here's the backside...

That was a great buy, Kim! I need to start going to the same flea markets you attend.

The US and anchor mark indicates that your clock was in the U.S. Navy inventory at some point. I've not found any information yet as to when this particular supplemental mark was applied, but it is not uncommon to see it on CDIA clocks. Perhaps Greg or someone else might have some info on it.

One thing I can tell you is that while these clocks were made and used during the war, they were also used for a great many years afterwards as well. Whenever one broke, it was simply removed from the aircraft and sent to be repaired at one of the instrument repair shops that were located at the large airbases. After broken instruments were fixed, they were then returned to the supply stocks to be eventually reinstalled in another aircraft that needed to have its clock sent off for repair. These repair shops not only fixed broken clocks but pretty much all of the different kinds of instruments found on aircraft. They often applied supplemental markings or stickers or decals to the outside or inside of clock cases to mark them as having been serviced at a particular station and therefore certified as being "airworthy" again. Sometimes the markings include dates and you sometimes see dates from the 1950s on WW II vintage instruments. More often than not they don't have such dates, or such markings have worn off or been removed by someone. This anchor marking may have been either an acceptance mark from when the clock was first delivered to the Navy, or it could be a repair marking from such a shop - I frankly don't know which but I would like to learn.

Some CDIA clocks are found with U.S.Navy Bureau of Aeronautics markings on the dial, though it is hard to read as it is printed in black on black. It is not uncommon for the Navy stamp to be found on the outside of the case as well. Clearly, a large number of these clocks must have been made for direct delivery to the U.S. Navy. The post-war repair tags make these clocks even more interesting when they are found.

Best regards,

Greg

The following info taken from a Waltham Advertisement-

Waltham Airplane Clock,Model XA
8715-15 Jewels
Constructed and tested in accordance with
the rigid U.S. Government Aeronautical
Specifications.

Waltham Airplane Clock, Model XX
8716-7 Jewels

Waltham Airplane Clock, Model XP
8729-15 Jewels, Flush Fitting Type

Waltham Airplane Clock, Model XZ
8730-7 Jewels,Flush Fitting Type



The Waltham Airplane Clock on the Spirit of Saint Louis was the Model XA 15 Jewel It was mounted on the instrument Board using mount #314

PS The model XP also came with 7 Jewels
The Model XA & XX were identical except the XA had 15 Jewels and the XX 7 Jewels



Frank Menez

Thank you, Frank.

Any idea of the date of the Waltham ad?

Thanks,

Greg

Greg
The ad has no date, however the ad has other items in the ad in addition to airplne clocks-

Waltham Eight Day Automobile Clocks

Walham Electric Automobile Clocks

The reason I am interesred in Waltham Airplane Clocks is that the Charles River Museum of Industry of which I am a Trustee has a Charles Lindbergh display which I set up. There has been some confusion on which Waltham was installed on the Spirit. The XA was installed and their was a cut out on the instrument board so it could be wound. There also was a cover with a knob to cover the cutout.

The CRMI has several Waltham Airplane and Automobile clocks on display.

Frank

Frank,
1932 was hand written on the ad.

Wayne

1932 is my birth year. Don't know why it was written on the ad?????????

Frank

Now I have told everyone on the MB how old I am

Good info, thanks.

Greg

Here is a smiths clock I picked up in a propeller blade.
I paid $57.00 plus shipping from England.
It is a WWII
It is mounted in a propeller blade.

Anyone know about these.

leCoultre movement.

Runs fine.

The red center knob stops the sub clock when refueling.

The right knob activates the sub clock; stop, start, reset.

The left knob winds and sets the big clock.

Face is around three inches
AM mark and crown on back

Face says: MK III A No. 4019/36
S SMITH & Sons (MA) LTD
REF NO 6A/676
L10/37

Another photo

w

Any comments

Perry
Here are the details from the official RAF description. I have been trying to locate the specification documents for years without success.

