Bow Shackles: Still the best!

[Apocalypse]

One of the biggest confusions is the difference between rated lifting gear and just a load rating.

So e.g. a rated Bow shackle of 4,75 toms SWL will exceed 28,5 tons before breaking.

A 9000lb winch and cable is only good for 9000lbs - the winch itself will only pull 9000lbs on the drum, and the cable will let go at a little more than 9000lbs.

To an office Johnny it’s all the same 9000lbs is 4000kgf and he thinks it’s as strong as a bow shackle, next thing you know someone is snatching off his winch cable and things get nasty ..

[XJ Junkie]

Same with a snatch rope. A 8T should break at a little above 8T

[Apocalypse]

Same with a snatch rope. A 8T should break at a little above 8T

well, depends on how the 8 ton is rated

If it's 8 ton SWL it must actually be good for 80tons.

if it's 8 ton breaking force, then it should be a little more than 8tons.

So, for instance, I carry 2 green 2 ton slings which are SWL 2 tons, so they will only break above 20 tons of load.

the Pofadder kinetic recovery rope has a 13ton breaking force rating. so it should break at a little over 13000 kgf

I've also got 20m long winch extension straps - they don't have a rating on them, but are for use with a 12000lb winch.


the thing with recoveries as that the force you apply is not relative to the weight of the vehicle, but to the force you apply to it by accelerating the mass of thee vehicle.

so eg - if you try and accelerate (or decelerate) a 3000kg vehicle at 100m/s/s you apply 300 000N of force (=30 000kgf) to the components - the weakest link will break.

ideally thats the softest part which should be well damped.

[XJ Junkie]

well, depends on how the 8 ton is rated

If it's 8 ton SWL it must actually be good for 80tons.

All snatch straps & ropes should be rated with MBS (Minimum breaking strength) & not SWL. Otherwise they’ll be stronger than the shackle, which isn’t desirable.

[Apocalypse]

well, depends on how the 8 ton is rated

If it's 8 ton SWL it must actually be good for 80tons.

All snatch straps & ropes should be rated with MBS (Minimum breaking strength) & not SWL. Otherwise they’ll be stronger than the shackle, which isn’t desirable.

Problem is that a lot of the stuff that’s available is actually lifting gear , not 4x4 Specific .

Stuff for industrial use is often rated at its max load without safety factor .

The thing is just to be mindful of what kind of rating the part has.

It actually amazes me that an awful lot of so called ‘trainers’ aren’t aware of how this all works .

[XJ Junkie]

Why would you use kinetic ropes or straps for lifting?

[Estee]

Is there a table or reference guide or calculation that would enlighten us more on this?

[XJ Junkie]

Another purpose for bow shackles

[Mike Nel]

Is there a table or reference guide or calculation that would enlighten us more on this?

I tried to Google for answer, but nothing yet.

I will keep digging

[XJ Junkie]

Estee there used to be one on the Liftlash www but I can’t find it now.