Omega Central Tourbillon – Part 2: History of Development

Apr 15, 2007,09:58 AM

Omega Central Tourbillon – Part 2: History of Development
By Michael Ting M.D.[1], Melvyn Teillol-Foo M.D.[2] and Suitbert Walter[1]

1 – Moderator
2 – Moderator

We reviewed the History of Omega Observatory Trials and Precision Records in Part 1 of this series. This installment reviews the ‘History of Development’ of the Omega Central Tourbillon.

Over the past 100 years the horological landscape has changed dramatically as consumer demand shifted from pocket watches to wristwatches.  In 1986, Audemars Piguet introduced the first production automatic tourbillon wristwatch and it was considered a technical marvel.  Even as demand for tourbillon mechanisms grew, they remained rare masterpieces of elite watchmakers due to the time required to expertly finish and meticulously assemble each tourbillon.
In recent years, watchmaking has evolved by fully incorporating computer-aided design (CAD) and computer numerical control (CNC) milling into the manufacturing process.  As a result of this modernization companies with little horological experience have been able to flood the market with new tourbillon wristwatches.  Many of these timepieces iterate simple interpretations of tourbillon or karrousel designs without new technical innovations.  Omega’s version of the tourbillon wristwatch, however, merits special attention. 

Omega decided to demonstrate their watchmaking prowess to celebrate their 100th anniversary in 1994 by producing a special “Haut de Gamme” timepiece. The zenith of the watchmaker’s regulating art was a tourbillon but not just any tourbillon; it had to be immediately recognized as an Omega. Therefore the decision to produce a central Tourbillon was taken. The project was codenamed Project 33 (P33) and begun in 1991 under the direction of Mr. Moritz Grimm and Mr. André Beyner who developed the movement together with the Omega technical office.
[PuristS’ Trivia] Mr. Beyner named his major projects using the odd year numbers starting from his birth year (1927) – P33 was his 4th major project.

Omega’s technical office faced many hurdles trying to develop the movement for P33.  It was not an easy task to relocate the escapement of a timepiece to the centre of the dial. By convention the hour and minutes hands usually originate from the center of a wristwatch.  This traditional display facilitates time telling but limits a watch’s mechanical design.  Given the paucity of space within a watchcase and the engineering principles involved, the escapement and tourbillon cage is usually located at the periphery of a watch movement.

Faced with the daunting task of bringing to life a new and unique tourbillon caliber in less than 3 years, Messrs. Grimm and Beyner searched through Omega archives for ideas.  The team found their inspiration in three of Omega’s past achievements:  the “Les Montres des Sables” pocket watches, the Dinosaure, and Omega’s famous 30mm automatic movement.  The design highlights of these watches formed the basis of P33:

Tourbillon in the centre:
In 1985, new technical and symbolically artistic exploits of Dominique Loiseau, the “Les Montres des Sables” were presented at the Basel Fair. The so-called “Sand Watches” was a collection of six uniquely complicated pocket watches built around a mobile, floating tourbillon cage, placed in the centre of an extra-flat movement, all sculpted and decorated with sand dune themes symbolising desert civilizations. These watches are now in the Omega Museum.


Figure 1: Set of “Les Montres des Sables” © Omega SA



Figure 2: “Les Montres des Sables” movement © Omega SA


The magic or mystery hands:
The use of classic hands was impossible because the central tourbillon occupies the place where hands are normally fixed. The solution was ‘hands’ that are etched on sapphire discs. In 1980, the "Dinosaure" watch (cal.1355), an ultra-slim analogue quartz model (1.48 mm) was introduced with the movement integrated in the case back and a transparent dial on which the hands appeared to float.
[PuristS’ Trivia] Prototypes and some collectors’ pieces were even thinner at 1.35 mm but the movements kept breaking during testing.



Figure 3: “Dinosaure” movement © Omega SA



Figure 4: “Dinosaure” watches © Omega SA


The movement diameter:
In tribute to the famous timing results of the 30mm calibres and of the first Omega Tourbillon (calibre 30I), the new Central Tourbillon movement also has a diameter of 30mm.



Figure 5: Cal. 30I Record Holder 10595933 © Omega SA



Figure 6: Disassembled tourbillon cage Cal. 30I © Omega SA


Technical Challenges

Flying Tourbillon:
Omega decided to build a flying tourbillon to reveal the full beauty of the tourbillon and for the proud owner to observe the escapement at the work.
The flying tourbillon was invented by Alfred Helwig in the 1920’s and is a further development of the classic Breguet construction. Omega uses a special developed ball bearing with 5 ruby balls. To reduce the play in the cage, several sizes of ruby balls could be selected in production; the variation between consecutive ‘sizes’ was only 2 microns.



Figure 7: Bridge screw, ruby balls and stud screw © Omega SA



Figure 8: Case and Platinum Oscillating Rotor © Omega SA
The case is of ‘monocoque’ construction; there is no case back on the watch – the encasement is done from the front.



Figure 9: Sapphire Discs © Omega SA
The two sapphire discs indicated the time; so the case is a functional part of the movement. The hands are not mounted on the movement but into the case.


The final solution devised by the Omega’s technical department was elegant, sophisticated, and unique.  The gearing for the plates (the clockworks) was moved to the periphery of the dials into the sides of the watchcase.  This mechanism was modified from the “Montres de Sables” pocket watches.

Since the traditional position for the center cannon-pinion and time indicators was now occupied by the tourbillon, engineers updated the ingenious display mechanism from the Omega Dinosaur.  The hands of the central tourbillon were etched onto thin sapphire crystal disks that rotated on top of one another to display the minutes and hours.

