The recently unveiled Gronefeld One Hertz Techniek wrist watch features Gronefeld’s signature Caliber G-02 hand-wound movement, which is known to connoisseurs not only for its nice finish, but also for its independent “dead seconds” complication that makes the off-centered seconds hand leap in one second intervals mocking those cheap quartz timekeepers. In two words, it rocks.
Measuring 34 millimeters in diameter and almost 10 millimeters in height, the beautifully decorated movement comprises 285 components, those including an independent going gear train for the dead seconds mechanism.
Since the complication requires loads of energy to keep going, the watchmakers equipped the watch with a second spring barrel that is used exclusively to supply the module with all the power it needs.
Still, even with two barrels, the watch will only work for some 72 hours (three whole days) after being fully wound.
As usual, the One Hertz Techniek sports a pretty complicated skeletonized dial with four sub-dials accompanying the huge sapphire circle of the off-center seconds hand indicator.
The, err, second in command is, of course, hours and minutes sub-dial that features four nicely executed Roman numerals on its chapter ring.
On its left, there is an easily readable (albeit, too oversized for my taste) power reserve indicator, and on its right is another indicator that makes it easier to operate the watch via the slightly oversized setting/winding crown. When the hand is in the first position (W), it means that the watch is ready to be manually wound; the second position (S) tells you that you can set current time.
Very convenient feature, that.
Since the movement is quite large, the polished titanium body (there is also a version in an extremely scratch resistant black DLC coating, which is promptly called One Hertz Techniek Nocturne) of the timekeeper is not terribly compact either. According to official specs, the case of the timekeeper measures 43 millimeters in diameter and is 12.5 millimeters thick, which still makes this beast wearable even for those who spend their weekdays in expensive business suits.
The only problem that I see here is that the watch will be limited to just 30 numbered pieces: it’s going to be really difficult to find an unused One Hertz Techniek after it goes on sale.
Gronefeld One Hertz Techniek watch specification
Movement: Manual, Caliber G-02, in-house, 285 comonents, 34 mm x 9.5 mm
Number of jewels: 39
Movement frequency: 21,600 vph
Power reserve: 72 hours (three days)
Movement decoration: Hand frosted and spotted black rhodium plated nickel silver main plate; hand-bevelled, micro-blasted bridges
Functions: Hours, minutes, off-center seconds, power reserve, Winding/Setting indicator
Case material: Titanium / Black DLC Titanium
Bezel material: Matches case
Crown material: Matches case
Case shape: Round
Bezel shape: Round
Case size: 43.00 mm
Case height: 12.50 mm
Lug width: No data
Hour markers: Engraved
Hands: Dauphine shaped
Water resistance: 30 meters
Strap: Hand-sewn matte black alligator leather strap with steel tang buckle (black DLC coated for Nocturne model), Grönefeld logo
Crystal: Sapphire, domed, antireflective on both sides
Case back: Sapphire, flat, antireflective on both sides