Omega Speedmaster Professional, a.k.a “Moonwatch”

27/01/2010

As a first timer to the Speedmaster scene, I initially found it a rather daunting task to decide which one to actually get. I first spent a couple days browsing the TimeZone.com Omega forum, which was extremely useful, and many resources thanks to Chuck (Maddox) set me on my merry way to purchasing my first fully-mechanical wristwatch.

Unlike any other watch, the “Moonwatch” presents a significant historical landmark. “It was 35 years ago today” and “What watches were worn on/near the moon…” are two must ‘read’ articles, which completely establish the significance of this timepiece.

The c.321 (a.k.a. Lemania 2310/2320):

The c.321 is based on a design development project titled “27 CHRO C12″ (27 mm diameter, chronograph, with extra 12-hour register) took place in the 1940’s by Albert Piguet and Jaques Reymond as a joint developement project between Omega and Lemania. Launched in 1942, the 27 CHRO C12 later became known as the Lemania 2310, or Omega c.321).

It was used not only in the Omega Speedmaster from 1957 through middle 1965 but also the renamed and re-cased Omega Speedmaster Professional from middle 1965 through middle October 1968, but also in DeVille, Seamaster and non-model marked chronographs during this era. It also was used in Omega non-model marked Chronographs earlier in the 1950’s under the 27 CHRO C12 calibre name.

It should be pointed out that it is ‘most’ likely a c. 321 movement based Speedmaster that was worn on the surface of the moon as discussed here.

Best described in that article,

“Is the c.861 Speedmaster worn by the Moonwalker’s? I can not state so because I have not seen proof that it was. I have seen evidence to prove that c.321 Speedmasters were worn on the moon. Thus, the c.321 Speedmaster was worn on the moon (at by least Aldrin and probably Sheppard). The c.861 might also have been worn on the moon by Moonwalker’s, but neither I or anyone else has been able to document it.” – Chuck Maddox

As described here the first wristwatch worn into outer space was strapped to the outside of Ed White’s EVA spacesuit, again an Omega Speedmaster Chronograph.

The c.861 family (a.k.a. Lemania 187x family)…

The c.861 was developed by Lemania starting in 1965. As nothing is created in a vacuum, the Lemania 2310 was likely used as a starting point for the development of the new calibre…

Changes from the Lemania 2310/Omega c.321 to the c.861 included:

The chronograph function was simplified from column wheel to a Shuttle/Cam system.
The balance wheel was changed from a screwed balance to a smooth balance.
This allowed an increase in the frequency from 18,000 bph (2.5 HZ) to 21,600 bph (3 HZ)
A flat balance spring was utilized.
Another change was made to the shape of the bridge from it’s previous “Arched”, “Wishbone” or “Y” shape to a Trapezoidal shape.

The revised movement was accepted for use by Omega, who started equipping Speedmasters in the October/November 1968 timeframe. The revised movement is known as the Lemania 1873 or Omega 861.

Distinguishing between c.321 and a c.86x based movements…

In November 2006 there was a thread over at the Watch-U-Seek Omega forum where member GBonanno queried: “Where and Why” did Omega/Lemania add this additional jewel. Members rbt, jmsrolls (Fr. John even emailed me asking me if I knew the answer: I only knew the what and when, not the where and why), were among those who participated in the discussion, but forum moderator Eptaz sleuthed out the difference and posted a picture:

Now, if you compare the part indicated inside the purple circle within the scan above, and compare with the picture provided by Eric’s (Eptaz) fellow WUS moderator Strela below:

You’ll see that it certainly appears that this is where the 18th Jewel is located…

It appears from looking at Serial Numbers on various watches it appears that the 18th Jewel was added several years prior to the switch to Rhodium plating (discussed below). We also know that Omega switched from a Coppery colored Gilt Plating sometime in the 1992/1993 epoch. One would think that Omega probably did this switch around the same time.

However, there seems to be little rhyme or reason around the transition… I own for example, a display back model with an Apollo XI caseback (which points towards an earlier example) marked 17 Jewels, but it has the 18th Jewel, and is plated in a Gilt that looks more yellow than coppery to me. Which could mean several things: One, perhaps mine is a put-together, Two, perhaps Omega wasn’t especially discriminate about assembly of parts and put some 18 jewel movements in watches with plates marked 17 Jewels. Interestingly enough, Eric (Eptaz) in an IM to me said that the person who first asked the question over at Watch-U-Seek had a displayback Speedmaster with the same configuration as my watch, so it might well be that Omega made some this way. I don’t know, but it’s very interesting.

Nomenclature Change:

To differentiate earlier gilt movements from Rhodium ones, Omega calls the Rhodium versions c.186x… So the Rhodium version of the c.861 is called the c.1861, the c.863 is called the c.1863, the c.866 is called the c.1866, and so on…

The information up to this point has been gathered from an article authored by Chuck Maddox.

Omega Speedmaster Professional c.1863 Movement (Sapphire) – 3573.50.00, a.k.a “Sapphire Sandwich”

‘The First and Only Watch Worn on the Moon’ (incorrect)

50m Water Resistant
Sapphire front and display back, hence ’sandwich’

“It’s the durable version of the moonwatch line. The Sapphire Crystal is not going to scratch easily, and as a result it’s lower maintenance than a hesalite. I like hesalite, but the Sapphire is a very good choice, especially for a first time purchaser.” – Chuck Maddox

“2002: ST 145.0811,1863

Speedmaster Professional “Moon” sapphire display back engraved The first and only watch worn on the moon, AR coated sapphire crystal, steel case, black leather strap with deployant buckle (PIC 3873.50) or bracelet (3573.50)”

From left to right: c.321 (with mesh bracelet), c.1863 3573.50.00, c.321.
Notice the c.321 movements only have 17 jewels, the c.1863 has an 18th on the intermediate.

Omega Speedmaster Professional c.1863 Movement (Hesalite) – 3572.50.00

‘First Watch Worn on the Moon’