warwicksail
Well-Known Member
Hi, I will be needing to lay a mooring for a 22' sailboat this year, Does anyone have any adive they wish to share on the matter....
Laying Swinging Moorings
- Thread starter warwicksail
- Start date
andrewbodenham
Well-Known Member
Well, my first bit of advice would be to give as much information as possible when posting a question, so that you can get specific and useful answers.
In this case, what type of boat, location of mooring, tidal range, bottom conditions, does it dry at low tide, do you want to DIY or get a professional job, etc.
In this case, what type of boat, location of mooring, tidal range, bottom conditions, does it dry at low tide, do you want to DIY or get a professional job, etc.
mikemonty
Well-Known Member
After that, you'd better have something to volunteer if he comes back with the info!
BlueChip
Well-Known Member
The traditional way where sinkers and not anchors are used is to get a large lorry wheel, lay it on a board. Bend a thick iron rod into a loop with legs and with the legs of the hoop in the wheel fill the wheel with concrete. In the absence of a suitable wheel, you can use hardboard to make a shallow cylinder. Rope it round the circumference to stop it opening up and fil this with concrete as before. Dont be mean, weight is everything.
When its set, get help to up end it and roll it down the beach at low water, fit the chain riser with pick up buoy. Have another thick shortish riser to a buoy.
As the tide comes in position a work boat or even your boat over the buoy and make of the rope riser as short as possible. As the tide comes in eventually the rising tide will lift the sinker, you will need lots of bodies in the cockpit to keep balance. Motor out to where the mooring is to be laid, lay out the chain riser overboard and using a knife on the end of a pole, saw through the rope riser. The sinker will drop into position.
I've done it this way twice, its not for the faint hearted but its effective and does work. Do it at your own risk!
Alternatively you could just pay someone to do it all for you
When its set, get help to up end it and roll it down the beach at low water, fit the chain riser with pick up buoy. Have another thick shortish riser to a buoy.
As the tide comes in position a work boat or even your boat over the buoy and make of the rope riser as short as possible. As the tide comes in eventually the rising tide will lift the sinker, you will need lots of bodies in the cockpit to keep balance. Motor out to where the mooring is to be laid, lay out the chain riser overboard and using a knife on the end of a pole, saw through the rope riser. The sinker will drop into position.
I've done it this way twice, its not for the faint hearted but its effective and does work. Do it at your own risk!
Alternatively you could just pay someone to do it all for you
VicS
Well-Known Member
[ QUOTE ]
get a large lorry wheel
[/ QUOTE ] The boat yard where I am based makes concrete sinkers which are squat, square, flat topped pyramids about a metre square on the bottom, about 1/2 metre square at the top and about 0.3 m deep.
They are made with a length (3 or 4 m IIRC) of very heavy chain (1" ?) cast into them with some reinforcing rods added as well.
The sloping sides make them a little more hull friendly if the boat sits on them at low tide.
If neil-s is around he'll be able to describe them in more detail as he made his own to the same pattern.
get a large lorry wheel
[/ QUOTE ] The boat yard where I am based makes concrete sinkers which are squat, square, flat topped pyramids about a metre square on the bottom, about 1/2 metre square at the top and about 0.3 m deep.
They are made with a length (3 or 4 m IIRC) of very heavy chain (1" ?) cast into them with some reinforcing rods added as well.
The sloping sides make them a little more hull friendly if the boat sits on them at low tide.
If neil-s is around he'll be able to describe them in more detail as he made his own to the same pattern.
Bajansailor
Well-Known Member
You could consider using two reasonably chunky high holding power anchors (eg 40 or 50 lbs each) in a bridle formation on the bottom, with some heavy chain (minimum of 1/2") on the bottom and suitable scope (if possible, re swinging room).
Use a good swivel on the riser chain.
One advantage of a system like this is that it is much easier to lay and to recover than very heavy weights.
The RNLI lifeboat moorings (used to - still do?) use 'Seaboard' type mooring anchors - they look a bit like a Bruce, but made from flat plate, and with a transverse stock in way of the chain connector.
(or another description could be a fisherman type anchor but with large angular flukes, and one fluke 'cut off').
I tried googling Seaboard anchors, but couldnt find anything about them.
Use a good swivel on the riser chain.
