Slimmer, with Precision and Power for a New Generation
Grand Seiko Enters a New Era of Technological Excellence
Making a choice is often difficult, and can get the best out of anyone who ever attempts it. For watch lovers back in the day, it was either choose a mechanical watch and enjoy its traditional character and autonomy, but tolerate its relative imprecision or wear an electronic watch that was up to ten times more accurate, but required a battery. It so happens that when you take a dilemma like this to the watch makers at Grand Seiko, they create the Spring Drive, that combines the best of both the existing two watch technologies in a watch powered by a mainspring that offers accuracy of one second a day. Spring Drive back in 1991, and today, remains one of horology’s greatest advances. And two decades after, Grand Seiko introduces a new generation Spring Drive caliber that is slimmer, even more precise and has a greater power reserve. Caliber 9RA5 takes Spring Drive technology to a new level of excellence and opens a new era in the history of Grand Seiko.
The Grand Seiko team, with an ambitious goal in mind, aimed to create a Spring Drive watch that, in size, performance and functionality, would set a new standard for any spring-powered watch. Their creation, Caliber 9RA5, did precisely that. Caliber 9RA5 delivers a five-day power reserve as opposed to the 9R6 caliber that is the mainstay of the current collection, an increase of 60%. Its monthly precision rate amplifies from ±15 seconds a month to ±10. The movement depth has been reduced from 5.8mm to 5.0mm and the speed of the date change has been greatly increased.
The re-design and re-positioning of the Magic Lever has made Caliber 9RA5’s thin profile possible. The Magic Lever, developed in-house in 1959, boosts the efficiency of the automatic winding mechanism by using the energy created by movement of the oscillating weight in both directions. In the new caliber, the new Offset Magic Lever is positioned away from the center of the movement to reduce its thickness. And to great remarkability, this is achieved with no loss of winding efficiency. To lower the center of gravity and achieve a comfortable fit on the wrist, the stem and crown are also positioned towards the back of the case. Although, Caliber 9RA5 may be slim but it has enhanced rigidity and shock resistance owning to the new layout of the gear train towards the center of the movement and a central bridge that holds them together. This One-piece Center Bridge achieves a shock resistance that meets the ISO standard for diver’s watches.
Thanks to a new IC package and to the selection of highly stable quartz oscillators that have gone through a three-month aging process, Caliber 9RA5 has an accuracy rate of ±10 seconds per month. For the first time in a Spring Drive movement, the IC incorporates a sensor to measure the temperature within the movement and is programmed to compensate for any inaccuracies in the crystal oscillation rate which may be caused by temperature change.
As with every Spring Drive caliber, 9RA5’s seconds hand moves in perfect glide motion and, through it, expresses the natural and continuous flow of time that resonates so deeply with the Japanese sensibility. In its finishing, also, the movement has a beauty that is uniquely Japanese and is inspired by the natural environment of the studio where it is made. The jewels echo the glittering stars that sparkle especially brightly during the early days of winter in the surrounding mountains and the delicate texture of the movement’s surfaces reflect the frost that winter brings to the trees.
To demonstrate its power, strength and precision, the first creation to be powered by Caliber 9RA5 is a professional diver’s watch. It has helium and water resistance that meet the challenge of saturation diving at depths of up to 600 meters. The case is in high-intensity titanium, which is 40% lighter than steel and more impervious to scratches. The power reserve is at the 10 o’clock position and the indicator is divided into five parts to show exactly and clearly how many days of power are left. The case, crystal and bezel are all designed for easy and safe disassembly for the maintenance that a professional diver demands. It is a watch entirely worthy of the high performance of the new caliber that powers it.
The watch is presented in a special Grand Seiko 60th anniversary box with an interchangeable blue silicone strap. It will be available worldwide in August as a limited edition of 700.
Grand Seiko 60th Anniversary Limited Edition
Professional Diver’s 600M
Spring Drive 5 Days Caliber 9RA5
Driving system: Automatic
Power reserve: 5 days (120 hours)
Accuracy: +/–0.5 seconds per day (+/–10 seconds per month)
Number of jewels: 38
Diameter: 34.0mm, Thickness: 5.0mm
Specifications:
High-intensity titanium case and bracelet
High definition sapphire crystal
Screw-down crown, screw case back
Water resistance: 600m saturation diver’s
Magnetic resistance: 4,800 A/m
Diameter: 46.9mm, Thickness: 16.0mm
Three-fold clasp with push button release, secure lock and extender
Limited edition of 700SLGA001
