Laying a mooring

[ QUOTE ]
Concrete on it's own is not very useful - it almost - but not quite - floats underwater! Where concrete blocks are used for moorings they tend to be really big - 3 tons to 8 tons were the sizes used in Hong Kong for yacht moorings (where you also get big winds at times).

[/ QUOTE ]

Sorry...BS!
 
[ QUOTE ]
Concrete on it's own is not very useful - it almost - but not quite - floats underwater!

[/ QUOTE ] Just for the record the density of concrete is about 2400Kg/m³
 
[ QUOTE ]
It's one of those subjects. Ask 20 guys and get 20 different answers. Basically, do what you do and be happy with it. Peleicanpete -Out!

[/ QUOTE ]

Acshully, not wrong, but should add the caveat, ask 20 people in 20 different locations...

The best advice is to find out the local customs, they have usually come about from decades of bitter experience.
 
Mooring (I presume swing mooring) is made from what you can get from scrap yards. But don't get anything you can't handle (lift) safely.
The best thing is to manufacture (or get) anchors at least 2.
You can manufacture a good anchor by attempting to copy an admiralty (fishermans ) anchor except you only need one fluke. You can add another fluke on the same side. A piece of railway line or heavy steel makes an ideal stock with a hole in one end for chain attachment and a fluke welded on the other end at an angle.

Chain to join the anchors must be as heavy as you can find. You could even use pieces mof railway line joined by shackles to make a semi flexible chain. Certainly if you have to buy new chain it won't be heavy enough if you can afford it. So look for old ship anchor chain. It not strength you are looking for in large chain size but rather long life. You want at least 1 inch diameter of the metal in the link. You need a minimum of 6 metres a bit more is better.
You shackle an anchor on each end and take a rising chain with swivel to the surface from the middle. This rising chain is problematic cos if it is too heavy it will sink the buoy with its weight but if it is too light it will wear too quickly. A stout rope may be better in this place but may be subject to chafe or wear if it lays on the bottom. Chain and rope would be best.

You can shackle on more chain with additional anchors at right angles to the first 2 from the centre. The advantage is that even under the strongest blow it will always pull near to square on to an anchor and so will not be moved in it s setting. If it does get dragged then the remaining anchors will eventually take up but far better if they never move.

Each individual anchor and piece of chain while being light enough to manage yourself will together work to make a good mooring. Of course you can add to it at any time.

You will probably find it worth investing in a scuba tank and regulator You shouldn't need all the extra gear and it should be quite safe at mooring depths ie 10 metres but do get some instruction on scuba safety. (Or find a friend with one). It is great however to be able to go down and check what is happening even free diving if it is not too deep.

If it is an old established mooring area like mine if you can explore with scuba or snorkel if it is shallow, you may find other mooring junk already in place. Even old engine blocks can have a chain wrapped around it and then connect to your mooring to provide further security. This chain should not move much so should last for quite a while if you have to buy thinner chain. My objection to old engines. wheels or even concrete is that for an awefull lot of weight you don't get much holding compared to an anchor.

Lastly if you have to move a heavy weight you can lift a lot under your yacht by taking the weight on a bridle from both jib sheet winches. The disadvantage is that it must hang under the keel so only good for deep water.

You will have more danger from shackles coming loose, chain wearing or (most insidious) swivel shackle wearing where you can't see it, than from the mooring of any sort dragging. Of course you need multiplle ropes to the boat. Your mooring should be inspected at least every 6 months. Hence the need for your own scuba tank.

good luck olewill
 
we got local forge to weld a loop onto a flat plate of 2 inch steel cannot remember dims
it sinks into the mud and has not budged
we found an old huuuuge shackle lying around the docks and attched that as weight too
local friendly lobster pot winches it up at end of season
 
You will probably find it worth investing in a scuba tank and regulator You shouldn't need all the extra gear and it should be quite safe at mooring depths ie 10 metres.

ehmm i think you will find that this is the most dangerous depth for a non qualified to dive at, because if they hold their breath then expansion on ascent is at its greatest, causing a burst lung then death.

only dish out advice if you know what you are on about.
 
Getting it under boat to take out there ....

I used to make it as close to tide line as possibleat top of slipway ... Let it set.

As I had a Land-Rover ... I used to then literally drag it down the slipway when tide was out. Boat had been brought to slipway and settled when tide went out. Connect a small can ... a line and then the chain to the sinker...... Heave rope / chain up onto boat and flake chain along boats deck.
Make sure chain has gone outboard before coming in through pulpit ... so that it can be slipped over side before letting sinker go.

