OFFICIAL JOURNAL OF THE BRITISH HOROLOGICAL INSTITUTE

MARCH 2019www.bhi.co.uk

100 HOROLOGICAL JOURNAL March 2019

Christophe Claret Celebrates 30 YearsHistory of a Master Watchmaker

Martin Foster FBHI

hristophe Claret made his first career move over 30 years ago in 1988 when he teamed with Dominique

Renaud and Giulio Papi, two watchmakers who joined with him in doing high-end restoration work. It was a horological genesis from which he has created an auspicious history worth celebrating in an industry requiring precision, perfection and performance, side by side with those who can make it happen. Claret is one of these special people, Figure 1.

Born into a wealthy, well-established family in Lyon, Claret graduated from the Geneva School of Watchmaking with honours in 1982 and spent ten months with Roger Dubuis, gaining hands-on experience with perpetual calendars. He took classes in corporate management, enrolled with the Chambre des Métiers in Lyon for a two-year training cycle and continued with significant personal research and development.

In 1987, Christophe met Rolf Schnyder, who had just bought the prestigious Ulysse Nardin brand and this marked the start of his career as a creative watchmaker. Schnyder placed an unprecedented order with the young Christophe, involving design, development and production of 20 minute repeater calibres with San Marco jacquemarts striking on a gilt bell. So Claret moved on from restoration work and began developing movements, a niche in which he became recognised and respected around the world. In 1991, he bought out Dominique Renaud and Giulio Papi and became sole owner of the business, which was renamed Christophe Claret SA.

As we know, Dominique Renaud and Giulio Papi went on to have successful careers together in their own right under the name of Renaud & Papi, makers of complications for the majors of the industry and a launch pad for other serious emerging horological talents such as Robert Greubel and Stephen Forsey. It was indeed an interesting time of development for those in the industry whom we all recognise today as the complications pacesetters.

In 1999 Claret acquired the Soleil d’Or, a magnificent mansion formerly owned by the watchmaker Urban Jürgensen and perched on the heights of Le Locle, Figure 2. Within a few years, he transformed it into one of the world’s cutting-edge watchmaking facilities. Here on site, he united all the relevant professions involved in the design, development and production of movements including other parts of the watch, including cases. Additions were made: annexes of 500 and 1000 square metres in 2002 and 2008. Then in 2009, to mark the twentieth anniversary of owning the building, he launched a concentrated mechanical ‘blend’ of the full range of the company’s skills. Named DualTow, this timepiece strongly ref lected Claret’s watchmaking philosophy: a single-pusher

Figure 1. Christophe Claret in 2011, aged 50, in the foyer of Soleil d’Or, formerly owned by the watchmaker Urban Jürgensen.

Figure 2. The Soleil d’Or mansion in Le Locle, bought by Christophe Claret in 1999 and fitted out as a precision manufactory for the production of his branded complication watches.

C

planetary chronograph and tourbillon combining technical excellence with complex aesthetics, Figure 3.

DualTow became a turning point in Claret’s career, a milestone that he wished to symbolise with an exclusive timepiece produced and distributed under his own name by the finest retailers.

In 2011 he produced the Adagio watch in Geneva, featuring a dual time-zone with day/night indications, large date and a minute repeater with cathedral gongs. In the same year he exhibited the Blackjack at Baselworld: it is a genuine miniature casino, on which one can play dice, roulette and, of course, blackjack. This timepiece marked the moment of finally emerging from the shadows of bespoke manufacture for the big brands to the official launch of Christophe Claret as a brand in its own right.

101March 2019 HOROLOGICAL JOURNAL

Figure 4. Margot is Christophe Claret’s first ladies’ watch complication. It features an ingenious mechanism that helps to ‘predict’ one of nature’s paramount questions: “Does he love me?”

Figure 3. Christophe Claret DualTow, a single-pusher chronograph with chrono levers disposed all around the column-wheel; with strike mechanism, tourbillon and a belt-type hour and minute display. Made for a short time from 2009 after establishing the brand.

