Monday, February 1, 2010

Vacheron Constantin - Patrimony Traditionnelle « Calibre 2253 » Collection Excellence Platine

For 2010, Vacheron Constantin presents the Patrimony Traditionnelle “Calibre 2253” watch in the Collection Excellence Platine. This model features a major astronomical complication in terms of technical application. Entirely constructed by Vacheron Constantin’s engineering department and developed over several thousands of hours, the new Calibre 2253 provides information derived from Earth’s orbit around the sun, notably a perpetual calendar, the equation of time and the times of sunrise and sunset. It has a tourbillon escapement as well.


The fascinating equation of time

The equation of time is probably the most fascinating complication in this outstanding model. Its purpose is to indicate the difference in minutes between the variable solar time shown by a sundial and the constant mean time of clocks and watches. For practical reasons, mankind has divided each year into 365 and a quarter days, each day into 24 hours, and the hours into 60 minutes each. However, because the Earth’s orbit is elliptical rather than circular, the time in relation to the sun varies daily. The noon zenith of the sun when it crosses the observer’s meridian seldom occurs at exactly 12 o’clock by his watch. In fact solar time and mean time coincide just four times a year – on April 15, June 14, September 1 and December 24. For the rest of the year, the difference between solar and mean time varies from minus 16 minutes to plus 16 minutes.

The oldest clock showing the equation of time was made by the mathematician Nikolaus Mercator in the 17th century. It enabled folk to covert the sun’s varying noon to the standard constant time shown on their watches. Since then, the rare instruments calculating the equation of time have been the work of extremely accomplished horologists.

Making this complication work does indeed call for particular skill. It depends on the equation cam, a waisted oval, shaped like a figure 8 and calculated according to the daily declination of the sun observed from a given spot. The cam rotates once a year while a hand following its contour indicates the equation of time at between 10 and 11 o’clock on the dial of the Patrimony Traditionnelle “Calibre 2253” timepiece of the Collection Excellence Platine.

When the sun rises and sinks

This timepiece displays another function seldom found in watches – the times of sunrise and sunset throughout the year at a given locality. This tricky complication also relies on a cam, the outline of which is calculated according to the latitude of the locality. It demonstrates both the skill of the manufacture’s engineers and watchmakers and Vacheron Constantin’s attention to its clients, for they can choose the place of the sunrises and sunsets. To this extent it’s a custom-made complication where the dials are paired at 8 o’clock and 4 o’clock on the face.

The tourbillon carriage, as always in the shape of the brand emblem, a Maltese Cross, rotates once a minute at 6 o’clock as a small seconds indication. The indications of the perpetual calendar are symmetrically laid out with the days, the months and the dates at 9, 12 and 3 o’clock respectively. The leap-year indicator makes a circumspect appearance on the upper right. 


An exceptional level of finish

The sophisticated finish of this watch is taken to the limits to match its complexity. As part of the Collection Excellence Platine this Patrimony Traditionnelle “Calibre 2253” unsurprisingly incorporates many elements in platinum, from its 43 mm case, water-resistant at a pressure of 3 bar or 30 meters, to its dial hallmarked “PT950”, its crown and its folding clasp in the shape of a halved Maltese Cross. There is one other most unusual, if not unique, horological feature: even the Dauphine hands that show the hours and minutes are fashioned in the same material – an incredible technical prowess. The decoration of the dial alternates silvered and frosted surfaces, with snailed chapters, circular-brushed subdials and diamond-polished filets. The applied hour markers and Maltese Cross are in white gold.

The Calibre 2253 movement also bears the prestigious Hallmark of Geneva, which is an independent and legally sanctioned label of workmanship, origin, precision, resilience and competence. This seal of watchmaking perfection, among the oldest of professional labels, is reserved for a handful of Geneva manufacturers. It means that such decorative aspects of the movement as Côtes de Genève, circular graining, chamfering and straight graining of the steelwork are entirely done by hand.

The finish of the thin bridge that holds the tourbillon is an example among many. It consists of rounding off the top of the rectangular steel bar with a file to create a gleaming barrel-vault along its upper length. The camber follows the shape of the bridge from its jewelled centre to its winged extremities. The entire operation involves grinding and smoothing the surface with a variety of stones and abrasive pastes and then buffing it to a high polish. To meet Vacheron Constantin’s standards of finish, this job takes around 11 hours and is done entirely by hand, but it does signify a properly finished movement.

Such is the complexity and level of finish of this horological masterpiece, that it comprises no fewer than 457 parts in a movement only 9.60 mm thick. That explains why the production is limited to just 10 pieces.

TECHNICAL DATAS

Reference    
Collection Excellence Platine
Patrimony Traditionnelle Calibre 2253
88172/000P-9495
Limited edition of 10 numbered pieces

Movement    
2253, developed and crafted by Vacheron Constantin
Stamped with the Hallmark of Geneva

Energy
Mechanical, manual-winding

Movement thickness    
9.60 mm

Movement diameter    
32.00 mm

Jewels    
30 jewels  

Frequency    
18,000 vibrations/hour

Indications    
Hours, minutes, seconds on tourbillon
Perpetual calendar
Equation of time, sunset and sunrise
(Ephemeris to the localization chosen by the client)  
Power reserve on the caseback
  
Power reserve    
More than 300 hours (14 days) - 4 main springs, coupled two by two

Number of parts    
457 pieces

Case    
950 platinum
Diameter: 43 mm
Convex sapphire crystal with anti-reflective coating on one side
Open-worked screwed-down back

Water-resistance    
3 bar, equivalent to 30 metres

Dial    
Sand-blasted finish, special “PT950” marking at 4.30
12 hour-markers and Maltese Cross in 18-carat white gold

Strap    
Dark blue alligator leather, hand-stitched with platinum thread
  
Clasp    
950 platinum folding clasp
Polished half Maltese Cross