Eliminate Weak Links with Quality Chain and Shackles
If you have not anchored your boat for a while, now might be the time to inspect your anchor rode. Unless you have an all-chain rode, it will most likely consist of a length of nylon line connected to a length of chain. The line may have a thimble spliced on at one end that connects to the chain with a screw pin shackle or it may have a rope-chain splice. The other end of the chain will connect to the anchor with a screw pin shackle or anchor swivel. Inspection requires laying out the rode, preferably on an asphalt or concrete surface where you can wash it and examine each component. Inspect the chain for excessive rust and wear. A little superficial rust is ok, but scaly rust that reduces the thickness and strength of the links is not. What about the shackles? Are they rusty? Take a look at the line. Is it showing signs of chafe or excessive wear? If it is time to replace any of these items, West Marine offers a complete selection of anchoring line, chain, shackles and other components.
Select the Right Chain
West Marine offers several types of marine chain. With the exception of stainless steel chain, it is all hot-dipped galvanized to prevent rust and corrosion. It is also manufactured to ISO (International Standards Organization) standards.
Proof Coil Chain is made of low-carbon steel which is not very strong as chain goes—but strong none the less. The actual steel has 55,000psi tensile strength. This grade of chain is sold under the names Grade 3, Grade 28 or Grade 30. Each link of proof coil chain larger than 1/4" is stamped “G3”. Where cost is a consideration, proof coil chain is a good choice for boats that do not have a windlass.
BBB Chain works well in many windlasses. It costs a little more than proof coil and has shorter links. It is made of the same low-carbon steel as proof coil and has the same tensile strength. Each link of BBB chain is stamped “3B”.
High-Test Chain uses high-carbon steel with 85,000psi tensile strength, which is 50% stronger than proof coil and BBB chain. Each link is stamped “G4”. High-test chain is sold under the names Grade 4, Grade 40 or Grade 43. The main advantage of high-test chain is that it saves weight over proof coil or BBB chain, since smaller chain can be used for a given load.
Polymer-Coated Chain is proof coil chain with a white (or other color) coating. Offered in short pre-cut lengths, it is only used in non-critical, light anchoring situations. The main advantage is that the polymer coating won’t rust or mar a boat’s finish.
How much chain do you need?
Cruisers that have larger boats with windlasses often have an all-chain rode that is 150'–300' long. All-chain rodes virtually eliminate the chance of the rode parting due to abrasion on rock or coral. They also reduce the need for long scope (except in shallow water) because the chain is heavy and lies on the bottom until severe conditions are encountered, when more scope may be required. The drawbacks to an all-chain rode are weight, expense and the need for a windlass.
Opinions vary on the amount of chain required. Chapmans recommends just 3'–8' of chain. The Annapolis Book of Seamanship recommends chain from 6'–44'. West Marine recommends a boat length of chain. While we can’t give a scientific reason for this, we have found that this just seems to work well.
Shackles and Swivels
Screw Pin Anchor Shackles are the most common way to connect chain to an anchor or something else. Shackles have a 6:1 ratio of working load to ultimate strength. We generally recommend that you select a shackle that is one size larger than the chain. For example, if you have 1/4" chain, select a 5/16" shackle.
Swivel Anchor Connectors are used to prevent the boat from twisting the chain. An additional benefit to using swivel anchor connectors is that they ride more easily over a bow roller when weighing anchor.
For more help with selecting chain, shackles, anchors and other ground tackle components, check our West Advisor articles Selecting the Right Anchor and Upgrading Your Anchor Rode. Of course, West Marine associates are ready to help at a store near you.