Mooring tackle expert needed

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Nicholas123

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I have a mooring that rotates 360 degrees in a fairly sheltered location & I want to stop the mooring line continually twisting so am considering adding this swivel to the system to prevent this. https://www.flickr.com/photos/38909344@N08/21185318474/in/dateposted-public/ The question is will it take the load?

The boat I think weighs about four tons but I can't imagine the strain coming on the line being anything like that. I am just concerned that the nut which appears to be welded to the central shaft might not be sufficiently robust.
 
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I wouldn't trust it by the looks of it...get something beefy and new,they're not that expensive.

This is the one I made for my boat.It's got a 25mm pin.

DSC_2745_zps3383d833.jpg
 
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No scale in that photo.
It looks old to me.
Will it rotate freely?
It's worth buying a new one that is as strong as the chain IMHO.
 
Swivels are very often the ' weakest link ', this has been noticeable in the 37 years I've worked on my and other club member's moorings; I usually change my swivel - which is over specced for the boat and location, with the shackles moused with monel seizing wire of course - every season, or at most every other year.

Considering what's at stake a decent sized new swivel costs peanuts.
 
I like this pattern:

http://www.yachtchandlers.co.uk/acatalog/Anchor-Swivel-Jaw-Jaw-Stainless-Steel-BBQ023806.html

But have been unable to find one in stainless of the size I require. You don't need to add extra shackles which keeps the length down, and helps prevent damage to your bow. You have the extra security of the nut and you can drill the pin for a split pin which is the only locking method that I fully trust. It is also very flexible for adding mooring lines or chains and can be removed easily.

Last time I bought one of these, SSSJJ16, 16mm:

http://www.mooringequipment.co.uk/swivels.html

I turned down the pin to take a split pin, but 45 quid! On the plus side it is strong enough to lift 2 1/2 of our boats off the ground.

I always run hot lanolin into the swivel to keep it sweet.
 
I want to be clear what your suggestion is.

1. Are you intending to put a swivel in the line (rope I assume?) attaching the boat to the mooring (ie the strop) so in the air, or between the riser (chain I assume?) and the point where the strop attaches to the riser so below the water?
2. What type of mooring buoy is it? Does the mooring strop attach to the top of the buoy or go underneath and attach directly to the top of the riser assembly?

These can affect the answer, but whatever, it's unusual to have to put a swivel in the strop as there should already be one at the top of the riser chain that should obviate the need for an extra one. Best make absolutely sure that this one is free to rotate before doing anything else. If the mooring is of unknown construction or of unknown service history I think you should seek local advice as a matter of urgency!
 
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lw395 said:
No scale in that photo.
It looks old to me.
Will it rotate freely?
It's worth buying a new one that is as strong as the chain IMHO.
Click to expand...

The photo's a pretty accurate comparison of the size,it's life like.
It's been buried in the mud next to my sinker for about fifteen years.There is actually very little wear but then it did'nt rotate in that position. Rotates perfectly ok,it is just stained with creek mud.
 
WLL - Working Load Limit
MBL- Minimum Breaking Load

WLL is the max you should be loading to, but it shouldn't break until the MBL...

Not sure on the sizes. The ones further down look like they are measuring the same way as chain so you'd match the chain diameter to the swivel.
 
Mine are 3/4 inches diameter and again whilst the nut is welded the other bits are rated and what appears to be drop forged steel..
Cost about £35 from gaelforce and in theory could be used to lift boat.
I can haul mine up onto my deck if necessary and remove it from the system.
I do have one as per the pic which was sold to me as suitable for my boat by a mooring specialist who works extensively on the Clyde but too small as far as I am concerned for my 8 tons.
 
To answer the OP question yes that swivel will be fine. The size of the shackles pins etc should be the same as the size of the chain. (Metal diameter in the link.) The little bit of discolouration of the surface means nothing. What really matters is the wear in the actual swivel area. Not always easily seen. Ultimately the welded nut or knob on the end of the swivel bolt will wear down until it slips through and the boat escapes. However at the same time the shackle pins/bolts will wear through and become thin. (and fail)
The problem with iron in the mooring is that the normally protective rust layer gets worn away with movement so new rust develops and wears away, giving rapid wear area along the faces that rub together. So really heavy chain like 8mm metal in the link might only be safe for a year.
Hence a close inspection of the whole mooring is vital every year or 2 years for really heavy metal gear. ie 12mm min metal diameter.

Re stainless steel swivel. Yes the swivel will last really well. However any iron (mild steel) that contacts the stainless steel will disappear really rapidly. I would guess at about 10x normal wear rate. So use either iorn through out or stainless steel through out not half and half.
I have an all stainless steel mooring tackle. The chain is huge and comes from the inside of a rotating lime kiln. About 12mm link dia. Very big circular links. Anyway being the nanny state I had to have my mooring inspected (every 2 years) by an approved proffessional. He fitted a new shackle in this chain.
It was around 18mm pin diameter. Huge for a tiny boat. Within a year this shackle was badly worn. I backed it up with a SS 10mm shackle. A few months later the iron shackle had worn through and fell off.
Likewise our mooring authority provide a buoy to use. (big ugly things) with a stainless steel rod and swivel built in. for years I had iron shackle to iron chain and that shackle on the SS wore through very rapidly. (hence the vaue of SS through out.
Stainless Steel is not completely safe however. It does not seem to wear in the usual manner and the chain has lasted for 10 years at least now. However one link went corroded in a strange manner. You might think toredo worm had got into it. On the outside of the link (not wearing surface) and only one link.
So still needs inspection. an fail without warning like SS shrouds.
To the OP 2 ropes are really desirable for safety going chain/buoy to the boat. You will probably find the swivel has so much friction that the 2 ropes will twist together. Not a real problem as the swivel will eventually turn to relieve twisating. Even if it looks bad. I( have seen a rope with a eye splice where with no swivel the rope twisted to unravel the rope lay and leave the splice liable to let go. Why does a boat always rotate in the same direction? olewill
 
