With the new Grand Complication watch in the Master Grand Tradition series, Jaeger-LeCoultre again demonstrates its attachment to its horological roots as well as its drive to bring watchmaking in line with the latest in research and development. The watch incorporates three complications that elegantly mingle homological history with cutting edge technology: a minute repeater, a flying tourbillon and a zodiac calendar – each a highly regarded complication of its own right and all constructed according to the latest of watchmaking standards and combined through the romantic soul given by true horologists, whose work is deeply rooted in their art.

This is the first time that Jaeger-LeCoultre is presenting a Grande Complication within the Master Grande Tradition line. However, as one of the driving forces in the world of high horology, the manufacture didn’t dwell on copying this marvelous concept; instead the watchmakers were keen on setting new standards by reinterpreting the idea from a modern viewpoint.

Traditionally a Grand Complication consists of three watchmaking complications. One providing an astronomical information – such as a perpetual calendar – the second a sounding system such as a minute repeater – and a third one showing one or more additional hands, usually a chronograph, but it could be any other complication, for instance, a tourbillon.

In the new Master Grande Tradition Grande Complication however those three complications do not merely coexist in the platinum case – they are intertwined in an almost poetic way: For the essence of the watch lies in its interpretation of astronomical timekeeping for the wrist. And there couldn’t be a better driving force than the pulsing heart of a flying tourbillon rotating around the dial, depicting a sky-chart of the northern hemisphere.

Enhancing the astronomical aspect, the tourbillon doesn’t count the passing minutes of the official day with its 24 hours, but it counts the time of the so called Sidereal Day, which is almost 4 minutes shorter than the solar day. A small sun rotating around on the outer spheres of the dial, where zodiac signs and an indication for the twelve months round off the heavenly display, indicates our ‘official’ time, also known as Mean Solar Time.

Its brand new Jaeger-leCoultre Calibre 945 is a highly complex mechanism with 527 parts, all of which require the hands of a single watchmaker to be assembled and adjusted. Concerning precision, it relies on the latest technology: a flying tourbillon sets the beat with an advanced silicium-escapement, specially developed for use within an ultra-light titanium cage.

Additionally, the watch incorporates an innovative minute repeater, the result of five years of research, where the sound is generated by an ingenious ‘crystal gong’ system in which form-improved gongs are attached to the watch glass. Together with a new striking mechanism called ‘trébuchet hammers’, delivering 80% additional power to that of ordinary gong mechanisms, the watch offers an unprecedented clear and harmonious full sound at the simple push of the slider mechanism.

Its classically shaped platinum case and the movement-parts finished to the highest of watchmaking standards are witness to the experience of 177 years in high watchmaking, which Jaeger-LeCoultre can look back upon. Meanwhile, the ultra modern siliceous escapement is a clear marker of the innovative spirit that drives the manufacture to the present. This unique combination makes the watch a true contender for the annual theme of “Invention through movement”.


Since the heydays of watchmaking, the Grande Complication is the epitome of absolute mastery in the field of watchmaking. In the times when watches were produced one by one on the bench of a single artisan, the mastery of only one complication already was highly regarded. But truly outstanding were those specialists, who were able to combine two or even three of those complex mechanisms in a single timepiece.

Today the recourse to a classical watchmaking concept is a rightful way to prove the mastership of the old art of horology. But what is more: Today’s master watchmakers not only have to have an intrinsic knowledge of the mechanics of their timepieces and yearlong experience in producing, finishing and adjusting even the tiniest parts, they also require a profound insight into the characteristics and effects – and the trapdoors – of new materials and computer aided production techniques. Thus the construction of a Grande Complication as a contemporary timepiece is as demanding as it always has been.


Jaeger-LeCoultre’s watchmakers interweave those three complications in the new Jaeger-LeCoultre Calibre 945, a movement that is developed form scratch to provide the highest possible performance. For their version of a Grande Complication, instead of a chronograph they integrated the flying tourbillon as third complication – the most complex version of this gravity defying escapement. They integrated it into the timing mechanism not only as a regulating device, but as the prominent showpiece of time itself in the perpetual calendar, acting as a hour hand depicting Sidereal time, with the dial showing the sky chart of the northern hemisphere. On the outside meanwhile, a sun completes a circuit of the dial in precisely 24 hours. Additionally, a ring shows the zodiac signs as well as the months and days.


The Master Grande Tradition Grande Complication is fully dedicated to astronomical timekeeping. Its main asset therefore – and its most striking feature – is the flying tourbillonacting as hour hand, showing not the mean time as found on all wristwatches, but the time unit used by astronomers to keep track of the direction of the stars: Sidereal time.

A day is basically defined as one rotation of the earth around its own axis. Depending on which point of reference is used, astronomy distinguishes between a Solar day and a Sidereal day. The former is measured with the sun as reference, the latter uses other, more distant fixed stars. Since the earth orbits around the sun as well as upon its own axis, the Solar day is slightly longer than the Sidereal day, differing by about one degree or almost 4 minutes.

To underline these celestial intentions that make the watch a perfect tool for astronomical observations, a zodiac calendar is placed on the outside edge of the dial together with a month indication to further depict the constellation of the stars at any given time of the year, with an annual calendar regulating the timing system.


