Laying a mooring...?

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iainzxr

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Hi all ... I'm going to be laying a mooring for our 34ft. yacht in a West coast Scottish inland Loch. How do you work out the required weight etc ... All info will be most welcome as I haven't done this before. I'm sure the local club will be very helpful but would still value all opinions.
 
It'll be a swing mooring ... sand and mud bottom ... not been advised about depth yet ... not sure what screw anchor is .... should get more info over the weekend.
 
Even the heaviest weight sinker will drag along the seabed in a gale / storm; is the sinker going to be dug into a hole, is it a diver job ?

Personally I haven't heard of screw moorings except ' Environmentally Friendly ' elastic band jobs, which I investigated for BORG re Studland; be very wary of these, not least as they are apparently untested in the UK, will require serious regular checks and maintainence, and I would be seriously worried about insurance.

If not dug in I'd be concerned about a drying mooring in sheltered Chichester, let alone in Scottish waters.
 
Looking at something like 2 mushroom type anchors .... heavy chain joining them ... short chain then rope riser .... but how big mushrooms ... chain .... etc.
 
BUT are they going to be dug in ?!!!

A rope riser sounds no good at all to me - I presume you're talking about from mooring chain to buoy ?

I've never heard of a rope riser even in balmy ( sometimes jolly rough ) Chichester - do you mean the mooring strop from buoy to boat ?

Beware of that, a friend had his boat on a relatively sheltered mooring, then a series of gales hit and he knew his boat was in trouble, but simply could not access her by dinghy.

The rope chafed through and the boat was destroyed.

Chain doesn't chafe through.
 
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One of the problems of laying moorings in Scottish Lochs is that in some areas, the seabed can shelve steeply so the actual depth you need to set the mooring in can be quite deep so you need to get some info from the locals as to what your depth will be.

A lifetime ago, my father and I used to lift and lay our mooring every year which consisted of two large fishermen anchors with approx. 50 foot of ground chain between them and then a chain riser to a steel junk wire.

Years later in the Gareloch I went over to using a 300 lb single mushroom but it got stolen by the local bad guy who it was reputed, stole peoples moorings during the Winter and then sold them back to his victims in the Spring so I went over to using massive concrete sinkers which could not be lifted by divers.

I laid one sinker mooring for my 31 foot Westerly off Largs which comprised a 5 foot diameter x 1 ft high concrete sinker cast in a steel mould with a 1.5 in loop welded to the base. Total weight was about 2500 lbs I used about 20 feet of very heavy ground chain then about three times the depth of water for a riser which I think was about 5/8" (ish)

To enable handling of the concrete sinker, I set up the steel mould on a large very solid pallet at the top of the slipway and mixed the concrete. After allowing about 6 weeks to cure, I used a pallet truck to shift the now very heavy concrete sinker to the foot of the slipway at low time Six hours later, I got the local mooring contractor to come in at high tide and lift the sinker and set it in place on the seabed.

These days, the norm in some areas is 1, 2, or 3 railway wagon wheels welded together to form a sinker with a length of Ground Chain and then Octoplait to the mooring buoy.

You should contact Gael Force in Glasgow as they took over FPM Henderson as they have stocks of chain and anchors.
 
I would have to say no ... I would imagine they have to sink into the mud/sand as they'll probably be in 8+ meters of water ... how would you dig them in? I live in the far North of bonnie Scotland so I haven't been able to talk to or see what others do with their boats. We've been on a wee pontoon for the past 3 years but due to Easterly storms I'm putting the boat South to the West coast for shelter .... While sitting here I would like to plan my mooring and start getting stuff together.
 
I would have thought of chain joined from the 2 mushroom spread... rising to the mooring buoy ... but ... 2 people ... one on the Clyde and one in Argyll .. have both said rope riser .... then rope from the buoy to the boat ...
 
iainzxr said:
I would have thought of chain joined from the 2 mushroom spread... rising to the mooring buoy ... but ... 2 people ... one on the Clyde and one in Argyll .. have both said rope riser .... then rope from the buoy to the boat ...
Click to expand...

The reason for a rope riser is chains waggle and wear out when not in use. Best is for rope + chain riser then the rope can rest all on the bottom but be pulled up when needed.
 
I'm pleased to hear there's nothing abrasive like shells, stones etc on Scottish seabeds then, or knifelike barnacles under buoys...

I've tried deep water moorings with chain or rope strops from buoy to boat, and that was enough to convince me ' chain every time ' - the 18mm nylon strops housed in thick plastic tubing were lucky to last 3 months; at wind over tide the boat went over the buoy and then the mooring strop got sawed by the barnacles beneath...

I'd say you have 2 distinct problems here;

A, the riser has to be chain,

B, the mooring sinker - and a mushroom anchor would have to be the size of a house to be sufficient - needs to be dug in.

I've worked on our relatively easy half tide & sometimes deep ( 20' is deep here ! ) - moorings for 38 years; I think you have reason to worry and start asking awkward questions - then make stipulations - if you're fond of your boat.
 