I use an 8 ton swl steel swivel in the riser which has a safety factor of around 5:1. Vastly overkill in one respect but will have many years of use/wear before its likely to fail. Shackles have 19mm pins so long life expected there as well.
 
Thanks for all your replies. I think I have been worrying unnecessarily & shall use the swivel between the twenty odd feet of chain & twenty odd feet of doubled up Nylon rope.
I maintain & have laid the mooring myself (it is the only way I feel happy with it & do not like relying on other peoples work).
It is important to inspect moorings regularly like other people have said because it is surprising how quick chain & gear wears through.

Thankyou for all your replies even the ones that have made me feel like I need counselling :D
 
Nicholas123 said:
......... twenty odd feet of doubled up Nylon rope........
Click to expand...

Not a good idea to double up rope. Doesn't take long for sharp little critters to take up residence and the stretching action of nylon lines against each other can wear them quite quickly. Far better to use a single heavier line such as polysteel which is cheap and stronger.
 
GrahamM376 said:
Not a good idea to double up rope. Doesn't take long for sharp little critters to take up residence and the stretching action of nylon lines against each other can wear them quite quickly. Far better to use a single heavier line such as polysteel which is cheap and stronger.
Click to expand...

It just happened to be a long bit of rope that came with the boat,besides I like the nylon aspect as it acts like a shock cord.
What are these sharp little critters of which you speak? (my nylon line lifts clear of the bottom when under tension so gets a pretty good washing. My main concern is ultra violet making it brittle).
 
Nicholas123 said:
It just happened to be a long bit of rope that came with the boat,besides I like the nylon aspect as it acts like a shock cord.
What are these sharp little critters of which you speak? (my nylon line lifts clear of the bottom when under tension so gets a pretty good washing. My main concern is ultra violet making it brittle).
Click to expand...

I had a deep water mooring in Chichester Harbour ( at a club, not my usual one - not Conservancy though I doubt it would be different ) - I found nylon strops from the large buoy to the boat only lasted around 3 months despite being larger than specified, with protection.

The underside of the buoy had loads of razor sharp barnacles, and when the boat nudged the buoy in light wind over tide conditions, the strop would loop around & under it; the barnacles were so sharp I was always covered in cuts to my hands after untangling it.

Also, a friend lost his boat, wrecked when the rope strop chafed through; a series of severe gales meant he was unable to get out to her to check and rectify it.

It's all personal choice, but I'd never have a doubled strop, never a rope only strop, and never re-use a swivel I felt sufficiently worried about to ask and post photo's - any doubts like that are usually a warning signal from oneself.
 
Seajet said:
I had a deep water mooring in Chichester Harbour ( at a club, not my usual one - not Conservancy though I doubt it would be different ) - I found nylon strops from the large buoy to the boat only lasted around 3 months despite being larger than specified, with protection.

The underside of the buoy had loads of razor sharp barnacles, and when the boat nudged the buoy in light wind over tide conditions, the strop would loop around & under it; the barnacles were so sharp I was always covered in cuts to my hands after untangling it.

Also, a friend lost his boat, wrecked when the rope strop chafed through; a series of severe gales meant he was unable to get out to her to check and rectify it.

It's all personal choice, but I'd never have a doubled strop, never a rope only strop, and never re-use a swivel I felt sufficiently worried about to ask and post photo's - any doubts like that are usually a warning signal from oneself.
Click to expand...

I don't have a mooring buoy with accompanying barnacles for my mooring strop to wrap itself around.

I can't help think that people that put a negative inflexion upon everything despite not knowing all the details probably lack confidence in themselves or do not have much real practical experience themselves to draw upon. I'm sure those people must be a joy to sail with :D
 
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Seajet said:
I had a deep water mooring in Chichester Harbour ( at a club, not my usual one - not Conservancy though I doubt it would be different ) - I found nylon strops from the large buoy to the boat only lasted around 3 months despite being larger than specified, with protection.

The underside of the buoy had loads of razor sharp barnacles, and when the boat nudged the buoy in light wind over tide conditions, the strop would loop around & under it; the barnacles were so sharp I was always covered in cuts to my hands after untangling it.

Also, a friend lost his boat, wrecked when the rope strop chafed through; a series of severe gales meant he was unable to get out to her to check and rectify it.

It's all personal choice, but I'd never have a doubled strop, never a rope only strop, and never re-use a swivel I felt sufficiently worried about to ask and post photo's - any doubts like that are usually a warning signal from oneself.
Click to expand...
Similar barnacles in Portsmouth Harbour.
For some moorings, a short strop to the top of a through-rod buoy seems to work best, but you have to be very sure of the rod and its eyes/swivels. Some don't even have a locknut or split pin or anything!!!
 
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