RAF MK1 aircraft clock key

Can anyone offer me advise as to what the correct winding key looks like for this clock?
I have been unable to locate any data on it?

Craig, I regret that no one appears to have a key to picture for the MK I clock. Might I suggest an image of the clock and of the movement. Maybe these would help illustrate what you have and what is needed in case someone has a commercial example.

Best regards,
Greg

I've also been hoping someone would respond so I could learn something about the Mk I myself. Do you have any photos or other information on them?

The ref number for this clock is 6A/433. I have quite a bit more information about the clock from its description in AP1275 if anyone is interested.

I posted the following information in another forum, but did not recieve any responses:

I have been trying to locate the ref number for the key used in the RAF Mk 1 Aircraft clock. The clock is described as follows:

“This clock is for general use of a crew in a cabin on a flying-boat. It has an 8-day movement and is key wound from the front.”

This clock was in service in the early 30's and into the 50's.

The clock features in AP1275, the RAF Instruments manual in the following editions:

April 1938
July 1946
March 1949
June 1952

Gone January 1953

When I look in the stores book, AP1086 (December 1945) no keys are listed as an accessory for this clock.

There is a key listed for compass correctors, 6A/365; described as; Keys, No.1

Is it possible that this key is what was used? Is anyone able to shed any light on this mystery?

I will post images of the movement once I get my hands on a camera.

Is there any indication of who made these clocks? It reminds me of some key wound clocks made by Smiths. I would expect that the key would be whatever the standard key would be that was typically supplied by the maker for clocks of that size and era.

While this example is not marked with a manufacturer, other examples I have seen have been made by T & F Mercer located in St. Albans. The case as AM markings.
This example appears to be serial number 7.
It has a Swiss made movement and is not marked in any other way.

Hi Craig
After a three year search I managed to acquire a Clock Mk1 last July to finally complete my collection of RAF Aircraft Timepieces up to the end of WWII. The Mk1 is certainly one of the better quality Aircraft Timepieces used by the RAF, and is a very scarce animal.
Mine was made by Mercer,the renowned chronometer makers. The movement is high grade, and has "T & F Mercer of St Albans. Reference Number 6A/433. Number 143/39. Clock Mk1" engraved around the bezel. Otherwise, externally it is identical to your picture.
I have also been unable to find any info. on the key used for this clock, so I am afraid I can't be of any help on that (Mine came with a huge monster key which is obviously not the original)
The RAF Museum in Hendon, UK, has confirmed that the Mk1 was used in both the Supermarine Stranrear (40 of which were made by Vickers in Montreal, Canada, for use by the RCAF) and the Short Singapore Flying boats.
The movements of the Mercer-made clocks have a platform escapement made in Switzerland, but the rest of the movement was apparently made by Mercers, who apparently supplied the majority of Chronometers used by the Royal Navy during WWII.
Incidentally, the RAF Museum Hendon does not have a Clock Mk 1, and the Stranrear Flying Boat they have was made in Canada (It came from Canada with all the instruments stripped out)
Would be glad to communicate further on this subject if it would be of any help.
Incidentally- congratulations on your excellent Web site.

Ben
I am pleased to hear you have added a Mk 1 to the collection. I had concluded that I was most likely never going to acquire one for my own collection.
Having done a little research into RAF aircraft clocks, I knew my changes were not going to be good. For example, of the 46305 aircraft clocks that I know were ordered by the Air ministry in 1939, only 140 were Mk 1's, as listed in the contract summaries.
I still find it odd that the AP1086 does not list a key for the clock. If you loose the key how do you replace it? Perhaps the key is part of the aircraft.
I will have to locate the Vol 3's for the Short Singapore or the Supermarine Stranrear as you suggest to see if they shed any light on the subject.
The Supermarine Walrus may also be a candidate.
I agree with you that they are a nicely made clock, its a pity my example appears to have been dropped, causing a little damage to the dial face and the reason why it does not function at the moment.
I have the full listing of the clocks at the RAF museum, but unfortunately they do not describe them in such a way as to allow me to identify them!
I hope you have noticed that the pages on my site are now consistent in style, now that I have got the idea of CSS sorted out. It was something I had been meaning to sort out for some time now. I have also updated the content to reflect new information on part numbers.
I have scanned a whole lot of documents to add to the site. I will upload them when time permits.
Perhaps you should post updated images of your collection just to see how green with envy I/we become. I still think you have at least another 5 or so unique part number referenced Mk2's to make the collection complete.
Regards
Craig

The key question has me thinking a'bit (which can be dangerous!) In the Navy, at least, not everyone was authorized to wind and set the ship's timepieces. For this reason, I was wondering who had the authority to check aircraft clocks and to wind them for each mission? Is it possible that the keys for these clocks were kept by the air-base watchmaker? Maybe the A.M. had lists of codes for the stuff the watchmaker was authorized to order.

