The Ship's Bell Code

Before the advent of the chronometer time at sea was measured by the trickle of sand through a half-hour glass. One of the ship's boys had the duty of watching the glass and turning it when the sand had run out. When he turned the glass, he struck the bell as a signal that he had performed this vital function. From this ringing of the bell as the glass was turned evolved the tradition of striking the bell once at the end of the first half hour of a four hour watch, twice after the first hour, etc., until eight bells marked the end of the four hour watch. The process was repeated for the succeeding watches. This age-old practice of sounding the bell on the hour and half hour has its place in the nuclear and missile oriented United States Navy at the dawn of the Twenty-First Century, regulating daily routine, just as it did on our historic vessels under sail in the late Eighteenth Century.

The striking of a Ship's Clock is geared to the twenty-four hour routine of the crew, essential to operate ships at sea.  A ship at sea requires a constant watch throughout the day (24 hours) and is divided into six "watches" (divisions).  Each division stands two watches per day in order to rotate the duty so that a division does not have the same watch day in and day out. The Ship's Clock will strike every half-hour from One Bell to Eight Bells and then repeat every four hours.