Vacheron Constantin Métiers d’Art Mécaniques Ajourées

When engraving morphs into sculpture 

Through its new creations, Vacheron Constantin weaves subtle ties between two worlds that evolved in similar ways in the late 19th century: architecture and watchmaking. Based on one of the stellar in-house movements, Calibre 4400, this sculptural work with its airy, transparent and finely arched construction exalting the art of openworking vividly evokes the large European railway stations symbolising the golden age of the industrial revolution. The engraver’s technique is reinvented to resemble that of the sculptor, revealing fascinating light effects conveyed through a three-dimensional architecture enhanced by another artistic craft: that of Grand Feu enamelling.

Also symbolising time in motion, horology underwent a similar evolution. The imposing pocket-watch calibres were gradually slimmed down by dint of long and patient work on reducing the size of components in terms of both diameter and thickness. The aspiration towards a more airy style gave rise to the first 19th century openworked watches reflecting an approach similar to that governing the architecture of the period: a will to reconcile aesthetic and technical concerns. The material of the calibres was hollowed out as much as possible to reduce their weight and let the light through, and this stylistic exercise called for perfect mastery of the science of horology in order not to impair the smooth running of the watch.  

An historical quest 
While the first entirely openworked Vacheron Constantin calibre appeared in 1924, the Manufacture was a pioneer in this field of stylistic research, since the first watch produced by Jean-Marc Vacheron in 1755 already featured an openworked and engraved balance-cock. Over the following years, the Manufacture relentlessly pursued this quest for mechanical transparency, as it produced movements comprising ever more finely fashioned components. After pocket-watches, it began producing openworked movements for wristwatches as of the 1960s, constantly pushing the boundaries of its art by openworking such complicated calibres as minute repeaters, perpetual calendar and tourbillons – including in ultra-thin variations.

Time has passed, yet the thirst for creative challenges remains as strong as ever. Witness the new release by the Manufacture of a splendid mechanical work evoking the large glass domed roofs of historical railway stations, supported by Gothic-inspired ribbed vaults. This impressive artistry is expressed through stunning hand-engraved work resembling the technique of sculpture and orchestrated by a symphony of curves forming a three-dimensional architecture literally flooded with light.

New milestones in the art of engraving 
Openworking a movement is a demanding art, since it involves hollowing out the mechanical parts as much as possible, while being careful not to impair the smooth running of the watch. Watchmakers generally start with a solid existing calibre on which they undertake a lengthy process involving conceptualisation, design and modelling, in order to weave the magic of openworking. The new Métiers d’Art Mécaniques Ajourées is no exception to this rule, since it features the first openworked version of an iconic in-house movement: hand-wound Calibre 4400. It took several hundreds of hours to achieve the perfect balance between airy aesthetic appeal and optimal functionality. The watchmakers and artisans of the Manufacture compounded the already impressive feat of removing almost half the material compared with the solid Calibre 4400 by addressing another challenge: that of transforming the new movement into an authentic three-dimensional architectural work expressing striking light and shadow effects. To achieve this, they have laid new milestones in the age-old art of hand engraving. Rather than using a bocfil or tiny handsaw to cut out the smooth surface of the mainplate and bridges before drawing them out with a file and chamfering them, the engraving artisans have carefully chased the parts around their entire circumference so as to create a true sculpture with its own volume and depth. Inspired by the ribbed vaults of late 19th century railway stations, they have meticulously applied their burins to creating delicate arches on the calibre in a fascinating architecture built around curves. These rounded shapes are a complete change from the straight lines of classic openworked movements, and imply an even more complex process of chamfering and hand-drawing. Amid a clever interlacing pattern of interior angles that only the human hand is capable of creating, the polished zones catch the light, while the matt finish of the hand-drawn surfaces further heighten the contrast with the radiance of the polished areas. The subtle alchemist’s blend of these hand-crafted finishes is further exalted by the relief effect of the engraved vaults in a process involving over three days of work for a single calibre and endowing it with unique character.  

When one artistic craft transcends another 
A contemporary reinterpretation of the ancestral art of hand engraving, the finely openworked mechanism of the Métiers d’Art Mécaniques Ajourées model is further ennobled by another artistic craft in which the Manufacture Vacheron Constantin has excelled since its origins: Grand Feu enamelling. Once again demonstrating the full extent of their expertise, the in- house enamelling artisans have created a ring topping the calibre by dint of meticulous work calling for extreme virtuosity, since the circular shape of the ring to be enamelled implies substantial risks of distortion. This perilous exercise thus brilliantly performed was compounded by a further difficulty: that of achieving one of the shades most difficult to create with Grand Feu enamel: a deep and opaque black.  This was a daunting challenge, since the darker the colour, the more the light reflects even the slightest imperfections. To render the full beauty of this black hue, the master enamellist had to create a perfectly smooth and uniform surface so as to avoid the appearance of any undesirable bubbles during the successive firings of the enamel.

Interpreted in black, blue and grey versions, the Grand Feu enamelled ring is accentuated by Roman numerals evoking those of the central clocks in the large railway stations of late 19th century Europe, thereby forming a visible connection with the architectural motifs engraved on the calibre.

