Seiko 6139

Seiko 6139 and later 6138 are pioneering automatic chronograph movements from Seiko.

Introduced in 1969, alongside notable similar movements from Zenith and Chronomatic and before the Lemania 5100 and Valjoux 7750, the Seiko was the first chronograph to feature a vertical clutch mechanism, an advance now found on many high-end chronographs. It was not a luxury movement, however, and was used in many utilitarian and tool watches, including a "speed timer" and diver.

The 6138/6139 is related to the Seiko 6100 calibre family, sharing some parts.

The 6138/6139 lack a running seconds hand. The central sweep seconds hand is only used for the chronograph function and there is no small seconds subdial. The day and date quickset mechanism is unusual for Seiko in that it is a crown pusher type: The date is set with a light press of the crown, while the day is set with a deeper press.

The "Pogue" Chronograph

In 1973, astronaut and former Thunderbird pilot Col. William Pogue, carried his personal Seiko 6139 into space on the Skylab 4 mission. This yellow-dialed watch accompanied an official-issue Omega Speedmaster, but he preferred the "speed timer" feature of the Seiko to time engine burns.

This became the first automatic chronograph in space, and the watch sold at auction in 2008 for $6,000.

Versions

There were two versions of the 6138/6139 chronograph produced. The later "B" movements feature a modified switching mechanism.

• 6138 - Sweep 60 second, 30 minute, and 12 hour chronograph counters
• 6139 - Sweep 60 second and 30 minute chronograph counters

All feature quick-set day and date.

See Also

• Automatic chronograph

External Links

• Just Because: Seiko 6139, The Other First Automatic Chronograph
• IN-DEPTH: Your Vintage Seiko Chronograph Buying Guide
• Revisiting An Icon – The Seiko Speedtimer

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Description: Self-winding chronograph Column wheel Vertical clutch Functions: Hours, minutes Quickset day and date by pushing the crown Chronograph: 60 second sweep 30 minute subdial Optional hour subdial Data: 12 lignes (27.0 mm), H: 7.2 mm (6139) or 8.0 mm (6138) 17 or 21 jewels 21,600 A/h Power reserve 45 h Production period: 1969-1979