Mooring Shackle mousing

fishermantwo

fishermantwo

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Now I know this subject has been done to death but I think it needs a revisit. Last week I was sailing one day and when I returned to my mooring I made sure everything was secure as bad weather was eminent. Next morning before daybreak I was on the water near my mooring again to go fishing and I noticed my yacht on the other side of the estuary, nose resting against a mud bank! I recovered my mooring onto the deck and started the engine and returned to the mooring area, picking up a new but vacant mooring. The shackle pin was moused with monel and the threads had gone. I had dived on the mooring about 2 months ago and it was fine.
Next day I used my hookah gear and dived on the "New" mooring that was laid by the same contractor. Same deal, the monel was immaculate but the pin could be easily rotated, I added a couple of electrical ties as a temporary fix. I will dive again later in the week and fit a new shackle. Thinking about it and planning to use 8mm electrical ties only to mouse the shackle I thought a good idea would be to fit some sort of abrasion protector where the swivel loop could contact the shackle pin and damage the ties.
In the photo which is just an 8mm shackle I prepared for this photo. The black bit is a piece of hard rubber boat roller I turned up. I recessed the side where the electrical ties will go and in the full size one I would machine a bit of a vee to keep the swivel in the centre of the pin.
Any comments or suggestions?
Had the same problem 40 years ago with monel mousing so I will be avoiding a mix of metals as much as possible.
 
As well as mousing the shackle, we make sure water cannot get to the thread by coating it with Loctite, or mastic before the shackle is assembled. If the thread doesn't get wet, it won't rust.

If you want to stop the swivel loop moving on the shackle pin, lash the two together with light line, self amalgamating tape, or electrical tape. Won't look pretty, but this will only be a problem if you are trying to impress passing fish.
 
Shanty said:
As well as mousing the shackle, we make sure water cannot get to the thread by coating it with Loctite, or mastic before the shackle is assembled. If the thread doesn't get wet, it won't rust.

If you want to stop the swivel loop moving on the shackle pin, lash the two together with light line, self amalgamating tape, or electrical tape. Won't look pretty, but this will only be a problem if you are trying to impress passing fish.
Click to expand...

Thanks for the reply. Wont be able to seal the threads this time as the job will be underwater.
 
I have always just tightened shackles as tight as possible then moused to be sure. There can be a fair bit of jerking on the shackles so some tendency to unscrew them. I have always found they rust together very tight after a while.
My mooring began with a provided buoy with a stainless steel shaft incorporating a swivel. I found that an iron shackle on the stainless steel seemed to wear away quite quickly. I got hold of some supposedly stainless steel chain from inside a cement making kiln. Anyway with 10mm stainless steel shackles (from China) I found the whole set up wonderfully free from wear after quite few years. The original iron mass was rusting away so I had added 4 old car tires filled with concrete. about 40kg each and there was a lot of the SS chain on the bottom with sundry anchors etc. Pretty solid I thought in about 3 metres of water.
Any way the government department as they have a habit of doing stuffed me up completely. They administer the moorings and decided that all moorings have to be inspected by an "approved" mooring company every 2 years. So I got this "approved guy to look at the mooring. Oh no says he that will never do. Old tires filled with concrete no no no. So in a fit of frustration I got him to fix it.
Well he moved it 3 metres. reckoned that is where it is supposed to be (Differential GPS etc) . He dropped a railway wheel down and attached my SS chain to it. It still has my SS shackle at the top but he fitted 2 iron shackles at 20 squid each (pretty big) with monel mousing wire. 500squid the whole job.
So after 30 years of caring for my mooring the job has been taken off me by government beurocrats. Ho hum I wait to see how long the iron shackles last. In the meantime I bought home about 5 metres of this round link chain. You just can't see any sign of wear after what must be about 7 years in the mooring. So just rattling on that is my mooring story. good luck olewill
 
As you say, if you're working underwater, then mousing is the only option. Before the insurance company forced our club to employ a contactor to service the moorings, we suffered all possible failure modes until we gave up using galvanised shackles. The quality had been dimishing over the years and the threads were so poor (and mostly zinc!) that they would not stand being unscrewed. Natural finish lifting shackles were used instead - two sizes larger - and they lasted a season longer without any failures.

It's best to accept that you will never want to re-use a shackle on your moorings, so other means are acceptable to lock the pin in addition to mousing. With an ungalvanized shackle, you can weld the end of the pin after fastening and any type can have the end of the pin distorted with a pair of large hammers so that the thread cannot move. My own preference for mousing is galvanized fencing wire, replaced at each inspection as it's so cheap.

Rob.
 
