Shackles

Depends whether he's had two or three Weetabix!

I reckon he could do both on two ;-) ... on a trike!

Lee D

That's the chap.

In message , Julian Pollard writes

Sahckles come in 3 ratings

Cheapest - untested, no stamp not to be recommended

Batch tested and stamped with batch number - OK for use with a standard rope.

Individually tested and stamped with serial no - recommended for KERR

On or around Sat, 30 Aug 2008 19:23:28 +0100, "Julian Pollard" enlightened us thusly:

asides from the matter of whether it's tested, you want at least 3/4 ton rating for normal towing, winching you need to look at the winch rating and the cable rating, the shackle should really match that.

KERR puts a big load on things, again, study the rope, it may have a maximum rating.

note that when doing winching with a big winch or KERR the attachment to the vehicle is of prime importance. You need uprated recovery points on the vehicle (aka Jate rings). However, you also have to consider what they're attached to - for example, many fit on the bumper bolts, which themselves have a shear stress.

heavy recovery stuff gets complicated, as you can see. The advice given about shackles is good though, pick a tested one, and don't go below 3/4 ton capacity. Beyond that you have to be careful. KERR should especially be used with care.

Could you answer the question please, Mr. Bliar? (Sorry, couldn't resist that one!) I wouldn't describe the above 'qualities' as ratings. I suspect that the OP wants to know how 'big' they should be. I agree that unmarked/untested items need to be avoided.

The rating of the shackle(working load limit as a lifting device) needs to be such that the rope breaks first. Lifting ratings in the UK have a safety factor of at least 5 (I think, subject to correction if someone knows otherwise) so a 3 ton shackle will withstand at least 15 tons before permanent deformation sets in. There's still a lot more capacity beyond that until breakage. Most nylon ropes sold as 28 mm OD 'Kerr' quote a minimum breaking load of about 15 tons. 3 strand 28 mm OD Nylon is similar.

All the above assumes, naturally, that the attachment points are at least equal in strength to that of the shackle. There's no point in having a strong shackle if the tin to which is attached is weaker. If the hazard is not understood - rope flying around is one thing: metalwork flying around is quite another and must be avoided! With a wire rope you don't really want either flying around.

My KERR rope is rated at 12 tonnes, and I'm pretty sure you are right about the x5 safety factor, so a 3-tonne shackle should be OK.

+1 to the remark about the point of attachment. If there's one thing more frightening than a shackle flying round at high speed on the end of a recovery rope, it the same with a revovery point and half a rusty crossmember with it. And remember that there is a lot of stored energy in a KERR rope. It won't go 'dead' like a polythene rope will - it will twang around the vicinity until it has dissipated all that energy. Snatch recovery is IMO a last-resort procedure, and needs perfect equipment and proper technique to be safe.

"Austin Shackles" wrote in message news: snipped-for-privacy@4ax.com...

I was tidying in the garage and I do have a couple of spare 3300lb rated carabina 0 type screw opening locking shackles if anybody would like to make an offer I should probably measure the opening I don't think suitable for webbing tho' Derek

The shackles I use for KERR are 6.5 tonne rated, those I use for ordinary towing are 2 tonne ones.