Strops, straps, ropes etc

[Trugga]

I've been reading through a few threads today regarding recovery equipment, as I've just purchased a a new tree stop and 3 bow shackes(rated 4¾T), and was wondering...

What is the difference, preferred use, description of:

Strop
Strap
Bridle
Rope

Bow Shackle
"D" Shackle

I'm sure an educated explanation would be beneficial to many of us.

Lawrence

[Road Hog]

D shackles are designed for a near straight on end pull,while Bow shackles can be used end on or side pull

[Drift]

strop when I worked on the port in Southampton was for lifting.

But off road I reckon its a terminology for a tree protector or Anchor strop or towing strop will be a flat usually nylon length, but can wear and deteriorate very quickly and should always be checked.

A Strap, Im unfamiliar with off road wise, other than to secure something.

A bridle is used to connect two two points on the front or rear of a car to one tow line, think of a horses bridle fitting the two bits.

A Rope can be anything from nylon to hemp or wire and intertwined and can be spliced.

All must be rated for the purpose used though.

A bow shackle is more circular

A D is in the name "D" shaped Im going back 20 odd years but I think we used Bow shackles on the port as they where rounded and less likely to jolt, look for the stamp Crosby on any shackle as they are about the best manufacturer and of course make sure they are rated.

I will check the shackles more as my memory is rather rubbish.

[horses45]

see i did learn thing on here

[Alfie]

I've just swapped some bow shackles with Drifty I'm sure he'll post a piccy If we ask nicely

[Trugga]

I have a selection of Bow and D shackles.

I am lead to believe that only Bow shackles are rated (stamped or embossed on the loop), whilst D shackles are not. I've also read that Bows are for use with rope/strops and D's for chains.

As of yet, I have not found any definative answer.

Whilst preparing my recovery kit for tomorrows punch hunt, I was aware of the different loadings/ratings available to me, and that any setup (combination of strops/shackles) is only as strong as the weakest link.

My winch (currently fitted to the front of the Sport) is an 8000lbs model - I understand that to be 8000lbs on the first layer of cable, nearest the spool.
8000lbs is 3628Kg
The Frontera Sport weighs _______Kg (I can't find the figure to hand, but surely no more than 1500kg).


This Bow Shackle is rated at 4¾T
Now, is that a metric Tonne or and imperial Ton? I'm guessing Imperial as the figure is 4¾ and not 4.75 and the loop diameter is ¾" (also embossed on the loop)

4.75 UK Tons is 4826Kg
4.75 US Tons is 4309Kg
4.75 Metric Tonnes is 4750Kg

So for safety's sake I'll use the lower figure.

For the moment then, my winch cable is the limiting factor.


Unrated D Shackle





Both the above were bought as "Tree Strops", the first from the Billing show and the latter from Britpart.
Both are rated at 1.5t in a straight pull (I need to work out what the lower case "t" refers to... appears both "T" and "t" refer to the same thing, although I'm still not sure whether UK,US or Metric, so again I'll err on the side of caution).

1.5t (or T) is therefore 1360Kg

If these strops are doubled (ie, the two fixed ends fited to a stricken vehicle and the pull effected from the centre) then they are rated at 3t each, which equates to 2721Kg

So now, if using a tree strop, that would be the weakest link.



I'm not sure what the above is actually called (I bought it from Craddocks some time ago - to assist in the recovery of Drift from his mine shaft). It actually forms a complete loop. It is rated (from the label) as follows:

1296Kg straight pull
908Kg 90° apex at hook

I also have the following tow ropes from Halfords (2t each if I recall correctly)





These two are only used for towing and not recovery work.

Then there is the chain:



and a couple of snatch blocks:



Plus the 48" Farm Jack and the trifor hand winch (which does not get out much these days)


Perhaps if we could iron out a few of the questions raised so far in this thread, we could add the results to the Wiki.

Lawrence

[Alfie]

The D shackles I have are rated with an swl. All the stuff we use at work has to be rated for insurance, if it's not rated we have to have it tested prior to use and the certificate put in a special lifting tackle register.
If memory serves me corectly all lifting gear is tested to 3 times its swl (safe working limit)
The whole point of tree strops is to stop the strop damaging the tree so the wider the better.