Tudor rocked the watch industry with its first appearance in 2012, the Black Bay. This collection, which has an exterior that exceeds the price range, has become even more attractive with the adoption of an in-house movement. What brought about that evolution was Tudor's half-century commitment to divers' watches.
Takeshi Hoshi: Photographs Photographs by Takeshi Hoshi (estrellas) Masamasa Hirota (this magazine): Interviews and texts Text by Masayuki Hirota (Chronos-Japan) [Article published in the September 2021 issue of Chronos Japan]BLACK BAY CERAMIC [Ref M79210CNU] Super anti-magnetic model based on Master Chronometer
Black Bay Ceramic An ambitious product that combines an almost ceramic exterior with a high-performance Master Chronometer-compliant movement. Practicality is outstanding. Automatic winding (Cal.MT5602-1U). 25 stones. 28,800 vibrations/hour. Power reserve about 70 hours. Ceramics x SS (diameter 41mm). 200m waterproof. 539,000 yen (tax included).Tudor jumped into the mainstream of diving watches with the second generation “Heritage Black Bay” (Ref.79230) announced in 2016. The retro-chic design that everyone will like, the long power reserve of about 70 hours, and the automatic movement that combines a silicon balance spring with a free-sprung balance are the best in this price range. It was high spec.
However, Tudor continued to improve on this masterpiece. The "Black Bay Ceramic" announced in 2021 not only used ceramic materials for most of the exterior, but also cleared the master's chronometer standard, which requires resistance to magnetic fields of 15,000 gauss. For a long time, the master chronometer standard that was dominated by Omega. Who would have thought that Tudor would also adopt it?
The structure of the case is also completely different from the existing Black Bay. At first glance, it looks like it's all made of ceramics, but in reality, the SS inner case is covered with a ceramic outer frame, and the SS bezel and back cover are combined there. The reason why I didn't use all ceramics is probably because I wanted to keep Tudor's unique rotating bezel mechanism intact and give it a screw-down case back. If the bezel is made of hard ceramic, the rotating bezel mechanism will be damaged, and if the inner case is made of ceramic, it will not be possible to cut the screws. Designing for sturdiness is the hallmark of Tudor's divers' watches since 1954.
Tudor has changed a lot since the 2012 Black Bay. This work can be said to be a model that symbolizes such an "attacking" Tudor. So how did Tudor pass the Master Chronometer standard, which was said to be impossible to introduce?
(Right) The exterior is unified in black except for the phosphorescent paint. As the photo shows, there is no trace of waterproof packing between the windshield and the bezel. What made the almost black experiment possible was the approach to the exterior that progressed after 2012. (Left) The bezel and crown are made of SS with black PVD treatment. The same is true for the crown tube. The small backlash of the crown, which is brought about by the thick tube and triple waterproof packing, is the beauty of the current Tudor. case side. The molding is almost the same as Ref.79230. However, the middle case was squeezed slightly. (Right) This model comes with a hybrid strap with leather and rubber lining (pictured) and a black fabric strap. Equipped with a folding clasp with a safety catch. The ball that fixes the safety catch is made of ceramics. (Left) The easy-to-understand benefit of the master chronometer is the adoption of a transparent back. The bridge has a fine blast finish. In addition, despite the ceramic case, the back cover is a screw-in type. It has an elaborate design in which screws are cut into the steel inner case and the back cover is screwed into it. Cutting threads into a ceramic case is difficult, but this structure makes it possible.The Latest Circumstances of the Manufacture that Introduced the METAS Inspection Laboratory
Master chronometer standards by METAS, which has long been the monopoly of Omega. Although it is theoretically possible, Tudor has cleared this standard, which was thought to be impossible for other companies to adopt. So how did it become possible? I would like to unravel the background and reasons.
The Cal.MT5400 series with a small diameter is installed in the "Black Bay Fifty-Eight" with a Cal.MT540239mm case. There are MT5400 with a diameter of 30.3mm and MT5402 with a diameter of 26mm. Self-winding (26mm diameter, 5.0mm thickness). 27 stones. Power reserve about 70 hours. Silicon balance spring and free sprung balance. C.O.S.C. Chronometer. Static accuracy within -2 seconds to +4 seconds.
The Master Chronometer standard by METAS (Swiss Federal Institute of Metrology and Accreditation) is currently the toughest standard for mechanical watches. Although it does not have the extreme shock resistance test of the Qualité Fleurier, it covers almost all of the functional characteristics required of a mechanical watch, such as accuracy, magnetic resistance, water resistance, and power reserve.
