Master Grand Tourbillon

Jaeger-LeCoultre celebrates the opening of its Heritage Gallery with the release of the Master Grand Tourbillon, an exclusive series equipped with a fascinating tourbillon mechanism. Made up of 78 parts weighing barely 0.28 grams in all, the grade 5 titanium tourbillon carriage spins elegantly on its axis once a minute. The date indication is adjustable in both directions and makes a bigger jump between 15 and 16 so as not to spoil the view of this magnificent technical accomplishment. In addition to the prestige of the standout complication, the automatic movement also features a dual time-zone display.

Reflecting 175 years of tireless striving for horological perfection, this watch issued in a platinum limited edition of 300 embodies the inventive spirit that has pervaded the entire history of Jaeger- LeCoultre. In tribute to Antoine LeCoultre, a technical pioneer who devoted his whole life to the quest for peerless accuracy, it comes in an imposing presentation box containing a piece of stone from the original workshop set up by the founding father of the Manufacture.


For Jaeger-LeCoultre, a tourbillon worthy of paying homage to the spirit of invention bequeathed by Antoine LeCoultre naturally had to meet all the demands of a high-prestige precision instrument. The engineers of the Manufacture were equally uncompromising in their determination to endow the Master Grand Tourbillon with superlative performances in terms of precision, reliability and sturdiness.

In tribute to the rich legacy of the Manufacture’s founder, this exceptional watch is delivered in a dedicated presentation box featuring a special recess housing a real fragment of the wall of Antoine LeCoultre’s workshop. This wall fragment – which was knocked down to built the entrance to the Jaeger-LeCoultre Heritage Gallery – represents a concrete reminder of the pioneering technical work of Antoine LeCoultre. This brilliant self-taught inventor, who learned the rudiments of his trade at his father’s blacksmith’s forge, devoted his whole life to the quest for absolute precision and reliability. His achievements have left an indelible imprint on watchmaking history and his spirit lives on more strongly than ever in the men and women of the Manufacture who continue to create exceptional models such as the Master Grand Tourbillon.


A tourbillon geared towards precision and sturdiness
For this limited edition, Jaeger-Lecoultre has devised a balance with a 11.5 mg x cm2 inertia capable of supplying the automatic movement with the energy it needs to keep the carriage in motion and to perform the characteristic 28,800 vibrations per hour expected from a high- precision movement. Among the screws arranged around its rim, four of them serve to make adjustments. This technique ensures constant adjustment over time that is unperturbed even by shocks. Any losses in energy due to friction are also reduced by the use of spyr-type gear-wheel teeth with a profile specially designed to ensure regular transmission of force. The lever is also more compact so as to fit into the limited space of the tourbillon carriage. Finally, the automatic movement is wound in one direction only, in harmony with lengthy research that has shown that, once on the wrist, a watch winds twice as fast this way than in the bidirectional mode.

Exceptional decoration for an exceptional movement
In keeping with the firm conviction that consummate artistry is expressed through even the smallest details, the decoration of the movement visible through the sapphire crystal case-back is worthy of the beauty of the complication. The exquisitely hand-crafted bevelling, drawing, snailing, circular-graining and buffing make a perfect match for the going-train bridge adorned with Côtes de Genève.

For the feather-like tourbillon that weighs in at just 0.28 grams, the engineers of the Manufacture opted for a carriage made from an ultra-light, precision-enhancing titanium alloy that is harder to work with because of its exceptional hardness. Tremendous care has been lavished on this noble mechanism with its polished sinks and fine sandblasted surfaces. The cambered escapement bridge cleverly follows the curve of the carriage. The single-piece oscillating weight in 22-carat pink gold is embellished with a stamped medallion motif adorned finely engraved matt and brilliant raised effects.

A time-honoured mechanism paired with unique functions
The genius of the inventive spirit consistently cultivated by Jaeger-LeCoultre has also found expression through associating the tourbillon with the home time/travel time principle – one of the refined technical features that has forged the reputation of the Manufacture and enables at- a-glance comparison of reference time and local time.

In the upper part of the dial, a 24-hour subdial maintains the time reference, or can indeed be used at any juncture to represent the second time zone. To ensure a fast display of the travel time zone as the main function, the local time is read off in the centre and can be adjusted either forward or backward in one-hour jumps, while automatically driving the date accordingly. This innovative date indication, adjustable in both directions, jumps between the figures 15 and 16 so as not to spoil the view of the impressive technical feat that is the main highlight of the dial.

The seconds display also testifies to the accuracy of this watch. It appears in the circular tourbillon opening by means of a three-arm hand including an arrow-tipped spoke that indicates the passing seconds in step with the revolving tourbillon carriage. In this way, reading off the smallest standard unit of time constantly draws the gaze to the hypnotic motion of the most fascinating horological complication of them all.

Movement : Mechanical automatic winding Jaeger-LeCoultre Calibre 978, crafted and decorated by hand
28,800 vibrations per hour
48-hour power reserve
302 parts
33 jewels
7.05 mm high
22-carat single-piece oscillating weight, openworked and decorated with relief engravings
Functions : local time enabling fast adjustment on both directions (travel time zone)
date hand synchronised with local time, adjustable in both directions
24-hour reference time indication
minutes
tourbillon regulator with seconds indication
Dial : sunburst black base with applied rhodium-plated gold numerals and hour-markers, 11 luminescent dots
Hands : hour and minute: Alpha type in rhodium-plated brass, luminescent
date : rhodium-plated brass with double red-varnished triangle
reference time : rhodium-plated brass
Crowns : 1 crown to start the watch and to adjust local time, reference time, minute and date
Case : ø 43 mm in 950 platinum cambered sapphire crystal, hardness N°9
sapphire crystal case-back revealing the movement
water-resistant to 50 metres
Leather strap : 22/20 in matt alligator leather and 18-carat white gold folding clasp
Reference : platinum 950: Q166 64 70