Time Keeping ca 1912

May 3, 2005
(This is also posted in the Guest Book Comments

How were clocks set and kept on time on the Titanic and other ships in 1912 ? I assume this could have been done by sun or star sightings ? (Hign Noon and Midnight, respectively, for example ?) While in Port at Southampton, a telephone call to the Observatory at Greenwich ? In port or at sea via wireless ? Set back or advanced an hour when the longitude was calculated ? (Every 15 degrees from London, for example ?)
Aug 10, 2002
The ship's clocks where compared to the ship's chronometers. While in port the chronometers could be compared to the port's noon signal. When at sea they didn't have any very good way of determining the error in the chronometers. More recently we'd get a radio time tick, and today there is a time function on your electronic nav. equipment. With the passage of time and comparisons while in port they gradually built up a record of chronometer error. Thus they could at anytime apply this error to get the accurate time at the then present moment.
On Titanic the ship's clocks were controlled by two Magenta Clocks in the Chart Room. These Magenta Clocks were compared to the chronometers, and adjusted accordingly. Today we change clocks one hour at a time using Zone Descriptions, in Titanic's time they calculated the time of Local Apparent Noon,(Sun on their meridian) during the 08-12 watch. Then they adjusted the clocks so Local Apparent Noon happened at 1200. That was how it was done on freighters. On passenger vessels, for the convenience of the passengers they did it at night, thus the testimony we hear about 23 & 24 minute clock retards that night. After evening stars they DR'd their noon position for the following noon and calculate time of Local Apparent Noon adjusted the clocks during the night, so that Local Apparent Noon happened at 1200.
I hope this helps you.
Charlie Weeks
May 3, 2005
Thanks, Charlie-

You've pretty well covered the subject. Thanks very much for the explanation.I had some other comments on the "Guest Book"...indirectly related to the question.

My question was really how was the ship's chronometer set in the first place ? And you covered that very well.This also explains why there was a difference in reported times from other ships such as Carpathia and Californian in as compared to times logged on Titanic.

I visited the RMS Queen Mary in Port many (many !)years ago when "she" was still sailing and there was one of the pages for passenger information lying about noting "The ship's clocks will be set back one hour at Midnight" (going westbound, I assume.) I should have kept this , but somehow it has gotten lost over the years. When we stayed at Hotel Queen Mary in Long Beach (not too many years ago!...in State Rooms on A and M Decks...two occasions) the room clocks were still in place but not operational. I believe they were originally electrically operated and synchronized with a master clock.

This is just another of those things that I really should have looked into during my Navy service. Our Division "Headquarters" (Excuse me but I've forgotten what the correct Navy terminology would have been !) was in what was an auxiliary Radio Room. There was a wall clock for official time and logging purposes and I assume the clock was set by a Quartermaster (QM specialty rating) daily by comparing it with the ship's chronometer...we never touched that clock !

Robert (aka "jnb" , The Ghost of John Neely Bryan)

Dave Gittins

Apr 11, 2001
Actually, it's a bit more complicated than Captain Weeks says.

It's necessary to distinguish between the chronometers kept for navigation and the clocks used for ordinary use.

The chronometers were rated by the suppliers. They determined how many seconds they gained or lost per day. When in use, they were checked whenever the ship reached a port that had the facility. This was generally a timeball connected telegraphically to an observatory. The usual procedure was for the observatory to check its time by a noon observation with a transit telescope. At 1300hr the ball was dropped. Officers watched through telescopes for the first sign of movement. They used stop watches to relate the time of the drop of the ball to the chronometers. I've added a photo of a time ball tower that served until the 1930s.

Radio time signals were experimented with as early as 1905, but didn't come into wide use until well after WWI.

The ordinary clocks were set as the ship's captain saw fit. The traditional way was to set them to agree with the longitude of the noon position. That was done on Californian. The big liners didn't necessarily do that. Carpathia, for one, was keeping a time equal to 47° 30'W, which she would have passed on the morning of 15 April, had things gone to plan. The time kept by Titanic is somewhat disputed and I won't go into the arguments. My own belief is that her clocks were set to match "stomach time" and give a reasonable time for dinner.

Personally I don't recommend "Longitude". The author hasn't a clue on how longitude was determined. Her demonisation of Maskelyne is quite out of place. Without his work, the wielders of sextants would not have had the data needed for celestial navigation. Many would be surprised to know that the chronometer that came into practical use owed almost nothing to John Harrison. It was really largely the work of Thomas Earnshaw.

Here's that time ball.