Now you wait for tide to do the job for you .... boat lifts ... sinker lifts with you ...

You may have to bring boat to sinker on slipway after dragging it down there ... just take care to have someone pick up line ... shorten to chain and let boat settle ... then as per rest above.

Of course this all assumes that you have a boat with bilge keels ...

/forums/images/graemlins/cool.gif
 
Re: Getting it under boat to take out there ....

On a permanent mooring don't use:
Anything stainless, doing so is A1 stupidity.
Galvanised chain except the bit that comes out of the water. Galvanising can actually increase the waste rate.
Concrete that has not been very well spudded to remove as much trap air as possible.


Try this. Easy, strong and insurance companies will have major problems proving it won't work cause it does.
Train wheels x 2
biggest black shackle that will fit to a length equal to water depth of 20mm black chain (not chinese made) plus whatever is need to wrap around train wheels.
Biggest black shackle again to water depth length of 16mm black chain to 20mm (min) black swivel to
either galvanised 12mm chain to boat or 20mm polyester 3 strand rope. These last two again water depth (high tide) in length plus waterline to bollard less 1/2 the tidal range (keeps the swivel working longer). Small line 1/2 water depth to buoy having 10-15kg of floatation. WELD up all connections using just general purpose rods.

bring boat in, pick up small buoy, pull small rope to get big rope or chain, fix to boat, open cold beer and ponder the joys of life.

Should not need to be looked at for 3 years unless it's a high tidal flow area or one of your neighbours (or even you) is leaking stray volts. Bascially you end up with 3:1 scope, a lot of shock resistance built in, simple to build and reasonably cheap.

Easy to lay. put on beach at low tide mark. Strap to 44gal drum/s and float into place when tide comes in. VERY VERY carefully cut lashings and bobs your uncle. WATCH OUT for when you cut the lashings the drums will pop up fast.
 
Re: Getting it under boat to take out there ....

3:1 scope, you must live in the outer hebrides if you have that much room for boat to swing around
 
GMac ... why direct at me ?

I have already said clearly NOT stainless ....

Have already clearly said about whacking the tyre a lot to get concrete well packed in ....

Have already mentioned black iron ....

But I do differ on the galvanized only above water bit ... many HM's req'ts for moorings state clearly galvanized or black iron ...
Second most are laid to 2x tide + short strop. EG. Langstone upper reaches such as around Eastern road north. About 12 - 13ft ground chain heavy, swivel then 12 - 13 ft riding chain and short strop to boat. The tide range here is approx. average 10 - 12ft. I actually have the specs scanned to my archive if anyone wishes to argue ? And the spec is as given out by LH HM .....
In normal circumstances the ground chain shouldn't actually lift much and provides a snubbing buffer before weight comes on to sinker. It's only as weather / current gets high that ground chain will then lift and add to the riding chains efforts. Sinker anchoring the ground chain.

3x .... must be an area with well spread out moorings ...
 
Re: GMac ... why direct at me ?

If using concrete, a useful tip I read somewhere was to cast in it a tube that goes down, round a big horizontal iron or steel bar well buried in the concrete to spread the load and back out.When you lay the mooring, the chain goes down, through the tube and back up. That way you can inspect and change the hardest bit without pulling the sinker out of the mud, and without diving.
 
Re: GMac ... why direct at me ?

The depths mention and at only 2:1 you must have very flat water but that's fine if you do. 3:1 is usually the shortest here and yes it appears we must have a lot more room, oceans of it.

Obviously you can use galvanised if you like. Having built/serviced 1000's of moorings over the years I just know black lasts longer more often than not.

We have government regs as well and they also are far from the best or safest set-up so mostly ignored. The rules to listen to are the insurance company ones.

SBC - If I read your title bit right, I didn't direct anything at you. Didn't even see your post to be honest. Skim reading and must slow down. Good to see you think similar though. Don't know about only a tyre full of concrete, that is pretty light.

2 train wheels, the spoked ones, buried in soft sand or mud will hold better than a square 2 tonne concrete (dry weight) block. Probably out last the concrete by a long while as well.
 
Re: GMac ... why direct at me ?

[ QUOTE ]
The depths mention and at only 2:1 you must have very flat water but that's fine if you do. 3:1 is usually the shortest here and yes it appears we must have a lot more room, oceans of it.

Obviously you can use galvanised if you like. Having built/serviced 1000's of moorings over the years I just know black lasts longer more often than not.

