Seiko Automatic Chronograph 'Bullhead' Archived Nivada (or Nivada Grenchen) should

Nivada (or Nivada Grenchen) should be a familiar name to vintage watch collectors

W" and their Mark XI aviator's watches) are enduring examples of reliable tool watches that are as beautiful as they are reliable

the Calibre 146 went on to be the base on which Zenith built its automatic chronograph movement

introduced in 1963

But when it does

Seiko Automatic Chronograph 'Bullhead' Archived Nivada (or Nivada Grenchen) shouldThough the Swiss often get all the glory for producing the first automatic chronograph in 1969, Seiko quietly released the Calibre 6139 a rugged automatic chronograph unit as early as May of the same year. In 1970, it made a few tweaks, adding an hour totalizer and a new quickset system, and released the Calibre 6138. Like its predecessor, the 6138 could be found in a number of unique dial and case configurations that have maintained collector