In its High jewellery version, the Métiers d’Art Mécaniques Ajourées welcomes another artistic craft into its fascinating orchestration: gem-setting. 42 baguette-cut diamonds light up the bezel, echoed by the 12 baguette-cut diamonds set on the clasp of the saddle-stitched 

hand-sewn alligator leather strap. The entire piece is set with 54 baguette-cut diamonds of approximately 2.80 carats.

A watch bearing the prestigious Hallmark of Geneva 
While the openworked architecture of Calibre 4400SQ reveals a wealth of fascinating hand- engraved work, it should in no way eclipse the technical performances of this splendid mechanism. Beating at a frequency of 28,800 vibrations per hour, the movement displays remarkable precision and offers an impressive 65-hour power reserve that is extremely user- friendly for a hand-wound calibre. Nonetheless, the mechanical aspects alone are not the only features to meet the highest standards of Fine Watchmaking, since the entire model is certified by the Hallmark of Geneva – a guarantee of quality, provenance, craftsmanship and durability appplying to the watch as a whole and providing the firm assurance of owning a timepiece that is exceptional in every way.

The art and technique of openworking 

Far more than a mere object of mechanical excellence indicating the time, a timepiece by Vacheron Constantin is by essence destined to be a full-fledged work of art capable of revealing all the beauty of unique expertise enriched by over 260 years of history. Ever since its founding in 1755, the Manufacture has consistently enhanced the beauty of its creations through artistic crafts exercised by skilled artisans. Hand engraving is one such technique. A demanding art calling for exceptional patience and dexterity, it was used right from the start as a means of achieving ethereal lightness. The first watch created by Jean-Marc Vacheron in 1755 already featured an openworked and engraved balance-cock. The quest for transparency then continued, with increasingly finely fashioned mechanical parts, leading to the creation in 1924 of the first entirely openworked calibre beating at the heart of a pocket watch. A past master in the practice of this extremely intricate discipline, Vacheron Constantin has given free rein to its creativity, progressively openworking both simple and complicated calibres, associating them according to its inspiration with other artistic crafts, and interpreting these miniature marvels both on pocket-watches and wristwatches from the 1960s onwards.

Not content with being one of the rare manufacturers capable of openworking such complex calibres as minute repeaters, perpetual calendars and tourbillons, Vacheron Constantin once again pushes the boundaries of its art by reinventing both the technique itself and the aesthetic codes governing it. The engraving thus becomes a sculpture, as the straight lines morph into interlacing curves, while the watch parts become architectural works creating mesmerising light effects.

Openworking, or the art of  
transparent and ethereal mechanical magic

The all-important initial touch of the watchmaker 
While openworking is a purely aesthetic approach in itself, it nonetheless induces additional complexity at each stage compared with a solid calibre. Everything begins with a lengthy consideration of the movement that is to be openworked as much as possible so as to reveal its inner beauty. This calls upon the full wealth of experience of the finest master-watchmakers, since it involves achieving a subtle balance between hollowing out as much of the material as possible, while ensuring that the calibre remains perfectly functional. The conceptualisation, design and modelisation phases take several hundred hours, a figure that increases in step with the level of sophistication of the calibre, particularly in terms of complications.

Enter the artisans 
Once this subtle balance has been found, the artisans take over, marking the start of a long period of patient, accurate and rigorously disciplined endeavours. The mainplate, bridges, barrel and other mechanical parts that have been previously drilled and cut out occupies their nimble fingers for dozens of hours until they are ready to reveal their appealing new face. Working by hand with each component in turn, the artisans creates subtle contrasts between the finished polish of the chamfering that will catch the light, and the matt effect of the hand- drawing that will accentuate the radiance. While this in itself a demanding task, it is rendered even more complex by the curved openings and interior angles – some narrower than 45° – favoured by Vacheron Constantin in its openworked creations, and which no machine could possible reproduce.

The chamfering and hand-drawing are followed by the engraving itself. For around one full week for each calibre, the engraver incises and sculpts the material with meticulous strokes of the burin in order to create the original motifs imagined by Vacheron Constantin, giving them their delightfully rounded relief. Each gesture is highly accurate – in some cases to the nearest tenth of a millimetre – and the aesthetic sensitivity of the artist-artisan is finely attuned to instilling each component with unique character.

Back to the workbench 
Assembling and adjusting an openworked calibre is a particularly complex task, since the loss of material resulting from the openworking inevitably leads to certain distortions of the parts. For the watchmaker, this means retouching them again and again until their impeccable interaction is guaranteed. Throughout this lengthy process, he makes sure that no dust settles in the hollowed-out surfaces, and also carefully complies with the extremely stringent standards imposed by the Hallmark of Geneva. He devotes special attention to each part, notably the chamfered parts, so as to ensure their perfect aesthetic and functional execution. This perfection is once again severely tested when casing up the movement, since the transparency stemming from the openworking highlights every single perfection, however tiny. Well before the start of the long sequence of water-resistance, reliability and precision testing begins, the calibre returns several times to the workbench until the full magic of a masterfully executed openworked movement begins to weave its spell. Just as as in other fields, the exceptional in terms of horology stems from an ideal blend of excellence and patience.