The general curve described by
a chain hanging from two
points which need not be at the
same heights is known as a
catenary. The famed St. Louis
arch is a catenary and Catalan
architect Antoni Gaudi made
extensive use of catenary arches.
For present and future admirals
the catenary comes into play
both when tying a ship to a
dock, towing a ship, and
anchoring a ship. During tidal
bores and tsunami waves
keeping the cable only
moderately slack requires
considerable dexterity.