Master Grande Tradition Tourbillon Jumping Date

MASTER GRANDE TRADITION TOURBILLON JUMPING DATE

REINTERPRETED FOR THE GRANDE TRADITION LINE: A RESTRUCTURED MOVEMENT CREATES A NEW AESTHETIC

KEY FACTS:

• High-precision calibre: new movement architecture creating a fresh aesthetic for Calibre 978, which in 2009 won the first modern-era chronometry competition
• Open-worked dial: new design highlighting the tourbillon and the signature ‘jumping’ date mechanism
• Sophisticated case: capturing the Grande Tradition design codes in a 42 mm case comprising 60 components
• Refined rounded-off bridges: new tourbillon and 24-hour disc aesthetic, elevated by 18K White Gold (750/1000) bridges

With the new Master Grande Tradition Tourbillon Jumping Date, Jaeger-LeCoultre revisits one of its most notable tourbillon calibres. The precise and reliable Calibre 978 made its debut 20 years ago and three years later, in 2009, the Manufacture celebrated a remarkable achievement in timekeeping precision as this calibre won the first modern chronometry competition. With a restructured movement architecture, the latest iteration of Calibre 978 is presented in a new 42 mm 18K Pink Gold (750/1000) case complemented by a fresh dial design and refined High Watchmaking finishes – a lively and elegant homage to the calibre’s illustrious past, issued in a limited edition of 100 pieces.

AN EXCEPTIONAL TOURBILLON CALIBRE IN PURSUIT OF PRECISION

Invented to enhance timekeeping precision by compensating for the effects of gravity on the regulating organ, the tourbillon has long been a field of dedicated research for Jaeger-LeCoultre, which created its first tourbillon movement in 1946. Since then, the Manufacture has continuously refined its approach to regulating organs, developing numerous technical innovations aimed at improving chronometric performance.

A chronometric distinction: A prime example of these advancements is the Calibre 978. In 2009, it won the first modern chronometry competition inspired by 19th-century observatory competitions – a demanding 45-day trial organised to mark the 50th anniversary of the International Museum of Horology in Le Locle, Switzerland. This trial, conducted by two independent official bodies, rigorously tested not only the precision of the watch’s movements but also their reliability during wear, by notably including resistance tests for shocks and magnetism. It unequivocally demonstrated both the validity of the tourbillon escapement’s original purpose and the exceptional quality and precision of the Manufacture’s craftsmanship.

An ultra-light regulating organ: The tourbillon of the Master Grande Tradition Tourbillon Jumping Date is made of 77 components and weights less than 0,5 grams.

An intuitive jumping date mechanism: When first unveiled, Calibre 978 introduced, beyond its 60-second rotation tourbillon, a playful yet thoughtfully engineered “jumping” date mechanism, which remains integrated into this new watch. The dates are displayed around the periphery of the dial, with the 15 and 16 positioned on either side of the tourbillon aperture and separated by an angle of nearly 90 degrees. Starting at midnight on the 15th of each month, the date hand glides to the 16th to ensure that the tourbillon is not obscured from view.

An ingenious 24-hour disc: The Master Grande Tradition Tourbillon Jumping Date features a 24-hour disc that can be adjusted independently from the main hour and minute hands. This disc indicates day and night (AM/PM) when synchronized with the primary time display but can ingeniously also function as a second time zone indicator.

HIGH WATCHMAKING MOVEMENT FINISHING      

As Jaeger-LeCoultre is constantly inventing, reinventing and improving on its own innovations, Calibre 978 is no longer precisely the same movement: it has been restructured in 305 components so that interesting elements can be seen through openings in the dial. The revised architecture is also complemented by more refined finishing.

This intricate finishing of components involves the expertise of 8 different workshops at the Manufacture to perform 10 types of decorations on the calibre among which perlage, bevelling, hand-bevelling, linear brushing, sunray brushing, Côtes de Genève, sandblasting and diamond polishing. Over 30 components are decorated by hand and 48 angles are hand-bevelled.

The two 18K White Gold (750/1000) upper bridges of the tourbillon and the 24-hour disc have been intricately polished to create a perfectly rounded half-moon profile using a High Watchmaking technique called berçage (rounding off), which necessitates the precise and skilful use of a burnishing file in a rocking motion. Viewed through the transparent sapphire case back, the bridges are decorated with sunray-style stripes – a Jaeger-LeCoultre signature finish known as Côtes de Genève soleillé. The radiating stripes perfectly complement the shape of the base plate, which showcases the classic tourbillon with its screw balance wheel and its decorated lower bridge. The design of the full-sized winding rotor has been carried over from the original Calibre 978, with a large cutaway in the finely finished, monobloc 22K Pink Gold (916/1000) oscillating weight that ensures a clear view of the tourbillon.

MECHANICAL CLARITY: A NEW DESIGN FOR FUNCTIONAL DISPLAY

The new Master Grande Tradition interpretation of Calibre 978 introduces a new dial aesthetic, open-worked to showcase major elements of the calibre, namely the tourbillon and the 24-hour disc, both held by White Gold bridges, as well as the jumping date mechanism. In addition to the large aperture for the tourbillon, the revisited movement architecture has made it possible to add a second cutaway at 9 o’clock that displays the calendar driver mechanism, which triggers the date hand’s rapid glide, enabling the owner to observe its function. Another aperture reveals the structural screws that hold a wheel staff at 2 o’clock – a window into the mechanics that provides visual balance to the dial.

The dial is rich in detail and decoration: a barleycorn pattern on 18K Pink Gold (750/1000) dial creates texture and visual depth beneath layers of deep blue translucent enamel, providing a luxurious contrast with the 18K Pink Gold (750/1000) hours and minutes hands and applied hour markers. A long gold pointer hand, tipped by the JL anchor in red, indicates the date, while a red arrow indicates the time on the 24-hour sub-dial.

Jaeger-LeCoultre has integrated Calibre 978 into a sophisticated new Pink Gold case that follows the Grande Tradition design codes, with multiple high-polished, brushed and micro-blasted finishes creating a captivating play of light over its 60 components. The elegant ensemble is completed by a classic black alligator leather strap with small-scale alligator lining and an 18K Pink Gold (750/1000) folding buckle.

With the Master Grande Tradition Tourbillon Jumping Date, Jaeger-LeCoultre honours the place of its eponymous movement in horological history, marrying proven precision to an elegant contemporary aesthetic.