mooring size??

[Contrails II]

Just a simple question....I hope.

I have a private mooring on rocky bottom with a 4,000 lb. concrete block. I am upgrading to a 41 foot sailboat with aprox 20,000 lb displacement.
Is this block heavy enough to secure a boat of this size in normal conditions and in winds of 30 to 40 kts?

thanks Rick

[rebel heart]

I'm not an expert on this subject, but for what it's worth:

The moorings in Avalon harbor are 2 ton concrete blocks, which go to boats like mine in the 43' loa / 26K displacement. Not sure if that's the city being cheap, but it's held me fast, although I've haven't sat out that much wind. Close, but not that much.

Never heard of anyone dragging a 2 ton concrete block though. They get partially submerged depending upon the bottom too.

[delmarrey]

This was brought up a couple weeks ago. Go here; Mooring-building one

[JusDreaming]

a good article http://www.hazelettmarine.com/pdf/Ch...g%20Report.pdf

[Kanani]

Far more important than the mooring size is the mooring attachments.

I was in Hawaii when we were forced onto moorings by the state and I was on the Embarcadaro moorings in San Diego. In both cases, the mooring blocks were 2-ton and I never heard of them being drug.

However, in both cases the State was responsible for maintaining the fastenings to the mooring blocks and in both cases there were several incidents of failure in either the chain or the fasteners.

In most cases, the failure was in the shackle that fastened the chain to the mooring block. In some cases it was the poor splicing of the thimble in the nylon rode. The thimble would turn in the line and chafe through it. It was supposedly inspected by divers or actual lifting of the block (by barge and crane) every year.

When I first took my mooring in San Diego, I dove on it myself. I found the shackle bolt completely unscrewed and ready to fall out. I went out and purchased my own shackle, installed it and wired it. I also replaced their cheap, junk chain with 1/2" ships chain for the 1st 15', shackled to 20' of 3/8" BBB then I replaced the Nylon mooring line with 3/4" high quality line that I slpiced myself. I wouldn't trust them to do anything.

[GMac]

Originally Posted by Contrails II

Just a simple question....I hope.

I have a private mooring on rocky bottom with a 4,000 lb. concrete block. I am upgrading to a 41 foot sailboat with aprox 20,000 lb displacement.
Is this block heavy enough to secure a boat of this size in normal conditions and in winds of 30 to 40 kts?

thanks Rick

The block could very easily weigh less when sitting on the seabed, it's a concrete thing. Saying that it is quite possible that it is plenty if shaped well and depending what's coming off it. With a well build mooring any load should 'just' be starting to be felt by the weight in 40knts odd.

It's not 'normal' condition's you need to worry about, it's the ab-normal that will be the problem time.