Pocket watches · Complication

Split-Seconds (Rattrapante) Pocket Watches

Needs research

Chronograph watches with two superimposed elapsed-time hands that can be stopped independently, allowing intermediate ('split') times to be read while the timing continues.

Mechanism

A clamp can grip the split hand's wheel, halting it for a reading while the main chronograph hand continues; releasing the clamp allows the split hand to fly back and rejoin the main hand.

Typical characteristics

Two coaxial chronograph seconds hands
Additional pusher to split and rejoin the hands
A split-seconds clamp mechanism acting on the secondary hand's heart cam

Construction and interpretation

Split-seconds, or rattrapante, work adds a second elapsed-seconds hand travelling with the principal chronograph hand. One hand can be held for an intermediate reading while the other continues timing. Releasing the held hand makes it catch up with the still-running recorder. This permits comparison of intermediate events without ending the main timing interval; it is not the same operation as stopping and resetting an ordinary chronograph.

The additional hand requires its own holding and return mechanism. Two superimposed hands may look like one when aligned, so a still photograph of the dial can understate the complication. Conversely, a pair of central hands does not establish split-seconds functionality without mechanism or operating evidence. Describe the separate controls, the available recorder displays and any documented limitations, rather than assuming every elaborate chronograph is a rattrapante.

Stage	Main timing hand	Split hand
Start	Runs	Runs aligned with main hand
Take a split	Continues	Held for intermediate reading
Release split	Continues	Catches up to main hand
End and reset	Sequence depends on construction	Follow the documented control sequence