Joining Tree Trunk Protector Straps

[AJ]

Why did 4WDmonthly use a shackle to join the 2 straps behind the tree in this months edition???

Pat? anyone?

[taziiy]

Because it was easy to do and undo when they finished

ive heard ur not ment to join snatch straps with shackles so i doubt it'd be a good idea with tree trunk protectors. but i dont think it really makes much of a differance, just one less bit of metal flying through the air if the thing breaks.

[FJ60]

But it shouldn't break!!!! amost tree trunk protectors are like 20tonnes. If you can break one good luck to you!

But it shouldn't break!!!! amost tree trunk protectors are like 20tonnes. If you can break one good luck to you!


yeah i know, but if its damaged or something, i dunno, thats just what i heard anyway, just a little safer.

[AJ]

But it shouldn't break!!!! amost tree trunk protectors are like 20tonnes. If you can break one good luck to you!


Most are 12,000kg Ultimate Tensile Strength
That would be very marginal with a 10,000lb winch and a snatch block

i think it was to demonstrate what to do if the tree is a 100 year old monster with a trunk so round that one tree trunk protector wont fit around it............ ;D

[FJ60]

Dont ya just hate how they rate evrything differently. The kilos/tonnes aint so bad but tonnes???

Dont ya just hate how they rate evrything differently. The kilos/tonnes aint so bad but tonnes???
not sure i understand this post FJ60 the metric systems pretty simple 1000kg =1 tonne maybe your refering to the old system where ton's is spelt like this, dont ask me how many kgs this is though because i wouldnt have a clue. it is confusing though, we live in a country were we use the metric system but some manufacturers still rate things in LBs.

1 Ton = .907 Tonne or 1 Tonne = 1.102 Ton ;D 1 Ton = 907.184 Kg Confused?? hehe 8)

1 Ton = .907 Tonne or 1 Tonne = 1.102 Ton ;D 1 Ton = 907.184 Kg Confused?? hehe 8)
thanks ofr that info roedao ???

[gleslie]

1 Ton = .907 Tonne or 1 Tonne = 1.102 Ton ;D 1 Ton = 907.184 Kg Confused?? hehe 8)


Sorry, not true.

1 ton = 2,240 lbs = 1.01605 tonnes

The ton you are refering to was known as a short ton ie: 2,000 lbs

[Jys5428]

If you've got a 10T winch and strait pull off a 12T tree protector all is good.
If I then add a pully to the tree end and run it back to the 4wd, what happens. If I for some reason still need to put 10T into the winch then that's 20T at the Pully. Does the tree protector fail???
In theory it should.

1 Ton = .907 Tonne or 1 Tonne = 1.102 Ton ;D 1 Ton = 907.184 Kg Confused?? hehe 8)


Sorry, not true.

1 ton = 2,240 lbs = 1.01605 tonnes

The ton you are refering to was known as a short ton ie: 2,000 lbs


hey i'm using a converting program....... thats what it told me..... it's what i believe :) nobody specified short or long ton :) thats why the metric system is far easier.... a Tonne is a tonne 8) a metric ton or tonne as we call it is 2,204 pounds or 999.717 kg. This little converting program makes ya sound smart doesn't it!! ;D :P

[JusCruisin]

If you've got a 10T winch and strait pull off a 12T tree protector all is good.
If I then add a pully to the tree end and run it back to the 4wd, what happens. If I for some reason still need to put 10T into the winch then that's 20T at the Pully. Does the tree protector fail???
In theory it should.


No - by employing the snatch block, you are halving the effort required by the winch (and doubling the time taken as you need to retrieve 2 inches of cable to move the vehicle 1 inch). This is not increasing the load on the tree protector - the vehicle weight has not changed.

However, if you have a 10T winch, 12T tree protector and require 20T of effort to free the vehicle, using a snatch block should allow the 10T winch to do the job. In this case, yes the 12T tree protector is under-specced for the job.

LBD, I've just re-read your post and I think I'm agreeing with you! :)

Now, wasn't that easier without imperial tons, short tons, metric tonnes and pounds?

[JusCruisin]

In regard to the original post, don't know. You should NEVER join TTP or snatch straps using a shackle (rated or otherwise). If I recall, there was an article in a previous issue showing the correct way to join 2 straps using a rolled-up newspaper or tree branch to ensure they will part company after the recovery operation.

