1896 One Hertz RGReference# 1896 One Hertz RGCompare
- Case: 18-karat rose gold
- Size: 43mm
- Movement: original hand-wound movement finished and assembled in-house
- Function: independent dead seconds mechanism, power reserve
- Power Reserve: approximately 72 hours
- Water Resistance: 30m
- Dial: solid silver
- Caseback: sapphire crystal
- Hands: flame-blued steel
- Strap/Bracelet: hand-stitched alligator leather
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.
Caliber G-02: The One Hertz’s caliber G-02 is a totally original, in-house developed movement featuring stainless steel bridges and exceptional fine finishing. In a dead seconds complication, friction of the mechanism has to be absolutely minimal so it does not interfere with the escapement and timing. For the One Hertz, Bart and Tim Grönefeld developed an independent dead seconds mechanism that is driven from its own secondary gear train with its own independent power supply. The dead seconds are driven from one mainspring barrel and the hours and minutes from another.
The One Hertz’s innovative dual drive train results in less friction compared to other jumping seconds mechanisms. A more constant amplitude is obtained and thus assuring superior accuracy.