Tightening of mooring shackle

[WindermereColvic]

Hi all,
I'll be fitting new strops to our swinging mooring in a day or two, by shackling a length of chain spliced to the strop to the mooring riser. I seek the forum wisdom concerning the following - How tightly should i do up the shackle pin?
It seems to me i should find a large spanner and lean on it with all my might, but i'm sure i remember reading somewhere they should be only hand tight and rely on the seizing to hold the pin in.....
I'm sure you lot will know!
Ta in advance, Matt

 

[Scareyclott]

I just did mine hand tight and used wire to seize it, this was how it was recommended by Maiden Marine in Windermere

Where are you moored?

Scott

 

[sarabande]

there is a view that black, industrial strength cable ties are suitable to 'mouse' the pin. And are resistant to UV degradation.


Recent PBO article on moorings refers.

 

[Robin]

If you lean on the shackle with a big spanner even large ones will bend a bit and distort. Just tighten with a spanner until 'tight' but undistorted and then mouse. I prefer to use thickish steel fencing wire, not even galvanised and plastic coated is even OK. Use two entirely separate wires for extra security. For each one twist the ends evenly, don't just wind one end around a straight other end, both parts need to be twisted together.

 

[prv]

If you lean on the shackle with a big spanner even large ones will bend a bit and distort.

Yep - but does this have any effect on their strength? I ask because it's the technique I use on my pontoon mooring lines. Maybe I shouldn't?

Pete

 

[Robin]

Yep - but does this have any effect on their strength? I ask because it's the technique I use on my pontoon mooring lines. Maybe I shouldn't?

Pete

I just don't see the point of tightening any more when it simply closes the jaws and can still be tightened more. For absolute security on below water shackles not inspected regularly (like for ground chains) I would even peen the exposed threads over with a hammer as well as using two mouse wires. I don't like using S/S wire or even monel wire where it isn't regularly visible to check.

I was once a mooring 'team leader' doing YC moorings over many years in Poole in an exposed location and we serviced all the moorings annually. We would sometimes see shackles where the pin threads had corroded and the pin would easily have undone were it not for the wire mousing. Other times the pins were so rusted in they would never come undone! The weakest parts always were the swivels and we always used larger sizes than simply matching the chain and always serviced on the basis of 'if in doubt throw it out'. In my time we never lost a single boat due to the clubs part of the mooring set up, on the rare occasion one did go walkies it was always the bit the owner was responsible for above the swivel, ie the strops (chain or ropes) that go on board which failed. Mostly failures would be from chafed through rope or occasionally broken chain because it was too small a size or was poor quality or both. Always use a size larger chain strop than for your anchor is a good maxim.

On a pontoon mooring it is very different because the shackles are easily seen and checked, I would tighten as far as but not beyond the distortion point, then mouse with monel wire (twice for safety because they are thin) or even a couple of black cable ties as someone else suggested.

 

[Lakesailor]

Just replaced a mooring strop on Feckless. I don't own the boat now, but do sail on her and help the owner.
Sad tale is that he bought (against my suggestions) two strops from the aforementioned chandlery which came with plastic pipe on and a length of chain spliced to the bottom end. That is all they sell.

In less than 6 months one of the warps has parted where it emerges from the pipe! I mentioned this to them and they just looked at me as though I was senseless.
Unfortunately the other warp had already lost it's shackle so the boat went walkabaout (fortunately unharmed)
I've spliced up a new warp without plastic pipe or chain and put a galvenised thimble in at the riser end. I've always used this method and not lost a boat in nearly 10 years on the lake.
The chain on the strop may have been the cause of the problem as I looked at it before Xmas and it had wrapped around the riser and the links had "locked" together (it's fairly big link chain). I couldn't free it off at the time as the wind hasn't dropped up here for a while and getting the buoy onto deck wasn't possible. This shortened the scope of the strops and caused a lot of "yucking" against the mooring buoy in the chop.

If your strops allow the boat to hang back from the buoy it should be OK, and your mooring is a lot more sheltered than ours.

The shackle thing needs at least a cable tie and as someone else mentioned, fencing wire makes great fastener. You need good pliers to cut and bend it. I'm not sure the tightness of the shackle should be under estimated. The one remaining shackle on the mooring (with strands of the strop left hanging from it) was only finger tight. I use a 8" shifting spanner to nip them up.
Most shackles don't have enough thread showing to peen over these days.

If you you want a hand send me a PM.

It's OK Scareyclot, your boat was still there this morning

 

[Scareyclott]

It's OK Scareyclot, your boat was still there this morning

Thanks Lakesailor.


Scott

 

[Shanty]

One point that hasn't been mentioned so far - the threads should be protected from rusting. Very little metal has to be removed from the threads before they are doing nothing to hold the pin in place, and you are solely dependent on the mousing.

I coat the threads with Loctite when assembling the shackle, others use mastic - same principle. Either will do.

The pin should then be tight - but no point in distorting the shackle, and the pin should be moused, as a last line of defence. I use fencing wire on large shackles, monel wire on smaller ones.