While it is possible for any mechanical watch manufacturer in Switzerland to be tested for a Master Chronometer, Omega had a monopoly until 2021. There are three reasons. First, unlike the C.O.S.C. chronometer, it is necessary to measure the accuracy while the movement is in the case. It seems simple at first glance, but if you don't want accuracy, you'll need to remove the movement from the case. Unlike the C.O.S.C. Chronometer, which tests individual movements, if you want to mass-produce Master Chronometer models, you have to set up an inspection space in the factory where they are assembled. Unless there is a will to adopt Master Chronometer on a large scale in the future, it is almost impossible to carve out such a space in the factory.
It is the Cal.MT5600 series that first appeared in 2015 that drives the Cal.MT5602 41mm diameter "Black Bay". This is Cal.MT5602 without the calendar. Automatic (31.8mm diameter, 6.5mm thickness). Power reserve about 70 hours. Silicon balance spring and free sprung balance. C.O.S.C. Chronometer. Static accuracy within -2 seconds to +4 seconds.And the other is the ultra-magnetic resistance of 15,000 gauss. To meet this requirement, we must at least use a hairspring made of silicon, which is completely non-magnetic. However, only a few watchmakers in Switzerland can use this component. Other important parts also need to be made of non-magnetic materials. These parts aren't hard to come by, but the non-magnetic material wears out easily. As far as I know, even in Switzerland there are only a handful of manufacturers capable of working with tribology.
And the last difficulty is "accuracy test in two different power reserve remaining states". This is to measure the accuracy when the mainspring is 100% and 33%. It seems easier than the 15,000 gauss test, but this is the most troublesome.
Cal.MT5602-1U is Cal.MT5602-1U which is a master chronometer version of Cal.MT5602. The finish was also changed to black. C.O.S.C. Chronometer and METAS Master Chronometer. 15,000 gauss magnetic resistance. Static accuracy within ±0 seconds to +5 seconds. Other basic specifications are the same as Cal.MT5602.The co-axial escapement used by Omega is based on the detent escapement that was once used by marine chronometers. It is complicated and the productivity is bad, but it has the advantage of being easy to maintain accuracy even when the remaining amount of the mainspring is low. This is said to be the reason why the Master Chronometer standard, which Omega helped establish, added a precision test with the mainspring remaining at 33%.
On the other hand, the Swiss lever escapement used in the majority of mechanical watches is highly productive and resistant to shocks, but its accuracy deteriorates quickly when the mainspring runs low. A lighter silicon escapement is said to alleviate the problem, but it's still not as stable as a co-axial escapement. That's why one designer at the Richemont Group bitterly remarked that the Master Chronometer standard was only premised on a Co-Axial escapement.
However, Tudor cleared these challenges and succeeded in passing the "Black Bay Ceramic" through the Master Chronometer standard. It doesn't seem to be a coincidence that the first model was made of ceramic, though. Gregory Pons, a French journalist, said, "The ceramic case and silicon balance spring (used by Black Bay Ceramic) are not magnetic, and the all-tungsten rotor is almost non-magnetic. That's why other models It may have been easier to convert it into a master chronometer compared to ”(Excerpt from “BUSINESS MONTRE”).
Master Chronometers are tested in the independent METAS lab, located within Tudor's workshops. All Black Bay Ceramic watches are also measured for accuracy at 100% and 33% power reserve. Only individuals that pass the 10-day test are shipped.According to Tudor, "Work with METAS began at the end of 2019, and it was decided to set up a METAS inspection process in the Geneva factory" (excerpt from "LE TEMPS"). What made the introduction possible was that the Tudor factory was so efficient that a watchmaker would not be expected to do so. The aforementioned SJX, who actually visited the Tudor factory in the Acacia district of Geneva, learned about the Toyota-style "just-in-time production system" including kaizen and the so-called "5S" ) is thoroughly written.
According to Gregory Pons' report, the METAS inspection process has been set up in a corner of the new building. Here, the finished watch undergoes static accuracy in 6 positions and 2 temperatures, 15,000 gauss resistance, water resistance to 200 meters, and 100% and 33% power reserve tests to ensure Master Chronometer compliance. receive.
15,000 gauss magnetic resistance test process on the first day. A clock set on the rail is automatically sent to the magnetic machine.What's interesting is that the 15,000 gauss anti-magnetic test is a complete assembly line. Ponce explains that there are still few Master Chronometer models produced annually, but the assembly line process is a testament to Tudor's future mass production of Master Chronometer models. The waterproof function is also checked to ensure that it complies with ISO standard 22810 (revised in 2010). It is an unlikely attempt to conduct not only a simple waterproof test but also a waterproof test in accordance with public standards for all individuals.
200m waterproof test on the first day. It is new that all individuals are measured according to the ISO 22810 standard established in 2010, rather than the usual waterproof test.Black Bay becomes even more competitive with the introduction of the Master Chronometer. But Tudor's strengths don't stop there. On the next page, I would like to touch on the exterior, which is another initiative. The reason why the current Black Bay has gained popularity is that it embodies the so-called "sick sports" beyond the excellent performance represented by the Master Chronometer.
