Introducing The Grönefeld One Hertz Techniek and One Hertz Techniek Nocturne

By: Kidist Amanuel


The Dutch watchmakers Bart & Tim Gronefeld have introduced two new watches to their One Hertz line with the Techniek and Techniek Nucturne. Techniek is the Dutch word for “technical.” “One Hertz” means “one cycle per second.” The name is a reflection of the open work dial that allows view of the One Hertz movement. The complex mechanics observed through the open dial is truly unique. The One Hertz Techniek is the world’s first and only serially produced watch ever to include independent dead beat seconds. (see this technology here)The open dial allows one to observe all the wonderful mechanics of these watches. There is also a limited edition of these One Hertz watches.


As mentioned, the One Hertz Techniek comes in two versions: the One Hertz Techniek has a high tech Grade 5 titanium case with natural polished and brushed titanium finish, while the One Hertz Techniek Nocturne has black DLC finish. Inside the case- and revealed through the open dial- is the Gronefeld’s own proprietary movement Calibre G-02. The dead seconds of the One Hertz are powered by the secondary gear train, which is independent of the gear train for the hour and minute indications. The complication of dead beat seconds is that the second hand advances in full steps of one second instead of the usual smooth sweeping action of mechanical seconds. Ergonomic winding and setting mechanisms can be selected by pushing the crown in. The back of the case is just as fascinating as the front. The power reserve and winding setting indication are made of stainess steel. The display case back features finely crafted stainless steel finger bridges. The One Hertz is the first series movement to feature all the bridges in stainless steel.


calibreThe dial of the One Hertz Techniek features large dead seconds chapter ring in sapphire, while indications, bridges and logo are finished with relief-engraved and beveled stainless steel. The tracks around the hours/minutes sub dial are made of stainless steel as well. The surface is laser engraved, so all the markers are shown in relief. The hour markers for 12, 3, 6, and 9 are Roman numerals and easily legible. The hands are easy to read as one side is micro-blasted and the other side is polished. The independent dead seconds can be prominently seen in a subdial at 7 o’clock position. The lever and spring of the power reserve indicator can be seen at the top of seconds dial at 11 o’clock.

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