Movement Quiz:

[Watch Carefully]

What is noteworthy about this movement?
All answers/guesses are welcome.
Cheers,
Brad
Seeland mvt.jpg

[JunMel]

Double barrel? Hi-beat?

[Watch Carefully]

But it IS a double-barrel movement. Why do you think that is?

[JunMel]

Well, it is double barrel and just imagine the size of those barrels compared to the balance wheel. I forgot that this is a vintage movement and Hi-beats came in around 70's.

[Watch Carefully]

The 2 barrels is the main clue...giving it a power reserve of 8 days!
I'd love to have such a watch, if it could be made to run very accurately. I know that M. Parmagiani makes a tonneau-shaped 8-day movement, but the cost is very high.

I wonder if a modern watchmaker could take a movement such as the one above and update it with high quality escapement components, decorate it a bit, and put it in a slightly larger modern case...

[JunMel]

I wonder how they made it isochronous for 7 days at most? Just how the force of the mainspring is maintained constantly for several days and not to worry of a constantly diminishing power?

Most watches that are powered to run for more than 24 hours with the mainsprings shaped like the musical Staff symbol is logical to run isochronous for about a day and a half and that is more than enough. Unless the 8-days or 10-days power reserve have additional governor mechanism that regulates the force of the tandem or even triad barrels from day 1 to day 7 so as to maintain a constant amplitude of the balance wheel then it is logical. But how it works actually, or how the mainsprings are shaped I have no idea yet. I need to dismantle a PAM 317 mainspring barrels.

IMO, isochronism is the most important feature of a chronometer watch, positional and temperature adjustments next. Actually, temperature adjustments and tests are rigorously done by the manufacturer of the hairsprings and the mainsprings. At C.O.S.C. nobody does temperature adjustments but only tests. I've read that mainspring manufacturers does tweak the mainsprings shape and resiliency in order to pass certain isochronism criteria. As you've said, if that particular movement is made to run accurately, I'll have to search for one too and encase it in my DS Elegance.

Best regards,
Jun

[Watch Carefully]

Oh, the 8-day Panerais (and JLCs) are really nice but, as you say, can be very large. I do not think that Parmigiani's 8-day is nearly so large, but all are quite expensive.

[RobertJWarren]

So it is a Seeland movement? Which caliber?