MK 10 ?6b/159

Did the Air Ministry ever recase(1956) the MK10 and issue it as a 6B/159? Thx,Bob.

The Mk. 10 (correct: NOT Mk. 10, but W.W.W. = British Army Watch, Wrist, Waterproof) was never used within the Royal Air Force.

Part of the W.W.W. specification is a sub-second. The 6B/159 (Royal Air Force) has a centre second.

So (i) no British Army recased for Royal Air Force and (ii) no sub-second watch used under a spec requiring a centre second hand.

Regards

Th. Koenig

Thx for that. I saw such a watch advertised and if I remember correctly it had been sold.. My,My, My.

Hello Mr. Koenig,

Thank you for clarifying the details regarding the W.W.W. specification and its use within the British Army versus the Royal Air Force. Your insights on the sub-second and center second specifications are particularly helpful.

I have a couple of follow-up questions:

1. Could you elaborate on the primary reasons for the British Army and Royal Air Force having different specifications for their watches?
2. Are there other notable differences between the watches used by these two branches during the same period?

I appreciate your expertise and look forward to your response. Also , can checkout my new Photo Editing App

The 6B/159 (alike the Mk. 11, 6B/346) are navigational wristwatches. When it comes to navigation, time precise to the second is essence. Therefore, WW II navigational timepieces (Navy as well as Air Force, wrist watches as well as pocket/deck watches) had center seconds. With center seconds it is simply easier to read the exact time under problematic conditions (low light, AA fire ....) than with sub seconds. (In the cold war era the German Navy had some IWC pocket watches for submarines with sub seconds, but this only as "iron reserve" in case due to a nuclear war all electronic devices did no longer work. In that situation with most devices no longer working you are no longer in need for precise time).

With the Army = ground troops you regularly have no need for time exact to the second. Therefore, the British Army went for the cheaper sub second and invested instead in watertightness (Air Marshal "Bomber" Harris commented on the wish of the watchmakers for watertight cases "When my boys are in the water, they do no longer neeed a watch"). The second hand than is more less needed only (i) to check whether the watch is working and (ii) how accurate it runs (To run into barrage fire of your own artillery simply because your watch is a minute per day fast is not really, what you want).

Regards

Th. Koenig

AS ALWAYS VERY INFORMATIVE