How should we define the beauty of a watch? Is it timeless in the true sense? Taking up the unprecedented challenge of attempting to find an answer to this grand question is the Micro Artist Studio, which produces Grand Seiko’s Masterpiece Collection. To explore the charms of the new models featuring Caliber 9R02, released to mark the 20th anniversary of Spring Drive, I spoke with Osamu Takahashi in charge of movement design and Kazunori Hoshino in charge of planning and design.
Since ancient times, the Japanese have cherished nature and found beauty therein. They are very sensitive to the changing of the seasons, from spring to summer and from fall to winter, and have placed great value in appreciating taste and elegance. Encapsulating such aesthetic sense peculiar to Japan is the drive mechanism unique to Grand Seiko: “9R Spring Drive.” To mark the 20th anniversary of Spring Drive, in 2019 two models featuring Caliber 9R02 produced by the Micro Artist Studio appeared in the Grand Seiko Masterpiece Collection.
Thanks to a manual-winding movement that achieves a power reserve of about 84 hours with Spring Drive, the model, whose glide motion seconds hand moves smoothly and soundlessly, quietly marks time while expressing a world mantled in snow. How was it born? In order to unravel the charms of a masterpiece that dramatically expresses the beauty of the natural landscape of Japan throughout the watch, I spoke with Osamu Takahashi, who was in charge of the movement design of Caliber 9R02.
Putting one’s whole heart into each and every process in watchmaking, from parts manufacture to planning, design, assembly, and adjustment—this is the pride of the craftspeople of the Micro Artist Studio, and is also a display of sincerity to the wearers of the watch. Osamu Takahashi, who was in charge of Caliber 9R02’s movement design, is also one of the experts who approaches watchmaking with that serious attitude. Takahashi talks about the development history of Caliber 9R02, the newest member of the Grand Seiko Masterpiece Collection.
“What became the base of Caliber 9R02 is Caliber 7R14, featured in the Eichi II that was released in 2014. While taking the benefits of this movement made for a Credor watch, which received worldwide recognition, our aim was to further evolve it to a level appropriate for the Masterpiece Collection, Grand Seiko’s highest-end collection. The main task was to achieve a duration of three days or more, exceeding the power reserve of about 60 hours achieved by Caliber 7R14. During a process of trial and error, we realized a duration of about 84 hours by developing a manual-winding Spring Drive equipped with two innovative mechanisms: the Dual-Spring Barrel and the Torque Return System.”
The Dual-Spring Barrel newly developed by the Micro Artist Studio, one of the two mechanisms featured in Caliber 9R02, adopts a special structure of incorporating two mainsprings in parallel for one barrel, in contrast to the conventional single mainspring for one barrel. Accordingly, it realized a 40% increase in the number of turns while maintaining the conventional torque.
The Torque Return System on the other hand, is an epoch-making mechanism that was developed by making full use of characteristics unique to the high-torque Spring Drive in order to extend a watch’s duration using the mainspring’s energy without waste. To express the feature in short, Takahashi says it is “a mechanism that winds itself up as the mainspring unwinds.”
“I think you can understand if you look at a wind-up music box; when the mainspring is fully wound up, it plays quickly, and as it unwinds it gradually becomes slower, doesn’t it? In a similar way with a mechanical timepiece, the torque is high when the mainspring is fully wound, but lowers as the mainspring unwinds. A watch and a music box differ greatly in that the mainspring of a watch operates while controlling the energy when the torque is high, in order to allow movement at a constant speed. Put another way, the portion of the mainspring torque being controlled is not being utilized. If you use this energy effectively, the watch can wind up the mainspring on its own and extend the duration while operating, for about 48 hours from a fully wound state with a large mainspring torque. The Torque Return System is the embodiment of this mechanism.”
For about 36 hours during which the mainspring unwinds and the torque decreases, this mechanism automatically concentrates on moving the watch. By combining the two mechanisms of the Dual-Spring Barrel and the Torque Return System, the models featuring Caliber 9R02 have achieved an 84-hour power reserve with Spring Drive, while maintaining the slim and compact feel unique to a manual-winding movement.
“In what way should we evolve Caliber 7R14 to a level appropriate for Grand Seiko’s Masterpiece Collection? In producing that watch, how should the respective elements be? I have advanced the development process while spending time carefully discussing such topics with all members at the Micro Artist Studio. Extending the watch’s duration was an important task, but in addition to such functional aspects, we considered all kinds of different patterns regarding appearance specifications, such as how to design the GS logo and where to position it, and took pains to bring it to its current form.”
Coming up in Part 3, we feature an interview with Kazunori Hoshino, who planned and designed Caliber 9R02.