Anchors and LongPac inspection

[tiger beetle]

One of the things the inspectors will be checking for is an anchor, chain, and rode on the boat, as per RRC 4.14:

"4.14 Suitable anchor, chain and cable, as determined by the anchor manufacturer's recommendation for the size and type of yacht."

It will really help out the inspectors if each skipper can locate, print out, and bring to the boat for the inspection their particular anchor's manufacturer recommendation.

For example, I will be using a Fortress FX-37, 50 feet of 5/16" G4 chain, and 350' of 5/8" nylon rode, to meet the requirement on my 45 foot boat. So I've printed out this page to have on hand for my inspection:
http://www.fortressanchors.com/fortress_anchor_guide.html

In the past it's been accepted that a chain length equal to the length of the boat is a reasonable minimum length - though the SSS has never written this down anywhere. The anchor does not have to be on the bow roller. In fact, I would recommend that it not be stuck out on the pointy end in an offshore ocean race - too easy to fall off (just ask Phil, whom I believe was the one to anchor abruptly and unexpectedly off Stinson Beach in 30 knots of wind during the 2007 LongPac). Better to have it lashed down safely somewhere you can get to it quickly if need be. Preferably directly above the keel.

- rob/beetle

 

[Alchera]

In the past it's been accepted that a chain length equal to the length of the boat is a reasonable minimum length - though the SSS has never written this down anywhere.

I would argue that's way overkill for a 'minimum' requirement. 15-20 feet of chain is more common for boats up to 40', and is typical for commercially sold anchor packages. To quote from the 'Don Casey Library' on the Boat US Web site:

"There are two schools of thought on figuring the proper chain length. Chapman’s suggests using one half foot of chain for each foot of boat length. But Earl Hinz, a former aeronautical engineer and inveterate Pacific Ocean sailor, in his work The Complete Book of Anchoring and Mooring, says “the chain lead should weigh at least as much as the anchor whose weight it is supplementing”. From his experience, he has determined that the length of the chain lead has nothing to do with the depth of the water or the length of the boat. He suggests using the following formula to help you determine the minimum length of chain lead you will need:

Min length of chain = (Anchor weight * materials factor)/Unit weight chain

Where materials factor = 1.0 for steel and 1.6 for aluminum

For example: If you have a 7-lb. Fortress aluminum anchor with a 1/2” twisted three-strand nylon rode, you would need to use at least 11.2 lbs. of 5/16” proof coil chain, which weighs 1.15 lbs. per foot. Therefore, you will need at least 9’8” of chain."

http://www.boatus.com/boattech/anchorin.htm

My point is that requiring a boat length of chain as a minimum is probably not appropriate. I would argue that any skipper that can demonstrate he has as much chain as either of the two methods above would suggest meets the requirement.

- Mark

 

[tiger beetle]

My point is that requiring a boat length of chain as a minimum is probably not appropriate. I would argue that any skipper that can demonstrate he has as much chain as either of the two methods above would suggest meets the requirement.
- Mark

The formulas seem equally reasonable to me. Anyone else have an opinion?

The first formula simply states a length, not a weight or material, therefore the chain needs to not be undersized.

The second formula has an implicit reasonabless test as it is based purely on weight, therefore the anchor weight and chain size should be appropriate to each other. Otherwise, our hypothetical 7 pound Fortress anchor meets the requirement with 4 feet of 1/2" BBB.

The goal is to come up with something that is reasonable and which can be applied equitably across the fleet; during the 1996 TransPac inspections Dan Benjamin came up with the anchor manufacturer's recommendation to standardize the test. Looks like we may be coming up with a standard for the second half of the equation - length/weight of chain. This would be a good thing to have.

- rob