BTW: A round a congratulations to Ben on his fortunate find.

Best regards,
Greg

Craig
I am still searching for some possible clue regarding the key used for the Clock Mk1. No answers so far.
In regard to your last posting Craig with reference my collection and the RAF Clock Mk2. I have never come across any Reference Number for the MK2 other than 6A/579. Do you know something that I don't?
I know the Mk2 was produced by several manufacturers apart from the ubiquitous Smiths.
For example, thanks to the generosity and kindness of Greg Crocket, I have one produced by the Goldsmiths and Silversmiths of London in my collection (Which I mentioned to you recently Greg is now fully restored and running well)and also have a picture of, but have never found one, produced by Richard & Co Ltd (No Time of Trip Hands are shown). All these bear the same Reference number 6A/579. Is this what you meant Craig ?

Hi Craig
I must apologize for so badly misunderstanding your post of January 11. It must have been one of my all too frequent stupid days, and unlike Greg, I obviously didn't even think at all.
When you wrote about the additional Mk2's I now realize that you were referring of course to the Mk2's with a suffix after the 2.
My collection does include three Mk2's, one early and one late produced by Smiths (They were slightly different) plus the Mk2 produced by the Goldsmiths and Silversmiths of London (Courtesy Greg Crocket). But in addition I do have a Mk2A, a Mk2B, Two Mk2C's (One with Time of Trip Hands, and one without, and a Mk2D. There is also a Mk3A and a Mk3B, and a Mk4, Mk4B and a Mk5ACA. The last three, despite the fact that they have metal labels riveted on the back stating that Smiths supplied them, are all clearly of US manufacture. These were undoubtedly supplied by the USA to the UK under the wartime Lease/Lend agreement.
Together with the MK1, this makes a collection of 14 clocks and constitutes all those used in non-foreign RAF aircraft up to the end of WWII.
Also in the collection there are four Cockpit Watches ranging from an original 1914 Mk4A 8-Day Watch (Started out in the RFC but was transferred to the RAF when it was formed in 1918, two MkV Watches (one luminous and one non luminous) and a wartime made cockpit watch of the type often used in Lancs. and Halifaxes etc. All the timepieces are in good shape and all work well and keep good time.
As you can guess the display cabinet for the collection is some 46 inches X 10 inches, hence the difficulty in trying to produce a picture small enough to post on this site which would be of much use. I could cover it with several photographs, but I feel that pictures of a whole mass of RAF timepieces would be of interest to only a very limited number of visitors to the Ch 185 discussion group, and my text already takes up far too much space anyway.
Also I just wanted to say that your figure for the production of the MK 1 clock sounds about right, as, if the Stranrear's produced in Canada are included, it comes fairly close to the number of Stranrear's and Singapore's produced, plus some spares.
So far I have been unable to find any signs of a clock of any type being fitted to the Walrus.
I hope this clears up my misunderstanding of your post.

Ben and Greg
Perhaps I was a little too vague when I talked about unique part number referenced Mk2's.
What I was trying to say is that with in each type of Mk2, A, B etc, there are a number of unique reference numbers. These reference numbers differentiate the clocks by the dial face lighting requirements.
What I was suggesting is that you may have say a mk2A, with a given reference number, but to have a complete collection you may also want to have the other 2 clocks which are the same but with a different dial face.

The table below shows all the possibilities.

Mk2 6A/579 Luminous
Mk2 6A/580 Non-luminous
Mk2 6A/1699 Fluorescent
Mk2A 6A/1002 Luminous
Mk2A 6A/1003 Non-luminous
Mk2A 6A/1274 Fluorescent
Mk2B 6A/1072 Luminous
Mk2B 6A/1073 Non-luminous
Mk2B 6A/1700 Fluorescent
Mk2C 6A/1104 Luminous
Mk2C 6A/1105 Non-luminous
Mk2C 6A/1595 Fluorescent
Mk2D 6A/1150 Luminous
Mk2D 6A/1151 Non-luminous
Mk2D 6A/1275 Fluorescent

As pointed out there are also a number of different makers of the clocks which also adds to the possibilities.