Claret’s expertise, combining respect for tradition and freedom to create, is crystallised in four lines of ‘Complications Watches’: Traditional, Extreme, Interactive Gaming and Ladies, covering concepts such as tradition, modernity, gaming and femininity. In 2012, Claret’s new Baccara – another miniature casino – continued his horological innovation in playful, interactive timepieces. Also in 2012, he produced the X-TREM-1, with a magnetic system to display hours and minutes. These were followed by the Soprano watch, a new model associating two of the finest horological complications: a 60-second tourbillon and a minute repeater with a Westminster chime, four cathedral gongs and four hammers.

Then in 2013 came the Kantharos. This mono-pusher, automatic-winding chronograph comes with striking mechanism and going-train remontoire. Its cathedral gong, visible at ten o’clock, chimes with each change of function. 2014 brought Poker, the latest addition to Claret’s trilogy of gaming watches. Maestoso followed: a wristwatch with a traditional detent escapement, which is usually designed to run in a perfectly stabilised position as found in the marine chronometer. Then came Claret’s Margot, an elegant and romantic ladies’ timepiece, Figure 4. Following Adagio from the ‘Art Piece’ range, Claret presented Allegro with many fine horological complications: a minute repeater with cathedral gongs, GMT, big date, small seconds and day/night indicator.

In 2016 Claret participated for the first time in the Salon International de la Haute Horlogerie (SIHH) in Geneva, in the Carré des Horlogers, an area of the exhibition space separate from the big players, dedicated to smaller niche producers.

The Maestro, with a seven-day power reserve, cone-shaped large date display, a 3D ‘memo’ function and a €52,000 (£40,400) price tag, came along in 2017. For 2018, Claret added aesthetics to it by unveiling the elegantly beautiful Maestro Mamba, which features a snake within the watch, Figure 5.

Figure 5. The Maestro Mamba with a three-dimensional Mamba snake entwined through the movement.

This year, Christophe Claret is celebrating a double anniversary – the 30th of his watchmaking facility, and the tenth carrying his name brand – by enriching his growing collection of complication watches with a limited edition model, the Angelico. Justin Koullapis reviews this quite amazing watch in depth on page 102. It is a fine way for Claret to claim his place high up in the innovation stakes of this industry and affirms his dedication to high precision, perfection and performance.

102 HOROLOGICAL JOURNAL March 2019

Justin Koullapis HonMBHI

s one might expect from a mature watchmaking enterprise with most processes carried out in-house (what the Swiss

love to call ‘manufacture’), Claret’s production facilities are replete with a large range of facilities and equipment. There is digital design, multi-axis CNC milling for machining base-plates and other shaped components, pinion production, hobbing, centreless grinding and burnishing of pivots, Swiss sliding-head lathes with automatic bar feed, heat-treatment, metrology, etc. Figures 1–4.

When faced with making complicated shapes in f lat material, the manufacturing horologist typically has a number of options: cutting/abrasive processes like milling and grinding, blanking, water-jet cutting, wire erosion, and laser cutting. Very small items like escapements may be made using etching or ‘growing’ methods like DRIE or LIGA, but these are extreme specialities. In Christophe Claret’s case, plates and other parts with stepped or 3D features are produced by classic cutting processes, such as multi-axis CNC milling.

For f lat parts, he developed his own laser cutting technology, called Flashcut, Figures 5A and 5B. He cites speed of production as one of his incentives for its adoption: ‘Using laser technology, which is widespread in the field of aviation and automobiles, can accelerate the process by a factor of ten [over wire erosion].’

Claret continues: ‘We were the first in the watch industry to use laser power Flashcut machinery. We went ahead, even though this technology tends to be poorly regarded within our profession. We were right to do so, since 70% of components are now produced using these kinds of machine, which also boast a mere 0% to 3% wastage rate, which is an incredible performance in the high-end segment.’

After the machining processes are completed, parts move through many various pre-assembly stages, for example the insertion of steady pins into steel springs. There are also dedicated hand-finishing areas where traditional finishes such as bevelling, spotting, black polishing and graining are applied, Figures 6A to 6C.

