ships bells

[sailingforever]

How do you tell time by ships bells?

[nolatom]

Bell is rung every half-hour up to 8 bells maximum, so "8 bells" is 4 hours, which is rung at noon, 4, 8, midnight; so 4 bells at 2, 6, 10 oclock, and so on. Even number of bells means an hour, odd means it's a half-hour.

You have to be able to tell which 4-hour block you're in (these were the watch periods in the old days).

[camaraderie]

Or...you look at your watch when you hear the bell!

[morganmike]

nolatom is right, but the bells are rung in groups of two to make it easier to figure out which hour you're in.

It's broken by watch:
Mid to 0400 - no bells (usually - though I guess back in the day they would do a muffled ring and turn the glass every half-hour.)
0400 to 0800 On Constitution, we didn't start bells until colors at 0700, when we would ring six bells. The first day watch really goes:

0400 8 bells XX XX XX XX
0430 1 bell X
0500 2 bells XX
0530 3 bells XX X
0600 4 bells XX XX
0630 5 bells XX XX X
0700 6 bells XX XX XX
0730 7 bells XX XX XX X
0800 8 bells XX XX XX XX

(each X is a ring)

and then the cycle repeats, 0800 to noon, noon to 1600, 1600 to 2000, etc. It's usually pretty easy to tell which watch you're in with only 6 watches a day. We usually secured ringing bells at evening colors, so it was quiet on deck from some time during the dog watch until morning colors.

[ebs001]

Here's what I found on a google search

Workshop Hints
Ships Bells
As early as the 15th Century a bell was used to sound the time on board a ship. The bell was run every half hour of the 4 hour watch. A 24 hour day was divided into 6 4 hour watches, except the dog watch (16:00 - 20:00 hours) which could be divided into two, 2 hour watches to allow for the taking of the evening meal.

After a mutiny on the Nore in 1797, British ships modified the bell system on the dog watch (16:00 - 18:00) so that the mutiny signal of 5 bells was never again struck.

Standard British Royal & Merchant Navy Clocks
from 1797
Middle (Graveyard) Watch 00:30 1 bell
01:00 2 bells
01:30 2 bells, pause, 1 bell
02:00 2 bells, pause, 2 bells
02:30 2 bells, pause, 2 bells, pause, 1 bell
03:00 2 bells, pause, 2 bells, pause, 2 bells
03:30 2 bells, pause, 2 bells, pause, 2 bells, pause, 1 bell
04:00 2 bells, pause, 2 bells, pause, 2 bells, pause, 2 bells Same as Standard
Morning Watch 04:30 - 08:00 Same as previous watch Same as Standard
Forenoon Watch 08:30 - 12:00 Same as previous watch Same as Standard
Afternoon Watch 12:30 - 16:00 Same as previous watch Same as Standard
Dog Watch 16:30 - 20:00 Same as previous watch 16:30 1 bell
17:00 2 bells
17:30 2 bells, pause, 1 bell
18:00 2 bells, pause, 2 bells
18:30 1 bell
19:00 2 bells
19:30 2 bells, pause, 1 bell
20:00 2 bells, pause, 2 bells, pause, 2 bells, pause, 2 bells
First Watch 20:30 - 00:00 Same as previous watch Same as Standard

Many thanks to Tony Gray MBHI who provided the names of the different watches.