Seiko's 6139 automatic chronograph - like the all original mid-1971 Seiko 6139-7002 here - was a historical movement in its own right, as it was one of the first automatic chronograph movements created, and rightly counts itself within the ranks of the first automatic chronographs, like Heuer's Calibre 11 and Zenith/Movado’s El Primero movements.
Back in the late 1960's, Heuer and Zenith had taken hold of the entire sports watch industry by racing to become the first to produce an automatic chronograph. It has been a feat debated who won, but in the background of this skirmish, Seiko quietly created their own at the same time, likely beating the Swiss at their own game – the Seiko 6139.
The 6139 was the first chronograph to have a vertical clutch, a feature considered by many to be one of the hallmarks of a superior automatic chronograph movement. The 6139 also features an automatic column wheel timing control, vertical coupling mechanism, and is an integrated chronograph – the first in the world – which means the entire 6139 movement was designed and built to be a chronograph, vice being an automatic movement with a mere timing module added.
With this movement, Seiko set the standard, which was followed by the Swiss watch industries 20 years later. The same movement configuration was adopted by Rolex when it made its own in-house movement for the Daytona in 2000, 30 years after Seiko released the caliber 6139 and 6138. This particular Seiko 6139, the 7002 variant, represents yet another variant of Seiko's famed 6139 automatic chronograph line.
This 6139 comes with its original Seiko-signed stainless-steel bracelet, NATO strap, springbar tool, and Pelican travel case.
1971 Seiko 6139-7002 Automatic Chronograph
DIAL: Original silver water resist-signed dial, with original minute and hour hands. Day/date complications – with Roman numeral/English variants – at 3 o’clock position work nicely.
CASE: Original 41.5mm x 44mm stainless steel case; crown is recessed.
CRYSTAL: Hardlex crystal, no scratches.
BAND: This 6139 comes with its original stainless-steel Seiko-signed bracelet, as well as a black, orange, and cream-colored nylon NATO strap, with stainless steel hardware.
MOVEMENT: Original Seiko 17-jewel 6139B automatic movement, manufactured in August 1971.
CROWN: Original recessed unsigned stainless steel crown.
CHRONOGRAPH PUSHERS: Chronograph pushers depress with a satisfying click, with a reset to zero every time.