ThePuristS Interview Kurt Klaus,
International Watch Company,

about the new Portuguese perpetual calendar

by AlbertoS

© May 2003


AlexG, Clément and myself took advantage of this year's SIHH to meet with Mr. Kurt Klaus in Geneva and talk about the new IWC Portuguese perpetual calendar. Mr. Klaus, who is officially a retired IWC employee, is still quite active in the company, and has actually been one of IWC's technical pillars for several decades now!

Who could therefore be better placed to speak about this sensational new watch than the man who singlehandedly invented one of the most ingenious perpetual calendar systems around, thus putting IWC back in the spotlight after the crisis of the quartz years?

I am very grateful to Mr. Klaus for having taken time out of what I know was a very busy schedule during the first few days of the show, and also for having shared with us what you will surely find to be a truly fascinating story about a man, a company and an idea...

What follows is an almost verbatim transcription of the discussion we had with Mr. Klaus in the morning of 9 April 2003, with limited editing having been done to improve readability.

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(Mr. Kurt Klaus - International Watch Company)

The Interview

TP: Mr Klaus, could you please tell us how the new Portuguese perpetual calendar came to be?

KK: Well, to do that I should first tell you a bit of the story behind this new product, and explain the way we work in our development department. But to explain this, I have to go back about twenty-five or twenty-six years...

That was a very hard time for the watch industry: quartz watches were on the rise, and nobody thought that mechanical watches had any chance to resist them. At that time IWC was also having a very hard time, and we were only working four days per week. As on the fifth day I was working for myself, and since in that period pocket watches were very popular, I thought of designing some sort of calendar function onto a pocket watch.
At the time IWC had no complications - they were only making normal watches indicating the time, sometimes with a date indicator - so I started to create a calendar. It was not a perpetual calendar, but was a very simple calendar indicating the date, the month, the weekday and the moon phase - of course, a moon phase with an error of one day after three years. It was nothing perpetual! (smiles)

Once I made this movement, IWC management said: "yes, this could be an idea", and from then on I was no longer working on my free time, but there was an official IWC project to make this pocket watch. We presented the watch at the Basel fair in 1976, and its success gave us some motivation to continue. We said to ourselves: "yes: the mechanical watch can still have a chance, provided that it has some complications".

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Accuracy was not a question - any cheap quartz watch was much more accurate than the best IWC mechanical watch, but we had to make them with complications. So we continued with that pocket watch, then with a pocket watch with one hand indicating the twelve zodiacs of the year, and many other things until the end of the 1970s. Then, practically from one day to the next, nobody on the street was asking for pocket watches anymore. They were finished, and everyone was only asking for wristwatches. I think we made the last pocket watch perhaps in 1978 or 1979, but these were no longer successful. The important thing, however, was that I had made a calendar system onto a pocket watch movement, and because we had no developing department at the time, I had done this alone. I was the designer of the movement, I had made all the prototypes, and for a time I was also working on the first production series myself. For instance, at the time, I made a few hundred skeleton movements of this watch.

But I had no possibility to create a new movement. Of course it was not impossible to create a new movement, but it would have required many millions we did not have. So was born the idea to take something we had, and to build something new onto that product. Today we call this "systems engineering", but it was basically the same approach then. It is actually with this idea that I could tell that our "systems engineering" at IWC was born.

Then, in the beginning of the 1980s, we had to switch from pocket watches to wristwatches. Management told me to make a wristwatch with a calendar, and I said: "Ok, now I have some experience to design calendars. But this time, if I create a new calendar, it should be something new: a perpetual calendar." Everybody thought that this was good, but all other brands already had perpetual calendars in wristwatches. So I started thinking of what I could do to have a success against all these other products already on the market.

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At first, I studied the other products to see how the other brands had made their perpetual calendars: not to make a copy or to know how I should design it, but to know what I should not do! The first things I saw which I didn't like were all the pushbuttons around the case, which I thought were complicated for the user. You had to set the date, then the moon phase by looking in an agenda to see where the moon was, while I wanted to so something easier to use, easier to design and easier to produce.

So I worked for three and a half, almost four years to make this calendar, once again working alone. There still was no development team, and I made my prototypes, some of the wheels myself, etc. Of course, I was not building a new movement - instead, as I had done before, I started to construct this calendar onto an existing automatic movement. As we did not have an in-house automatic movement at that time (actually we had a very thick one, but it was too thick to make a perpetual calendar), I used a Jaeger-LeCoultre automatic movement.

TP: Which one did you use, the 889?

KK: Yes, the 889. Then the president of IWC, Günther Blümlein, said that a perpetual calendar would be good, but that we should do more: "I want you to build this perpetual calendar not onto an automatic movement, but on our chronograph movement. "So I started again, because I now had to adjust the indicators of the calendar, of the date, and of the weekdays into the positions dictated by the chronograph. It was not completely a new start, but I had to transform what I had already done.