Having done a little more research and reading I have now concluded 2 things about keys and the Mk1 clock.

1 The compass corrector key is not likely to be the key, as it would have been made of Brass due to its magnetic properties. I also understand that Brass may have been a little too soft given the force required to fully wind up the spring.

2 I have found evidence that suggests Instruments fitters would wind the 8 day clocks up, once a week.

The answer is that just about any key that fitted would have been used and that this key would not have to be specified in any of the aircraft component sections in the AP1086 vocabulary. Air stations at the time would have had any number of other types of clocks on charge that required winding by a key as well. Thus I believe the keys used will feature in a ground based area of the vocabulary, under something like “barrack equipment”.
This I believe explains why no keys are listed for the aircraft that carried Mk1’s.

Hi Craig
I think your assessment in regard to a key for the RAF Clock Mk1 is probably just about right.
I have no experience of how things were done in the RAF in peacetime, but in WWII there was always an instrument mechanic or fitter on site, and many of the Mk1's must have seen wartime service. It would probably be he who would look after such things as winding and checking these clocks as part of his regular inspection detail. After all the Mk1 was the only RAF aircraft clock which required a key to wind it, and I very much doubt that there was one key per aircraft. (If there were, they would soon be lost in the flying boat bilges or dropped overboard, or even more likely, offered for sale at the local pub.)
In regard to our misunderstanding about the various Mk2 types. When I first started out on my collection, I very soon decided not to include examples of all the variations in reference numbers based simply on whether the clock had luminous hands or not. For a start, doing so would have almost doubled the size of my collection without adding any really significant noteworthy detail to the display. Also, by far the preponderance of the clocks I initially came across had luminous hands. Then I actually found one or two where the reference number on the dial did not match the hands. (This may have been the result of cannibalization while in private hands, but also during WWII, as most of these clocks were sent to a central depot for repair, and they often swapped parts regardless of reference numbers.
I therefore decided that, as the only difference in these reference numbers was in the luminosity or not of the hands, that I would include only one example of each mark - unless there was a really significant difference, such as a different manufacturer for example, or a change in the mechanism and/or its design. There are several examples of such significant changes which did not result in changes in reference number.
I am in the final stages of putting together an illustrated book or manual to accompany my collection, and of course the different reference numbers you refer to are included in it, together with the relevant A P’s and other information regarding manufacture and use. Also, where I have been able to confirm it, I include information on the types or marks of aircraft using such clocks.
Finally, I suggest that we both hold on to, and continue to use the keys that came with our Mk1 Clocks.

Craig, or Ben,

In the list posted by Craig, the words "Flourescent" and also "Luminous" are used to describe various sub-models:

Mk2A 6A/1274 Fluorescent
Mk2B 6A/1072 Luminous

Does the above word choice signify a difference of some sort - or is it of no consequence?

Thanks,
Greg

Hi Greg
Good question.
I have been uncertain about the actual difference between 'Fluorescent' (as the Air Ministry AP's spell it) and 'Luminous' ever since I started seriously collecting RAF clocks.
I thought the only recourse was to consult the Oxford Dictionary (Being Brit. It has to be Oxford - Webster's just doesn't quite cut it in this case)
Oxford defines Luminous as quote_- "Bright or shining in the Dark" whereas Fluorescent (Which is the way Oxford spells it) is defined as quote - "Having or showing fluorescence." and Fluorescence is defined as quote - "Light or other radiation emitted by a substance when exposed to incident radiation of a shorter wavelength such as X-rays or ultraviolet light > the property of emitting light in this way."
Interestingly though, Oxford gives a second definition for Fluorescent as quote - "Vividly Colourful."
I therefore came to two conclusions:
A) Someone in the Brit. Air Ministry of that time did not know how to spell.
B) By 'Flourescent', they really meant "Vividly colourful"
I have come across such clocks with other than white hands and numbers. Hard to describe their Brownish/Pink colour as "Vivid", but that could well have been due to passage of time, as many of these clocks are some 60 to 70 years old now.
(I know I am not so colourful as I once was)
Incidentally the luminous hands and dial numbers used that horrible radio active stuff which is no longer allowed (I hope the stuff on mine is now well decayed otherwise I am probably radioactive)
Those are my thoughts anyway, but I would like to hear others.