We have government regs as well and they also are far from the best or safest set-up so mostly ignored. The rules to listen to are the insurance company ones.

SBC - If I read your title bit right, I didn't direct anything at you. Didn't even see your post to be honest. Skim reading and must slow down. Good to see you think similar though. Don't know about only a tyre full of concrete, that is pretty light.

2 train wheels, the spoked ones, buried in soft sand or mud will hold better than a square 2 tonne concrete (dry weight) block. Probably out last the concrete by a long while as well.

[/ QUOTE ]

Hi Gmac ... I think you must have used the Quick Reply bit . that unfortunately ties the post to last one posted. In this case mine and it appeared to point a finger at me ...

The tyre - if you go back to my post ... a long way back in this thread .... is a large truck tyre. The reason for it is to give a circular former ... another way to do it is to use thin ply and curve that round in a circle. Both tyre or ply are sitting on a flat ply plate to give bottom so it can be completely filled centre as well. The ply plate aslo allows the whole thing to be slid down the slipway by "towing" with a suitable tractor or Land-Rover etc.

Th 2-1 is based on a lot of moorings close to each other and using good heavy sinker / ground chain.
 
Re: GMac ... why direct at me ?

[ QUOTE ]
Hi Gmac ... I think you must have used the Quick Reply bit . that unfortunately ties the post to last one posted. In this case mine and it appeared to point a finger at me ...

[/ QUOTE ]
No worries mate /forums/images/graemlins/smile.gif

[ QUOTE ]
The tyre - if you go back to my post ... a long way back in this thread .... is a large truck tyre. The reason for it is to give a circular former ... another way to do it is to use thin ply and curve that round in a circle. Both tyre or ply are sitting on a flat ply plate to give bottom so it can be completely filled centre as well. The ply plate aslo allows the whole thing to be slid down the slipway by "towing" with a suitable tractor or Land-Rover etc.

[/ QUOTE ]
Again I should read better and a very good idea SBC. If you want to get even tweakyier make the bottom a bit concaved and go for the extra suction. It can add a lot of holding in softer bottoms. The more surface area in contact with the bottom is all good.
 
Re: GMac ... why direct at me ?

[ QUOTE ]
[ QUOTE ]
Hi Gmac ... I think you must have used the Quick Reply bit . that unfortunately ties the post to last one posted. In this case mine and it appeared to point a finger at me ...

[/ QUOTE ]
No worries mate /forums/images/graemlins/smile.gif

[ QUOTE ]
The tyre - if you go back to my post ... a long way back in this thread .... is a large truck tyre. The reason for it is to give a circular former ... another way to do it is to use thin ply and curve that round in a circle. Both tyre or ply are sitting on a flat ply plate to give bottom so it can be completely filled centre as well. The ply plate aslo allows the whole thing to be slid down the slipway by "towing" with a suitable tractor or Land-Rover etc.

[/ QUOTE ]
Again I should read better and a very good idea SBC. If you want to get even tweakyier make the bottom a bit concaved and go for the extra suction. It can add a lot of holding in softer bottoms. The more surface area in contact with the bottom is all good.

[/ QUOTE ]

Agree totally about the concave underside .... we used to pile a bit of sand and then a sheet of plastic over ... that gave a dome to create the concave ... doesn't need much only inch or so and it supposed increases dramatically.

I used to do the "drop" in place of sinkers but found odd ones would "knife-edge" in and then its' devils own job to get it righted and flat. So then developed the luther "slow-drop" using the winch etc. on foredeck ... meaning the sinker was lowered to sea-bed ... Then once tide was out - those that we laid in fully drying moorings were then dug out at one side ... rock into the dug-out, dig out other side ... then rock the sinker on the centre ridge to get it to bed in ... hard work but improved holding tremendously.


Anyway ... no worries - no mooring I laid has failed as far as I know ...
 
A smooth low profile mooring block is better than a lump with bits for the ground chain / riser chain to snag on.
A large round metal plate or concrete and chain filled tyre that sinks in to the seabed works well, suction more than its integral weight anchors it.
With engine blocks you can end up with the ground chain wrapped around it.
 
[ QUOTE ]
A smooth low profile mooring block is better than a lump with bits for the ground chain / riser chain to snag on.
A large round metal plate or concrete and chain filled tyre that sinks in to the seabed works well, suction more than its integral weight anchors it.
With engine blocks you can end up with the ground chain wrapped around it.

[/ QUOTE ]

Smart man or woman even if still in bed /forums/images/graemlins/smile.gif
 
You must log in or register to reply here.

Share this page

Top