recovery from the towball.. (only if you have to)

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Originally Posted by isuzurover

So you carry a tow rope AND a snatch strap???

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no......not really.......

i have done a big no-no as far as snatch straps are concerned.....and towed a vehicle or two back onto the road......
a snatch strap isnt designed for constant forces......its only designed for a quick stretch and release.....




i dont have a tow strap as such......but i do have a tree trunk protector.....which i could probably use.......
but i would rather abuse my snatch strap......it has a bit of give and feels a bit safer......
and its also due for replacing......it has been used about 8 or 9 times.....
and ive heard they are really only meant to do about half a dozen recoveries.....



but i once recovered some idiots on some sand who knew their centre diff wasnt working......but still were out there anyways.....
they didnt have any recovery points......so i had to pretty much loop it around some part of their towbar......and it damaged the edge of my strap......

i was very tempted to leave them there.....but they had kids with them....and it was getting dark.......

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Originally Posted by weeds

first question i would ask is.....whats the rope rated too?

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diameter squared = rough guide for SWL.

for natural fiber rope....

for bonus money whats the mulitplier for synthetics that float (and sink if you know it)

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Originally Posted by PAT303

Has anyone actually seen a tow ball snap off?. Pat

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Not me. But I have heard the wives tales.
Some lightweight towballs (i.e. fitted to cars, not 4wd's) have a shank of about 3/4" max, take the threads into account and you're down to about a 15mm core.

I remember seeing one old towbar that was actually just a ball shaped sleeve which a coach bolt passed through.:(

Regarding the ratings of tow-bars.
I've designed truck towbars before and the rating for those is in compression. The idea being the towbar must handle a hard stop of 1g (i.e. the entire towed weight) acting forwards and down at a 20 deg angle, the maximum material stress is also specified but I can't remember exactly what right now, but it's similar to the stress that will withstand 1,000,000 cycles fatigue.
So your one-hit factor of safety is about 3 before it will bend if all is good.

Most 3,500kg rated 4wd towbars I've seen would not meet the standards for 3,500kg on a truck. The tongue needs to be quite heavily gusseted to withstand the bending stress applied.

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Originally Posted by Blknight.aus

for natural fiber rope....

for bonus money whats the mulitplier for synthetics that float (and sink if you know it)

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Rope types are diameter squared times the numbers below.
Nylon x 2.25
Polyvinyl x1.25
Polyethylene x1.45
Manila x1
Polypropylene x1.6
Polyester x2
Silver x1.16
Sisal x1.0