I have found more reference material on the Mk 1 aircraft clock that sheds a little bit more light on the subject.
In the RAF air publication (AP1275 dated April 38), the following statement is used to describe the clock.
"This clock is for general use of a crew in a cabin on a flying-boat. It has an 8-day movement and is key wound from the front".
In a RAAF air publication (AAP228), which is largely based on the RAF publication, the following statement is made, "This clock is a portable model and is for the use of a crew in a cabin of a flying boat. It has an 8 day movement and is key wound from the front".
So it appears that the clock may have only been fitted to the aircraft when a clock was required, suggesting it may have been wound before hand.

Luminous refers to timepieces with markings that glow under their own power. Flourescence means that an outside light source is needed.

Luminous timepieces, up until around the 1950s or so, worked by using a paint that was made from a mix of radium-226 and zinc sulfide. Radium-226 is a radioactive isotope of radium that is relatively stable with a half-life of about 1,600 years. This means that it takes that many years for half of it to decay into its constituent isotopes which have relatively short half-lives. During this decay process, radium-226 emits a steady but very, very slowly declining level of alpha particles and gamma rays (1,600 years to get to half it original strength). By itself, radium-226 is not going to be emiting much light unless there is a lot of it and then it will only be a faint blue glow (called Cerenkov Radiation). That is where the zinc sulfide comes in. Zinc sulfide reacts when stimulated by a radiation source and gives off photons (visible light). By making a paste of radium-226 which is the energy source and zinc sulfide which is the light emitting material, you get a glow in the dark material that needs no external light or energy source. It will glow constantly until one of two things happens - either the radium decays to the point of being too weak to stimulate the zinc sulfide (this would take a great many thousands of years) or the zinc sulfide gets 'burnt' by the radium-226. By 'burnt' I mean the high energy gamma radiation crystalizes it into a form that it can no longer be excited into giving off photons.

The radium paint on a military timepiece with this material on it will be between 50 and 100 years old and so it will have only barely begun to decay and will be close to its fullest power today. The zinc sulfide will have been 'burnt' after 20 to 30 years and so today in a 50 to 100 year old timepiece with this material you will see very little if any glow unless someone has painted some more zinc sulfide on top.

In general the radium-226 is not going to be a big problem unless you wear a watch with it for an extended time (many years) or unless you keep a number of radium painted clocks a few inches from your body for many years. The really serious threat is to people who open up such a timepiece to work on it. To the extent there is any dust from decomposed luminous paint gets into the air and you breathe it in, or worse to the extent a person scrapes off the luminous paint to 'make the clock or watch safe' and those paint scrapings/dust is breathed in - that becomes a cause for concern. The reason is you really do not want any radium-226 particles down in your lungs where they will stay for a long time constantly bombarding your insides with gamma radiation - even small amounts. You especially do not want this stuff getting around young people since radiation acts over the years and the younger a person is when they are exposed the longer this stuff has to work on them.

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Welcome Aboard Internet Horology Chapter 185 Chapter 185 Discussion Site Main Page Horological Discussions, Questions and Answers Military Timepiece Discussions - EXCLUSIVE! RAF MK1 aircraft clock key

Hello, I purchased 16 RAF Clocks in the early 70s and as you know had a large Fusee Movement in them. I only have one left now which you will have seen pics of. To the Point, Most came with a key and as they were all the same i must assume they were original. I have 3 keys left and I only need 2 ,one for my RAF Clock and the other for my German U-boat Clock which fits the same key. I have sized the winder of RAF Clock with my Multi Key size gauge and it makes them a size 8. If the enquirer wants one of my Keys I will send it to him FOC. All the best ,Ged.

Jim,

Thank you for your explanation of Flourescent and Luminous dial markings.

The tech information regarding luminous compounds was also highly informative.

Ged. At last we have at least an idea of what the key might look like.

Best regards,
Greg

Ged

This is a very kind offer on your part to make, one which I thank you for. As I wish to make my clock as orginal as possible I will accept your offer. Please Google me and we can discuss the details.

Regards
Craig

Hello Craig, My email address is gednjoyce@aol.com Write to me with your postal address and I will send key FOC as promised. Regards, Ged.