Günther Blümlein wanted to build it onto a chronograph because he felt that we had to do something more than all the others. My idea to make it simpler to use than all other perpetual calendars was ok, but it was not enough! And at that time there was no chronograph with perpetual calendar on the market.

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TP: How long did it take, from the day when you were first asked to develop this perpetual calendar, until the day you considered it ready?

KK: It took about four years, initially not working on it every day, but towards the end I was working full time on this calendar. Of course I was working without any computer system: as there was no CAD, I made my drawings with a pencil. I had a small pocket calculator and I had all trigonometric functions in the brain (laughs). Because of this I was constructing all the systems by trial and error.

TP: Those four years also included the time it took you to adapt it to the chronograph base?

KK: Yes, that decision was taken just at the beginning of the project. First, I had the idea of the perpetual calendar, then I made some drawings of how it could be made, and finally we had the idea to do it on a chronograph movement. It was the unforgettable Günther Blümlein who thought of this. Again, I was working alone, as nobody quite believed that this would become a real product, except Günther Blümlein. Towards the end of the construction process, in 1984, he came to my office every morning, asking me: "How are you? Is it good, yes? Continue!" And so he gave me all the motivation to actually do it, because it was hard work: I had to build all the prototypes and make the small parts practically by hand as there were no electro-erosion machines, etc.

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By the springtime, one morning at 5 o'clock in April 1985, I finally finished the first three DaVincis! That was a hard day and night. In the evening, I drove to a city near Bienne called Grenchen, where was the printing company which was making the discs for the year indicators. I needed those discs, and when I arrived there they were not quite finished baking in the oven to fix the print, so I waited. When I was finally able to take them, I went back to the factory, and at 11 in the evening I started to set them in the first DaVinci movement. By 5 o'clock three pieces were finished, and by 8 or 9 in the morning those first prototypes were in Basel. That was the first day of the 1985 Basel fair, and of course the DaVinci chronograph perpetual calendar, with the most accurate moon phase indicator of its time, was the big sensation of the fair.

TP: How did you feel when you saw that people were giving such wide acclaim to this watch?

KK: I felt tired! (laughs) But afterwards I was not so enthusiastic, because I knew that this was just the beginning. The prototypes were working, but then I had to help start the actual production. Fortunately this was not so bad: the Basel fair was in April, and I think that more or less in August we delivered the first DaVincis.

TP: That was very quick!

KK: Yes, it was very fast. (smiles)

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TPS: Why did it take so long for IWC to combine its two biggest hits by putting this perpetual calendar in the Portuguese case, especially given the success which the latter has had in the past?

KK: Well, the Portuguese came after the DaVinci. It was originally made in the 1940s, and in 1990 or thereabouts somebody came to IWC wearing one of the old Portuguese watches on his wrist. We all ended up around him, saying things like: "oh, this is a nice piece," and "we should make a new series of this Portuguese watch." So we decided to make it in a limited series for the anniversary of IWC in 1993. A limited series of 1750 pieces, made exactly the same as in 1940, and using the same movement.

This is something unique of IWC. We have three pocket watch movements designed in 1930 -1935, and all three are still in production today, with only one modification: about 25-30 years ago, we added the Incablock shock protection to them.

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TP: And how are these pocket watch movements being used today?

KK: Well, we use them in pocket watches, as we still have a very small pocket watch production, and in the Portuguese minute repeater, for instance - that is a pocket watch movement.

So first there was the DaVinci, then in 1993 there was the Portuguese, which was a big success but was limited, and we wanted to continue with the Portuguese. So, two years later we made the Portuguese chronograph rattrappante and the automatic winding chronograph, we had the idea to design a complete new automatic movement in the size of a pocket watch. I put it by IWC's management, and eventually Günther Blümlein told me to start working on it.

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TP: Why did you choose to adopt the Pellaton winding system at that point: was it just for historic reasons, as it was a traditional IWC system?

KK: Tradition was one of the reasons. The Pellaton winding system is like a symbol: every good watchmaker in the world, seeing it, is able to say: "this is an IWC." But there were also other reasons.

It was first made in about 1950, and whenever we had to repair old watches from the 1950s and 60s in our after sales service, we have never had to replace any part of the winding system. So I said to myself: "why should I invent something new when we already have the best automatic winding system in the world?" So it was chosen not only for tradition, which is one part, but more importantly for the quality of the system. We had produced automatic watches using this IWC system until 1985-90, and we decided to use exactly the same parts as in the last automatic calibres we had made.

We first used it for the Portuguese 2000, and then management wanted to make a big pilot watch using the same movement, so we added - not me but WE, because by this time there was a real development team - the date indicator to this movement. At that time, once we added the date indicator into the movement, I had the realisation that the way was now free to set a perpetual calendar on top of it.

