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Edward, you can buy a tow hitch like yours with the tow hitch pin in the other direction, or you can drill yours to suit, I think BMKal redrilled his.
The only explanation I have heard for having the Shackle Pin axis in the horizontal line is 1. that it looks better ????, 2. the shackle doesnt flop about.
Not good enough reasons if you want your shackles to last, Regards Frank.
Was this for the front or rear of your vehicle?Quote:
Originally Posted by BigJon
That wasn't my tow hitch, just a photo I copied from the net, but it does seem odd that they are designed in that way. I just had a quick squiz in a 4WD magazine and noted that ALL the competition vehicles using bow shackles as front recovery points had them mounted horizontally.Quote:
Originally Posted by Tank
Edward :)
Does that make them right, if most people do it wrong does that make it right.Quote:
Originally Posted by I Love My Landy!
The riggers guide book on page 70 says:
"Shackles are designed to take vertical forces only. Diagonal forces will strain the shackle and lead to eventual failure."
So in the majority of cases "Ignorance is Bliss,", Regards Frank.
No argument with you there Frank, just trying to say that I find it strange that manufacturers design recovery points with such a flaw.Quote:
Originally Posted by Tank
By the way thanks for searching that book to find that information.
Edward :)
Rear. The ARB rear step bar for the RRC has a very long towbar tongue (square bit) and it also is not horizontal (slopes upwards towards the rear).Quote:
Originally Posted by I Love My Landy!
The one I made has a down turn at the end to get the shackle perpendicular to the ground and as noted has the shackle mounted vertically, not horizontally.
At the front I currently have one tow hook (off a 6 tonne Isuzu truck) mounted to the bullbar. When I source one I will fit one on the other side as well.
Frank,
what if he mounts the shackle like his pics and then uses another shackle in the bar mounted one which would cause the 2nd to be mounted verticaly like you suggest...this would give some freedom of movement both in vertical and horizontal plains.
IMO using a bridle is a good opiton and should be wire rope with a snatch block (pulley) to allow the required freedom of movment...
It would'nt make much difference esp. if the line of pull was a fair way off centre, it's not often you will find an anchor point directly in front or rear of you.Quote:
Originally Posted by uninformed
If you look at most ARB bars with towing lugs on the bar with horizontal pin holes you will find they are bent inwards.
When a shackle is pulled other than vertical or straight ahead the pin becomes jammed in the horizontal pin hole and the body of the shackle is pulled sideways against the pin, as the damage gets worse the pin no longer lines up with the thread/hole in the shackle body, this will eventually lead to total failure of the shackle and you dont want a shackle body flying through the air on the end of a snatch strap, Regards Frank.
These are sold and will have the same problem
https://www.aulro.com/afvb/
I suspect that the shackles must be strong enough to tolerate the binding on the shackle pin otherwise these would not sell.
Perhaps frequent replacement of shackles is the way around it.
Just out of interests sake, since this topic arose I've looked into many of the bow shackle recovery points that are being sold, and the vast majority of them have the pin mounted horizontally (like in the photo above). Seems strange that manufacturers will design them with such a flaw. I reckon most people (me included) would not be aware that bow shackles are not meant to be mounted horizontally.Quote:
Originally Posted by slug_burner
Edward :)
If anyone is interested in that rigging book Frank mentioned, part of it can be viewed here:
http://www.riggingtraining.com.au/Ri...ide_part_1.pdf
(Funnily enough I found the link on this site!)
Edward :)