Introducing the Grand Seiko 60th Anniversary Limited Edition SLGH002 with New Slim Hi-Beat MovementBy Sumit Nag
With the calling off of Grand Seiko and Seiko’s first ever Japan based watch fair, in light of the present global health scare, it’s tad disheartening that for its 60th anniversary Grand Seiko will not be able to hold an appropriate celebration, any time soon.
But if the watches created for the occasion are anything to go by, what a celebration Grand Seiko must’ve planned. Perhaps we’ll get to celebrate the brand after all, when the situation has cleared up. For now, we focus on the watches at hand.
There’s already been one wave of watches announced earlier in January. You can read about them, here.
Today’s wave includes a recreation of the original 1960 Grand Seiko, in three variations; a 60th Anniversary Limited Edition Professional Diver’s 600M fitted with the Spring Drive 5 Days Caliber 9RA5, the Elegance Collection Grand Seiko 60th Anniversary Limited Edition set of watches and, lastly, the Grand Seiko 60th Anniversary Limited Edition SLGH002, powered by the brand new Caliber 9SA5 Hi-Beat 36000.
Grand Seiko 60th Anniversary Limited Edition SLGH002
The 60th Anniversary Limited Edition SLGH002 builds on the Grand Seiko Style that was defined in 1967, but with discreet cosmetic updates. For one, the watch sits with a thickness of just 11.7mm, which make for an elegant profile. Broad bevelled, visibly wider lugs and bezel alternate with polished and brushed finishes, giving the 40mm yellow gold case a great sense of presence despite the watch being quite thin.
Matching the more prominent lugs, the elements on the dial — the hour markers, hands and date window — are likewise given greater volume so that nothing on the watch face looks out of place.
Now the reason why the watch is as thin as it is, is because of that new movement, the Caliber 9SA5 Hi-Beat 36000. Grand Seiko says that the new movement is 15% slimmer than other Hi-Beat Calibres that are presently in production.
This was made possible by a new approach to their gear train layout, which has all of the components laid out on a single horizontal plane. Its barrels are in series followed by the wheels, again in series, and finally the escapement assembly. From barrel to escapement, every component relates to one another in series, with nothing that receives power by transmission type gearing.
The next innovation in the movement comes courtesy of a brand-new escapement design. The new mechanism allows for the escapement wheel to directly transmit power to the balance wheel. But there is still a traditional pallet and fork assembly. So what happens is that when the escapement wheel spins in one direction, it hits the balance wheel directly and when it spins in the opposite direction it gives impulse to the pallet fork.
The pallet fork and escapement wheel are made using MEMS technology, which includes specific notches onto the components where lubricants are better held and for longer. Therein, making the Caliber 9SA5 Hi-Beat 36000 not only a more efficient movement, but also one that will require maintenance less often.
The last bit of innovation that must be mentioned is ta new free-sprung balance developed for this calibre. Preceding Hi-Beat movements used flat hairsprings while the 9SA5’s hairspring includes an overcoil, the shape of which was engineered after having put the initial prototypes through 80,000 simulations.
Self-winding Caliber 9SA5 Hi-Beat 36000; hour, minute and running seconds; instantaneous date; 80-hour power reserve
40mm 18k yellow gold; 100m water-resistance
Crocodile strap with 18k yellow three-fold clasp with push button release
Limited edition of 100