One advantage of a system like this is that it is much easier to lay and to recover than very heavy weights.
The RNLI lifeboat moorings (used to - still do?) use 'Seaboard' type mooring anchors - they look a bit like a Bruce, but made from flat plate, and with a transverse stock in way of the chain connector.
(or another description could be a fisherman type anchor but with large angular flukes, and one fluke 'cut off').
I tried googling Seaboard anchors, but couldnt find anything about them.
William_H
Well-Known Member
As you can see from the comments much depends on your capabilities to manouvre large weights and if you have a large tidal change and if the location is drying.
My own experience is with non drying moorings with little tide change.
Around here large concrete weights are sometimes used but are put into position by professionals with large ex fishing boats with a crane.
So DIY requires the use of anchors and chain (which you can amnage alone) rather than lumps of concrete and almost certainly requires a diver usually with scuba gear to place and connect. Most mooring maintenance is then done by diving.
If you want to use anchors etc rather than one big weight you need to collect as much really heavy chain as you can find and heavy scrap metal from which a fisherman's type anchor with one fluke can be welded. Basically you have an anchor on each end of a very heavy chain as long as possible but at least twice length of water depth. The riser chain is connected via a swivel shackle and goes up to the buoy.
For more security more anchors can be added ie in 4 different directions from the centre of the chain on their own chains to give a precisely located centre to the mooring.
You may find that if it is an old mooring area there may be weights already there and abandoned. It may be cheaper to run chains from various existing weights to your location or use one existing weight and one or more anchors. Again the riser going up from the chain at the required location. If it is a drying mooring then that is easy but for non drying you will need to dive.
So it all depends on circumstances but this may give an insight into how we do it in the Swan River.
Don't mix stainless steel with iron as corrosion will be rapid.
Use as heavy a chain and shackles as possible as they will wear quite fast. Mouse or tie all shackle pins and don't forget the swivel shackle to allow boat to rotate without screwing up the chain.
good luck olewill
My own experience is with non drying moorings with little tide change.
Around here large concrete weights are sometimes used but are put into position by professionals with large ex fishing boats with a crane.
So DIY requires the use of anchors and chain (which you can amnage alone) rather than lumps of concrete and almost certainly requires a diver usually with scuba gear to place and connect. Most mooring maintenance is then done by diving.
If you want to use anchors etc rather than one big weight you need to collect as much really heavy chain as you can find and heavy scrap metal from which a fisherman's type anchor with one fluke can be welded. Basically you have an anchor on each end of a very heavy chain as long as possible but at least twice length of water depth. The riser chain is connected via a swivel shackle and goes up to the buoy.
For more security more anchors can be added ie in 4 different directions from the centre of the chain on their own chains to give a precisely located centre to the mooring.
You may find that if it is an old mooring area there may be weights already there and abandoned. It may be cheaper to run chains from various existing weights to your location or use one existing weight and one or more anchors. Again the riser going up from the chain at the required location. If it is a drying mooring then that is easy but for non drying you will need to dive.
So it all depends on circumstances but this may give an insight into how we do it in the Swan River.
Don't mix stainless steel with iron as corrosion will be rapid.
Use as heavy a chain and shackles as possible as they will wear quite fast. Mouse or tie all shackle pins and don't forget the swivel shackle to allow boat to rotate without screwing up the chain.
good luck olewill
Eygthene
Well-Known Member
At our sailing club moorings at Mylor in the river Fal, our swinging moorings must meet the Truro Harbourmaster's specification. I can let you have a copy of the spec. sheet (PM me with your e-mail address), which details the design requirements (block weight, chain sizes, assembly details) for different lengths of boat.
Our mooring area has a tidal range of about 5.5 metres maximum and the depth is no more than 1m below the keel at low water springs. The area is well sheltered except in winds from north through to east where the fetch is over 1 mile. The current reaches a maximum of 0.5 kts.
We have a contractor who lays our moorings and he uses a flat-bottomed barge with a powerful hoist. We assemble the moorings on the beach, near the low-water mark in March and he lays them at the beginning of April and lifts them at the beginning of October (to clear the area for the Oyster dredgers). The blocks and ground chains remain on the beach over winter, but we normally take the risers and buoys home for storage.