While researching mooring failures for a PBO article, I found much conflicting opinion among mooring contractors. Much of it was of the 'me dad did it like that all his days, so it's all right for me' kind. However the Harbourmaster at Fowey, Captain Paul Thomas, has considerably wider experience than most and he stressed that a major cause of mooring failure - after chafed through/inadequate boat ropes - is swift corrosion of the shackle pin threads. These are, of course, hidden and rarely examined underwater. He pointed to a display board in his office showing a score of examples of failed chain and shackles, and offered his opinion that many folks ( including sub-contractors ) wind up the pin as tight as a big wrench and a long lever can get it. This is unnecessary and damaging, he asserts, for that 'crushes' and strips the zinc coating microscopically where the male thread of the pin enters the female threaded hole, exposing unprotected mild steel ( microscopically ). That's where the corrosion starts, he believes - showing several examples of pins which seem to support the idea - and then it accelerates.


IMG_1845.jpg



Top mooring contractors 'Diving Belle' - who guarantee their work - use double BLACK cable ties which are less vulnerable to UV degradation than white and also, apparently satisfactorily, stainless steel 'cable ties' to secure the pins from rotating. Other contractors use a wide variety of materials, including monel wire, stainless wire, fencing wire, nylon fishing line, and domestic electrical wiring 'flex'.

All seem to agree that there is no substitute for BIG gear with built-in redundancy and frequent and meticulous inspection.
 
I'm off to do some moorings at our club shortly.
All our risers, and bridle chains are made up with a large ring on one end so they can be reaved back on themselves, eliminating any need for shackles.
In some cases a bridle may be shackled in order to reduce chain size to fit a bow roller, but this will only be done if it is above the support buoy where it can be inspected on every trip to the boat.
If, as in some cases shackles are used under the water they are always welded.
 
Several failures around here with bottom shackle pins rusting and coming out, mostly not moused. I grease mine well and mouse with monel but, pull a few links down and add a second shackle which takes the weight. If that fails, there's still the one at the end of the chain. Dive spring and autumn to check and just about to order new 22mm grade 40 chain and 36mm polysteel riser, ones fitted have lasted 9 years.
 
>Thanks for the reply. Wont be able to seal the threads this time as the job will be underwater.

Before dismissing Loctite and and mastic buy some and see if they dissolve in water. My bet is mastic won't dissolve but Loctite could. The other thing you could use is underwater epoxy.
 
Here on the river Blackwater the st lawrence fairway committee use stockholme tar on the threads ( obtain from horse tack shops) plus cable tiesf or mousing
There is no real advantage in using galvanised shackles as the chain wear on them soon rubs through the galvanising. However, most purchasers like to see galvanised ones so that is what i sell them
For details about our moorings go to www.stlawrencefairwaycommittee.com
Sorry could not miss the advert opportunity!!
 
Many years ago an old-timer told me to never rely on a shackle when attaching a riser to a ground chain or trot.
His method was to tie the riser to the ground chain with a clove hitch and use a shackle or wire to prevent the knot undoing.
When I looked after the club moorings I implemented his advise and never lost a mooring due to a shackle failure or corrosion.
When ever a chain needed replacing it was always due to wear of the chain links where they touch.
 
I still would not like to rely on a moused shackle in any part of my mooring, if it was not able to be constantly seen.
 
KREW2 said:
I still would not like to rely on a moused shackle in any part of my mooring, if it was not able to be constantly seen.
Click to expand...

Yes. On Menai Strait, which is as tidal and exposed as any moorings should be, the contractors don't use shackles at all, they weld 'paper clip' type connectors. I realise this is not very helpful to the OP who is going to do the job underwater but this is the optimum method.
 
William_H said:
I have always just tightened shackles as tight as possible then moused to be sure. There can be a fair bit of jerking on the shackles so some tendency to unscrew them. I have always found they rust together very tight after a while.
My mooring began with a provided buoy with a stainless steel shaft incorporating a swivel. I found that an iron shackle on the stainless steel seemed to wear away quite quickly. I got hold of some supposedly stainless steel chain from inside a cement making kiln. Anyway with 10mm stainless steel shackles (from China) I found the whole set up wonderfully free from wear after quite few years. The original iron mass was rusting away so I had added 4 old car tires filled with concrete. about 40kg each and there was a lot of the SS chain on the bottom with sundry anchors etc. Pretty solid I thought in about 3 metres of water.
Any way the government department as they have a habit of doing stuffed me up completely. They administer the moorings and decided that all moorings have to be inspected by an "approved" mooring company every 2 years. So I got this "approved guy to look at the mooring. Oh no says he that will never do. Old tires filled with concrete no no no. So in a fit of frustration I got him to fix it.
Well he moved it 3 metres. reckoned that is where it is supposed to be (Differential GPS etc) . He dropped a railway wheel down and attached my SS chain to it. It still has my SS shackle at the top but he fitted 2 iron shackles at 20 squid each (pretty big) with monel mousing wire. 500squid the whole job.
So after 30 years of caring for my mooring the job has been taken off me by government beurocrats. Ho hum I wait to see how long the iron shackles last. In the meantime I bought home about 5 metres of this round link chain. You just can't see any sign of wear after what must be about 7 years in the mooring. So just rattling on that is my mooring story. good luck olewill
Click to expand...

