Perhaps emboldened by the very positive reaction at BaselWorld 2003 for their new UR-103, the Baumgartners paid a visit to the Harry Winston booth and introduced themselves to managing director Max Büsser. While it may well have been a spur of the moment friendly social call, the Baumgartner’s were aware that Büsser was a good man to know. The brothers were well acquainted with Vianney Halter: in fact they had acted as sponsors for Halter’s candidacy into the AHCI a few years before; Halter and Büsser were behind the mind blowing Opus III.

Further discussions with Büsser followed in Geneva and both parties' interest in collaboration grew. Büsser wanted to alternate a ‘crazy’ Opus model with a more traditional one. Vianney Halter’s Opus III was as zany and crazy as they come; Christophe Claret’s reversible Opus IV, with tourbillon, cathedral gong minute repeater, date and a huge central moon phase was a traditional model (in what other series of watches but Opus could a watch like that be called traditional?). Büsser was on the look out for someone who could think ‘outside of the box’ and create the Opus V.

By the middle of 2003, Büsser decided URWERK had all the qualities he was looking for. URWERK put three initial proposals to Harry Winston; the first was considered too risky technically to complete in the time frame available (however, elements of the project may see light of day in the future); the second had the time going past on a type of continuous band; the third showed the little cubic satellites and this was the one chosen.

When the satellite proposal was agreed, various configurations were considered. Notice anything special on the case above?

Frei drew up further sketches on the satellite theme and finally the layout of that radical system was agreed. Büsser had stressed that central to the Opus series was the merger of the DNA of Harry Winston and the independent watchmaker. Feeling that the satellites represented URWERK, they consequently searched for a complication to represent Harry Winston. As Harry Winston is well known for its use of retrogrades, the idea of a retrograde minute soon emerged– a decision Baumgartner nearly came to regret!

Suggestions and proposals flew back and forth and by the end of the year the final design was agreed. The end result was very much a partnership with Harry Winston contributing essential design elements to the case: including the crown cover and the back of the watch.

The technical drawings take shape.

URWERK and Harry Winston now had just over twelve months in which to turn a technical drawing of something never dreamed of before - let alone constructed- into a functioning and reliable timepiece.

The satellite system The retrograde minute - easy on paper!

Here URWERK’s relationship with Christian Gros more than proved its value. Thomas Baumgartner had decided to go back to a quieter life in Schaffhausen and Felix, looking for a new atelier, moved into some spare space at Gros’ workshop. Having a world-class case and parts making precision Christian Gros (left) with Felix Baumgartner (right).
machine shop virtually ‘on tap’,
was vital to the quality and punctuality of the final product. Anybody under the impression that the use of modern CNC machines makes manufacturing parts child’s play, may be surprised to learn that just programming, tooling, setting up the CNC machine and making the 100 base-plates for the movement, took a team of three nearly three months. And that was for just one part!

Once the technical details of ensuring that operating the Geneva crosses on the satellites at 90 degrees to the norm was worked out, the satellite system progressed relatively smoothly. Baumgartner invented an ingenious and simple solution (now patented) for operating the satellites with Geneva crosses; the satellites function as their own cross!

The retrograde minute on the other hand proved much more troublesome. Retrograde mechanisms are traditionally controlled from their center axis; in the case of the Opus V, the center of the retrograde was occupied by another complication – the satellite system. Baumgartner knew of no other retrograde mechanism that dealt with another complication in its center and, therefore, had no Model to test functionality of the satellite system.
technical reference to go by. This was breaking completely
new ground.

Click here for an animation of a standard retrograde function (bottom center symbol). Courtesy of MontresPassion

Baumgartner had already solved the problem months before . . . on paper that is. The minute hand would be attached to a large diameter, precision ball-bearing circling the satellite system and powered by a double star. The problem was that specialist micro- bearing manufacturers told him repeatedly that making a large diameter ball-bearing with such a thin cross-section was impossible. Impossible? The word isn't in Baumgartner's vocabulary.

From a design sense the minute hand is on the left of the hour indications for a number of reasons; technically it makes sense on the left; aesthetically it helps to balance the visual weight of the hour satellites on the right; thirdly, URWERK's research showed a strong preference for time indicators moving in a clockwise direction. Placing the minute hand on the left allowed URWERK to fulfill all three criteria.

The bearing which circles the satellite system. This unfinished prototype has the minute hand attached.
The small double- star inside the bearing transmits power
to the satellite system and to the retrograde minutes.