After many stages of processing, all parts for a single watch are collected into a ‘kit’, which is then stored away under lock and key until it is ready for assembly, Figure 7. Assembly and final production are performed in smaller ateliers of around half a dozen watchmakers. The construction of a given watch is the responsibility of a single watchmaker, Figure 8. In one of the ateliers, the watchmakers chatted with us and showed us

A

Figure 1. Star Micronics Swiss-style sliding-head lathe, with bar feeder. In this type of lathe, machining is performed by a series of pre-set cutters positioned radially around the chuck. Cuts are all taken as close to the collet-style chuck as possible. Cuts can be taken while the material is moving forward, pushed through the chuck from behind. This requires high-precision ground blank stock, so that it can slide through the chuck whilst being turned.

Martin Foster and I travelled to Christophe Claret’s hillside headquarters in the town of Le Locle for an illuminating visit to a company whose impressive range of skills and manufacturing methods are all gathered under one roof. Vision and imagination are evident in accommodating so much contemporary horology within an ancient and historical manor house and its precincts.

The Christophe Claret AngelicoA Detent Chronometer for an Anniversary

some of the finer points of assembly of the Maestro Mamba, a watch whose technical points are rather overshadowed by a miniature vivid green snake coiling around the movement, See Figure 5, page 101.

They use an interesting helium-leak pressure-testing system during prototyping of watch cases, Figure 4.

Claret has strong form when it comes to complex mechanisms. His first commercial commission was in 1987 from Ulysse Nardin, for the production of 20 minute-repeating watches with jacquemart automata.

Since that time, he’s produced over 120 (mostly complicated) calibres and watches for 65 outside brands, including Arnold, Bovet, Bulgari, Corum, Daniel Roth, Franck Muller, Gerald Genta, Girard-Perregaux, Harry Winston, Jean Dunand, McGonigle, Parmigiani and Speake-Marin.

As might be expected, the watch he created for his double anniversary this year is technically very interesting and of a pronounced aesthetic style typifying his work, see Front and Rear Cover. I was able to examine the watch at SIHH this January. Dubbed the Angelico, it’s named after the pious Fra Angelico (born Guido di Pietro), a fifteenth-century Italian painter.

103March 2019 HOROLOGICAL JOURNAL

Figure 2. These turned parts, straight off the lathe in Figure 1, have a threaded end, a square, bearing shoulders and cut teeth.

Figure 3. One of the furnaces in the dedicated heat-treatment area.

Figures 5A and B. The Flashcut laser cutter was developed in-house by Christopher Claret. Vastly quicker than other production methods, this 6kW laser cutter takes only 27 seconds to cut out a tourbillon carriage plate, and no more than three minutes to cut out the dial of his Baccara watch, including its dragon motif, shown here. There is no need for any deburring.

Figures 6A–C. Some of the bevelling is done at these dedicated stations furnished with wooden polishing discs. After polishing and bevelling, some pre-assembly work is carried out, for example pressing posts into these steel springs.

Figure 4. Pressure-resistance of prototypes is tested with a helium leak detector. The watch case is filled with a specific isotope of helium. Any gas escaping from the watch is electrically ionised, and can be detected by the device’s internal mass spectrometer. It can detect leaks as imperceptible as a 1cc bubble escaping from a part in 1,050 years.

104 HOROLOGICAL JOURNAL March 2019

Figure 7. Christophe Claret shows a ‘kit’ of completed parts for a single movement; in this case the caliber EMT17 for the exquisite Margot ladies’ watch.

Figure 8. Each watch is the responsibility of a single watchmaker, who starts with the ‘kit’, who does all the final finishing whilst assembling, modifying and adjusting.

The watch incorporates a number of features which, although somewhat anachronistic, certainly lack nothing in their execution. There is a fusee, linked to the mainspring barrel by a high-tensile line. A six-minute tourbillon carries a pivoted detent escapement. Minutes are indicated by a bejewelled index that orbits around the edge of the movement, while a pair of jump-hours, for two time zones, are displayed near the lower edge. The time zones can be set independently using the pushers in the case band.

In addition to these headline features, the watch also hosts a raft of subtle technical aspects discussed in greater detail in the captioned boxes herein.