15. The Mark III clock has an 8-day movement with chronograph action for the centre second-hand and subsidiary 12-hour time-of-trip dial. This also replaces the watch Mark V. It may be used in a manner similar to a stop-watch for timing over short distances, computing the average speed, and for the measurement of a period such as the time of a trip with or without landings. Mark III (with adaptor plate) and Mark IIIA clocks are interchangeable on the instrument panel, and, except for mounting details, are identical.
16. The adaptor plate which is added to the Mark III clock conforms to the flange dimensions of the standard 3.75 in. instrument case. The clock is secured to this plate by means of a U-shaped clamp. Two studs projecting from the back face of the clock-case pass through clearance holes in the clamp. The adaptor plate fitted on the instrument panel is gripped between the flange of the case and the ends of the clamp by screwing up the nuts on the studs.
17. The movement is fitted in the case in such a manner that slight distortion does not effect the accuracy of time keeping within certain limits. The Mark IIIA has no adaptor plate and is fitted to the instrument panel in the usual manner.
18. The Mark III and Mark IIIA clocks have similar operating knobs in the lower half of the case. Care should be taken in the operation of the knobs, as too much force may result in the distortion or loss of a knob. The delicate chronograph mechanism, though of a larger scale than that of an ordinary stopwatch, is liable to be damaged if the control knob is roughly handled.
19. The time-of-trip hands and the centre secondhand are started, stopped, and returned to zero by successive pressings of the knob located at 4 o'clock. In action and purpose the knob is used in a manner similar to that of a stopwatch, the centre secondhand indicating to one-fifth of a second.
20. The arrester knob at 6 o'clock is used to interrupt the running of the time-of-trip hands. This enables the actual flying time to be recorded on a trip involving intermediate landings. It is turned to arrest and restart these hands. A coloured tell-tale is coupled to the knob to indicate to the pilot whether the time-of-trip hands are set for recording or waiting. It shows red for recording and white for waiting or idle hands, and is visible through a hole in the main dial just above 6 o'clock.
21. The arrester knob is linked to the chronograph knob at 4 o'clock. When the latter is pressed to return the time-of-trip hands to zero, the arrester knob is reset automatically and the arresting device put out of action. Thus, the hands are free and idle at the zero position and prepared for any subsequent record when the chronograph knob is operated again.
22. The knob at 8 o'clock operates in a manner similar to the keyless movement of a watch. It is turned for winding, and pulled out and turned for setting the main hands.
23. The lever for regulating the escapement is situated on the rear of the clock. The indicating hour and minute hands, the even numbered hours, the dot at 12 o'clock on the main dial, and time-of-trip hands are luminous in the luminous clocks.
24. The specification requires that when tested (a) at normal temperature (10 deg. C to 20 deg. C) with the dial either vertical or horizontal, the clock shall not accumulate an error of more than one minute during any period of 24 hours within six days of winding, and (b) at -20 deg. C and at + 50 deg. C, within six days of winding, that it shall not accumulate an error of more than 0.5 minute during a four hours' run.

From AP1275 March 41

Craig,

Wow,

I sure asked the right guy.

Thank you so much for all the information.

Do you happen to know what kind of aircraft these were used in.

I was guessing some sort of bomber for the RAF.

Best regards,

Perry

http://germanwatch.proboards43.com/index.cgi?board=gene...ay&thread=1147195441

Craig here is a website that is most enjoyable.

I posted my American Clocks on it for hoots.

It also has Japanese and German Clocks.

Naoki (Student 3 is an expert on translating Japanese.)

Hi Perry.

Aircraft clocks are not aircraft specific. They generally come in two sizes - ones that fit 2 inch spaces on panels and ones that fit 3 inch spaces. The larger ones tended to be installed in larger aircraft and the smaller ones in smaller aircraft were there was less room, but this is not a hard and fast rule. Also, given that aircraft clocks were regularly removed and serviced when they broke, they were generally not returned to the same aircraft from which they were taken - normally a repaired clock that was originally on some other aircraft or a new one from stores was requisitioned by the mechanic to replace the broken one. What this means is that in general it is not possible to tell what kind of aircraft in which a particular clock was last installed, unless of course you removed it yourself or have trustworthy provenance with it.

A larger clock such as your Mark IIIA could certainly have come from an RAF bomber, but it is equally possible that it came from an RAF transport or cargo plane or large trainer or obervation aircraft or such.

You are very lucky to have acquired it for such a low amount as this type of RAF 'time of trip' clocks typically sell in the $200 to $400 range and yours is an especially nice example. Many of these are pretty battered, not by their use during the war but by automotive road rally people who bought up many of them when they were sold in large quantities for surplus after the war. Road rallies were (still are to a lesser degree) common past-times in England where you drive from town to town in your little sports car on a set course maintaining a set speed in an alloted amount of time. These time of trip ex-RAF clocks were perfect for the job, but the result is many of them are found in somewhat battered or less than perfect working condition these days.