Marine: why do they use chains for anchors?
Self-tutoring about marine customs: the tutor wonders why chain, rather than just line, is used on an anchor.
The following is by my understanding.
A lifetime ago, I learned that rope – which I guess mariners also call line – is preferable to chain in perhaps most scenarios. However, chain seems to be preferred for attaching an anchor to a vessel. Why might that be?
It turns out the mass of the chain is important to the anchor’s function: the chain provides ballast to help hold the vessel in place from below. In particular, enough chain is extended with the anchor so that the anchor itself, ideally, will not be disturbed as the boat moves about on the surface. Rather, the chain, lying along the bottom, may rise or fall by a few links, depending on the vessel’s position above.
With the above in mind, it seems that a chain is best for the weight its links can provide, plus its flexibility of being able to rise or fall by the link.
Interesting, eh?
Source:
Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.