Downsizing Chain

[Kelldog]

Greetings to all;
I am looking to replace my manual windlass ( ughh!) with an electric one on my 42ft Piver. I have 80ft of 5/16th now and I want to downsize to 1/4" but have 150ft of it and then 250" of nylon rode.

Is this feasable in terms of holding power? Say in 40 knts of wind? (most times it is around 10 or less)

Kelly.

[daddle]

Good idea. Electric windlasses are pretty nice to have.

I suspect most will consider 1/4" chain too weak, too light, for your boat. 5/16" would be my choice. 40 knots of wind at anchor develops an impressive force on the ground tackle. I run this boat very light, so only have 100' of 5/16", then 5/8" nylon 3-strand rode. It's a trade-off. The short amount of chain keep me busy with adjusting the rode as the wind pressure changes - to keep the rode off the bottom. If I had a coral-crushing chunder-beast floating-chandlery I'd have 600' of 3/8" and not have to get up so often.

[noelex 77]

Downsizing the chain will not have any noticeable impact on the anchors holding power in strong wind, but I agree with Daddle, 1/4 inch chain, even if it was high tensile, is weak for a 42 foot boat.

[Dockhead]

What they said. By the way, 400 feet is quite a lot of rode, especially coming after 80 feet. We have 100 meters of 12 mm chain and find it adequate even for the extreme anchoring conditions of Normandy (30 foot tides!).

[smj]

I believe the 1/4" ht has a higher working load than 3/8 bbb. I would be more concerned with the size and type of anchor for good holding power.

[Dockhead]

Originally Posted by smj

I believe the 1/4" ht has a higher working load than 3/8 bbb. I would be more concerned with the size and type of anchor for good holding power.

Higher theoretical working load, but can be easily compromised and can't be regalvanized (ruins the strength). Notwithstanding the Dashew's recommendation, I don't personally like the idea of undersized HT chain. Seems overstressed and overengineered to me, with too much risk of failure and life limited by impossibility of regalvanizing. I would rather suck up the weight and use G40 chain of the recommended size for your boat.

Of course size and type of your anchor is still more important than your rode (assuming you have enough for decent scope in all conditions), as the guy said.

[rtbates]

Originally Posted by daddle

Good idea. Electric windlasses are pretty nice to have.

I suspect most will consider 1/4" chain too weak, too light, for your boat. 5/16" would be my choice. 40 knots of wind at anchor develops an impressive force on the ground tackle. I run this boat very light, so only have 100' of 5/16", then 5/8" nylon 3-strand rode. It's a trade-off. The short amount of chain keep me busy with adjusting the rode as the wind pressure changes - to keep the rode off the bottom. If I had a coral-crushing chunder-beast floating-chandlery I'd have 600' of 3/8" and not have to get up so often.

Myabe not until the coral police come cart you off to jail!
KEEP YOUR ANCHOR CHAIN 100% OFF THE CORAL 100% OF THE TIME

[capt_douglas]

You don't indicate the type of chain you have (BBB, Hi-test, Proof) so it's difficult to make a recommendation.

1/4" Proof is rated for 1300# and weighs about .65#/ft
5/16" Proof is rated for 1900# and weighs about .95#/ft

Don Casey: Ground Tackle: Selecting Anchors and Rodes by Don Casey
BoatUS: Anchoring
Beth and Evans: http://www.bethandevans.com/pdf/Anchorsteps.pdf

Changing from a manual windlass to a powered one is much easier. Having pumped a Simpson Lawrence SL-555 for a couple years, the move to power was something I had no problems doing and wondered why I waited so long.

There are a number of articles and how-to's on the web for installing a windlass as well as determining the right size. Since you're considering changing chain and that has a direct relationship to the size of windlass I'd suggest choosing the chain and rode first (assuming no change to you anchors) then look at windlasses.

[Adelie]

Originally Posted by Dockhead

Higher theoretical working load, but can be easily compromised and can't be regalvanized (ruins the strength). Notwithstanding the Dashew's recommendation, I don't personally like the idea of undersized HT chain. Seems overstressed and overengineered to me, with too much risk of failure and life limited by impossibility of regalvanizing. I would rather suck up the weight and use G40 chain of the recommended size for your boat.

G40 & G43 are ht (high test) chain. The difference is G43 is an ISO Standard, slightly shorter link I think. Neither is heat treated so repeated regalvanizing would not be significantly detrimental to strength. I believe these are high carbon steels giving the higher strength.

ProofCoil(PC)/G30 & BBB are both low carbon steels with no heat treatment. The difference between them is link length.

Comparing:
G30/BBB 3/8" has 2650lb wll, breaking strength of 10,600.
vs.
PC/G40/G43 1/4" has 2600lb wll, breaking strength of 7,800.

Working load limits are comparable, but breaking stength for G40 is lower. Given the better quality control for G40 the lower factor of safety is justifiable.

If the OP has 5/16" chain on their 43' boat already, then it is probably ht/G40/G43, or the previous owner seriously undersized the chain with BBB/G30/PC.

Assuming Dockhead meant Alloy Chain (G70/80/100) when he/she said High Test (HT) then I agree. Alloy chains are heat treated meaning that regalvanizing is detrimental to strength, if you can even get the chain galvanized in the first place.

[Bash]

I'm going to disagree with most of the above. The Piver 41AA's main hull is built with a bit more rocker than most trimarans, which makes it all the more important to keep weight out of the ends. The weight savings of carrying 1/4" HT is significant enough to make this a desirable tradeoff, especially if the OP understands that he won't get the lifespan from this chain as with something larger. As it has been mentioned previously, one loses the option of regalvanizing after a few years under this plan.

[vreference]

I'm curious - and maybe it's be discussed - is anyone using synthetic rope yet? You can get rope used for offroad winches rated at 10,000lbs or more that would weight a fraction of what chain does. Name brand 100' sections is fairly pricey ($700) but I imagine it's available for quite a bit less elsewhere.

I suppose you don't have to worry about chain chafing on some hidden object underwater but I wonder how often that would really come up.

[daddle]

Chafing is a real problem. An attentive skipper will keep the non-chain part of the tackle off the bottom - as no good comes from rode lying on the bottom. Such adjustment do make for interrupted sleep sometimes.

There is no place for low-stretch synthetics in an anchoring setup. Nylon is the synthetic of choice. Nylon is very strong, but that's rarely the issue compared to chafe.

[gosstyla]

Originally Posted by daddle

...There is no place for low-stretch synthetics in an anchoring setup. Nylon is the synthetic of choice. Nylon is very strong, but that's rarely the issue compared to chafe.

Actually there may be. I know the Dashews experimented with this a few years ago to avoid the "sling shot problems" with nylon. I don't know what they concluded.

[foggysail]

If I had my choice, I would have purchased 1/4" HT chain for my Maxwell HWC2200 windlass. I DID NOT HAVE A CHOICE! But of course, I could have gone with a smaller windlass. My idea of installling a windlass was to be sure the windlass would do all I expected without me having to manually help it. OH, I use an 88# anchor along with 5/16HT chain.

YOU MAY NOT HAVE A CHOICE EITHER! In my particular case, Maxwell did not offer a gypsy to accommodate 1/4"HT chain on the HWC2200 windlass. Next, is 1/4"HT chain strong enough?

I think it is with a a 2600# working load. Many boats would find cleats ripped from their decks with that load. But there is also a wear factor that worsens over time. Link wear certainly will compromise strength and the wear only needs to be in one link.

Foggy