The argument that the strap shouldn't break is a dangerous one that should only be used by those looking to win a Darwin award. Due to a lack of standards (and QA from the odd manufacturer), a brand new strap may not even support it's advertised breaking strain.

[Jys5428]

If you've got a 10T winch and strait pull off a 12T tree protector all is good.
If I then add a pully to the tree end and run it back to the 4wd, what happens. If I for some reason still need to put 10T into the winch then that's 20T at the Pully. Does the tree protector fail???
In theory it should.


No - by employing the snatch block, you are halving the effort required by the winch (and doubling the time taken as you need to retrieve 2 inches of cable to move the vehicle 1 inch). This is not increasing the load on the tree protector - the vehicle weight has not changed.

However, if you have a 10T winch, 12T tree protector and require 20T of effort to free the vehicle, using a snatch block should allow the 10T winch to do the job. In this case, yes the 12T tree protector is under-specced for the job.

LBD, I've just re-read your post and I think I'm agreeing with you! :)

Now, wasn't that easier without imperial tons, short tons, metric tonnes and pounds?

Yeah you did agree with me ;D

[GUJohnno]

Isn't the idea of a tree trunk protector to protect the tree from damage. Surely a shackle would cause some damage to a tree.
Of course not as much as a wire wrapped around the tree...

[cpt-mud]

in theory joining tree trunk protetors should not be a problem if saftey guidlines are followed, a dampner put around the join , as well as on the cable, should provide adequate protection for both the tree and driver. a good quality shackel should be ussed as the opposig forces would be dreat.
http://i6.photobucket.com/albums/y207/cpt-mud/1154toyota.gif

[Adomw]

Lads

I can't see the problem with joining TTP with a shackle - after all you will conect the cable or pulley to the TTP with a shackle no?

You don't connect snatch straps because of the kinetic energy that is stored in them due to the stretch.

TTPs have very little stretch by comparison so it should be safe.

I would rather use shackles than a newspaper because if the newspaper comes apart then your shackles pully and winch rope will be heading your way.

my $0.02

Ado

[RageRacing]

Lads

I can't see the problem with joining TTP with a shackle - after all you will conect the cable or pulley to the TTP with a shackle no?

You don't connect snatch straps because of the kinetic energy that is stored in them due to the stretch.

TTPs have very little stretch by comparison so it should be safe.

I would rather use shackles than a newspaper because if the newspaper comes apart then your shackles pully and winch rope will be heading your way.

my $0.02

Ado


winch cable and winch extension straps also stretch and stor energy, and are just as dangerous as a strap with a shackle, however the shock load should be not there so the chance of snappage should be decreased to a very safe level, and in addition, there should be a dampner over the shackle any way

[V8 Landy]

As long as there is a dampener irt should not be a prob

[swaddo]

If you've got a 10T winch and strait pull off a 12T tree protector all is good.
If I then add a pully to the tree end and run it back to the 4wd, what happens. If I for some reason still need to put 10T into the winch then that's 20T at the Pully. Does the tree protector fail???
In theory it should.


Hmm i think you have your wires crossed a little lbd. from my understanding of physics using a snatch block will not double the weight of your car :D

eg. consider a 10T load being recovered

we all know straight pull = single cable thus entire load is supported on the single cable.

Using a snatch block means that there are 2 cables. The load is supported equally (assuming no resistance in the pully) and thus each
cable supports half the total load. there is still 10T at the tree protector, but 5T on each side of the cable.

Note that since the winch is mounted to the car the scenario is equivalent to a 2 pulley arrangement.

more info here.
http://science.howstuffworks.com/pulley.htm

My physics is a little rusty but Im pretty sure this is right

Cheers
Blake

edit: it pays to read the whole thread. Just noticed the other explanations http://www.iamviet.com/forum/images/smilies/smilie_yellow_icon_redface.gif

I must have misread LBDs post in the same way as JusCruisin

[swaddo]

also a little bit of interesting info regarding conversions Were you aware that Google is quite good at converting stuff?

try typing the following
convert 13 litres per 100 km to km per litre

yields the following results
(13 litres) per (100 km) = 7.69230769 km per litre

it works for most things I have tried ... even cubits :)
1 kilometer = 2 187.2266 cubits