The Seiko 6139 is a self-winding mechanical chronograph movement produced by the Japanese watch company Seiko. Introduced in 1969, the Seiko 6139 is widely regarded as one of the first automatic chronograph movements ever produced.
The Seiko 6139 movement features a column wheel and a vertical clutch, which are both key components in a chronograph mechanism. The movement has a frequency of 21,600 beats per hour (3 Hz) and features 17 jewels. It also includes a date complication, which was a novel feature at the time.
The Seiko 6139 movement was used in several different watch models, including the popular Seiko 6139-6002 "Pogue" model, which was named after astronaut William Pogue, who wore the watch during the Skylab 4 mission in 1973.
One of the notable features of the Seiko 6139 movement is its reliability and durability. The movement was designed to be easy to service, and many examples of the Seiko 6139 movement are still running today, decades after their production.
The Seiko 6139 movement was eventually replaced by newer chronograph movements from Seiko and other manufacturers, but it remains a popular choice among watch enthusiasts who appreciate its history, reliability, and innovative design.