Home Forums General Discussion Forum RR Pocket Watch Regulation

  • This topic is empty.
Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
  • #48367

      I’ve just overhauled a Waltham 18, 17 jewel pocket watch. It is keeping really good time, compared to some of the 5 to 11 jewel movements I’ve done. What would be a normal +/- seconds per day for a Rail Road type pocket watch?


        From an article attributed to Ed Hahn:
        The constant in all of this was that railroad watches needed to maintain a standard of timekeeping of less than 30 seconds of error over a week “.


        And keep in mind that it was ( is ) not acceptable for an accurate watch to lose or gain a large amount every day,..IE 10+ one day, and 30- the next, even if it averages out to meet the weekly rate.
        Much better to have it gain/lose 4-5 seconds per day, steady. Better example of constant Isochronism.

        So how’s it doing ???

        Best regards,


        david pierce

          The standard for railroad watches and certified chronometers in general was + or – two seconds per day or one minute per month in six positions within a given temperature range. Crystal controlled electronic watches can hold the time within 5 seconds per month in any position within a greater temperature range, which is why they overshadowed mechanical watches.
          David Pierce


            I guess I have a long way to go. It gains about 30 seconds per day.

          Viewing 4 posts - 1 through 4 (of 4 total)
          • You must be logged in to reply to this topic.