Fortis Mens 710.10.37 M – F-43 Jumping Hour Watch

A Most Venerable Watch Complication Renewed

Analog watches tell time by way of hands that move in a circular motion. A “jump hour” complication replaces the traditional hour hand with a window through which the numerical hour is displayed. When the hour advances, the window (or the disc below it) makes an instant jump to the current hour.

Jump hour watches are not only appealing from a horological point of view; they are also functional, because reading the time using this configuration is unambiguous. In the hands of skilled watchmakers, the jump hour complication also presents opportunities to conceive of new and interesting arrangements such as the Fortis B-47 Mysterious Planets timepiece, introduced last year.

This year, at Baselworld 2013, Fortis introduced its latest jump hour model – the F-43 Jumping Hour – a watch that highlights the complication with artful simplicity. Like the B-47 before it, the F-43 Jumping Hours houses the Fortis F-2024 automatic movement, comprised of a highly modified ETA base with the jump hour mechanism added entirely by Fortis. A small portion of these components are visible through the dial; a wider view of the movement is visible through the glass caseback. The F-2024 employs 21 jewels and an Incabloc shock absorber. It beats at 28,800 vibrations per hour.

Fortis Mens 710.10.37 M – F-43 Jumping Hour Watch

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But the dial is where the spectacle of the jump hour complication plays out. A matte-textured, smoky-gray disc covers a better part of the dial. Through its translucent surface, Arabic hour numerals appear on the dial plate below. The current hour is displayed through the circular aperture on the disc. When the hour changes the gray disc rotates clockwise, while the centrally mounted minute hand continues its customary rotation around the dial. Design details include chrome hour markers as well as a thin chrome frame around the aperture.

The watch’s two-part case is 43 mm in diameter and made of brushed stainless steel. Sapphire crystal with anti-reflective coating applied to both sides protects the dial side of the watch; the caseback screws down adding to the watch’s water resistance to a depth of 656 feet. The large crown is characteristic of many Fortis Space and Aviation models and features the Fortis logo. Each watch in this 500 piece limited edition is individually numbered on the caseback.

The neutral tones of the F-43 Jumping Hour are well suited to either a bracelet or strap, but the matching brushed-steel bracelet shown here is the most robust choice with its thick triple-link construction and folding clasp.