Gronefeld One Hertz with Dead Seconds Other countries

The new Gronefeld One Hertz plays with a fairly old complication that has almost become obsolete after the infamous Quartz Crisis of the 1970s, but got a fresh breath of life during the last decade as luxury watchmakers around the world struggle to find new ways to attract new customers to their products.

In a couple of days, during the Baselworld 2011 show, the duo of Dutch watchmakers Tim and Bart Grönefeld are going to present their new hand-wound watch that features a rare dead-seconds complication.

What’s dead seconds? The first thing that comes to mind is, perhaps, the time you have to spend in an elevator with a stranger. However, European watchmakers use the term in a different way referring to the deliberately non-smooth fashion the seconds hand travels around the dial, but let me start with a brief explanation though.

Normally, the way the seconds hand moves depends on how fast is the balance wheel of your watch, which is measured in “vibrations per hour”: VPH (although, sometimes, they refer to it as “semi-oscillations per hour,” which is basically the same.) Since there are 3600 seconds in an hour, a normal mechanical watch has its second hand (if available) making VPH/3600 jumps per second.

Gronefeld G-02 hand-wound caliber with dead seconds complication

If your timekeeper’s balance wheel beats at 28,800 vph (which is almost a standard for a contemporary movement,) then the seconds hand on your watch makes 28,800 / 3600 = 8 small steps to travel from one mark on the minute track to the other. Some watchmakers (like Zenith with their El Primero family and TAG Heuer with the Carrera Mikrograph chronograph) have faster mechanisms that beat at even more impressive 36,000 semi-oscillations per hour allowing the seconds hands travel in an even smoother fashion.

That’s why it is called a “sweep second”: it runs so fast that its “jumps” look like a continuous, flowing movement that differentiates mechanical watches from the majority of electric timepieces.

On the other hand, dead seconds complication makes the second hand make precisely 1 “big” step per second, like a quartz watch does.

Although the complication is not very popular now because a quartz watch is not deemed “cool” any more, it is still not an easy task to accomplish.

Gronefeld One Hertz hand-wound watch in rose gold

However, the two Dutch brothers somehow managed to create their own manufacture-made movement with such a function.

The Gronefeld G-02 hand-wound movement is made of 285 components and sports two spring barrels: one for the going train and the other for the independent dead seconds module.

Also, the beautifully executed movement features a couple of more useful functions: a power reserve indicator (at 12 o’clock) and a setting-winding indicator at 3 o’clock. The latter makes it easier to operate the winding crown.

Gronefeld One Hertz hand-wound watch in stainless steel

As to the styling, the Gronefeld One Hertz looks absolutely terrific, although there is something to it that makes one remember art objects from the German-based Porsche Design studio.

According to the Dutch brand, the watch will be produced in two versions: stainless steel “1912” and rose gold “Dune.” The former will be limited to 12 pieces and the latter will only be produced in 20 copies.

Looks like a very desirable, interesting, and potentially very expensive piece for true enthusiasts.

See also: Girard-Perregaux 1966 Full Calendar in White Gold

Photos: Grönefeld




Gronefeld One Hertz hand-wound watch specification

Price: TBD
Movement: Manual (hand-wound,) caliber G-02, 39 jewels set in gold chatons, 285 parts, 35 mm x 9.4 mm, two barrels, 21,600 vph, in-house, Made in Netherlands
Movement decoration: Spotted rhodium plated nickel silver main plate; Stainless steel hand bevelled bridges, micro-blasted, circular grain on the top, relief engraved on micro blasted surface
Functions: Hours, minutes, dead seconds, power reserve, setting/winding indicator
Power reserve: 72 hours
Case material: Stainless steel / Rose gold
Bezel material: Stainless steel / Rose gold
Case shape: Round
Bezel shape: Round
Case size: 43.00 mm
Lug width: N/A
Case height: 12.50 mm
Dial: Brown, Grey
Numerals: N/A
Hands: Dauphine
Water resistance: 30 meters
Strap: Hand-sewn matte black, alligator leather with stainless steel or rose gold engraved tang buckle to match case
Crystal: Sapphire, antireflective on both sides
Case back: Sapphire, antireflective


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