The Master Grande Tradition Grande Complication is the only watch in high horology to use a flying tourbillon to indicate the celestial time. This indication happens through a complex mechanical construct under the dial, which is itself divided in three different levels: the lowest is a disc turning once every 24 hours with a sun marking the hour at the outer end. On top of this circles a second blue lacquered disc with the star field of the northern hemisphere and the flying tourbillon mounted upon it. In this construction, the flying tourbillon is hovering above the movement in the sky-chart-dial – which itself is mounted on a ball barrel and eight rubies for smooth operation – only connected through a set of wheels and pinions reaching through the whole movement to the other side, where the winding barrel is housed.

The cage of a flying tourbillon, rather than being supported with a bridge at both the top and bottom, is cantilevered and thus held only at the underside. The whole mechanism consists of 73 parts and measures 12.42 millimeters in diameter and 3.85 in height. Built of lightweight titanium, the cage is reduced to its bare essence, providing an unobstructed view at the escapement system and is placed on a lubricant-free ceramic ball bearing. The 10-millimeter monometallic balance wheel with its regulation screws and the Breguet balance spring has an inertia of 11.5 mg cm2 and is beating at a powerful rate of 4 Hertz.

The silicium parts of the escapement therefore are clearly visible: the watch’s anchor with its integrated pallets and the escape wheel. This escape wheel is a completely new design for reasons of lightness and easy handling. The anchor with integrated pallets has a straight form for better aerodynamics. Using silicium parts not only improves the longtime precision of the watch through its lubrication free performance, it reduces the inertia of the components about a third in comparison to the classically used steel, yielding a 15 percent increase in the efficiency of the whole movement.

Due to the perfectly identical production process in the silicium wafer technology, the most complex forms can be replicated identically. The Research and Development Department of the manufacture has already gained a lot of experience in the use of silicium escapement parts during its 5-year research for the development of the Master Compressor Extreme LAB, the world’s first totally lubricant free watch.


For counting down to the minute, the watch is equipped with an additional feature – a complication which alone would make it a masterpiece: a minute repeating mechanism that makes time audible by striking on demand.

The sound delivered by a musical watch relies heavily on the gongs which are the essential sound producing elements. To deliver the best possible sound, Jaeger-LeCoultre has developed a completely new cathedral gong, creating an extremely rich sound. These gongs are made of a special alloy and manufactured completely in one piece; their cross section being square and not round in order to provide a larger contact point for the hammer which in turn can strike more forcefully.

Usually the sound of a repeater gong is enhanced by the vibration of the case of the watch. The manufacture’s experts however installed a different kind of ‘loudspeaker’, using their patented ‘crystal gong’, in which the gongs are attached to a layer of metallic foil coated onto the watch’s sapphire glass. With this invention it is possible to make the watch waterproof, because the dampening effect of the gaskets is offset by the crystal gong. This is a key to the true usability of any timepiece.

Pushing the slider on the side of the platinum watchcase, two small hammers can be seen striking on the backside. For them the watchmakers invented a special mechanism christened the ‘trébuchet hammer’ to improve the sound of the actual striking. Instead of a traditional hammer they devised a dual-axis-system with a special joint on a moveable arm. Upon activation, the hammers are accelerated until they touch a small finger, whereupon a second moveable arm is released, thus helping to accelerate the hammers further shortly before the impact. This method utilizes around 80 percent of the force applied by the spring, whilst traditional hammer systems only deliver a mere 10 to 30 percent of the power originally applied.


The newly designed and constructed hand winding movement 945 embeds classical horology and modern technology in a clearly visible way: All components are decorated with sunburst pattern, circular graining, double sailing or are satin brushed to enhance the classical aspect of the construction. The steel parts are polished and beveled, the adjustment screws blued and the screws for the settings are rhodium plated. Looking on the dial side of the watch however, another spectacular aspect of this Grand Complication can be admired: here the whirling tourbillon is outfitted with the high-tech escapement components which have the dark shimmer of silicium contrasting well to the highly polished silvery titanium grade 5 tourbillon cage.


To prove the reliability of the work, the Master Grand Tradition Grand Complication, once completely finished and encased, has to prove itself in the 1000 Hours Chronometer Test – a reinforced version of Jaeger-LeCoultre’s famed 1000 Hours Test, which as well takes into account all aspects of the official COSC-Chronometer test. All in all, the test certifies the water and shock resistance of the complete watch as well as its smooth operation and precision of this avant-garde escapement.


The case design follows the code of the Master Grand Tradition line: classical in style and precious in materials. This Master Grand Tradition Grand Complication will be produced in a limited edition of 75 pieces in white gold, honoring the exclusivity of the movement, which is so complex and the interactions between its three complications so delicate that the whole mechanism has to be assembled by one single master watchmaker.

The movement is then encased within a round white gold case, in which polished lugs and case back contrast with the brushed case sides. While a sapphire glass in the back allows one to lovingly examine the finely finished movement, the front is covered by a domed sapphire glass and a sloping bezel, which underlines the classical look of the watch and provides the 44 millimeter diameter watch with a pleasing design, concealing its height of 15.6 millimeters. Combining a good part of Jaeger-LeCoultre’s fundamental expertise in high horology and coagulating it in a single timepiece, the Grand Complication is a worthy member in the club of the Master Grand Tradition line. It embodies the epitome of classical horology mingled with cutting edge technology.