swing mooring

[KREW2]

Hi
Hope someone can help. I've just put my boat on a new swing mooring which has been professionally laid. My problem is the chain is 12mm, too thick to roll easy through the bow roller and just fits around the cleat. All in all its very hard work to moor. The boat is a Gib'sea 84 and looking at other boats around they seem to have smaller chain going on board.My question is will 8 or 10mm chain be ok for my size of boat?
thanks in advance KW

 

[FullCircle]

Well I have 10mm chain securing my anchor to the boat, and that is 11m / 6 tonnes. Have you considered a docking line of about 18mm 3 strand doubled up or similar with a bit of stretch in it? Wont jerk about so much then, and won't tear the anodising off the fairleads or cleats.
My swinging mooring has this arrangement, with a short lead of line to a small mooring buoy marker which makes picking up so much easier.

Jim

 

[halcyon]

We use 12 mm on our 27 footer, and the wife has no trouble, and I would not go any smaller.

Brian

 

[KREW2]

HI
can you roll it through the bow roller with the retaining pin in
regards KW

 

[StephenW]

Suggest thick polyprop. of around 25mm+ thick say 2-2.5m long to a seized shackle( make sure the shackle is proofed and substantial) , spliced loop on boat end and a pick-up buoy on a separate line, say 1.5m long. As a previous poster said the rope will avoid snatch loading by stretching slightly., Where the rope goes over the bow roller slip some flexible pipe to reduce wear.

 

[Lakesailor]

[ QUOTE ]

Where the rope goes over the bow roller slip some flexible pipe to reduce wear.

[/ QUOTE ]

Do not do this. Sunlight will harden the pipe. It will crack and break where it passes over the bow roller and then cut through the strop.
This happened to a Moody 33 on the mooring next to mine in 12 months! Two strop, two pipes, both affected.

 

[KREW2]

Hi
I want to bring chain on board to attach to the cleat, what I want to do is reduce the size of the last 3 metres of the chain from 12mm to 10 or 8mm, is this going to be adequate for a boat with a displacement of 3000kg?
regards KW

 

[graham]

How sheltered is your mooring.?Theres a big difference between a river mooring where it never gets rough to a more exposed mooring where the boat may be being thrown around a bit.

If it does get rough have a good look at your mooring bollard/cleat and its fixings.
Your boat isnt going to snap 10 mm chain provided its good chain,the shackles are usually the weakest link.Sieze them on with galvanised wire.

 

[fireball]

It really does depend on where your mooring is ... but in the harbour our mooring chain terminates at the mooring buoy and we have a thick 3 strand (16/18mm?) line with a spliced hard eye at one end, and eventually a soft eye splice at the other (just cleated for now, but harder work) as the main mooring line, and a backup 8mm chain. It does require a swivel and I would suggest an old football or something else to go around the gubbings just above the mooring buoy to stop it rubbing against the hull (wind against tide senario!)
We do currently protect both the warp and chain with that seethrou pipe, but having read the advice on here I'm keeping a very close eye on it ... should be ok for the chain!

Ah - I should say that this is for a 30'er fin ... and the vast majority of boats around us use exactly the same method - some double up on the warp...

 

[halcyon]

We do not have the pin in.
Pick up the pick up, haul aboard over bow roller, normally the chain follows, haul back and drop over bollard. If you want to but the pin in to stop it jumping off, you can now fit it.


Brian

 

[Dipper]

You are not going to break 10mm chain or even 8mm chain. With swinging moorings, any failure will be a result of degradation of the components – usually shackle pins. Correct fitting, regular checks and renewing as necessary should prevent these problems.

Go for the 10mm chain. Using 8mm means you will have to use a smaller shackle in the system. Also, the chain will eventually start to corrode and with 8mm there is a larger surface area to volume ratio so the loss of strength will be quicker and more critical.

If you are worried add a second, short length of chain or a strop to the 12mm chain and lead to a second cleat. This also spreads the load between the cleats/bollards or you can leave it slack as an emergency back up.

