Mooring Buoy Holding-Block Weight ?

[Mark Cammiade]

We live on the west coast of Canada and are planning on putting down a mooring bouy in a semi protected harbour. Does anyone know a good anchor (block)weight to boat weight ratio.?

Thanks alot
Mark

[capngeo]

We don't use much in the way of blocks down here... Helical screws and triple anchors to a kellet are the norm.... Y'all just dump a block down and shackle to it?

[zeehag]

san diego uses 2840 pounds concrete block. they DO drag if the boat is heavy and the lines are short.

[Cheechako]

Originally Posted by capngeo

We don't use much in the way of blocks down here... Helical screws and triple anchors to a kellet are the norm.... Y'all just dump a block down and shackle to it?

Empty engine blocks reportedly work good.
Zee...2800 lbs and it moves?? I didnt think sd got any big wind.... We get gusts to 70 and more in the winter....

[zeehag]

we had 90+ kts in winter for storms the past 4 yrs, 60+ years prior. i have had boats sitting on moorings since 1999 december, and i was anchored in a-9 for 3-4 years prior to that. the china chain incident was during 65+ kt wind at 0200 easter sunday morning 1999--anemometer of breakaway boat was pegged at 65kts. broken.
my formosa was moored in 2008 in a 90+ kt storm and i felt the block do endos 3 times. since then i had my lines lengthened and and double i was about 10 ft closer to my northwest neighbor before i lengthened lines. sdmc didnt believe me. is fact. is truf. i was there. bubby was skeereded when that block rolled. so was i....was righteous..
our bad storms are generally la and el nino generated, encouraged, spawned, whatever, but they come down coast like freight trains from pnw. righteous. they build in strength until the last one is generally over 70 kt winds. i do not like them. they are cold and mean. the 90 plus kts is special and a new thing....3 yrs in sequence, now.
winter in sd is not a fun thing. is one reason why i was in sucvh a hurry to leave there. 90 plus kts with 38 degree temps sukks.

[smurphny]

Concrete is not a great material for moorings because it is too buoyant compared to cast iron. Use a mushroom anchor. The long shank and fluke/cup of a mushroom along with their density make them best. In muddy bottoms the multiple engine block idea works if you put short sections of pipe over the chain where it threads through the blocks and then a good sturdy swivel tying together a couple of large old cast iron V8 or 6cyl. engine blocks (not aluminum blocks from your old Vega).

[SailFastTri]

Originally Posted by zeehag

san diego uses 2840 pounds concrete block. they DO drag if the boat is heavy and the lines are short.

Agree with Smurphny. Concrete has a density of 150 pounds per cubic foot. Water has a density of 62.4 pounds per cubic foot. This means the relative density of concrete in water is 87.6, or 58.4%. This means the 2840 pound block really weighs about 1635 in water. Steel or iron is a much better material for this because of its higher density.

[Uncle Bob]

My mooring is two old cast steel loco wheels shackled to 7 metres of 3/4 stud link chain. When checked 12 months after laying the diver could not reach the wheels they had sunk so far into the mud and the chain appeared to be about 2 metres shorter. Doesn't move whatever wind is blowing. Perfect system for a mud bottom.

[zeehag]

concrete blox are great if not pulled out of water every year for inspection. after being drug up and out of the mud, they tend to be more mobile. sdmc no longer checks their moorings in jan--is done in june now so the blox do not roll. the mud sucks em down into itself.

to this block is attached 1 inch chain X about 30 ft, with a 3 ft tag line for the mooring lines provided to run to your boat, i insisted on 2 lines for my formosa and i insisted on as long as they would give me, added a bunch by making a bridle from my mast to my hawse holes and attaching lines thru each hawse--the way i did it added 10 ft to the actual rode in use. much better. i attached one line to the first chain link and the other to the second chain link.

these concrete blox have been in use since the origination of the moorings in sd bay. i donot know what year that was--but the blox have not been changed, they look great and still hold when allowed to have proper length lines.

[bangkaboat]

Originally Posted by Mark Cammiade

We live on the west coast of Canada and are planning on putting down a mooring bouy in a semi protected harbour. Does anyone know a good anchor (block)weight to boat weight ratio.?

Thanks alot
Mark

Mark,
You should be able to get all of the stats on the buoys used by B.C. Parks, by contacting them.

This may give you an idea, as well, but it says it's only been there for less than 2 years: Oak Bay Mooring

There's a guy who was selling them for Brentwood Bay and/or Maple Bay for $2,500 . He was using 1,000lb weights, but I believe that they were concrete.

[S/V Alchemy]

We use railway car wheels of cast iron, about 900 lbs. each, and secured to half-inch chain with an inflated tire at the surface. We are behind a low and cruddy sea wall built by German POWs...from which war isn't clear...and we can get pretty violent wave action OVER the wall, but those moorings don't easily move.

Concrete ones do.

[Mark Cammiade]

Thank you guys so much I'm a little leary of cast iron because of rusting. I was wondering how much the formosa yankee clipper weighs?

Cheers
Mark

[capnorv]

We moored our 13 ton Hans Christian 34t on 2000# concrete with 1 1/4" nylon and chain on both ends...no problem. New boat is 27 tons and I'm leary. I plan on having a second block and a couple anchors added, and increasing the rode to 1 3/4", probably overkill, but cheap insurance. Our anchorage can see 60=75 mph in the winter, but doesn't last more than a few hours.

[bangkaboat]

Mark:
FORMOSA 41 YANKEE CLIPPER sailboat on sailboatdata.com

[Bricky]

For our boat, a Seawind 1000 we used an old tractor wheel with wheel weight attached. Not sure on the weight but guessing about 250 to 300 kg. Then 12 mts of heavy 32mm stud link chain, about 150mm long 90mm wide joined via swivel to about 8 mt of 50mm x 12mm.