Unfortunately it requires an experienced bloke with a boat equipped with a digger job ( floating JCB ) - if in shallow enough range, or divers; and bear in mind, chain in deep water lasts much longer than in shallow oxidised water, but it doesn't last forever...

When faced with the hassle and expense of replacing deep water moorings, it's extremely tempting to turn away for another year or 20, especially for companies; beware !
 
iainzxr said:
Chain's looking good ... but how do you dig in an anchor on deep water?
Click to expand...

Going back to my previous post about laying two fishermen anchors.

We set up the moorings so as to dig in the anchors as follows,

First anchor at the bow on a loop of rope and connected to the ground chain which was laid out along the deck to the second anchor at the stern.

The Riser chain connected to the mid point of the ground chain should also be laid out along the deck.

Second anchor (connected to the other end of the ground chain) over the stern again supported with a loop of rope.

First anchor lowered using the rope with chain paid out at same time. When the anchor was on the seabed, let go one end of the rope loop and recover entire length of rope leaving the first anchor to hold the boat via the ground chain to the second anchor. You also need to pay out the riser chain which should be attached to your marker / floatation buoy.

Boat should then be maneuvered round so that the boat is now pulling on the first anchor via the second one which is still over the stern.

With the engine in gear gradually pay out the rope loop on the second anchor so as lower the anchor and stretch out the chain out on the seabed. Increase power to start digging in the first anchor.

When it is seen that the first anchor is set. lower the second anchor all the way to the seabed while maintaining power on the prop. When the anchor is down, recover the rope (engine in neutral to avoid prop fouling)

Pick up the mooring buoy and now drag in the second anchor.

Above could be done for Mushrooms esp if they have a steel eye on the dome which a rope loop can be put through.

I should add that this was done from a old wooden motor cruiser so the odc dent from anchors here and there did not matter.

Couple of rules.

Never pay out the anchors via chain directly, use the rope loop as that more than halves the weight.

Have a very sharp knife handy just in case

Work out exactly the sequence of event and work the sequence.

Make sure every shackle is "moussed" and riveted over

Never use copper wire to "mouse" the shackles

Make sure the swivel on the riser is about twice or three times the diameter of the riser chain

Hope that made sense

That was back in the early 60s when I was in my mid teens
 
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I've anchored relatively small boat, up to 8m, in west coast sea lochs for many years (Etive, Duich and Hourn) we used 5 gallon oil drums filled with concrete and chain concreted into the top, usually with a few bits of scrap metal pushed between to links to make sure the chain doesn't pull out. The advantage of using 5gallon drums (old hydraulic oil drums) is that they can be cast on the beach, manhandled and rolled. For an 8m boat I used 2 groups of 4 drums and about 15m of ground chain, with a swivel in the centre, going to a chain riser and a big buoy on top, to take the weight of the chain, then a short chain to the boat. I used 10mm galvanised chain.

The technique was to cast the drums on the beach roll/drag them to near the low water mark, rig the chains etc. Put a sacrificial line onto one of the clumps of weights, then wait for high water and use a powerful launch to drag the mooring into place. We'd usually buoy off the towing line and use if the drag the mooring ashore for inspection/recovery. In practice we found that the weights sunk into the mud and the sand quite quickly and were very difficult to shift. More often than not, we had to get the line very tight to the launch at low water, and let the buoyancy of the launch lift the weights out of the mud as the tide rose, before we could drag them ashore. We used an old AquaStar 27 as the launch.

Both Etive and Duich had quite muddy bottoms, as many West Coast Loch do, once you get past the LW mark.
 
Something that might make a very good concrete sinker is the concrete lids fitted over concrete chambers, they are circular 150 mm thick CIA varies upto I think 2.4 meter, that have a square hole 600x600 to place manhole over, so this hole would allow for mud to Ozze through, they come with lifting eye. Milton pipes stock them in Sittingbourne..I think they make them you could ask for one with stainless steel lifting eye.Just thought they make ready made sinkers.not that I know.
 
Jcortsophine,

Not sure everyone can or wants to ' rivet over ' - peen ? Mooring shackles but otherwise totally agree.

Laying anything - including a shipwreck on a seabed - it's going ro drag, sorry t's a real pain to lay a mooring in deep water but that's the proverbial IT, you're stuck with sorting IT properly !

The balance is, your deep water moorings are a fraction of the price of around here, so fin keel boats are reasonable ideas for you; just remember to get a tender like a young lifeboat, and a suitable place to keep it onshore along with secure car parking.
 
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Seajet said:
Even the heaviest weight sinker will drag along the seabed in a gale / storm;
Click to expand...

No it won't if it's right for the job. We've been mooring based fo23 years and nevervhad a problem except for wear when using nylon strops. Our mooring fo the last 10 years comprises a 2.5 ton concrete block (weighs half of that wet) 19mm long link chain, 8 ton swl swivel and a 36mm octoplait polysteel riser to a soft buoy. Twin 24mm 4 strand polyprop strops over the bow rollers have lasted 5 years so far and all has stood winds in excess of 80 mph.
 
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