Eventually Baumgartner found someone who managed to develop the techniques to make the bearing. However, when it was trialled in a prototype, he found that the 12mm (1/2”) traction spring which returns the retrograde - itself a non-traditional solution - was too strong; this caused large variations in torque across the arc of the minute hand and used far too much energy overcoming the spring. The solution was to make a spring with a smaller diameter wire, however, they were already at the limit of the possible with a minisucule cross-section of 0.1mm (100 microns). He experimented with ever decreasing wire diameters until he obtained the characteristics he needed at 0.05mm (50microns), or half what was previously thought to be the bottom limit. Unfortunately, to get those perfect springs meant throwing away 90% of them. Obtaining the traction springs needed for the 100 Opus V watches, necessitated testing each one of a 1000 springs and rejecting nine hundred of them.

Note. To put the diameter of the 50 micron wire of the traction spring in perspective, the average human hair is 70-100 microns.

Felix Baumgartner - " Less than two months before Basel I was still not sure if I would be able to have these traction springs made to the specifications I needed. I was certain that the movement would work; however, there were a couple of little doubts at that stage if it work in time.

The 12mm traction spring beside a paper clip Stretched giving an idea of the minuscule diameter.

The painstaking effort was worth it, because the retrograde mechanism ended up using only 15% of the movement’s power. This, coupled with incredibly tight tolerances and precision in the manufacture and assemble of parts, resulted in the watch having a five day power reserve. There are not many relatively ‘simple’ watches around with a five day power reserve, let alone one with a complex three dimensional satellite system turning over two axis, an extremely large retrograde minute (possibly the largest ever made) moving over 120 degrees, a day/night indicator, a power reserve indicator, and a service interval indicator. This is a truely incredible feat and testament to the quality of design and construction.

Three specially shaped springs under the satellite system not only permit the whole system to be turned counter clockwise without damage, they also permit the deliberate playful bounce of the minute hand when it returns to zero.

The back and front of the satellite system. On the left image you can see the three springs in between the hour
cubes. They allow the satellite complication to rotate in reverse and bounce the minute hand on its return to zero.

The ARCAP P40 movement baseplate after micro-blastingThe back of the minute hand and its bearing

The ARCAP P40 movement plate before (left) and after microblasting. To simply machine these 100
baseplates, took a team of three nearly three months. That includes programming the CNC machine,
making the necessary cutting tools, producing prototypes and then the 100 pieces for the series.

That does not include finishing!

The case starts from a cast block and is then machined to look like the unpolished case on the right

Notice just how complicated the case shape is.

VIDEO ! Click on the image above to see how the CNC machine makes the plate.
In reality it takes over 90 minutes to machine each piece. Warning-file size 7.8mb !

Sébastien preparing the satellites (left) and then assembling the satellite system.

After over nearly two years of work, seven fully functioning and finished production models were finished and presented at BaselWorld 2005.

VIDEO ! Click on the image above for a video of the Opus V in operation. (Warning-file size 4.8mb)

At BaselWorld, I was very fortunate to have a chance to examine a few Opus Vs under a 30X stereo microscope. Staff cringed when they saw the microscope come out - usually with good reason - and those at Harry Winston Fine Timepieces were no exception. To everybody's surprise, however, including my own, the finish of the Opus V was found to be absolutely flawless at that high magnification. Both the technical and aesthectic execution were nothing less than superb.

Vianney Halter - "When I first saw the Opus V at the HW booth, I could not resist turning it in my hands and playing with it for at least 20 minutes, which happens seldom. No doubt, at Basel 2005, Felix’s watch was the one which impressed me the most."

Peter Speake-Marin - '"My first impression on seeing the Opus 5 was that of a logical and perfect conclusion to the series. In my opinion the most stunning of the collection by a very gifted independent watchmaker."

Volker Vyskocil - "I found the Opus five to be an extremely artistic combination of art and technic. It appears that the watch is capable of hypnotizing and transferring the mind to a level where time is not really the most important unit . . . a trait rarely seen in a timepiece."

Once again we have to thank Max Büsser from Harry Winston Rare Timepieces for having both the foresight and confidence to give horological stars as Felix Baumgartner and the other Opus constructors the opportunity to shine. Let us hope that the Opus V, said to be the last Opus, is only the last in the Opus series . . . until the next one.

Whether or not the Opus series is permanently laid to rest, and Büsser himself has hinted that the door on Opus is closed but not locked, I very much doubt that he will be satisfied with producing 'ordinary' traditional complications. With or without Opus, I have a feeling that will be seeing some very innovative and interesting watches from Harry Winston Rare Timepieces in the not too distant future.