NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: How Many Chronometers?
From: UNK
Date: 2009 Sep 21, 22:46 -0700
From: UNK
Date: 2009 Sep 21, 22:46 -0700
Hello from a frequent reader, but not a member of the list. I'm a former US Navy officer and did my sea time on destroyer types (Pacific and Atlantic) in the NAVSAT (pre-GPS) days. The ships had three mechanical (wind-up) chronometers, gimbaled in their boxes - with dessicant - and placed in a dedicated drawer in the chart room. The drawer was on the ship's centerline and the chart room was located behind the bridge. Do keep in mind that the chronometers were as useful as the decommissioned magnetic compass. Time was kept via NAVSAT, compared daily with radio signal, and backed up with the officer's wrist watches. Sextant navigation was also a dead practice, but that's another story. Back to the topic: my sea time coincided with the advent of affordable accurate quartz wristwatches. As an experiment on one of the ships, we rated our two dozen watches instead of resetting to NAVSAT time. The purpose was to compare watch brands and purchase price. We found the mid-priced watches of two particular brands did as good as the expensive watches and all were much more consistent than the ship's chronometers as long as we wore the watch. One unexpected result: the watches experienced an occasional "jump." We suspected this was a result of the "jerk" accelerations the ship experienced in pounding storm seas. Each watch had a different jump, but the ship's chronometers had the same jump - the chronometers were the same brand but of different ages. I wonder if, twenty years later, today's affordable watches are still susceptible to the jerk. I can say that my modern Casio watch is much more accurate and consistent than my "good" Citizen watch of twenty years ago. One second in two years for the $30 Casio (landlocked). Joe ------------------------------------------------- [Sent from archive by: joseph_schultz-AT-rrv.net] --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---