Neil_Y
Well-Known Member
Looking at mooring a 5800kg yacht on clay in the Baltic, no tide, and no waves to speak of, what sort of ground tackle do people suggest...
Laying a swinging mooring
- Thread starter Neil_Y
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andsarkit
Well-Known Member
What depth and how much swinging room?
Will you have to lay it yourself without heavy lifting tackle?
Does your insurance demand professional installation and maintenance?
My current mooring in Dittisham is a concrete block with a chain riser going to a buoy with a rod through the centre and a swivelling ring on the top. Seems fine and is lifted annually by the Dart Harbour mooring barge.
When I had my own mooring on the Exe which is exposed, I had a long ground chain of 3/4" stud link chain with a ground anchor on each end. This can lift off the seabed in extreme conditions to avoid shock loadings. The anchors and ends of the ground chain disappeared into the mud and there was very little corrosion where oxygen was excluded. The riser chain went through the centre of a spar buoy with the swivel exposed on top and no joins under the buoy.
No doubt someone will be able to recommend a modern version using Polysteel rope or you could check what other people around you are using.
Will you have to lay it yourself without heavy lifting tackle?
Does your insurance demand professional installation and maintenance?
My current mooring in Dittisham is a concrete block with a chain riser going to a buoy with a rod through the centre and a swivelling ring on the top. Seems fine and is lifted annually by the Dart Harbour mooring barge.
When I had my own mooring on the Exe which is exposed, I had a long ground chain of 3/4" stud link chain with a ground anchor on each end. This can lift off the seabed in extreme conditions to avoid shock loadings. The anchors and ends of the ground chain disappeared into the mud and there was very little corrosion where oxygen was excluded. The riser chain went through the centre of a spar buoy with the swivel exposed on top and no joins under the buoy.
No doubt someone will be able to recommend a modern version using Polysteel rope or you could check what other people around you are using.
Farmer Piles
Well-Known Member
As above, I can only relate to what we do here - which is very similar to andsarkit and his area.
Most of the harbour authorities and boatyard moorings around here are on long trots of chain with risers to a buoy with an eye on top. Most of the private ones will have a block on the bottom, can be concrete but because of where we are it is usually granite. Then a 1 inch or 25mm bar through the middle bent at 90 degrees underneath and then at the top, bent around to make an eye. I would guess around the 1t mark for a 6t boat. Then usually 2-3m of 3/4 inch or 20mm chain, going to a 12mm chain riser. How you do the top is up to you. The most common is to have the riser go to the big marker buoy and then about 1.5m below the surface have it T off to a length of chain with a loop on the end to throw over a post or cleat. Or have a strop or strops to moor with. A length of rope with a pick-up buoy on the end of that.
As mentioned above, the heavy chain acts as a spring in rough or windy conditions.
Hope this helps a bit.
Most of the harbour authorities and boatyard moorings around here are on long trots of chain with risers to a buoy with an eye on top. Most of the private ones will have a block on the bottom, can be concrete but because of where we are it is usually granite. Then a 1 inch or 25mm bar through the middle bent at 90 degrees underneath and then at the top, bent around to make an eye. I would guess around the 1t mark for a 6t boat. Then usually 2-3m of 3/4 inch or 20mm chain, going to a 12mm chain riser. How you do the top is up to you. The most common is to have the riser go to the big marker buoy and then about 1.5m below the surface have it T off to a length of chain with a loop on the end to throw over a post or cleat. Or have a strop or strops to moor with. A length of rope with a pick-up buoy on the end of that.
As mentioned above, the heavy chain acts as a spring in rough or windy conditions.
Hope this helps a bit.
Stemar
Well-Known Member
Obviously you have to meet the local requirements, but if you can do pretty much what you want, I'd say that the ideal would be a heavy chain with an anchor on each end - your own private trot - and a riser in the middle. If that isn't practicable, I know people who take a truck tyre and fill it with concrete, setting a loop in the top. Even better might be a U-shaped tube you can feed the riser through, as there'd be no eye to corrode. Mine is a railway wagon wheel buried 120cm in the mud, but that'd be hard work where you've got to dig underwater!
As for pick up strops, I use polysteel, a UV resistant polypropylene and have two lines. Done right, they should have a longer life than chain, which can wear surprisingly quickly, and both my little monohull and my current cat sit better to them, with less swinging, than to a single line, plus they have the advantage that they float.
As for pick up strops, I use polysteel, a UV resistant polypropylene and have two lines. Done right, they should have a longer life than chain, which can wear surprisingly quickly, and both my little monohull and my current cat sit better to them, with less swinging, than to a single line, plus they have the advantage that they float.
Ian_Edwards
Well-Known Member
I've not laid my own mooring for 30years or more, but when I did I used a heavy ground chain between two concrete sinkers, with a 1/2" chain riser (much like the post above). A large buoy was tee'd into the 1/2" chain with a short strop, 2-3m long. The 1/2"chain was made long enough to go over the bow roller and onto a substantial cleat. The end of the chain had a rope pennant and a pick-up buoy, just to make mooring easier.
Since we were doing this our selves, we made the mooring weights in old Hydraulic Oil drums, 25L drums if I remember correctly. We cutting the tops open, filling with stones and concrete, putting 6 or more links of 3/4" chain in the top 1/3rd of the mix with a few links showing out of the top, and placing bits of re-bar through the links of the chain to give the chain more grip in the concrete.
We then used multiple drum to make up the appropriate weigh for each end of the mooring.
The advantage of using the drums, where, they could be made on the beach, just about man handleable, (they can be rolled around) without heavy machinery.
