quattro's overview of the Grand Seiko Kodo Constant-force Tourbillon, reference SLGT003, offers a crucial look at Grand Seiko's first complicated mechanical watch. This piece not only details the watch's innovative constant-force tourbillon mechanism but also explores its design evolution from a concept movement to a GPHG award-winning timepiece. Understanding the Kodo's technical achievements and design philosophy is essential for appreciating Grand Seiko's haute horlogerie aspirations.
The
Grand Seiko Kodo Constant-force Tourbillon was introduced in
2022 as ref.
SLGT003, a limited edition of
20 pieces.
credit: @yuu.sekiguchi
It was the first complicated mechanical watch from the brand in its six decades years of history and it combined a constant-force mechanism and a tourbillon as one unit on a single axis.
Two years earlier, in 2020, Grand Seiko had introduced the βT0 Constant-force Tourbillonβ, a concept movement that had yet to be realised into a wristwatch.
Both the T0 and the Kodo were designed by Mr. Takuma Kawauchiya.
credit: Grand Seiko
The SLGT003 featured a 43.8 x 12.9 mm case made up of a platinum inner case contained within an outer case of Brilliant Hard Titanium.
The
two case materials combine most evidently at the
tapered end of the
lugs where a
small open space between each
lug adds a lightness and unique aspect to the overall design.
The main specificity of Caliber 9ST1 is to integrate together the constant-force carriage (left) and tourbillon carriage (right).
The sounds of the escapement and of the once-per-second impulse of the constant-force mechanism are said to create a regular βheartbeatβ, hence the name of the watch, βKodoβ being the Japanese word for heartbeat.
The watch was awarded the 2022 GPHG Chronometry Prize.
Below, Akio Naito, President of Seiko Watch Corporation, and watchmaker Takuma Kawauchiya receiving the prize.
credit: @xx_jiii_xx
The same year, Grand Seiko made a Piece-Unique variant of the Kodo, the SLGT001, the concept of which was based on musΕ η‘ε, which roughly translates to βone and onlyβ or βsecond to noneβ.
While the standard version had a monochromatic grey palette, the SLGT001 was set apart by its colour: heat-blued and gilded components against rhodium-plated bridges.
And the SLGT001 was also distinguished by its full Brilliant Hard Titanium case (instead of a mix of platinum and titanium).
The watch was
sold by
Phillips and a portion of the proceeds from the sale went to the
Childrenβs Heart Foundation.
Finally, in 2024, Grand Seiko released a third version of the Kodo, the SLGT005.
credit: Hodinkee
The watch was technically identical but dressed in brighter colours of silver tones and pale greys, hence the βDaybreakβ nickname.
credit: @windovermatter
As in the initial SLGT003, the case is a two-metal combination of a platinum inner case with a Brilliant Hard Titanium outer case.
The
light beige calfskin strap emphasises the
opposition between this new Kodo, inspired by
morning and the
initial one, inspired by
twilight.
The
single axis combining
tourbillon and
constant-force mechanism can still be admired.
One
last shot.
credit: Sjx
Not being a fan of watches with openworked dials and movements, the Kodo evokes mixed feelings in me.
I admire the craftsmanship, but I'm not drawn to it.
Especially since the watch's transparent structure, which makes the wrist visible through the dial, also gives me pause.
What do you think?
Thanks for reading.
Best, Emmanuel
