Bernd,

So glad to hear Born Free did not regain freedom.
There where several notes last year in Latitude 38 about a brand of anchor swivels that had a bad history of failures. Not sure if these may be used on moorings as well.

Looks like your day was saved by some sharp and willing fellow mariners, they have my respect, I think I would have their bar tab covered at the club for some time if I were you.

I applaud your good fortune.

Here is the link to the article in Latitude 38 regarding anchor swivels.

[url]http://www.latitude38.com/lectronic/lectronicday.lasso?date=2009-05-15[/...

Steve

You were, indeed, fortunate, Bernd. Thanks for the warning.

[QUOTE=Steve Frost;16425]Here is the link to the article in Latitude 38 regarding anchor swivels.

[url]http://www.latitude38.com/lectronic/lectronicday.lasso?date=2009-05-15[/...

Steve[/QUOTE]

There's a big difference between a permanent swing mooring and an anchor. With an anchor a swivel is rarely needed, I have not used one in 40 years. Your anchor time is usually short duration and the chain can untwist when raised if it twisted..

This is the result of chain twist on a permanent mooring. This chain is at 1:1 scope due to the lack of a swivel and the chain twisting up and shortening....
[IMG]http://www.pbase.com/mainecruising/image/102702039.jpg[/IMG]

On a permanent mooring a top swivel is usually very necessary especially in areas of high tidal ranges as the boat swings around, and around, and around sometimes for weeks depending upon usage. Do this enough and the chain twists and shortens to 1:1 scope and sucks the ball under. If a storm comes up you simply un-set the mooring and drag it or shock load the gear until you have a failure.

The problem with the vast majority of moorings is they are grossly under designed. Swivels are too small, placed in the wrong locations or are of an unsuitable design.

Chain is also almost always far to light/small for storm purposes and "shock loads" the gear.

At a minimum for a C-36 my design criteria would be:

*8000 Pounds of granite, 500 pound mushroom (min) or screw mooring
*USCG/USN bottom chain (1 1/2" X 22 pounds per foot) to 1.5 X Depth
*3/4" Top chain to 1X depth
*1" Swivel MINIMUM directly below ball
*Dual unequal length polyester pendants with Vectran storm snugs added to go over the chocks in storms.

I use a 1 1/4" swivel for our CS-36. Our town requires a swivel on moorings as part of the local ordinance.

This is my eye to eye swivel for a 36 footer.
[URL="http://store.hamiltonmarine.com/browse.cfm/swivel-eye-to-eye-1-1-4-galv-..."]http://store.hamiltonmarine.com/browse.cfm/swivel-eye-to-eye-1-1-4-galv-...

This is the bottom chain on one of my moorings, the lighter of the two. My storm mooring is the type with the cross bars in the links.
[IMG]http://www.pbase.com/mainecruising/image/92683374.jpg[/IMG]

P.S. Glad to hear your boat survived!!!

Thanks for the clarity. I do not have experience with setting a mooring, have tied to a couple not knowing what for sure what was below the surface.

Pardon my ignorance... What is "USCG bottom chain"? And polyester pennants? Great for chafe resistance, but aren't the best mooring pennants nylon for shock absorption? We use Polydyne (polyester cover over nylon core). Mine rode out Hurricane Sandy.

[QUOTE=jworth3;16434]Pardon my ignorance... What is "USCG bottom chain"? And polyester pennants? Great for chafe resistance, but aren't the best mooring pennants nylon for shock absorption? We use Polydyne (polyester cover over nylon core). Mine rode out Hurricane Sandy.[/QUOTE]

USCG/USN bottom chain is what the USCG & USN uses to moor cans, nuns and other large objects and it has a Mil Spec rating.. It is also called "stud link" or open link chain depending upon which type you buy.. They sell it at surplus auctions and my mooring guy buys it two or three times per year. There are also other re-sellers who buy it at governement auctions and re-sell it. The government auctions seem to be the best deal because the government replacement schedule has it barely worn at all, and it costs a fraction of what it does new. I think my bottom chain in 1 1/2" (links are 9" long and it weighs 22 pounds per foot) cost me about $400.00 13 years ago. I am sure there are other sources as large tankers and oil rigs also use it. The connector link stuff will easily last 15-18 years as bottom chain.. The non-connector link stuff will last 10-12 years depening upon size.

Yale has switched over to polyester/polyester in the Polydyne II pendants. Our mooring field is one of their main test beds as Skip Yale is a member of our club.. I've worked with him on chafe issues and pendants.. The braid is such that they retain the elasticity but the pendants survive chafe considerably better than polyester/nylon. That said polyester/nylon is still better than straight nylon...

Feel free to read this:

[B][URL="http://www.pbase.com/mainecruising/mooring_prep"]Mooring Preparations & Precautions[/URL][/B]