OK, there is a lot to think about in this thread.
Why is a shear force preferable?
and why do most of the recovery courses recommend using the tow pin.
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OK, there is a lot to think about in this thread.
Why is a shear force preferable?
and why do most of the recovery courses recommend using the tow pin.
The shear force is always the same, but the difference between where the pin is loaded and where that load is resisted gives the bending moment on this pin. The standard inserts load the pin close to the outside receiver to minimise bending and maximise strength.Quote:
Originally Posted by black betty
Probably because the people running those courses haven't thought about it or don't understand it. The recovery course my wife had to attend for work told people to never let down their tyres on soft surfaces.Quote:
Originally Posted by black betty
Grains of salt may be required.
Just to clarify.
I DON'T snatch from the towball. Never have, never will.
I have snatched from the towbar pin and will continue to do so. I have also snatched with a shackle through the towball hole with no qualms.
If you are bending towbar pins, towbars, shackles, etc then you SHOULDN'T be doing a SNATCH recovery. The vehicle is too badly stuck. Stop and do a rethink.
If anyone can supply one of those slide in shackle mount thingies that will suit an ARB on a Classic Rangie then I will buy it. I can get one made locally (Horsham) for around $125. The off the shelf units don't work, they are not long enough.
Quote:
Originally Posted by BigJon
I think this is the key so many miss....if you are having to snatch that hard.....then snatching is the WRONG method of recovery in that situation.
Well said BigJon.
First critical step of any recovery is stop and look and think...trouble is many don't.:angel:
Mark
I feel very bad for the people on the other end of your snatch strap. If you break a pin, it is they who will suffer, not you.Quote:
Originally Posted by BigJon
Continuing with such a practice after being informed is far worse than doing the same while ignorant.
Many of those pins are very hard and will fast fracture rather than bending.
still waiting on the tow bar info daugal....:angel:.....show me the money baby..:D
cheers
I'm awaiting your photos and measurements. HR aren't sold much here.Quote:
Originally Posted by cucinadio
Good thing you are in another country then.Quote:
Originally Posted by Dougal
Does some "knowledge" imparted by an "expert" over the net change the forces in a recovery? How is the recovery worse?
As I mentioned I have never seen a bent pin, much less bent one myself. Now all of a sudden the pin is goint to fracture?? Show me the pics of all these bent and fractured pins you have seen and maybe I will change my tune.
When I can come up with a better (cost effective) solution I will use it.
Incidentally in the last four years I have done about 10 or less snatch recoveries. All have been "gentle" (walking pace or less), because as I mentioned if you are pulling hard enough to do damage then you are using the wrong recovery technique.
Mate.... Dont want you to fall from that horse you're sitting on, its pretty high!!Quote:
Originally Posted by Dougal
https://www.aulro.com/afvb/images/im...009/06/864.jpg
Snatch strap released by 'snapping pin' will shoot back, I cant remember, but I did the calcs once... And having no shackle attached will give the other vehicle a lovely "Whack"...
Adding a shackle etc to the equation is adding more risk...
Quote:
Originally Posted by Sprint
Sprint... one hiccup in your theory... SWL as in 4.5Tonne SWL... means Safe Working Load...
That's not the load it will break at... it's load that is considered safe , taking into account the required safety factor.
Others here will know more accurately than me.. but the difference between SWL and MBL (minimum breaking load) if usually a factor of about 5. So your 4.5 tonne SWL shackle will probably break at around the 22 tonne mark.
The ratings on snatch straps are not swl.. Thats why your snatch will break before the shackle and it's crucial if you have to use a shackle.. that it is connected to something strong and secure enough...
Mark