Gronefeld G-02 One Hertz

The Grönefeld One Hertz is the world’s first and only series wristwatch with independent dead seconds. It features a beautiful solid silver dial and an entirely in-house developed movement with stainless steel bridges and exceptional fine finishing. Dead seconds is where the second hand advances in full steps of one second instead of the usual smooth sweeping action of mechanical seconds. With the One Hertz, Bart and Tim Grönefeld have resurrected this long-neglected horological complication and re-positioned it on the pedestal of high precision. Until the arrival of the One Hertz, dead seconds – secondes mortes in French – in wristwatches was usually derived from constant force devices. The Grönefeld One Hertz is unique among wristwatches in that to maximize precision, its dead seconds are powered by a secondary gear train, independent of the gear train for the hour and minute indications. While the dial is dominated by the over-sized dead seconds, elegantly shaped blued-steel hour and minute hands make for easier reading of the time in the sub dial at 2 o’clock. The hour/minute sub dial is visually balanced on either side by a power reserve indicator at 11 o’clock and winding-setting indicator at 3 o’clock. Winding and setting are ergonomically selected by pushing the crown in, instead of pulling it out, and the winding-setting indicator shows the selected mode. What’s more, the counter-poised seconds hand ‘hacks’ – i.e. stops – when ‘setting’ is selected, to ensure maximum precision when setting the time. The dial is crafted out of solid sterling silver then blasted with brass particles to attain a frosted finish with a slight sparkle. The soft sheen contrasts superbly with the flamed-blued hands, making for excellent legibility. The graceful curves of the displays are complemented by the three-dimensionality of the multi-layered dial, which is beautifully framed by the highly-polished red gold case and bezel. All applied dial elements, including the dead seconds chapter ring, are rhodium plated with circular graining and beveled edges. The bevels are polished with diamond paste to a brilliant gloss to create scintillating reflections of light, echoing the high-end finishing of the stainless steel movement bridges visible through the display back.


  • Role CAD Designer - Dial and Hands

  • For Gronefeld

  • Date Design xx.10.13 Released 27.03.14

  • Type Haute Horology

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