 

[Billjratt]

I've occasionally used bolts through shackles when the original pin had got lost or exessively worn.
Inevitably there is extra thread which can be cross-drilled for a clevis pin or piened.
I wonder why the manufacturers make the pins so short? Perhaps there is a case for pinching the shackle in a vice while tightening so as to get that extra little bit of thread through, which can them be popped with a centre punch and/or peined.
Since all these shackles should be black iron to be compatible with the chain, surely mousing and eyes must be considered in the same way. (No SS/monel, etc. )

 

[GrahamM376]

I saw four moorings fail last year, in two cases the (underwater) shackle pin threads had rusted away and they hadn't been moused. I always grease the threads, tighten hard then back off half a turn and double mouse with monel. So far (touch wood) not had a failure.

 

[Enya]

My boat is (in Summer) on a swinging mooring in Portsmouth Harbour and sometimes takes considerable wind battering. The mooring has suffered at the top end from rusted shackles (however tight you get the shackle), rope fraying and shackles working loose. Fortunately, partly because I monitor it carefully, so far the boat has not gone walkabout.

I also put a diver down twice last year to check and reinforce what is under the water.

The monel seizing wire that you buy in chandlers is really too small for the job. I use uncovered garden wire and black cable clips. However, I am unsure of the garden wire. It is more pliable than fencing wire but may be more prone to rust or breakage.

Has the forum any views on this?

 

[doug748]

Just to muddy the water even further.

I was never right happy with moused shackles and now use the type closed with a nut, bolt and split pin, shown here:

http://www.liftinggearprod.co.uk/li...hackles_british_standard_lifting_shackles.htm

Scroll down to the type described as the "Crosby Safety Pin". You can spanner these as hard as you like, as before, lubricate the threads.

 

[Lakesailor]

If you don't want to use fencing wire (which can be a bit of a struggle) try the wire from the sheep fencing itself, which is thinner and more pliable.

 

[ffiill]

You remove shackle pin and replace it with a bolt of same thread size but with enough spare sticking out to add either a locking nut and spring washer or a nylock.Even better if you can weld it together
You can try split pinning but getting holes aligned is a pain.
Other wise I guarantee that sooner or later the pin will work loose whether or not it is siezed with wire and drop out.
If you use non rated(chinese shackles) the chances of this increase!
I dropped three pins off 3/4 inch shackles which had been tightening with a spanner and seizing with wire.
Even on rated shackles I find the pins have a sloppy thread-alright if you are using it for lifting when you can keep a check but little use if its in constant use working on a mooring.
My boat survived in an 8 week period a trip on its own down Loch Duich and twice in perfect calm floating here and there at the head of Loch Duich!
I have some ancient shackles and they were made with a fine tollerance fit both at screw end and collar below eye end. Modern ones without fail are sloppy which is great if you need to get them apart but means the pin can flex and work against its thread.
I do not like the free to rotate pin with nut and split pin because all that is keeping it together is the split pin!-the nut serves no other purpose than a big washer!

 

[doug748]

........I do not like the free to rotate pin with nut and split pin because all that is keeping it together is the split pin!-the nut serves no other purpose than a big washer!

I have only seen a shackle pin held by a split pin and washer in dinghy sizes and would agree that is very dodgy.

Lest confusion creep in, the link above shows a threaded nut and bolt secured by a split pin.

 

[Lakesailor]

Other wise I guarantee that sooner or later the pin will work loose whether or not it is siezed with wire and drop out.
!

I haven't had any failures with fencing wire. It's very tough to bend, needing good pliers.

 

[Seajet]

Lakesailor,

I can't help thinking the 'mousing' in that photo requires a lot more turns ( with thinner stuff I admit ) through shackle pin & the bow, then twisted together at the ends, wire-locking style; also is it me or is only 1 shackle there moused ?

I double mouse with monel, and do the pins up pretty tight before that; I have worked on quite a few moorings with my club over the years, this seems to work ( with relatively massive over - spec' chains & sinkers ).

Another point I haven't seen mentioned - but have only time for a quick scan - is that the mousing / wire locking should be biased in the direction to tighten the pin.

One point to beware of with rope strops, presume this doesn't affect Windermere but as a general comment, I found that in wind over tide conditions the boat goes up to the buoy and the strops drop underneath it; where there are razor-sharp barnacles !

 

[Lakesailor]

That piece of fence wire has been on the previous shackle for 2 years and is now on that new one. I only replaced ithe shackle because of pin wear. Believe me, the force needed to bend that wire is enormous. A simple pin unwinding could not even stress that wire.
I've used monel mousing wire and found any friction busts it off in no time.

As for your point about direction. That pin could only unwind about 1/5th of a turn. It would need to unwind possibly 7 turns to fall out.

The other shackle was fitted by the moorings contractor and has the threads peened. That was fitted 2 years ago.

However, when this poor weather is over I will be adding more fence wire to the other shackles as belt and braces.

 

[PeterR]

I look after the moorings at our club and every boat that has ever gone adrift in my time was because of a shackle failure. Below the water our contractor peens over the threaded end of the pin with a hammer and anvil and adds a plastic cable tie to mouse it. According to him any form of wire of dissimilar metal to the shackle (S/S, Monel or whatever increases the corrosion of the pin) A previous contractor used to weld the pins in but that was even worse. The weld corroded rapidly leaving the weakened pin to fall out.

Above the water, if you want to leave the strop in place permenantly I would use the same technique. If you want to remove it for the winter I have always greased the pin heavily with waterproof grease, hand tightened with two adjustable spanners and moused with monel wire.