The Topper Blog consists mainly of original writing by Rob & Russ Caplan with occasional special contributions and interviews. All photography in the blog is taken at Topper Fine Jewelers , or on location unless otherwise indicated in the photo captions.

The OMEGA Constellation Globemaster and the Progression of OMEGA's Co-Axial Movement



During Baselworld 2016, OMEGA announced a new version of the Constellation Globemaster, an annual calendar. It was around this time that we took delivery of several steel models of the three-hand Globemaster announced in 2015. This post will look at these models as well as the four major levels of co-axial movements found in the current OMEGA watch collection: 2500d, 8500b, 8500c, and 8900.

2500d (examples include the Seamaster 300 M and De Ville Prestige)

This is the most basic of OMEGA movements and the one found at their entry level price point for automatics. The 2500 calibre is based on the 1200 calibre of the 1990s and early 2000s which in turn was based on the ETA 2892-A2. Examples of popular 1200 calibre watches are the Seamaster 300M models 2254.50.00 and 2531.80.00. Even back then, that calibre wasn't a stock 2892-A2 as it featured more jewels, superior decoration, and was a chronometer grade variant. The primary difference between the 2500 and the 1200 has been the introduction of the co-axial escapement; a reduced friction escapement system that enables watches to go longer between services than did those using a Swiss lever escapement.

The A version was introduced in 1999, followed almost immediately afterward by the B version between 1999-2000. The main difference between A and B is that the palette bridge was made sturdier in the B because the pallet fork in the original A calibre could shift upon mild shocks.

The B version was on the first steel De Ville co-axial chronometers as well as in the first Aqua Terra models such as the 2503.50.00.

The C version came out around 2005 and was included in the first Planet Ocean models (e.g. 2201.50.00). The primary difference between B and C is that the C slowed down the movement from 28,800 vph to 25,200 vph. With the modern version of the 2500 calibre, the main feature benefit over an 1200 calibre is that it boasts a service interval around double that of its Swiss lever escapement predecessor.

The current production OMEGA 2500 calibre uses the D calibre which was introduced around 2011. This calibre of the 2500 features a full three-level escapement. The three-level escapement makes the movement more stable, and is how the inventor of co-axial George Daniels originally envisioned it. The D calibre boasts superior stability over the two-level A, B, and C versions.

8500b (examples include Omega Planet Ocean and 38mm Constellation )

The 8500 calibre is a movement built from the ground up around the co-axial escapement. For that reason it is often referred to as a "co-axial calibre". All "co-axial calibres" have co-axial, escapements, but not all watches with co-axial escapements are a co-axial calibre. The two most well known movements that are co-axial, but not co-axial calibres are the 2500 series (described above) and the 3313 used in watches such as the Speedmaster Broad Arrow 1957 and the original Aqua Terra Chronograph.

When the 8500 made its debut in 2007, it featured several advanced features not found on the 2500. Among the most significant was the dual-barrel power reserve which both elongates the power reserve up to 60 hours and allows the watch to maintain consistent accuracy throughout all levels of charge. In addition, a time zone function allowed changing the hour hand (as when travelling across time zones) without hacking the watch. Another upgrade was a new Nivachoc shock absorber that was an improvement over the 2500's Incabloc shock absorber. The 8500 was also a much more beautifully finished movement.

Around the time the 2500D was introduced in 2011, the 8500 calibre in watches such as the De Ville Hour Vision and the Aqua Terra were upgraded to a B calibre, and new models such as the redesigned Planet Ocean were also introduced with a B calibre. While the B featured many small improvements over the A, the biggest advantage of the B was the use of a silicon hairspring which made the watch more resistant to both magnetism and mild repetitive shock.

8500c Master Chronometer (examples include Aqua Terra Master Co-Axial)

In 2013, OMEGA introduced an upgraded version of the 8500 in which all relevant mechanical components (escapement wheel, pallet fork) were also made out of anti magnetic materials. The original watch to introduce this anti magnetic movement came out in the Aqua Terra >15,000 Gauss. While the calibre was called the 8508, it was essentially an 8500 with special aesthetic features: the most significant being ">15'000 GAUSS" displayed on the rotor.

In 2014, OMEGA released an entire collection of Aqua Terra models with the same technology, but without the special 8508 rotor. These watches instead featured the term 'Master Chronometer'.

8900 (examples include the Globemaster and 2016 Planet Ocean)

The 8900 calibre made its debut in the 2015 Globemaster, the subject timepiece of this post. As I understand it, the mechanics of the 8900 are not substantively different than the 8500c. The main difference lies in the level of certification and the standards used in the respective certification procedures. While the 8900 is still certified by the COSC before it is cased in the watch, it undergoes further testing as a fully cased watch by the third party testing organization, Swiss Federal Institute of Metrology (METAS). METAS testing is done to externally validate quality standards beyond those used by the COSC. Watches that pass the METAS certification process earn the designation of Master Chronometer.

While the COSC rates a fully charged watch movement in five positions, Master Chronometer watches undergo a second certification that essentially validate the capabilities of the 8500c. METAS ensures that the watches are accurate not just to the COSC standard of negative four to plus six seconds a day, but that they are accurate to the stricter specifications of zero to plus five seconds a day.

