The name Grönefeld has been associated with fine watchmaking for over a hundred years. In 1912 Johan Grönefeld began making quality timepieces in the ancient town of Oldenzaal in the Netherlands. Presently his grandsons Bart and Tim have followed in his footsteps by establishing their own range of luxury timepieces. Amazingly they still occupy the same workshop originally used by their grandfather all those years ago.
After years of extensive training in Switzerland, Bart and Tim finally released their first watch in 2008. Ambitiously this incredible timepiece was called the GTM-06 Tourbillon Minute Repeater. The watch was limited to only ten pieces and included specially designed channelled lugs to improve acoustic resonance. In 2010 they introduced a second model called the One Hertz. This phenomenal timepiece lays claim to being the world’s first wristwatch with independent dead seconds. Traditionally watchmakers achieved this mechanical feat from a constant force device. The Techniek is a superb new open worked interpretation of the watch. In my recent Baselworld 2013 article I featured this beautiful timepiece as one of my top ten highlights.
With case dimensions of only 43 mm x 12.5 mm the One Hertz Techniek isn’t particularly large by modern standards. These subtle proportions should appeal to the discerning collector. I can also imagine a watch of this size would be very comfortable to wear for most occasions. Principally this is down to the classical design and use of Grade 5 titanium in production. Grönefeld only manufacture a limited amount of watches each year, which makes this piece highly exclusive. On that basis I suspect this watch would be selected for special events rather than everyday use.
Of all the One Hertz models this version is definitely my personal favourite. I feel the skeletonised façade give the timepiece a whole new and exciting dynamic. The multi-layered dial wonderfully displays all the intricate mechanics of the watches movement. I love the three-dimensional sub dials displaying hours/minutes and independent dead seconds. Grönefeld have superbly relief engraved, bevelled and finished all elements of this composition by hand. The overall result is a master class in haute horlogerie.
Bart and Tim Grönefeld have developed a technically brilliant and sophisticated movement to operate the One Hertz Techniek. The Calibre G-02 is a 39 jewel mechanical hand winding movement that comprises 285 components and oscillates at a frequency of 21,600 vibrations per hour. It is pertinent to mention the complication also incorporates a unique secondary gear train to supply power to the independent dead seconds mechanism. This accomplishment is visible through the sapphire crystal case back. The watch features hours, minutes, independent dead seconds and a respectable power reserve of 72 hours.
The wonderful One Hertz Techniek is also available in a black DLC (diamond like carbon) coated titanium version called the Nocturne Techniek. Both models have hand-sewn matte black, alligator leather straps with steel tang buckles. The watches are limited to 30 pieces each and are engraved with individual serial numbers. The suggested retail prices range from € 49,500-€ 52,500 (approximately $66,129-$70,136).