Omega trench watch movement identification help

[markoh]

Hello all,

I have this Omega trench watch which I believe to be born as a wristwatch. It has been laying im my stash for years and finally took it to my watchmaker to see if he could get it running again.

My watchmaker did some disassembly but was not able to identify the caliber. There are no identification marks under the dial neither. Movement has broken centre wheel pinion. Serial dates movement to ~1913.

I measured the diameter of the movement multiple times. As an average the diameter is 32.29 mm, which is between 14-1/4 and 14-3/4 lignes. Did some serious Googling based on 32 - 33 mm size, but no luck.

I’d appreciate if you members could help me to identify and verify what movement this is. Any help is welcome, thanks.

 

[dancazacu]

Hi, i think it’s a 12’” ligne caliber and you will find more about old trench watches here:
https://omegaforums.net/threads/omega-regina-trench-watches.62646/

 

[OMTOM]

I would say that your movement is an Omega 15'''S - which Omega shows as having a diameter of 34.6. To measure the diameter of your movement, you'd have to remove it from the case.
Estimating a date from an Omega movement number is difficult - they didn't run in sequence! Dating in this period would normally be done from the case number (which you don't show). I would guess it's more likely to be 1916 - 1917.

 

[JimInOz]

I agree with Tom, cal 15''' S 15p.
And as Tom also noted, the plate diameter needs to be measured, measuring the diameter of the bridges only gives an approximate dimension.

 

[markoh]

OMTOM

I would say that your movement is an Omega 15'''S - which Omega shows as having a diameter of 34.6. To measure the diameter of your movement, you'd have to remove it from the case.
Estimating a date from an Omega movement number is difficult - they didn't run in sequence! Dating in this period would normally be done from the case number (which you don't show). I would guess it's more likely to be 1916 - 1917.

Thanks for the information! I’ll measure the de-cased movement when visiting my watchmaker next time.

Case number is 5719065.