Open Face
An open-face pocket watch, historically known as a Lépine, is a classic timekeeping device designed without a protective metal cover over the dial. This structure allows the user to read the time instantly without any obstruction. Originally viewed as a fragile design reserved for the wealthy, it eventually became the golden standard for safety and precision, particularly within the railroad industry.
Anatomy and Layout:
The Pendant and Crown: The winding stem and crown (the knob used for winding) are located exactly at the 12 o'clock position.
The Bow: A secure metal loop attached to the pendant at 12 o'clock, used to snap on a protective pocket watch chain.
The Dial (Face): The watch dial features prominent hour numbers (often bold Arabic or classic Roman numerals) and highly visible hands for rapid, clear legibility.
Sub-Second Dial: A smaller, recessed register tracking seconds is standard, typically positioned at the 6 o'clock position.
The Crystal: A transparent protective layer made of glass, acrylic, or synthetic sapphire that sits directly inside the bezel to cover the face.
The Case and Accessing the Movement:
Because there is no front lid, the case consists of a solid chassis with distinct access points:
The Front Bezel: Holds the crystal. It can either be unthreaded (snapped off) or unscrewed counterclockwise to give watchmakers access to the hands and dial.
The Rear Case: Protects the mechanical movement. Depending on the model, the back will be a screw-off back (threaded like a bolt), a snap-off back (pried open gently using a case knife at a small lip), or a hinged back that flips open to reveal an internal dust cover protecting the gears.
Key Variations:
Standard Open-Face: Winding stem at 12:00, sub-seconds at 6:00.
Sidewinder: A watch utilizing a movement originally manufactured for a "hunting case" (which opens with a lid) but mounted into an open-face case. This results in the winding stem pointing to the 3:00 position while the seconds register remains at 6:00.
Skeleton: A modern aesthetic variation where portions of the dial are omitted, exposing the mesmerizing, moving mechanical gears beneath the crystal.
Historical Significance: The Railroad Standard:
During the late 19th and early 20th centuries, disastrous train collisions prompted strict timekeeping regulations. Under standards established by professionals like Webb C. Ball, the open-face design became mandatory for all railroad-grade watches after 1908. Authorities banned hunting cases because an engineer could misread the time if a hinge jammed, or misinterpret the hands through a dirty glass window. The open-face layout guaranteed an instant, foolproof reading of the exact time.
Anatomy and Layout:
The Pendant and Crown: The winding stem and crown (the knob used for winding) are located exactly at the 12 o'clock position.
The Bow: A secure metal loop attached to the pendant at 12 o'clock, used to snap on a protective pocket watch chain.
The Dial (Face): The watch dial features prominent hour numbers (often bold Arabic or classic Roman numerals) and highly visible hands for rapid, clear legibility.
Sub-Second Dial: A smaller, recessed register tracking seconds is standard, typically positioned at the 6 o'clock position.
The Crystal: A transparent protective layer made of glass, acrylic, or synthetic sapphire that sits directly inside the bezel to cover the face.
The Case and Accessing the Movement:
Because there is no front lid, the case consists of a solid chassis with distinct access points:
The Front Bezel: Holds the crystal. It can either be unthreaded (snapped off) or unscrewed counterclockwise to give watchmakers access to the hands and dial.
The Rear Case: Protects the mechanical movement. Depending on the model, the back will be a screw-off back (threaded like a bolt), a snap-off back (pried open gently using a case knife at a small lip), or a hinged back that flips open to reveal an internal dust cover protecting the gears.
Key Variations:
Standard Open-Face: Winding stem at 12:00, sub-seconds at 6:00.
Sidewinder: A watch utilizing a movement originally manufactured for a "hunting case" (which opens with a lid) but mounted into an open-face case. This results in the winding stem pointing to the 3:00 position while the seconds register remains at 6:00.
Skeleton: A modern aesthetic variation where portions of the dial are omitted, exposing the mesmerizing, moving mechanical gears beneath the crystal.
Historical Significance: The Railroad Standard:
During the late 19th and early 20th centuries, disastrous train collisions prompted strict timekeeping regulations. Under standards established by professionals like Webb C. Ball, the open-face design became mandatory for all railroad-grade watches after 1908. Authorities banned hunting cases because an engineer could misread the time if a hinge jammed, or misinterpret the hands through a dirty glass window. The open-face layout guaranteed an instant, foolproof reading of the exact time.