I came across this document that lists all the american instruments that were intended to be fitted to the british designed Handley Page 0/400 bomber near the end of WWI for the ASC. Can anyone shed any light on what model aircraft clock this is?

Correction

The aircraft type should read O/400.

Hi Craig.

I have only ever heard of one type of Waltham aircraft clock of that era - though I know of 4 minor variations. My guess is they did not specify since there was basically only the one choice.

Three of the variations have to do with the markings on the dial, and one variation has to do with the case material.

The first dial marking variation has an A.S.S.C. U.S. Army marking in the center of the dial which stands for Aviation Section, signal Corps - the name of the U.S. air force between July 18, 1914 and May 20, 1918. The second dial marking variation has a U.S. Navy marking. I am not positive about the A.S. marking on the Navy version, but I think it stands for Aeronautical Section. The third dial variation is A.S. U.S. Army where the A.S. stands for Air Service which was the new name of the U.S. airforce from May 24, 1918 through July 2, 1926. Clocks with this marking could have been made anytime during these years and so many are post-war. You need to look at the movement to determine production year, though the movements are very simple to exchange so it is hard to tell if you have a movement that originally came with the dial and the case. The fourth variation is the case material one. All of the cases on these were originally painted flat black and most of them are made of white metal/zinc. I have seen a few, though, where the case material is brass. I think the brass cases may have been made for some of the Navy aircraft - to resist saltwater corrosion. I do not know if the brass cases were later improvements making them late or postwar, or if they were made early in production before a need for cost savings kicked in, or if they were simply a cotemporaneous version along with the white metal/zinc cases.

All of them have radium paint markers on the dials and hands which made them readable for night flying operations without cockpit lights. The description in your document - 'night dial clock' - is descriptive of all four of the varieties of this basic Waltham aircraft clock.

Given the July and September, 1918 dates of the order in your image, plus the fact that the Handley Page O/400 was a bomber used by the Army I would guess that the clock supplied would have been the A.S. U.S. Army marked, white metal/zinc case variety.

All of these have basic Waltham 37 size, 8-day movements that were used in a number of different Waltham clocks of the time.

Here are photos of the three dial marking variations from my little collection of these - the first is the Navy version (note - the minute hand on this one is an incorrect replacement, but that is how it was when I bought it); the second is the U.S. Army Aviation Section, Signal Corps version; and the third is the U.S. Army Air Service version. All of these photos were taken of the clocks with their screw-on bezels and glass crystals taken off to see the details on the dials. The glass crystals are plain flat glass.