Oh you're good and a constant amazement
x a million.
But John is right in parts
, no way you would want to hang a big cruiser off a 900kg square concrete block. A donut shaped one maybe, but it would still be a bit lite. He is also right about picking up any old mooring you find, not the brightest idea as you have no idea what's going on down where you can't see it.
If John wants to anchor through a hurricane
more power to him. Personally I'd far prefer to be on a good mooring.
A good simple cheap long lasting mooring -
A big feck off weight - be it concrete, a few trail wheels, a tractor if a soft bottom (I did like that one), anything big and heavy is usually good. Best is a big gear wheel
off an old press or similar. The ones about 10-12ft across are magnificent.
Considerations - the bottom type. Soft bottoms will take most things and prefer round, donut or flat shapes over square block type. These will sink in and/or create a good vacuum and increase holding a lot.
If using concrete 'spud' it when you pour it. A concrete 'spud' is basically a commercial
vibrator and looks and works quite similar to the things seen in XXX shops. With this buzzing away it gets most of the air to the top and out of the concrete so can dramatically increase the wet weight of the block. Done well the block will lose only 10-20% of it's dry air weight when immersed, not the up to 60% if not spudded. The same thing happens, not quite as well though, if you firmly tap or bash the mold
as you pour, hard work though as you want to do it a lot.
Hard firm bottoms it's all about weight and irregular shapes. Square blocks tend to work better on these.
Don't forget about the weights height if in shallow water. You don't want to run aground on your own weight.
BIG mooring lug/s. Go as big as you can so it takes forever to wear out. More than one is good for when the 1st one wears out.
From big weight lug the biggest shackle you can fit between that and a length of pre-loved stud link chain, off a ship. Length approx. water depth
at high tide. Size for a 30-50fter around 1 1/4" to 1 3/4". Bigger boats go up a bit but not to much or it won't work. This chain could easily last 30 years so a good thing.
Then another 'biggest shackle' from the stud link to some 3/4" to 1" mid link chain. Length about water depth
again. Biggest shackle again to a 1" -1 1/2" swivel.
Then off to the 'Head Rope'. Polyester 3 strand with a loop spliced each end. Size 3/4" to 1 1/2" depending on size and comfort level required. Reeve one end onto the swivel and the other loop drops over your bollard. Length of this rope
wants to be water depth again so when it's on your boat the swivel is off the ground at all but very low tide. Wear sleeve, chafe protection, wear sleeve, chafe protection.
From the top loop of the Head
Rope run a 1/2" polyester 3 strand to a small buoy, one with a handle on loop on top is best. This is the 'Buoy rope' and wants to be long enough that when the boat is not on it most of the head
rope is sitting on the bottom. Movement means wear so when everything is sitting doing nothing there is no wear.
When you arrive by boat boat hook the buoy, pull up head rope using buoy rope, drop head rope on bollard, job done.
Dos and don't -
Do remember chafe protection
Do weld up shackles is best, mousing well and things like that are OK done very well.
Do use head rope to pull up swivel for a eyeball now and again, it is the highest wear item.
Don't use galvanised chains, swivel or shackle. They can accelerate wear.
Don't forget chafe protection.
Don't plan on re-using the shackles. They are cheap and expendable, unlike your boat.
DON'T DON'T use polyprop ropes. Evil evil evil. Any here with them are instantly condemned.
With regards to using non-galvanised steel gear
. Rust needs O2 and you don't have to go too deep for that to fade away so no O2 no rust. Self-colour (black) gear is also a lot cheaper.
Otherwise a good simple mooring that has few moving parts
so less to wear. We have 6000 odd with in 20 miles of me right now and the failure rate is less than 1%, may I add, unlike anchors (sorry couldn't help myself
). More than a few of these moorings are open directly to Chile
which is 6000 odd miles away i.e. the open ocean.
All are inspected on a 3 yearly basis which usually includes a swivel swap out and maybe the top chain in some places.
How it works? Simple really. When there is no load the boat sits happily. As the load increases the boat has to lift
the top chain which off-sets that load. As the weather
goes further bad the boat has to start lifting the bottom chain. Basically the worse the weather
the more the boat has to lift and the shock loading are taken out by the increasingly heavier chain.
One easy, cheap, tried and tested well performing mooring, have fun.