Railroad chronometers, or Railroad Standard Watches, are specialized timepieces that once were crucial for safe and correct operation of trains in many countries, including England, the United States, Canada, etc. A system called Timetable and Train Order, which relied on highly accurate timekeeping, was used to ensure that two trains could not be on the same stretch of track at the same time.

Regulations of the watches used by critical personnel on the railroads (engineer, conductor, switch yard controlers, etc.) were specified almost from the beginning of widespread railroad use in the 1850s and 1860s. These regulations became more widespread and more specific as time went on, with some watches that were "railroad standard" in one time period falling away to no longer being qualified in others. There was no absolute, universal definition used across different railroad lines, each company appoint one or more "time inspectors" (typically a watchmaker) who decided which watches they would work on and accepted as usable. In the United States, the American Railway Associate held a meeting in 1887, which resulted a fairly standardized set of requirements, but not all railroads adopted them.

One notable watch inspector was Webb C. Ball. His first job as a time inspector was when he was brought in by the Lake Shore and Michagan Southern Railways in 1891 after a crash and was tasked with bringing their time inspection standards up to industry normals. Ball's career eventually lead to him being the time inspector on more than half the United State's railways, leading to more a far more uniform set of standards in the U.S.

In 1891, the Dueber-Hampden Watch Company heavily advertised their line of 17-jewel watches, and soon after, railroads stopped accepting 15-jewel watches. By around 1900, hunter case watches were no longer accepted, while the smaller 16 size watches were.

A typical railroad's requirements for a watch in the early 1900s might include:

• only American-made watches may be used (depending on availability of spare parts)
• only open-faced dials, with the stem at 12 o’clock
• minimum of 17 functional jewels in the movement, 16 or 18-size only
• maximum variation of 30 seconds (approximately 4 seconds daily) per weekly check
• watch adjusted to five positions (face up, face down, crown up, crown down, or sideways)
• adjusted for severe temperature variance and isochronism (variance in spring tension)
• indication of time with bold legible Arabic numerals, outer minute division, second dial, heavy hands,
• lever used to set the time (no risk of having the stem left out, thus inadvertently setting the watch to an erroneous time)
• Breguet balance spring
• micrometer adjustment regulator
• double roller
• steel escape wheel
• anti-magnetic protection (after the advent of diesel locomotives)

The Waltham Watch Company and the Elgin Watch Company were both used as early as the 1860s and 1870s as railroad standard watches. Later, Dueber-Hampden Watch Company, Hamilton Watch Company, Illinois Watch Company and many of the other American watch manufacturers, all produced railroad grade watches.

The Time Signal Service of the United States Naval Observatory was used to ensure accuracy of railroad chronometers and schedule American rail transport.

The minimum requirements were raised several times as watch-making technology progressed, and the watch companies produced newer, even more reliable models. By WWII, many railroads required watches that were of a much higher grade (as many as 23 jewels, for example) than those made to comply with the original 1891 standard.

See also

• Pocket watch

References

This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (July 2008)

• Just What Is A Railroad Watch?

External links

• American Watchmakers-Clockmakers Institute
• Ball Watch Company
• Elgin Serial Numbers
• Howard Serial Numbers
• Just What is a Railroad Watch?
• Waltham Serial Numbers