Windlass Rope and Chain

[Mark Turner]

Hello,

I need your expert advise. I have to replace the rope/chain for my windlass and need recommendations on the length of each. I have a 1965 37' Owens cruiser (ie heavy boat) and while I'll mostly use it in the Sacramento Delta, we plan on docking and cruising it in the San Francisco Bay during Indian Summers. 30 feet of chain and 250 feet of rope has been recommended by a marined supply shop. Does that make sense to you all?

Thanks,

Mark

[ssor]

I sail the Chesapeape Bay in a 30 ft Islander about 4 1/2 tons. I carry thirty ft of 3/8 chain and 300 ft 5/8" three strand nylon. In forty ft of water a 7:1 scope is 280 ft. My anchor is a 35 pound CQR. I carry a 15 pound North Hill on twenty ft of 1/4 " chain and 200 ft of 1/2" three strand for a stern anchor. I sleep well at night. :D

[Mark Turner]

I found this write-up on a WoodenBoat Forum member's website. I didn't ask him if I could mention his name, so I won't. I'm posting it here in the event someone later does the searchy thing looking for the same kind of information I was looking for.

Cheers, Mark

How much Anchor Rode do I need

Ground tackle

The typical pleasure boat anchor rode is a long length of nylon line shackled to a short length of chain at the anchor end of the rode. The chain is there mostly to add weight to the shank of the anchor, helping the anchor dig into the bottom. The rope part of the rode must be nylon. Nylon line is not only strong it is also elastic. When waves roll into an anchored boat, the nylon stretches like long rubber band, preventing the destructive jerking that occurs with a less stretchy rode. Both three-strand and braided nylon ropes make excellent anchor rode. Three-strand gives greater elasticity at lower cost, but braided nylon is more flexible, making it a better choice when the rode is fed through a deck pipe for stowage.

Ground tackle – is the whole anchoring system, including anchor, chain, shackles and line. Anchors also must have something to attach them to the boat. This is called the anchor rode and may consist of line, chain or a combination of both.

Anchor Size - the ground tackle needs to be of a size suitable to the vessel. As a rough guideline for boats of moderate size and displacement, the primary bow anchor ought to weigh at least 1-lb. per foot of length on deck. Bigger is better. One additional anchor, made up and ready with its rode attached, should also be carried aboard. An anchor needs to have some sturdy galvanized chain between it and the anchor line, no less than 15 or 20 ft. Again, more is better. Most experienced cruising sailors fit one of their bow anchors with an all chain rode, often using a windlass with a chain gypsy to handle it.

Rode – is the length of line and or chain that attaches the anchor to the boat. Simply put, the chain lead should weigh at least as much as the anchor whose weight it is supplementing.

Scope - the angle of the rode is described in terms of water depth to rode length i.e. 3 to 1 means that the rode is three times as long as the depth of the water. Seven to one would be "more" scope or a shallower angle. The more scope the closer the shank of the anchor is to the bottom, the better it holds.

Powering - refers to a technique of freeing a stuck anchor. Take in any extra rode you can by motoring up on the anchor and then tie the line off on the cleat. Have your mate stand back and motor the boat past the anchor. The boat can put considerable strain on the anchor, more than most hooks can take so be careful.

Anchor rode

What size rope do you need? A good rule of thumb is 1/8" of rope diameter for every 9 feet of boat length. As example, if you have a 26-foot boat, you need 3/8" line, but you should buy 1/2" rope for a 28-footer. To determine how long your anchor rode should be, multiply the deepest water you expect to anchor in by eight. If you expect to anchor in 25' of water, you need 200' of rope.

What length of chain do you need? A good rule of thumb is the length of chain lead in feet ((minimum) = (weight of anchor, lb / unit weight of chain, lb/ft) times anchor materials factor (1 for steel, 1.6 for aluminum)). As an example, for a 20H Danforth Hi-Tensile anchor with a 1/2" twisted 3-strand nylon rode, you would use at least 17' of 5/16 inch Coil chain, weighing 1.15 pounds per foot.

[paladin]

general rule of thumb...at least one boat length of chain...long haul cruisers use 3 boat lengths of chain fastened to the aforementioned nylon rode, minimum 7 or 8 to one scvope for the deepst water that you expect to be in....minimum of two anchors set up to be deployed at 45 degree angles for storm conditions....and it goes up from there....

[John E Hardiman]

If your going up the delta, you will need two kedges as well as the bower. One of the kedges should be only slightly less than the bower, the other a light "swimout" for when you do put her up on the hard (or in the case of the delta the "significantly thicker").

You will also need 3-4 100' lenths of mooring line if you intend to spend any time anchored out up there. Currents can be fast and are reversing in narrow channels (but you most likely know this).