Complication · Timing
Deadbeat Seconds
Partially verifiedA seconds hand advancing in exact one-second steps.
Definition
A seconds hand advancing in exact one-second steps.
Historical origin
Descended from the deadbeat escapement of precision clocks, and applied to watches for unambiguous reading against a time signal.
How it works
A jumper or an additional escapement-controlled wheel holds the seconds hand between steps, releasing it once per second.
The mechanism must not disturb the balance, so energy for the jump is usually stored and released separately.
Pocket watch context
Used in observation and scientific pocket watches.
Wristwatch context
A specialist modern complication, sometimes chosen for its visual contrast with a sweeping hand.
Clock context
Precision regulators used deadbeat escapements so the seconds hand stepped exactly.
Identification
- A seconds hand that steps cleanly once per second
- A dedicated jumper mechanism visible in the movement
Servicing notes
This is specialist work. Levers, springs and cam profiles in complicated work are calibre-specific, and incorrect reassembly commonly damages parts that cannot be bought. Refer the movement to a watchmaker experienced with this mechanism.
General guidance only. Complicated mechanisms should be assessed and serviced by a qualified watchmaker or clockmaker specialist, not adjusted at home.
Diagram
Sources & references
- de Carle, D., Watch and Clock Encyclopedia
- Britten, F. J., Old Clocks and Watches and Their Makers
- Horological Journal (British Horological Institute), technical articles
Where sources disagree, the disagreement is stated rather than resolved silently.