Needless to say, the Angelico is a superb piece of technical horology, certain to delight the collector who wants something very different. The company is said to have spent seven years developing the escapement, and a further year making it work in a tourbillon. Christophe Claret is undoubtedly one of the cornerstones of independent Swiss watchmaking. The Angelico is a watch definitely worthy of this important milestone in his timeline. Prices are CHF 238,000 for rose gold and CHF 218,000 for titanium (approximately £182,000 and £166,600 respectively).

Figure 9.

d

c

b

Figure 10.

e

f

Stop-Work

The stop-work is partly exposed, and at first sight appears to be of the Maltese cross type, but is actually an unusual geared arrangement, Figure 9. Normally, the cross itself blocks further advance after a certain number of lobes has been presented. In the Angelico, the cross, indicated at a, has a pinion fastened to it, b, and this in turn drives a free wheel on the fusee arbor. When fully wound, a protuberance on the face on this wheel (not shown) abuts against the dovetail face c, which is part of a protrusion d on the underside of the fusee cock. When fully unwound, the opposite dovetail face abuts. The wheel therefore does just under one revolution per cycle, whilst the fusee makes nine turns. The lobes and gaps on the cross serve only to drive it round and prevent motion between stations.

Once the watch is fully wound, excess torque by potential careless over-winding is dissipated by a simple clutch using a pair of sprung ‘Breguet-toothed’ wheels, e and f, the upper of which can slide freely up and down the squared fusee arbor, shown here from its underside, Figure 10.

a

105March 2019 HOROLOGICAL JOURNAL

Mainspring and Fusee

The watch uses a pair of mainsprings in parallel. In practice, there are two springs in the same barrel, separated from each other by a disc. The outer ends of both are fixed to the same barrel wall. Modern watches with two springs normally employ them in series, so as to obtain a ‘longer’ effective spring, and therefore a more even power delivery. Indeed, in his Maestro watch with a similar barrel, the barrels are geared such that the springs are effectively connected end-to-end. No doubt the Angelico needed a lot more power, hence the use of springs in parallel, Figures 11A and B.

They claim that there is less energy lost to friction by using a line (‘cable’ in Claret parlance) rather than a chain. Be that as it may, the line used here is a 0.18mm thickness high-molecular density polymer called Dyneema. It’s said to be able to lift 9kg.

The fusee delivers the drive to the great wheel via a concealed epicyclic train, shown here in cross-section, Figure 12. As a brief reminder, reversing the escape wheel on a detent escapement could be catastrophic. This ‘Sun and Planets’ epicyclic system automatically applies maintaining power, delivering a nett torque to the going train in the correct direction even when the fusee is being turned backwards during winding.

Jump-Hours Safety

Claret is particularly pleased with the fact that the pair of jump-hour displays operate absolutely instantaneously on the hour. In Figure 13 A snail g goes round anti-clockwise once an hour. Resting upon it is an arm h with a ruby roller at its tip. Centred over the arm’s pivot is the spiral spring. The arm rises progressively, and falls smartly under the action of the spring when the ruby passes the tip of the snail. The tail of this arm has two beaks, i and j; as the cam falls, it causes each beak to drive its respective star wheel forward (with hour disc attached) with a jumper completing the action. This all forms something of a feature at the rear of the movement. The levers k and l are for the wearer to alter the two hour indicators independently.

However, as those who are familiar with rack striking know only too well, unless arrangements are made, the minutes indicator cannot be turned backward past the hour without damaging the mechanism. In the Angelico, the drive from the set-hands work to the snail is via a train passing under the snail wheel and terminating in a wheel with internally-cut lobes shown at m, Figures 14A and B.

Co-axial with this, but not fixed to it, is an upper wheel n, carrying a pawl, shown in red, that engages with the internal lobes, Figures 14A and B. This upper wheel drives both the snail wheel for the hours and the large toothed ring carrying the minutes indicator. When the user sets the time, if m is moved clockwise the lobes drive the pawl positively and n along with it. When turned the opposite way, the pawl spring will permit the drive until extra resistance is felt from the snail meeting the dropped tail of the jump-hours device. The pawl spring will be overcome and the lobes of m will click freely without any further movement of the hours or minutes, thus preventing damage to the movement. Note that CAD drawings show springs in their relaxed state, which is why the u-shaped pawl spring, shown ghosted in Figure 14A, appears to pass through the pawl rather than resting on its crest.

nm

Figure 11A. Figure 11B.