G'day olewill,
Yes its interesting who gets to be a qualified contractor. Locally its just a matter of getting your name on the list. Interesting the bit about the SS chain. I was servicing a friends mooring Christmas time after his boat came off the mooring from the same old failure. While I was searching for his remnants I wandered into the next mooring and its was like looking at jewellery. The chain was stainless, looked like 8mm thick and perfect circles about 100mm across. I checked it out and it was perfect. I was always suspicious of SS permanently underwater and I commented to my friend that I will be checking that mooring again at a later date.
Insurance is the problem we are all going to have to face. Locally and this mean you too olewill, companies have stopped covering boats on swing moorings. They had stipulated that moorings had to be serviced by these so called professionals annually. The high number of failures of moorings because of these professionals is going to cause a lot of grief that has only just begun. The two main boating insurance companies in Australia will not even give 3rd party cover anymore. I am with Apia and my mate tried for cover for his boat [Sydney/Pittwater] with the same company and got turned down. Rang about and got the same reply.
 
Don't let me forget!

To dig-out / find a couple of mild-steel mooring shackles which were down for six seasons .... as you won't believe the condition (good) they are in..... (must post photo's as proof.)

OMG ..... this process is 'Donkeys Years' old ..... & some of you 'Donkeys' are old! ;)

It was 'told-ter-me' by me Engineering Tutor in about 1975 ..... & it works! .... and can be achieved in a domestic oven (200 - 230 C). :rolleyes:

Heat them to temperature & coat with linseed oil & cook-off for a further ten-ish minutes.

Apparently a common term for this process is refereed to a 'Chinese Galvanising' .... or an 'oil-bath' .... but I don't have enough oil or an appropriate bath.

Plus .... on a negative :confused: ..... you'll fume & stink the kitchen out .... so treat SWMBO to a day-out with her Pals .... & get on with the job ... :D
 
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fishermantwo said:
G'day olewill,
Yes its interesting who gets to be a qualified contractor. Locally its just a matter of getting your name on the list. Interesting the bit about the SS chain. I was servicing a friends mooring Christmas time after his boat came off the mooring from the same old failure. While I was searching for his remnants I wandered into the next mooring and its was like looking at jewellery. The chain was stainless, looked like 8mm thick and perfect circles about 100mm across. I checked it out and it was perfect. I was always suspicious of SS permanently underwater and I commented to my friend that I will be checking that mooring again at a later date.
Insurance is the problem we are all going to have to face. Locally and this mean you too olewill, companies have stopped covering boats on swing moorings. They had stipulated that moorings had to be serviced by these so called professionals annually. The high number of failures of moorings because of these professionals is going to cause a lot of grief that has only just begun. The two main boating insurance companies in Australia will not even give 3rd party cover anymore. I am with Apia and my mate tried for cover for his boat [Sydney/Pittwater] with the same company and got turned down. Rang about and got the same reply.
Click to expand...
A chain supply co once told me that they supplied stainless steel chain to a customer on the River Crouch.
The chain failed very quickly & they had to compensate the customer
They had tests done on the chain & it turns out that upriver in the crouch the water passes though a geographic layer of ( i think he said) iron ( not enirely sure of which element) the presence of this in the Crouch kills the stainless.
As a result they do not knowingly supply stainless steel chain for risers to users in the Crouch
 
Last weekend I picked up / salvaged a 35' yacht which had come adrift from its mooring and wound up aground. Once again, a moused shackle was the culprit. On my mooring I just tighten the shackle up hard and pein over the threads of the shackle pin (which usually sits a mm or so proud) with a hammer and, where necessary, a centre punch. Then it will not wear loose but can always be undone if necessary. The three other boats over recent years that have come adrift in my area (Blackwater) have also all been on moorings using inappropriate seizing wire.
 
One problem i often see is that owners use 2 mooring lines in case of chafe
But they fix them to the top of the buoy with a single shackle in stead of 2 separate ones so if the shackle comes loose they go adrift
 
Technically you shouldn't be using "Screw Pin Shackles" for this kind of mooring application. The correct shackle is an "Anchor Shackle" which uses a "bolt type" pin and there is split pin to hold the nut in place. The shackle body is not threaded. The advantage is that the pin can gently rotate in the shackle without danger of coming loose. Screw Pin Shackles are designed for use when the shackle pin needs to be frequently removed, such as on a halyard. Anchor Shackles (Bolt Type) should always be used when inspection is difficult or less frequent.
 
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