I don't own a lot of modern Omegas, but the one I own that gets the most wrist time is undoubtedly my 1957 Trilogy Railmaster, which uses an 8806 movement. So, a while ago I was browsing Instagram and saw that Omega came out with a promotional shot featuring an 8800 movement being assembled in the manufacture.


This caught my eye, because it's essentially the base caliber of the 8806. I thought this looked really familiar, and I realized that the jewel placement for the gear train seems to be roughly same as on the 2500/1120/1109 calibers.

As it turns out, it seems that the pivot placement of the automatic module also matches. (it seems like some of the areas where there used to be only steel pivots have been replaced with pivoted wheels and ruby bearings).

And the more you look, the more similarities there seem to be.

Anyways, as I considered the 8800 series of movements to be of a completely novel design, like the 8500/8900 series, I thought was pretty interesting. That said, I suppose it makes sense that Omega used similar architecture to 2500 in the movement designed to replace it.

For reference, I pulled the pictures of the 2500 movement from this cool comparison of Omega's 1120, 2500, and 8900 movements. The picture of the full 8800 is from this review of the Seamaster 300m.

 

The 8800 shares a very few parts with the other movements you mention. With Omega part numbers, the origin of the movement that the part comes from is in the part number. So for example most of the parts in the 8800 have 8800 in the part number, and this means that they are specific to that movement and were not used again from an earlier caliber.

The area that shares parts is the winding an setting area of the 8800, so things like the winding pinion, sliding pinion, yoke, setting lever, setting lever jumper, intermediate setting wheel - these are all from the Cal. 1120.

This is not at all unusual with Omega (and other brands) calibers. No one reinvents the wheel just for the sake of it, well not always anyway. I recently ordered a spare yoke - again part of the winding and setting parts. The part number is 72203301111. So you can tell from that the first movement this part was made for was the Cal. 330 bumper autos. But this part is used in many subsequent movements - 340 series, 350's, 360's, 370's, 410, 420, 470, 490's, 500's, 550's, some of the 560's, all the way to the 600 series manual winds.

Many of these movements are not at all close to each other, and their production spanned several decades, but they all share this one part.

Back to modern movements, the escapement parts from the 8800 (co-axial wheel and pallet fork) are used in the new 3861 Speedmaster movement...

As for the architecture there's only so many ways to arrange a few wheels to make a watch work in a given space, so the fact these look similar really has nothing to do with the previous movements, but with the function and envelope that the movement was to fit in. The 8800 is substantially different to the previous 2500 and 1120 series movements.

Cheers, Al

 

Curious then: why are the 8800's so much thicker than the 2500's?

 

The 8800 is 0.5 mm thicker than the 2500, so they aren't a lot thicker...

 

That makes sense. I'm an aspiring engineer, so I find it really interesting when seemingly different movements actually have a lot in common, like how the architecture of the Longines 430 seems to closely echo that of the mid-500 series Omegas. There's also the distinct similarities between the Soprod A10, Miyota 9015, and the Seiko 4L35. Of course, all these movements have dozens and dozens of small details that make them each different from each other in terms of performance, serviceability, and durability, but part of what I find interesting is how movements that are different can have quite a bit in common.