The escapement was constructed with a solid gold balance wheel and a blued Breguet balance spring with a Phillips overcoil.  The seconds’ indicator was shaped into the Omega symbol and incorporated onto the tourbillon regulator as well.  By using a cage constructed of lightweight titanium, the 41-component tourbillon assembly only weighed 0.46 grams; the balance wheel alone weighed 0.20g. The lightweight tourbillon and a platinum rotor mounted directly into the caseback for ideal mass and winding efficiency both contributed to achieve a final power reserve of 45 hours.



Figure 10: Cal. 1170 prototype © Omega SA



The completed automatic central flying tourbillon design consisted of over 320 individual parts and Project 33 was renamed ‘caliber 1170’.  Three years of product development transpired before Omega’s caliber 1170 was patented and successfully brought to production.  The technical team successfully completed its mission and the watch was presented at the Basel Fair in 1994 to commemorate Omega 100th year anniversary.



Figure 11: Geneva Wave © Omega SA
Putting the Geneva Wave decorations on the main plates


Figure 12: Beveling tourbillon cage © Omega SA


Omega spared no expense on the appearance of their commemorative tourbillon.  Cased only in precious metals, the central tourbillon had a solid gold dial with hand guilloche using traditional methods. Some models even had jeweled bezels and bracelets!  Omega created a new ‘Haut de Gamme’ department specifically for the production of this new timepiece.  Staffed with only two master watchmakers, a total of 39 watches were completed from 1994 to 1998.  This actual number was far less than the anticipated initial production rate.
[PuristS’ Trivia] The first-generation central tourbillon watches are recognized by the bell-like sound of the oscillating platinum weight that was amplified by the watchcase.


Figure 13: Omega Central Tourbillon © Omega SA



Figure 14: Jeweled Bezels and Bracelets © Omega SA



Figure 15: Jeweled Bezels and Bracelets © Omega SA


Continuing Development History



Figure 16: Cal. 2600A front © Omega SA



Figure 17: Cal. 2600A back © Omega SA

In 1998, the first modification of the caliber 1170 was made.  To eliminate the rotor noise, the platinum weight was no longer mounted into the caseback but was attached to the backside of the movement employing a slide bearing with two jewels.  This new movement was designated the Cal. 2600A and only twenty were produced from 1998 to 2002.
[PuristS’ Trivia] A variety of engraving patterns on the Cal.2600A tourbillon base without standardization were used.



Figure 18: Cal. 2600B © Omega SA
In 2002, a major facelift was done and Omega began to expand its ‘Haut de Gamme’ department.  Designated caliber 2600B, Omega incorporated a new tourbillon cage and recalculated the Phillips overcoil in the Breguet hairspring used in the escapement.  The monopiece index was replaced by a double-piece index and the ‘Omega’ sign of the cage was adapted. The movements are assembled and regulated by Omega and then sent to COSC Bienne for the chronometer tests. A new dial design gave an updated look and the hand engraved pattern on the tourbillon base was standardized as a sunburst pattern. A bridge replaced the retaining plate of the intermediate wheel.
[PuristS Trivia] Due to its special shape, this bridge is called ‘Penguin’ within the “Haut de Gamme” department.
Cal. 2600B is still in production today (April 2007).



Figure 19: Cal. 2633A skeleton movement © Omega SA
In 2004, a skeleton version of the Cal. 2600B was presented. The technical characteristics are identical but all bridges and the mainplate are skeletonised and engraved by hand. The skeleton Cal. 2633A is still in production today (April 2007).
[PuristS’ Trivia] Engraving pattern on Cal. 2633A is called ‘Paving Stone’ within Omega.



Figure 20: Skeleton Omega Central Tourbillon © Omega SA


Also in 2004, a ‘piece unique’ based on the Cal. 2633A but with a Singapore flag on the oscillating weight (Cal. 2634A) was produced.

By 2007, the ‘Haut de Gamme’ department at Omega is headed by Mr. Cyrano Devanthey and the seven watchmakers produce approximately 50 tourbillon watches per year. Without a doubt, the caliber 2600B has been the most expensive and technically challenging movement to construct in Omega’s vast inventory…until now.

In Part 3 of this series, we will present a dissection and analysis of the new Coaxial Central Flying Tourbillon!

More Trivia
All Central Tourbillons:
Have a power reserve of 45 hours.
Have a frequency of 3Hz (21,600 A/h).
Are water-resistant up to 30 m.
Have a solid gold hand guilloche dial (except the skeleton version which has a sapphire dial).
Have a 950 platinum oscillating weight


To be continued in ‘Omega Central Tourbillon – Part 3…

The authors acknowledge the kind assistance of the ‘Cellule Haut de Gamme’, Museum and Press Office of Omega SA with the preparation of this article. The copyright of archive photographs from Omega SA is acknowledged and annotated. Other Article-specific Text and Photographs Copyright are assigned to , 2007. All rights reserved.

This message has been edited by MTF on 2007-04-15 10:00:06 This message has been edited by MTF on 2007-04-19 10:20:52

More posts: Ballon BleuCalibresFlying TourbillonMuseumSpecialities

  login to reply

Comments: view entire thread


What a report, gentlemen. This is going to become. . .

 By: Jack Forster : April 15th, 2007-16:21
. . .a reference benchmark which journalists and enthusiasts alike will return to again and again. Thank you; a great read; now if only I could afford for my interest in observatory tourbillons to be something besides Platonic . Jack

Michael, Melvyn and Suitbert, thank you so much

 By: Valentin Blank : April 16th, 2007-23:13
for this second part, which was just as exciting to read as was part 1. By the way, I have never seen the jewelled version as shown in fig. 15. Although normally I don't like jewelled watches (and would never wear them) this one looks surprisingly clean a... 

fantastic post

 By: SteveH : April 17th, 2007-14:16