 

[William_H]

Strength of the chain is not a question. As dipper says 8mm or less would be more than adequate. The reason heavy chain is used is because chain wears at the rub point between the links. So providing you check the light chain over all its length I would suggest more frequently than every 2 months then you will have no problems. if you are concerned you can fit a paralell chain or rope over that distance from the 12wmm to the boat.
However I think the answer to your problems will be a substantial buoy with enough bouyancy to hold up all the chain at high water. (when the max weight of chain is being supported) A pendant to the buoy or the chain at that point can be slipped over the cleat or bollard. preferably 2 pendants. The down side is that the buoy can damage the topside paint work so try to pad the edges of the buoy. regards olewill

 

[KREW2]

Hi
Many thanks for all comments I have read them all with interest. The mooring can be exposed to easterlies as it is just off the new sailing acadamy in portland.It is in 4 meters at LWS and consists of a dead man with ground chain leading onto 19mm chain with a 12mm chain riser which is bought on board by about 4/5 meters of rope attached to a pickup bouy
perhaps it would be possible to bouy and float the 12mm riser and take off 4/5 meters of 10mm chain to bring on board.
thanks again for all your help KW

 

[Lakesailor]

[ QUOTE ]


If you are worried add a second, short length of chain or a strop to the 12mm chain and lead to a second cleat. This also spreads the load between the cleats/bollards or you can leave it slack as an emergency back up.

[/ QUOTE ]

In fact if you use a nylon strop and make it shorter than the chain it will act like a snubber and take the initial surge and jerk, which leads to less shocks to your bollard or cleat.

 

[halcyon]

There is a minimum size chain, for a boat spec, our habour master issues it for our moorings. If your boat requires 12 mm then you should have 12 mm.
Our moorings are open to the East, the last big blow we had took out 14 boats, mainly from draging ground tackle, or breaking under size gear. But most of the boats lost were between the boat that broke free and the shore, being drove ashore by the loose boats, not by failure of there mooring.
So please remember it's not only your boat that may be at risk, it's all the other owner's around you, or bewteen you and the western shore.

Brian

 

[KREW2]

Hi
Whilst I agree there is a minimum size this must be dictated by the size of a factory fitted bowroller if the largest size it will take with the retaining pin in is 10mm one should expect this to be strong enough to hold the boat in all conditions
KW

 

[halcyon]

Sorry but for you to use our club moorings you would need to have 12 mm chain for that size yacht.
The question is, is the bow roller intended for anchor chain, or for a permanent swinging mooring?
If you had stood watching 14 boats sink one afternoon, you could not stand up in the wind, and there was 6 foot waves coming through the moorings. Or see about the same number of boats piled on top of each other in Falmouth, you would be looking at going up chain size, not down one.

Brian

 

[KREW2]

Hi again
Just done a recky in the dinghy around the moorings all seemed to have 10mm chain going on board, my insurance company seem happy with the factory fitted bow roller 12mm chain will fit over and I can get the pin in after but only between the links.I also went to my local chandlers this morning and asked his opinion obviously he thinks 12mm is better than 10mm we both felt bringing 10mm chain on board with 5 ton breaking strain was not compromising saftey as this was unlikely to be the weakest link I think it possible the bow would rip of before the chain snapped
regards KW

 

[Dipper]

I have 10mm chain for my 26ft boat and I’m on the other side of the harbour from you. I have been on moorings in deeper water with 12mm chain and in a breeze and short handed it can be a little difficult to haul on board.

The downsides to the 12mm chain would be:

1. The weight bringing it on board. Depends on the strength of the crew and the wind and also the depth of water. There is not a lot of tide at Portland so it shouldn’t get too deep. Also, as you have a longish rope leading to the pick up buoy, this can be easily secured first and the chain hauled up later by a stronger person or by two people. As you suggested, you could take most of the weight of the chain with a large mooring buoy – this is quite a common arrangement.

2. The size of your roller and cleats. If the chain fits these then no problem.

3. The chain will last longer (possible 3 seasons) and in the last season it may become rusty and stain your hull and decks. 10mm chain might need renewing every two years so is less likely to become as rusty.

Since it sounds as though the 12mm chain fits your roller, you could keep it for the moment and see how you get on. Make sure the chain has settled before fitting the roller pin as there is a risk you could end up taking the strain on the pin/roller rather than the cleat. Probably not a problem but it could put an unnecessary load on the forestay fitting.

 

[doug748]

I am sure you are doing the right thing. I have a bigger boat than yours on 8mm chain and always sleep OK. You could lift the boat up and play conkers with it on 12mm.
As others have said, keep an eye on the shackles. I like to fit a rubber snubber in the system to reduce the dreaded snatching. Brian.