Pryamid moorings? Dor-Mor or others?

[Fogg]

Has anyone had experience with the pyramid mooring for larger sailboats? Much of the data I see has mushroom data up to about 40' but not much larger and not for serious winds. We have pretty deep mud at our mooring field and hope to accommodate a sailboat up to a about 60 feet long in about 20-25 feet of water with 6' tidal range.

Thanks for any opinions, positive or otherwise....

Fogg

 

[CalebD]

Dor-Mor and helix moorings are now being recommended at our club on the Hudson River. During Sandy we had about 20 boats out of some 80 get loose that came to a bad end. As a result a lot of introspection and investigation has been done resulting in the recommendation of Dor-Mor (and helix) anchors. After hurricane Bob many New England mooring fields have switched to Dor-Mors.

As for the weight and length of a boat 40 - 60 feet you would need a pretty heavy Dor-Mor, see their sizing chart in their link:
http://www.dor-mor.com/
You would also need very over sized chain and extremely robust pennants and hardware to hold boats as big and heavy as you mention. It will not be cheap but it should be effective.

Our 27', 7000# boat survived Sandy on a 300# mushroom and I know of several club members who's boats survived on Dor-Mor anchors.

 

[Fogg]

Caleb,
Thanks for some good validation. Cheap it won't be, but effective, we hope. I've still got to convince my club marina committee that the required leap of faith will be a good one in the long term.

 

[Spindrift NH]

I looked into Dor-Mor last year when I was researching moorings for my 30' Catalina. The Quote I received from them was $4,500 for a full mooring set-up, mud bottom, 10' deep. That quote was without shipping!
OTOH, they seem to have superior holding capacity.

 

[Fogg]

Thanks, Spindrift. The quote I got for the 60' able to defend against 100 knot winds was close to twice that, delivered fully rigged and deployable. Maybe the numbers aren't so far fetched. Seems that you pretty much get what you pay for.

 

[tkanzler]

Well, not for nothing, but I don't think $9K for a mooring (plus shipping and placing) is that much money for a setup that can handle a 60 ft boat in 100 mph winds. It won't even be that big, like 3 ft on a side and a bit taller, plus chain, and all fit on a single pallet, so shipping shouldn't be much. New Hampshire to New Haven by common carrier should be a piece of cake as long as you have a way to take it off the trailer, or a trailer with a 3500 lb lift gate.

 

[shemandr]

Well, not for nothing, but I don't think $9K for a mooring (plus shipping and placing) is that much money for a setup that can handle a 60 ft boat in 100 mph winds.

Especially if you consider that the company will have liability. I'm sure they limit liability in the contract but still if they say it will handle whatever condition then it'd better do it.

 

[tkanzler]

Especially if you consider that the company will have liability. I'm sure they limit liability in the contract but still if they say it will handle whatever condition then it'd better do it.

I would think the yacht club will have liability to some degree, too. If the intent is to safely secure a sailboat up to 60 ft in 100 mph winds, then it better do it. I'm not a lawyer and don't pretend to know the law, but I would think (guess) that the company insuring someone's 60 ft baby would go after the YC's insurance if the mooring installed and owned by the YC for that very purpose failed. Or so it seems to me, especially with everyone trying to hold 'someone else' responsible for everything these days. I'd be curious to know what those with legal or insurance backgrounds think.

 

[CalebD]

One of the problems with mushroom type anchors is that they actually want to stand up straight on the bell. Most of the weight is in the big bell while the shaft or stem is quite long but not heavy enough to counter balance the bell. The rounder the shape of the bell the more likely it is to want to stand up straight as the center of gravity is in the bell.
If the shaft sticks up you can get the dreaded "chain wrap" which reduces the scope of the mooring as the bottom chain wraps around the stem, bell or both. This is a failure mode that is not common with a Dor-Mor based mooring.
This "chain wrap" scenario is unlikely to happen with a Dor-Mor as the stem is quite short by comparison. The Dor-Mor tends to bury itself in the bottom leaving nothing for chain to wrap on.

As to liability issues it may be important to remember that with marine accidents the analysis usually comes down to finding contributing factors such as: was the mooring rated to hold such a craft in the given conditions? An expert in this area might be consulted who might cite that the most robust mooring system is known to be the helix mooring followed by the Dor-Mor with the mushroom being less reliable than either. A bunch of engine blocks tied together with chain would be considered a poor choice for mooring hardware. If your club made the choice to use a better mooring system it should be seen as a "reasonable" thing to do and thus limit their share of liability.
Your club could also protect itself by limiting the use of this mooring in the event of a named tropical storm. I am not sure if a liability waiver for use of this mooring would be binding but it might be worth looking into.

 

[CarlN]

Have you looked into a Helix mooring? Increasingly common in New England mooring fields. Astonishing holding numbers.

 

[Fogg]

Will look further into helix moorings ASAP. I understand the install is complicated and quite costly. I'm also not sure about proper inspection since pulling the helix out frequently could become prohibitively expensive and counterproductive. Practical Sailor recommends a diver for the inspection. Much to be learned. Thanks to all for input so far. I'm still in the woods about way too many details.

Any further data, perhaps on helix experiences would be appreciated.