Figure 12.

Figure 14A. Figure 14B.

Figure 13.

g

k

l

j

h

i

106 HOROLOGICAL JOURNAL March 2019

Next we consider the issue of amplitude-limiting. Without this, the balance might sometimes go round more than once on the same excursion, releasing the escapement a second time. Devices to prevent this have been used since the days of Arnold, although in most cases the effect was obtained by somehow limiting or sensing the expansion of the balance spring.* In Claret’s system, Figure 16, there is a loose collar, r, over the lowest part of the balance staff. It can rotate freely, independent of the balance. It has a flexible blade extending radially, s. Next, there is a pin, t, fixed to the underside of the safety roller, something like the impulse pin in a lever escapement.

As the balance goes round, the pin drives the radial blade ahead of itself. At the end of a normal vibration, the balance reverses direction, leaving the blade resting quietly behind. As the balance comes round from the other direction, the pin again meets the blade, at its opposite side. The pin leads the blade ahead again and so on.

* I am grateful for the assistance of John Griffiths, Jonathan Betts and Anthony Randall, in their discussions with me regarding amplitude control. Extensive details are described in Catalogue of Watches in the British Museum: Pocket Chronometers, etc, by Randall and Good, 1989.

** Gould describes a very similar system, but unfortunately does not illustrate it.2

ENDNOTES

1. Gould, R. T., The Marine Chronometer, its History and Development (London: J. D. Potter, 1923), p214.

Pivoted Detent Escapement

The escapement is similar to the one used in the brand’s Maestoso watch, said to have taken seven years to develop. For the Angelico, they have fitted it to a tourbillon, which took an additional year, Figure 15 and Front Cover.

Some details of the design are still in flux. Claret have indicated that if they can maintain the reliability and timekeeping stability (approximately 2 seconds per day), they may alter the tourbillon from six minutes’ rotation to three.

The detent escapement offers a number of obstacles to its use in a portable watch. To get around some of these problems, Christophe Claret has devised interesting modifications to the escapement.

Presumably to reduce the amount of mass held at a largish radius (thereby increasing the momentum of the balance), the Angelico has no impulse roller to speak of; instead the impulse jewel is held in an oblong fitting attached to the balance staff (o, in the figures). In a classical detent escapement, the balance is planted close to the escape wheel, and the roller of such a radius that it intersects the space between two escape teeth. Here its edge performs the vital safety function of preventing an escape wheel from passing, except during impulse.

In a statement of supreme self-confidence in the design and execution of their detent, Christophe Claret have provided the Angelico with no such safety device, nothing to stop the escape wheel in the event of a trip.

There is a separate anti-trip device, to prevent the detent from inadvertently unlocking. A small roller, p, mounted below the

Figures 15.

discharging pallet, has a passing hollow. The free end of the detent q curls round the balance staff, to engage with this hollow. Any percussion tending to move the detent away from the escape wheel is blocked by this safety finger against the roller. The passing hollow allows the detent to be unlocked only when the balance is oriented to receive an escape tooth.

In the event of an over-energetic impulse, the pin will attempt to drive the blade farther than normal. However, there are two banking pins, u and v, fixed to the tourbillon carriage, situated just ahead of the limits of the blade’s normal positions. These pins are key to the safety action: any tendency for the balance to swing further than desired will immediately be arrested by the balance pin driving the blade into contact with one of the fixed pins, thus preventing further motion of the balance. Jarring is somewhat ameliorated by the blade’s flexibility.**

Having a loose piece on the balance that comes into and out of play must certainly affect the stability of rate. Regarding the tendency of a detent to set, Claret inform me that the Angelico does not suffer from this problem, presumably due to the relatively light balance (compared with antique watches) and the higher beat, which in this case is 18,000.

pq

o

Figure 16.

o

pq

r

st

u

v

The author would like to thank Christophe Claret and all his staff, especially Alexandra Beurier, who enthusiastically responded to my many requests for information, and for the numerous drawings that they prepared specially for this article.