length of chain

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Sea
Midshipman
Posts: 1
Joined: Tue Sep 02, 2003 4:59 am
Location: Dampier West Australia

length of chain

Post by Sea »

Hi... I was wondering if anyone has ideas about the length of chain needed if you are using chain and rope? What is the optimun length of chain to be used? My yacht is 40' steel, around 10 ton, I was thinking about 5/8 rope with 15' of 3/8 chain. What do you think?

Cheers Joe
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Nick
Admiral of the Blue
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Joined: Sun May 12, 2002 4:11 pm
Boat Type: Albin Vega 27 and Morgan Giles 30
Location: Oban. Scotland
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Chain

Post by Nick »

There are two points to consider. First, chain is used for weight and to ensure a horizontal pull on the anchor. In a blow the warp will quickly be pulled up so that the catenary is much less - ie the warp is almost a straight line. If there is sufficient chain between the warp and the anchor then the chain will resist this effect and continue to lie horizontal or nearly horizontal along the sea bed. 15m of chain might be enough in most conditions, but maybe not if you are going to anchor in deeper water sometimes . . .

Also, warp can abrade badly on some sea bottoms.

As I understand it the main advantage of warp is that it helps prevent snatching due to its elasticity. Also, for small vessels it is lighter.

Why do you not want to use an all-chain rode? Or at least enough chain for most water depths with warp for the odd occasions when you have to let out a lot more scope in a blow or anchor in really deep water. Your boat must have plenty of room for 50m chain at least, backed up by 50m of warp.

- Nick 8)
Guest

Post by Guest »

Have to agree with previous poster about using all chain for a boat your size, especially in an area with coral, no? The rode & chain you describe is what I use on our J/36 - built of balsa-cored fiberglass, to reduce weight to about 10 tons for racing. We anchor in sand and mud, primarily. I would expect your boat 4' longer, out of steel, to weigh substantially more and need heavier tackle.
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