adam Bourne]

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

[born2trot]

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