3 Minute Marks on Pilot’s Chronographs: (Partially) Debunking Myths and (Some) Dead Reckoning

Yes, I vaguely referenced just this watch at the end of my OP, and still don’t get into it for now! 😁

You appear to be onto it!

At least with respect to the UK, unlike the U.S, and many other countries, I’m finding some evidence that long distance calls were structured in successive 3-minute increments:



While the above isn’t particularly detailed and could permit of different interpretation, it accidentally led me to quite a different angle on this topic: vintage British (and French?) “telephone timers” …




I meanwhile found a few early versions of “Phonograph” from the U.S. that separately reflect the U.S. structure (with subsequent minutes being called “overage”)




Accordingly, it would seem the mess is finding some order as follows:

For some early- and mid-20th century chronographs (particularly those with otherwise “normal” dial layouts and mere demarcations at 3/6/9), it appears likely that these helped UK (or some other European) long distance callers with rate conventions (charged in 3 minute blocks) but would have been of nominal use in North America and many other countries (with a structure of 3-minute minimum followed by single minute increments).

This is a rather interesting and cool outcome! I’d like best to see more documentation on this UK convention, which other European countries to which it applied, etc. - but indirectly the market for 3 minute increment European call timers is very compelling!

It’s also interesting to find these designs were seemingly disseminated to markets regardless of whether the demarcations were so applicable?!

I’d like to find any equally-compelling information around what to me now seems like a separate matter of what seems more intentionally designed pilots watches with features such as “big eye” 15 minute totalizers with lumed 3-minute indices. I could be fairly labeled as biased at this point, but Instill find it entirely implausible that especially-made military pilots chronographs were adjusted for so highlighting these increments in these ways (as opposed to the more “common” dial 3/6/9 demarcations) due to long distance calling - especially when it is separately established these time increments are otherwise broadly used in navigation at the time.

There may be at least two convergent stories here (if not more)!

Thanks; I think this all piles on to conclusion that in North America (and many other countries), calls were not charged in successive 3-minute increments but instead a 3-minute minimum followed by single minute increments.

And, given that it seems the structure was seemingly different in the UK and perhaps other European countries, it raises all sorts of interesting possibilities regarding manufacturers’ choices in including or not including these demarcations.

We’re there sometimes market considerations, such as watches targeted mostly to non-European markets omitting this dial feature?

Did companies ever make market-targeted versions of the same dial (such that one may in theory determine whether a specific watch was sold into one market or another)?

Are the notable absences in mid-century Omega and Rolex watches due to those companies’ more typically non-European reach?

These and many other interesting things, though still confounded by e.g., @DirtyDozen12 ’s wise observation that sometimes aesthetics trumped even utility.

Anywho, thank you for these additional bits showing the differences in US rate structures. 👍

To time a standard holding pattern is my guess

Very interesting posts, thanks to everyone. Besides long distance call charge plans varying between countries, perhaps hotels used to charge their guests in 3 minute blocks in the days before direct dial even though the telephone company in the same jurisdiction might have charged in 3+1 minute increments. This wouldn't surprise me given the propensity of hotels to (still) gouge their guests any way they can. 3-minute blocks would have made their job easier too.

For those following the thread, I've now gone back through my original post and added some edits and notes to all this progress from later in the thread.

Having slept on it, my own views have advanced to roughly the following state:

(1) When people assert that all 3-minute demarcations on chronographs were for timing long-distance calls, I believe they are wrong to a degree in two overlapping ways: this is not true of all watches highlighting 3-minute increments (such as those with deeper design alterations targeted to pilots and navigators), and it is not true that the more simple 3/6/9 demarcations were useful to all long-distance callers, in that it appears to be targeted toward the UK and possibly some other European countries were long distance calls where charged differently than in the US and many other countries.

(2) When people assert that all 3-minute demarcations on chronographs were for reason of pilots/navigation, I believe they are also wrong to to the degree of the extent of the UK/European long-distance call timing watches.

(3) There appear in effect be at least two different categories of watches highlighting 3-minute increments: first, those that merely emphasize the 3/6/9 minute marker on otherwise standard chronograph dial designs, and second, those that were specifically marketed to pilots (or built exclusively for military pilots) that go further in exaggerating the legibility of 3-minute (or multiples of 3) increments (such as "big eye" designs, 15-minute totalizers marked only in 3-minute increments, using lumed hands and indices on the totalizer, etc.). That said, I'd certainly want further direct and period information on this latter category to confirm that, for example, Breguet was not in fact altering it's military-exclusive pilots watches purely so that the pilots could better time long distance calls!

(4) In all, to me it currently seems that if someone enquires after 3-minute marks on chronographs, the best short answer is in effect "in some cases they were almost certainly intended for UK/European markets to help time long distance phone calls (and the existence of UK/European desktop call timers is the best evidence for this), while in other cases (especially in watches marketed toward pilots and navigators with more concerted design changes to highlight 3-minute increments) there were very likely utilities in navigation served by emphasizing and making more legible the 3-minute demarcations (but more period documentation on this would be best).

A few more interesting variants pilfered from our UG forum

And, for when it’s time to get into military pilot’s watches that had instead 4 minute emphasis… 🍿

Do you happen to know the utility of the sub at 12, with what appears to be either a 48 second or 48 minute maximum?

if I’ve seen a 48-something counter before I’ve forgotten where 👎😕

I’ve found that these were early timers for switchboard operators, and:

The “S.G.D.G” was a type of French patent (so presumably sold by Zenith i to at least the French market)

Similarly, “D.R.P.” appears to have been a type of German patent.

I’d assume, but can’t be sure, that the other patent date and number on the dial were Swiss patent related.

So, perhaps mark as possible that markets other than the UK with successive 3-minute charge structures included France (prior French telephone timer linked above is prior evidence), and Germany.

I also know of these marked for the “G.P.O.” (UK’s “General Post Office”) as the GPO would facilitate long distance calls