West Coast of Scotland, remote location, deep water Loch, soft muddy seabed. never had one move.
Since we were doing this our selves, we made the mooring weights in old Hydraulic Oil drums, 25L drums if I remember correctly. We cutting the tops open, filling with stones and concrete, putting 6 or more links of 3/4" chain in the top 1/3rd of the mix with a few links showing out of the top, and placing bits of re-bar through the links of the chain to give the chain more grip in the concrete.
We then used multiple drum to make up the appropriate weigh for each end of the mooring.
The advantage of using the drums, where, they could be made on the beach, just about man handleable, (they can be rolled around) without heavy machinery.
West Coast of Scotland, remote location, deep water Loch, soft muddy seabed. never had one move.
William_H
Well-Known Member
As said much depends on your available facilities if you are DIY. For DIY. The first thing is to scout around for really heavy chain. 25+ mm around 10 to 15 metres long. Also look for s/h anchors. You fit an anchor to each end of the heavy chain. You then shackle riser chain to centre of heavy chain. You could conceivably lay these anchors and chain from a boat but best might be to SCUBA dive and lay them out on stretched heavy chain. Anchors can be fabricated one fluke fisherman's style anchors made of heavy angle iron. Fit a horizontal bar to ensure fluke always goes down. (2 flukes if you are going to drop it in from above.
You can add more heavy chain shackled at right angles to first heavy chain with additional anchors. This makes centre of mooring location very controlled.
The riser chain if you go chain must have a swivel preferably at top where you can see it and must be as heavy chain as possible. More chain thickness gives longer life. So 10mm chain might need to be replaced after 1 year (certainly 2) While 20mm chain might last a long time. In any case all needs to be inspected every year or perhaps with heavy gear every 2 years. Shackles likewise will wear quickly. Make sure they are moused (lock wired) to stop unscrewing. Do not use any stainless steel amongst iron.
The problem is that a single weight can drag if it is lifted by boat bouyancy on waves and if it is to be effective will be far too heavy to manage yourself while the chain and anchors mooring can be man handled in parts then assembled on site. ol'will
You can add more heavy chain shackled at right angles to first heavy chain with additional anchors. This makes centre of mooring location very controlled.
The riser chain if you go chain must have a swivel preferably at top where you can see it and must be as heavy chain as possible. More chain thickness gives longer life. So 10mm chain might need to be replaced after 1 year (certainly 2) While 20mm chain might last a long time. In any case all needs to be inspected every year or perhaps with heavy gear every 2 years. Shackles likewise will wear quickly. Make sure they are moused (lock wired) to stop unscrewing. Do not use any stainless steel amongst iron.
The problem is that a single weight can drag if it is lifted by boat bouyancy on waves and if it is to be effective will be far too heavy to manage yourself while the chain and anchors mooring can be man handled in parts then assembled on site. ol'will
Graham376
Well-Known Member
Ours is 2.5 ton (dry weight) concrete block with 8m of 19mm chain to swivel then 34mm octoplait polysteel riser to soft buoy. Mooring strops attach to thimble at top of riser.
Neil_Y
Well-Known Member
Thanks for all the replies, it's given me something to think about. It has to be a DIY solution as it's miles from any marine/engineering.
Daydream believer
Well-Known Member
I laid a mooring for a client, as a marker, whilst they were abroad in their 39 ft boat. It was agreed that it would NOT be used as a mooring. It had Polystel for the full length. They just wanted to make sure that the spot was reserved oposite their house on the shore.
However, one of our boats, a Jeneau 40 lost its buoy, so used the temp mooring for what was supposed to be 2 weeks, whilst the club workboat dragged for the now sunken chain.
It took just 4 days plus a bit of fairly light, wind against tide, for the 38mm polystel ( less than 1 season old) to wrap around the keel whereby it was cut like a knife & the jeneau went walkabout. The problem was that the polystel floated & caught . We had considered using it for moorings, but it would need a weight placed in its length to hold it down & prevent that. It would always be a target for the rudder, keel & prop when leaving & arriving at a mooring.
I can see its use as a mooring strop though.
Stemar
Well-Known Member
I only use it for my mooring strops. They're shackled to the chain riser just below the mooring buoy, above the swivel. One piece of rope, with a brummel splice around a hard eye in the middle and an eye splice at each end.
Refueler
Well-Known Member
I am Baltic Based ... so question :
Where are you placing this mooring ?
Water depth average ?
Its all well and good people quoting 'what THEY did' ... but depth / location etc. can affect what you use.
OK - second thing : Baltic can actually get quite rough ... my mooring is a private channel upriver 'inland' behind my house ... I have had my 5m mobo break free and ended up other side of river ... My main boat 4 ton Motor Sailer causes my pontoon to strain the shore posts that secure it ... I've given up driving in posts in the water to fix it.
During Swedish Archipelago cruise - one of the other boats ... a moderate sized Cat actually broke the pontoons pin joint to main pontoon in rough weather.
Anyone who thinks baltic does not get rough ... sorry - it can. Like the North Sea - being relatively shallow - the sharp waves can form very quick and can be serious risk.
Graham376
Well-Known Member
Whether polysteel can be a problem, depends on the particular mooring and tackle used. A big spring tide here is only about 3m and water shallow so, risers are a lot shorter than for large UK tidal range. In our case, the weight of swivel and chain at bottom of only a 5m riser prevents the polysteel from floating so no danger. It is a problem with the drying moorings using all rope, care needed when going between them with the tender.
