Grand Seiko Debuts New Hand Wound Hi-Beat Caliber In SLGW002 And SLGW003 With White Birch Dials
The caliber 9SA4 is Grand Seiko’s first hand wound Hi-Beat movement in over 50 years.
Grand Seiko has always been known to enthusiasts for the beauty of its nature inspired dials, high level of finishing in its hands and dial furniture, and, increasingly, for the artistic execution of some of its more widely produced mechanical calibers, which complement the extremely fine hand finished movements found in some of its higher end Spring Drive watches, including the Spring Drive 8 Day. Grand Seiko has also been exploring the world of high complications – in the past, through the Credor brand, which has produced the collector favorite Eichi watches as well as chiming complications, and also through the constant force Kodo tourbillon.
In the domain of fundamentals in watchmaking, Grand Seiko has done something very few other modern brands have done, which is to introduce a new escapement. The Grand Seiko caliber 9SA5 was launched in 2020, with a high frequency (36,000 vph) freesprung balance, and Grand Seiko’s new Dual Impulse escapement, which has an escape wheel which gives impulse to the balance directly, like a marine chronometer, in one direction, and indirectly via a lever, in the other.
For Watches & Wonders 2024, Grand Seiko has introduced a new, hand wound version, the caliber 9SA4, in two new watches, both with White Birch dials; cases are 38.6mm x 9.95mm. Both models are part of the Evolution 9 Collection. The two new models are SLGW002, which is an 80 piece limited edition in rose gold at $45,000, and SLGW003, in Brilliant Hard Titanium, at $10,700.
The introduction of caliber 9SA4 marks the first new hand-wound Grand Seiko Hi-Beat movement in over fifty years. The first Hi-Beat movement was introduced by GS in 1968, in the automatic 61GS and a hand wound Hi -Beat came out the same year, with the 45GS. The first new Grand Seiko Hi-Beat automatic finally returned to the GS collections in 2009, in the 9S8 series – the first GS Hi-Beat caliber in 41 years.
Caliber 9SA5’s Dual Impulse escapement is only the third escapement to enter industrial production since Omega adopted the Co-Axial escapement and launched it in 1999. While the original Daniels design for the Co-Axial escapement was intended to provide the oil-free, direct impulse action of the marine chronometer combined with the self-starting and locking capabilities of the lever escapement, the Dual Impulse escapement from Grand Seiko primarily provides better efficiency, as well as the chronometric advantages of direct impulse in one direction, and impulse to the balance in both directions (the single impulse design of the chronometer escapement is one of its disadvantages in a wristwatch). The Dual Impulse escapement is also self-starting and has the locking advantages of the lever escapement as well.
The 9SA5 was first introduced in the 60th Anniversary SLGH002, as a 100 piece limited edition, but the caliber is now available in a number of different models,
According to Grand Seiko, the 9SA4 is definitely not just a 9SA5 with the rotor and automatic winding train removed. GS says that “nearly 40%” of the movement has been redesigned, with special attention paid to creating a pleasantly tactile winding experience.
The movement demonstrates Grand Seiko’s approach to movement finishing. The beveling is very clean, albeit applied with a diamond cutting machine, and the movement stripes are very finely done and perfectly aligned across the bridges. Screw and jewel countersinks are mirror polished as well. As with the 9SA5, the balance, with its rim mounted timing screws, is fixed under a balance bridge for better stability, and there’s a power reserve indicator on the main train wheel bridge as well. Power reserve is 80 hours and the movement, while not ultra thin, is still relatively flat, at 31mm x 4.15mm.
Part of this redesign was the click for the crown wheel, which is in the shape of a stylized wagtail bird’s head.
Hand wound movements nowadays are not rare as such but the great majority of mechanical watches sold are now, and have been for many decades, automatic. It is however unusual to see a new hand wound movement launch, and especially one which we can expect to see more widely produced. I’m a fan of hand-wound movements although I appreciate the added convenience of an automatic.
There is something about winding a watch every day that puts you in direct physical contact with its machine nature and makes you a more intimate part of the life of the watch than the more passive experience of a self winding caliber. The caliber 9SA4 is, if you already love the experience of winding your watch or even if you’ve never owned a hand wound watch and want to try it, a welcome addition to Grand Seiko’s lineup, and proof of its continuing commitment to strengthening the foundations of its collections.
The Grand Seiko SLGW002 and SLGW003: cases, 38.6mm x 9.95mm, in rose gold or Brilliant Hard Titanium; water resistance 30M, antimagnetic to 4,800 A/m (amperes per meter). Sapphire crystals front and back. Movement, caliber 9SA4, Hi-Beat, hand wound with Seiko Dual Impulse escapement, controlled to +5/-3 seconds per day (COSC for comparison is +6/-4) running at 36,000 vph in 47 jewels; 80 hour power reserve, with power reserve indication on the movement bridge. SLGW002, 200 piece limited edition, $45,000, SLGW003, regular production, $10,700. For more visit Grand-Seiko.com.