This was because 20 years ago, when I was designing the perpetual calendar for the DaVinci, I used the same parts of the date indicator - the 24 hour wheel and the rapid corrector system - and this idea made it possible to have a rapid correction system in the DaVinci using only the crown. So, when I started to design the same perpetual calendar in the dimensions of the new caliber 5000, I did not have to invent something new: it was practically a copy of the DaVinci calendar, but 38 mm diameter.

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TP: And yet there is something quite new in this perpetual calendar...

KK: Yes. The date is the same as I used the same parts to move the date; the months and the year are a little bit different in their dimensions, especially the year Indicator; and the moon phase is the same.

Now, the accuracy in the DaVinci is off by one day after 122 years. This time, because the plate is bigger than the DaVinci, I had more room so I calculated a new number of teeth for the transmitting wheel of the moon phase. This is how I arrived at the better accuracy of 577 years, which means one day of deviation after 577 years.

TP: This is the most accurate moon phase on the market today...

KK: Yes, and the most accurate ever in a perpetual calendar. The only one with a better accuracy is the Lange und Sohne 1815 moon phase. So first I started to say that it is the most accurate in production, and today I like to say that it is the most accurate moon phase in a perpetual calendar. (smiles)

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Initially I made a traditional moon phase, and a few movements were produced with this in a limited edition made for Cellini. This is a traditional moon phase, which looks the same as the DaVinci and all other moon phase indicators. Then, only a few months ago, the designer who was designing the dial and the case said: "this is the moon phase we have had for 100 years, and every brand has this moon phase. We should do something new."

So he came to me with the idea of making a rotating disc with a hole, over a black moon on a plate. I said: "you are crazy, how will this disc rotate? We need a wheel to make this disc move." I thought about it all day and night, and then I went back to see him and said: "ok, I see a solution to do it." So a few months ago we changed the moon phase to this system, with just one hole. Then someone said: "why just one hole? We could make two holes and have two moons, and it would look different."

TP: Did you have the idea of developing a perpetual calendar plate for the caliber 5000 from the very beginning?

KK: The idea came when we just started developing the new movement, the caliber 5000. We also developed the date indicator in the beginning, but we did not produce it until later so that we would have something new for the pilot watch. At the time, I also thought that through this disc it would be possible to create the same perpetual calendar as with the chronograph movement for the DaVinci. So we had the idea from the very beginning, but I only started to design it two or three years ago.

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TP: Did you have to make big modifications to the calendar plate to adapt it to the Portuguese, for example to be able to display the two moon phases in this new fashion instead of the traditional one?

KK: Not to the moon phase mechanism itself. The moon phase mechanism is exactly the same as in the DaVinci, so we could go back to the traditional moon indicator if we wanted it... but of course we don't want to! (smiles) And I wanted to preserve the most important and delicate pieces from DaVinci calendar, such as the date changing lever and the months disc - these parts I took from the original DaVinci, and they are the exact same parts in both calibers.

But the distance between the day and the month indicators was bigger, and I had to set an intermediate wheel to compensate for the distance - I actually needed to add two wheels to keep the indicator turning in the same direction. The distance between the weekday and the moon phase was also bigger, but I did not add another wheel, and instead made a different, bigger one - so quite automatically I achieved this new accuracy! (smiles)

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TP: Are there any other developments around the Pellaton system planned for the future?

KK: Yes. As I said, the Pellaton system is an IWC tradition, it's technically the best, and I think we should continue with it.

TP: Will you introduce a new, smaller auto winding calibre then?

KK: Yes, of course. We must do it in the future. It is a possibility, and I think this will be the trend.

TP: Compared to the other Portuguese watches, this one is larger - is this due to the use of a sapphire glass instead of a plexiglass? Was the choice of using sapphire made because people complained that the Portuguese 2000 used a plexiglass?

KK: We often have the same problem also with the DaVinci. People say that such an expensive watch should not come with a plexiglass, so we can set a sapphire glass on the DaVinci if the customer wants.

This is why this time we said - not me but the whole team together - that we should stop using plexiglass for these special watches, and use sapphire glass instead. To do this, we had to make the case a little bit thicker, and to keep the proportions we also made the case a little bit larger.

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TP: Could this movement have enough torque to also power a chronograph?

KK: There is no plan in our team to develop a chronograph on the caliber 5000 base. But we have a lot of other ideas for this base...

TP: Indeed, one of the things which seems to be obviously missing from the Portuguese line is a tourbillon watch... will we maybe get to see one sometime in the future?

KK: (pauses) What is a tourbillon? (smiles)

TP: Mr. Klaus, thank you very much for having told us the wonderful story behind IWC's perpetual calendar movement, both that of the original one developed for the DaVinci and that of its latest incarnation, the gorgeous Portuguese perpetual calendar.

KK: For IWC it is important that behind each product there is a history. There is the history of the Portuguese watch, the history of the pilot watches delivered over 60 years ago to real pilots, and today you can see that also the DaVinci has a history!

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