swinging mooring...need to use chain

[gary3029]

After a previous post about swinging mooring I went to my local chandlers and asked for some thick rope suitable for a swinging mooring. He asked where my boat was moored and refused to sell me any rope!!! Yep a very helpful, honest chandlers. He said that he was not prepared to sell me any rope for that purpose and advised I use at least 12mm chain. He didn't have any chain and accepted he had lost a sale.
Ok have sourced 12mm chain. My questions are: is there any way I can introduce a shock absorber into the chain. I did think some rubber blocks around the sampson post? Should I use a large rope as my primary and chain as a backup, at least the rope will give some when the boat take a pounding...which is often!!

 

[JamesDavis]

Re:

Use the chain as advised but attach a length of warp which is slightly shorter than the chain (about 3 Metres). The strain is taken on the warp and if it does chafe through the chain is there as a back up. Keep it simple as you can end up in a right tangle.

 

[VicS]

The catenary in the mooring chain between the bouy and the sinker should absorb the shock loads. Hopefully the riser is attached to the sinker via length of very heavy chain that will absorb the loads in even the strongest blow. Our moorings have 12ft ( I think) of 1" chain between the sinker and the riser and thats only for smallish boats as we do not have large boats.

 

[Ecosse120]

I am going through the same process at the moment. I intend to connect to the buoy with some pretty hefty rope rather than have the chain on board the boat. This should allow some shock resistance.

 

[FWB]

Mine is chain only. I have covered the chain with plastic tubing to guard against chafe. Shock loading is taken by the weight of the chain. (I imagine).

 

[simonfraser]

i guess it depends upon the weight of your boat, my trimaran, 1ton is secured by 1.5 inch diameter nylon rope inside transparent tubing, not the slightest sign of wear after 12 months
inho it's chafe that's the trouble, if you guard against that you can use rope
and inspect the rope, i check mine at least once a fortnight
what does your insurance co advise ?

 

[Lakesailor]

Have a peek at This Thread. At the bottom of the page.

 

[doug748]

I expect you can be quite exposed, as some moorings are here in Plymouth. The fetch can be a couple of miles in certain conditions. It is the wave action that causes severe chafe in poor weather, and I must agree with your chandler - I always use chain. I shackle a heavy rubber snubber (the one that looks like a spinster's best friend) across 3 ft of the chain to take the worst of the snatch loads and this has worked well. In the past I have allowed a fairly long strop but this does allow the buoy to attack your topsides in wind over tide conditions; this year I am going to experiment with pulling the buoy fairly tight "up and down"...

 

[wcarpenter]

Would agree with use of stubbers to take up some shock in the chain. I use two giving me about a foot of stretch between the two loops.

 

[William_H]

In several thousand moorings around Swan river I don't think I have seen one that has chain onto the boat. Chain usually rises far enough to get near the surface then a swivel is fitted with 2 ropes to the boat.

Rope is a worry onto the actual sinker because of the risk of chafe and damage on the sea bed objects including the sinker.
Some moorings at a nearby island have a small buoy fitted about 1 metre above the sinker but well under water to keep (the chain in this case) off the sea grass. I wonder if that would not be a good idea to enable a rope to be used for the whole mooring.
I reckon rope would last much longer than chain unless it were such a heavy chain that it would be too much weight to lift onto the bow or to hold up with a buoy.
A lot of heavy chain means you need a big buoy which inn turn is too heavy to lift onto the bow which means it stays in the water bumping your topsides and growing weed.
The thing is while I might advocate all rope I haven't done it myself nor seen it done.
So I would advocate a few metres of the heaviest chain you can find then aswivel then ropes to the bow. olewill

 

[Lakesailor]

I'd go with that. Just been discussing same about a mooring on Coniston (non tidal) and thought a chain sinker - swivel - rope riser in a deep mooring would be sound. I tried a chain strop and nylon strop from bouy to foredeck. The chain rusted badly in 8 months. The nylon warp is still there a year later.

 

[tangomoon]

I am always perplexed that anyone would use a buoy with a metal bar and eye each end to rub up against their gelcoat when buoys having rope with a soft eye each end is easily available and therefore doesn't scratch.

 

[gjeffery]

I had a mooring in Chichester Harbour. The boat dried at LWS and the chain riser was not much more than the tidal range to ensure that the boat remained in the centre of the (narrow) rythe, and did not foul boats on adjacent moorings. Drying out with the rudder stuck in the bank was the problem that made me give up that mooring.

I was committed to a chain from the buoy to the deck cleat. Predictably, this snatched horribly. The snatch was reduced to a tolerable degree when I doubled up the mooring chain with a nylon rope, incorporating a rubber snubber, and set to take all the mooring load.

 

[vyv_cox]

We moored for many years on the Menai Strait, strong tides, occasionally rough water and lively winds. Advice from the mooring contractors was always to use chain for the pickup, so we complied and used 1/2 inch. To overcome rubbing when wind-rode and during turning, I obtained some fire hose to cover it, which was most effective and highly attractive to a variety of marine life.

One day I picked up the mooring of the contractor and, guess what? His pickup was rope! The only point I can think of is that he used his boat every day so could keep an eye on any chafe, whereas leisure boats could go weeks without use. His rope was hefty stuff, about 1.25 inch diameter with a big eye splice on the boat end. It was far easier and more pleasant to handle than chain.

 

[Aja]

On the west coast of Scotland very few moorings use chain. The only examples I can think of are in Tobermory, where it is usual to find multiple occupancy.

My mooring man uses nylon multi-strand stuff about 2" in diameter for the junk with a polythene tube to cover.

My mooring is pretty exposed to E and SE.


Rope is removed at end of season and mooring sunk.
Donald

 

[laserman2]

is it indeed!!

 

[GMac]

We service over 5000 moorings. 50% are highly exposed i.e land one side, open ocean the other.

Less than 100 would have chain coming onto their boat. 98% of then would have a head rope which is equal in length to the water depth they are in. Less than 5 would have chain 12mm or smaller anywhere in the system even the very sheltered ones. 99.9% of the moorings are looked at once every 3 years. Failures maybe 6-10 a year the day after very very big blows. 99% of failures are owner fixed up moorings i.e polyprop ropes or undersized gear. Average running cost approx 50 quid a year, which is the 3 yearly lift and tidy up where required by us, the contractor.