Here's a look inside an A11 Elgin, grade 557, 15/0 size, 15 jewels, made about 1944, military wristwatch.
A11 is actually a specification. There are "A11" wristwatches from multiple manufacturers with different characteristics. Some of the best known A11 watches are Elgin grades. A-11 watches were also made by Bulova, and Waltham.
One difference in some military (A11) grades is the presence or absence of a sweep seconds hand. The sweep seconds hand is a hand turning from the center of the dial, as we are used to on modern wristwatches.
This grade 557 has a sweep seconds hand, as do most A11 watches.
Shown here is the extra exposed wheel on the back for the seconds hand, driven by the 4th wheel. The 4th wheel normally provides seconds (60 turns per minute) on an older style watch with an offset sub-seconds dial. That offset is not a style choice on an, for example, a typical pocketwatch, it is the physical location of the 4th wheel in the movement.
On this movement, that extra wheel drives a pinion in the center, attached to a shaft running through a hollow center wheel post though to the front where the long seconds hand rides. The movement is otherwise just like a movement with an offset seconds hand.
The extra seconds wheel has an odd number of arms, five. Removing it gives some watchmakers trouble an sometimes leads to a broken off post. Removing this friction-fit wheel requires a specially designed puller to pull it straight off.
Also notice the characteristic black exposed ratchet and main wheels.
There's the characteristic military description on the case back.
In spite of being widely used in the military, in the field, these are rather primitive wristwatches. They are fragile, lacking the features, not invented at the time, that make wristwatches practical as we thick of them today. For example, there are not shock protected jewel mountings, and very little protection from dust and moisture. In spite of their attractions, they make poor daily use watches for most people. A One good wrap on the edge of a table will break the balance staff.
Interesting, field repair of military watches did exist. It's hard to picture a watchmaker in a foxhole, but I guess it did happen. It's worth noting however that field repair consisted largely of replacing whole assemblies, or even the whole movement. It was practical, but not exactly "repair".
During WWII, the Elgin Watchmakers' College was essentially taken over by a military command and a curriculum suited to field repair of military watches was put in place.
See the
album for this project here.
