Your Chain Explained: Understanding Anchor Chain
Understanding the various types of anchor chain and the advantages—and disadvantages—of each will keep you linked in for the long haul.
All chain’s the same, right? Well, no. There’s actually a variety of types and grades that cruising sailors should know about. What follows is a primer on understanding anchor chain and how to use it properly.
The most popular varieties of galvanized-steel windlass chain include high-test or grade 40 (usually marked HT, G4, or HT4); triple B or grade 30 (marked as BBB or 3B); and proof coil, also grade 30 (often marked PC, PC3, or G3). Each has attributes and shortcomings. BBB and proof coil are made from low-carbon steel; heat-treated high-test is made from a high carbon-manganese alloy.
HT chain is widely used because of its “strength-to-link” factor: Its working load limit is nearly twice that of BBB, and it has the highest weight-to-working load ratio. In other words, it allows the use of a thinner link, which means more chain can be stored in a given chain locker. Its links are also windlass calibrated, which means that they should fit any wildcat with an “HT” designation. Such links also tend to resist tangling in the locker.
Most PC chain is designated as “non-calibrated for windlass use.” This means it’s not designed to be used with a windlass wildcat. Period. Unfortunately, this caveat is unlikely to be stamped directly on the chain, so you can never be certain if the chain falls into this category. (If chain is verifiably approved for your windlass, it may be used for anchor rodes.) PC chain has roughly the same working load as BBB and the same number of links per foot as HT; for 3/8-inch chain, the ratio is 9.8 links per foot of chain. It’s worth noting that some windlass manufacturers, for obvious reasons, don’t offer a PC wildcat. If someone offers you a pile of cheap PC chain, beware.