METAS also subject the watch to a series of tests that OMEGA innovations only first seen in the 8500a enable it to pass. For instance, one of the tests ensures that the rate is fairly close when the watch is at both a 33% charge and at full charge while another insures that the power reserve achieves the promised 60 hours. This is only possible due to the use of dual barrels on all 8500 Calibres. There are also tests such as the 15,000 gauss magnetic resistance test that only the most recent version C of the 8500 could pass. METAS also performs other tests such as water resistance which is only possible to validate on a fully cased watches. WatchTime magazine has a great article that describes the METAS Test in more detail. OMEGA also provides a description of the METAS certification here.

The Globemaster

Today, the Globemaster is in the Constellation family and takes many design cues from the 1950s Constellations. In the 1950s, when the original Globemaster watches were produced, they were a similar alternative to the Constellation which could not be imported into the United States and Canada due to a trademark dispute. Since OMEGA could not sell watches labeled as Constellation through the Norman Morris Company, their U.S. distributor at the time, they adopted the name Globemaster. The name Globemaster was a tribute to the Douglas transport aircraft manufactured between 1949 and 1955. The giant plane had two-decks, four-engines, and was designed to transport military troops and materials to theaters across the globe.

Considering the Globemaster features the most sophisticated OMEGA movement and embraces new materials, it makes sense that OMEGA would name and base the watch off a less recognized watch than the Constellation. The Globemaster has history, but not so much identity in people's minds that it would require a strict adherence to the source material like there might be for a more established model. In fact, in OMEGA's 831-page anthology Omega--Journey Through Time, there is but one page dedicated to the Globemaster. In fact, after the trademark naming issue was resolved in 1956, the Globemaster name took on a different role. It was used in the place of the Constellation's symbolic five-point star on the lower dial of some non chronometer models. Production of these lower-end Globemasters continued into the early sixties.

Original ads of Globemasters from the 1950s. (source: Omega--Journey Through Time)

The 2015 Globemaster features a series of design choices without roots in the original Globemaster, but that do stem from the Constellation. While Omega--Journey Through Time does not show any Globemasters with fluted bezels, they do appeared on some Constellations of the mid 1960s. The modern version takes this historical element and reintroduces it in scratch resistant tungsten carbide. While most facets of the new watch (both case and bracelet) feature a brushed finish, the highly polished fluted bezel and signed crown provide a nice contrast.

Furthermore, the dial has the famous twelve sided “Pie Pan” dial that harkens back to the 1952 Constellation. Instead of featuring the riveted triangular hour markers of the original 1952 Constellation, or the luminous dots inside those markers that appeared on actual Globemaster watches in the late 1950s, the markers of this year's version are rectangular with large lume strips. This shape of marker also appeared on Constellations of the late 1960s. One element on the new Globemaster, but not present on the original 1952 version is the date complication. While a date window did make an appearance in the late 1950s, it did so at the three o'clock position, while the new Globemaster sports a frameless beveled window at six o'clock. The time zone function that goes all the way back to the 8500a is of course present in the Globemaster, and can be set forward or backward in one-hour increments, making it convenient for globe hopping travelers. 

A 1960s Constellation with a fluted bezel. One of many historical references for the 2015 Globemaster.

The Globemaster is 39mm and features a similar dial aperture to the slightly smaller 38.5mm OMEGA Aqua Terra. We've included some side by side pictures of them to show how similar they are. In essence, the Globemaster is a sporty dress watch while the Aqua Terra is a dressy sports watch.

Below are photos of the four variants of all steel Globemaster models: silver dial on a bracelet, silver dial on gray alligator, blue dial on a bracelet, and blue dial on blue alligator strap. Bracelet models retail for $7,000 and strap models are $6,900.

The applied OMEGA name and logo, polished and lumed baton hands and hour markers.

The beveled date aperture and the rhodium-plated hallmark Constellation star of the Globemaster.

The 2015 Globemaster's blue sunburst “Pie Pan” dial set within the polished and fluted tungsten carbide bezel.

The many brushed facets of the Globemaster case and bracelet contrast nicely with the polished fluted bezel and the signed crown.

The 3-row stainless steel bracelet with slightly curved central links and signed clasp.

The open butterfly clasp of the stainless steel bracelet.

The screw-down sapphire caseback giving a view to the 8900 movement, the signature Central Observatory medallion, and mainspring barrel one of two.

An inverted view through the caseback showing mainspring barrel two of two and the Nivachoc shock absorber.

The light blue lume signature of the Globemaster hands and hour indices. Note the abbreviated hour marker at six o'clock which allows space for the date window.

The opaline silver "Pie Pan" dial option on gray alligator strap.

Note the polished hands still provide good contrast for legibility on the light dial option.

A view of both mainspring barrels and various jewels under the sapphire crystal caseback.

With the rotor positioned on the top half of the 8900 movement, you can see the blackened screws, the free-sprung co-axial movement, and the unique balance bridge.

The upper dial of the opaline silver dialed Globemaster.

The lower dial, date window, and integral lugs of the modern Globemaster.

The fluted bezel encased “Pie Pan” dial in opaline silver.

The brushed steel case side, signed crown, and bezel of the Globemaster on leather strap.

The modern Globemaster with blue dial on blue alligator strap.

The modern Globemaster with opaline dial on steel bracelet.

A comparison dial view of the Globemaster (left) and the Aqua Terra (right).

A comparison case side view of the Globemaster (left) and the Aqua Terra (right).

The Topper Blog consists mainly of original writing by Rob & Russ Caplan with occasional special contributions and interviews. All photography in the blog is taken at Topper Fine Jewelers , or on location unless otherwise indicated in the photo captions.