We do have an area of 12 month moorings which we can have lifted or leave in situ. We have to get them inspected and serviced by a diver every season if they are not lifted.
Our mooring area has a tidal range of about 5.5 metres maximum and the depth is no more than 1m below the keel at low water springs. The area is well sheltered except in winds from north through to east where the fetch is over 1 mile. The current reaches a maximum of 0.5 kts.
We have a contractor who lays our moorings and he uses a flat-bottomed barge with a powerful hoist. We assemble the moorings on the beach, near the low-water mark in March and he lays them at the beginning of April and lifts them at the beginning of October (to clear the area for the Oyster dredgers). The blocks and ground chains remain on the beach over winter, but we normally take the risers and buoys home for storage.
We do have an area of 12 month moorings which we can have lifted or leave in situ. We have to get them inspected and serviced by a diver every season if they are not lifted.
earlybird
Well-Known Member
My experience of laying moorings is at Ravenglass, a sandy, drying estuary, scoured by strong tides. Under these conditions, concrete sinkers, even if seemingly well buried, tended to rise to the surface. The density of concrete, being little different from that of sand, caused this I suppose. Cast-iron gave fewer problems, but wasn't immune. Old cylinder blocks were often used, but a more massive casting, if you could find one, was better. Heavy chain to the sinker is good, as wear is a problem. As said before, the main difficulty in DIY is handling heavy weights
jhr
Well-Known Member
[3889]
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Similar conditions off Hoylake but there the sinkers sink, requiring riser to be extended each year.
Local knowledge seems to be the key.
BTW, anyone tried casting a sinker in situ? Any reasons why it might not be a good idea?
Local knowledge seems to be the key.
BTW, anyone tried casting a sinker in situ? Any reasons why it might not be a good idea?
Stemar
Well-Known Member
If you go the concrete route, one idea I've seen, but not tried (haven't had to lay a mooring yet) is to cast a U of pipe ito the concrete with a bar set into the U to sread the load. You then use a loop of chain as your riser and you can insect and change it without getting down & dirty with the sinker.
willie4646
Well-Known Member
Check the range of the rise and fall of Spring Tides. youre riser should be 1.5 times of the largest tide any more and your boat will sail all over the place putting extra strain on the mooring
smonard
Well-Known Member
DO NOT use a Jeep straight 6 engine block! I hauled one into a lake in Upstate New York a couple of years ago. My boast was only a 19foot open daysailer but it dragged the engine during a gale and the boat ended up beached.
bazobeleza
Well-Known Member
Many, many, years ago I laid one in the Dee Estuary, I filled a small wagon tyre with concrete, left two holes through the centre concrete for heavy chains, rolled the whole lot out as far as I could at low water, attached it on a short chain and rope to a large inflatable and waited for the tide to rise, then when there was enough water to float it cut th whole lot free in the desired place.
The tyre sunk, the riser chain rose, the mooring bouy bobbed about. the riser chain did however cut through the front tube as the tyre sank.
Still got the dinghy (patched). All done with mates who with the lack of caution of youth had a great and wet muddy day out. The mooring is still in service today I believe. /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif
The tyre sunk, the riser chain rose, the mooring bouy bobbed about. the riser chain did however cut through the front tube as the tyre sank.
Still got the dinghy (patched). All done with mates who with the lack of caution of youth had a great and wet muddy day out. The mooring is still in service today I believe. /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif
Marmalade
Well-Known Member
A sinker is fine as long as it's dug in. If it's pulled out it won't re-set. At Marconi we have 100 boats plus on swinging moorings with an excellent record on breakaways. We use two 90lb danforths (one up tide and one down tide) on a bridle of 19mm chain with a riser from the middle of 13mm chain. Link in a zinc anode as electrolytic corrosion of shackle pins is the worst mooring killer - better still weld shackles closed also. Put a swivel at the buoy and guard against chafe with plastic tubing around warps.
cliffordpope
Well-Known Member
It occurs to me that if the desired weight exceeds what you feel confidant of carrying, slung under your boat, why not cast it and lay in sections?
Attach the chain to a base sinker, then thread more concrete rings down the chain like a stack of polo mints.
Attach the chain to a base sinker, then thread more concrete rings down the chain like a stack of polo mints.
