The Diamond Standard

by Thomas Byczkowski

Admittedly the first look at the new line of Jaeger-LeCoultre doesn’t immediately knock you off your feet the same way the Master Compressor Extreme LAB did. But recall that the design of the latter could be compared with the prototype of a car manufacturer that shows what might be, rather than what is currently produced. The few Extreme LAB watches produced come directly from the machines used in the R&D laboratory of the manufacture, not from an ordinary assembly line.
With the new line Master Grande Tradition, however, the watch manufacture in the Vallée de Joux instead wants to bring the gains of modern technology directly to the counter. But—and this is what makes the whole affair so interesting—the watchmakers at Jaeger-LeCoultre at the same time did not forget their rich history, which might explain the classic, understated look of the new collection.
This strategy is strikingly similar to how Patek Philippe 
revealed its first silicon movement a few years ago. The firm housed the movements in their classical annual calendars 5350 and 5450, providing a loupe to view through case back to scrutinize the grayish wheels that were made of silicon wafer.
However, a few years back Patek Philippe only trusted themselves with two highly limited series, preparing to replace the silicon parts if they turned out not to be working as wished.
Jaeger-LeCoultre is seemingly much more confident about its new technical approach. The Master Grande Tradition is not planned as a solely limited series. With some five years’ more time for research and development, the technological approach of the Le Sentier-based manufacturer is light years away from the first concepts that the big three (Rolex, Patek Philippe and Breguet) were testing as the new silicon-based material popped up in the watch world.
   
The new line in detail
Jaeger-LeCoultre set out to equip each watch of the line with two complications. The first two models are called Master Grand Tradition à Répétition Minutes (a regulator-styled repeater) and Master Grande Tradition à Tourbillon à Quantième Perpétuel (a tourbillon with perpetual calendar) and arrive with two newly designed movements housed in very finely crafted cases. The repeater is in yellow gold limited to 100 pieces and the tourbillon is made in platinum, red or yellow gold, with the latter version limited to 300 pieces.
This of course gives a hint to the complexity of the movements. The repeater movement 947R is based on the caliber 947 with its ingenious crystal gong, and the tourbillon (called 987), which features details known from the caliber 978 of the Master Tourbillon collection, but here combined with a perpetual calendar module. Both watches have hand-finished calibers and classically shaped dials with dauphine hands.
To spice up the line, the watchmakers insert a silicon escapement treated with a special diamond coating into this unlimited collection. The escapement of course cannot be seen, even through a loupe, so the manufacture refurbished its famed “1,000 hours test” to a “1,000 hours chronometer test” to make the reliability of their concept at least indirectly visible.

Diamond-coated silicon
All watches of the Master Grande Tradition line feature an escape wheel and an anchor, both consisting of silicon and treated with a diamond coating. The company first used silicon in their aforementioned Master Compressor Extreme LAB watch, which Jaeger-LeCoultre advertised as the first watch ever running completely without any lubrication.
As a reminder: silicon is extremely hard and does not wear through friction. Its low friction coefficient makes it an ideal material for the escapements, for it delivers a much greater percentage of the force that is fed into the system through the mainspring when compared to a traditional escapement.
Being less inert than the heavier metal parts, silicon allows the movement to run with a greater efficiency. And there are almost no limitations to the potential shapes of the parts thanks to engineering with computer-aided silicon wafer technology. This guarantees perfect repetition, with each piece coming out identical–even on a microscopic level. As a result, it’s much easier to assemble an escapement. Here, the pallets can be made of a single, specially designed unit that needs no further adjustment.
As for the coating, the watchmakers at Jaeger-LeCoultre have had a natural restraint against using the well-know silicon dioxide coating—which is basically performed by baking the silicon parts in an oxygenated air. The coating easily cracks if not handled with extreme care—a fact which Jean-Pierre Musy, director of Patek Philippe’s research laboratory, freely admits. Special training is necessary for the assembling watchmakers and the need of rubber-coated tweezers.

Tribilogy
However—and here we dive deep into the theory of wear, called tribilogy—according to Jaeger-LeCoultre the oxygenation does not reduce wear: thus the reason for using it is superfluous in the eyes of Jean Claude Meylan, the engineer who performed coating-tests in the manufacture for over two years.
According to his claims, those oxy-coated parts deliver much worse long-term wear results than a classically lubricated escapement. This means that the lightness and reproducibility advantages of silicon are essentially canceled out by wear.
Having tested a whole batch of coating alternatives, in 2008 the engineers came up with a special diamond coating in which the growth of this ultra hard carbon structure is synthetically induced to a thickness of five microns on the surface of the silicon part.
This is easily accomplished since carbon and silicon are in fact closely related in the periodic system of elements. Its exorbitant hardness is due to its perfect atomic symmetry. In science this is called diamond-like structure as it is only found in diamonds and stands in for their property.
After this growth process, the parts are individually treated by a plasma-laser, which polishes the surfaces on a nano-level, thus creating a perfectly shining and rupture-free face. Meylan performed tests in Le Sentier with this new coating in movements running with 10 hertz, for—as he claims —otherwise there will hardly be any visual effect.
The overall effect of this new coating leads not only to an unseen hardness and no wear, but also to a friction coefficient that is only half of oxidized silicon. This increases the efficiency of the movement around 15 percent in comparison to the latter. What’s more, the inertia of the material is only a third that of standard metal components.