Rattrapante . . . Split-Seconds . . . Doppelchronograph . . . the “Queen of Complications” for Chronographs. Whatever we may call it, the split-seconds chronograph is the highest form of complication for the chronograph.

For chronograph enthusiasts who are into racing, rallies and motorsports, or even industrial production, the split-seconds chronograph is the ultimate “tool”. By “splitting” the two second hands, we can record the time of two separate events, for example, the times for two cars passing the start / finish line, as they complete laps of a race. We can also record the times of consecutive laps of a particular car, using a single timepiece. In a rally, we can measure the time differential between a car’s arrival at a checkpoint and the time specified for that checkpoint in the rally instructions.

We call this complication “split seconds”, because there are actually two second hands that appear to be a single hand. With the chronograph running, we press the split-second pusher and the split-second hand stops, while the main second hand continues moving ahead. Press this pusher again, and the split-second hand rejoins the main hand, “catching up” (“rattrap”, in French).

From the late 1800s, several Swiss watch companies were making split-second stopwatches and split-second pocket (handheld) chronographs. The split-seconds chronograph combines the split-seconds stopwatch with a pocket watch that displays the time of day, to give the user the ultimate tool for timing.

These traditional rattrapante chronograph movements had two column wheels, one to control the standard operations of the chronograph (start / stop / reset) [on the left in the photo below] and one to control the split-second hand [on the upper right in the photo below].

Two large “pincers” that engaged with the column wheel for the rattrapante mechanism would squeeze closer together to stop the split-second hand; with the next press of the split second pusher, they would then open again to release this hand.

Rattrapantes for the Wrist

With the increased popularity of wristwatches in the 1920s, the Swiss watch brands faced the challenge of producing much smaller versions of these complicated movements. The traditional Swiss pocket chronographs used 17 or 19 ligne movements; those for the wrist had to be reduced to around 14 ligne, to fit in 36 or 38 millimeter cases. Patek Philippe introduced the first rattrapante chronograph for the wrist in 1923, with a handful of other brands soon following suit.

Briteling’s Rattrapante — The Duograph

Willy Breitling showed his first split-second chronograph for the wrist (named the “Duograph”) in the company’s 1940 catalog, but assembling these complicated chronographs for serial production must have proven to be difficult. It was only in 1943 that the Breitling Duograph would enter serial production, with the first model being the Reference 762, a 36 millimeter chronograph powered by the Venus 179 movement.

The Breitling Duograph chronograph featured in this posting (shown above) is from early 1943, likely one of the first Duographs produced by Breitling. This particular watch has a tachymeter scale printed on the dial, an element often associated with racing and motorsports.

Soon after introducing this first model (Reference 762), Breitling would follow with the larger waterproof model (Reference 764), measuring 38 mm across the dial. Three-register models which added an hour recorder would soon follow, the Reference 766 (non-waterproof) and Reference 791 (waterproof). The ultimate development of Breitling’s rattrapante chronograph was a Datora model, that provided a full calendar, indicating the date and moonphase.

In the book, Premier Story, referenced below, Fred Mandelbaum confirms that the Duograph remained a very rare model, with Breitling producing only 350 Duographs over the period from 1943 to 1970 (yes, that’s right, approximately 13 pieces per year over this period). Most of these chronographs were produced to fill special orders from customers, as the Duograph was not the sort of watch that a distributor or retailer would keep in inventory. With there being no standard production models, we see considerable variation between samples of the Duograph chronograph, especially as Breitling offered two and three register models, stainless steel and gold cases, and even different style crowns.

The Rattrapante is “Democratized”

In 1993, International Watch Company (IWC), starting with the cam-based Valjoux 7750 movement, added cams and levers to created an “economy” version of the split-second chronograph. The resulting Calibre 79230 movement lacked the elegant design and beauty of the traditional rattrapante chronograph movements, but could be produced at a substantially lower cost than the traditional style of rattrapante chronograph movement and were relatively easy to adjust and maintain.

Since IWC’s development of the Calibre 79230 movement, IWC and several other brands offered a variety of cam-based rattrapante chronographs starting at around the $10,000 price point, with pre-owned versions of various models being available in the $5,000 range. The movements don’t have the beauty offered by the pair of column wheels and powerful pincers found in traditional rattrapante chronographs, and the thickness of the IWC movements is a drawback for some collectors, but with the adoption of the Valjoux 7750 to the split-second task, these chronographs have become far more accessible to enthusiasts.

Thanks

Thanks to @Timepieces_and_Moments for offering me the fantastic Duograph Reference 762 chronograph featured in this posting and to @WatchFred for the advice and logistical support relating to this watch. Thanks also to Fred for the fantastic information that he has published about Brietling’s Duograph chronographs and for providing the photos of Breitling Duograph models shown above.

Additional Reading

The Premier Story book, by Fred S. Mandelbaum, is the definitive reference on Breitling’s Premier chronographs, and includes an excellent chapter covering the Duograph models. Order this excellent book through WatchPrint.com, HERE. See also the book Breitling — 140 Years in 140 Stories, available through Amazon.

Ph Zhou, on Hodinkee, July 14, 2016 — In-Depth A Detailed Survey Of The Split-Seconds Chronograph And Its Cousins.

Jack Forster, on Hodinkee, May 22, 2018 — Technical Perspective The Split–Seconds Caliber 79230 And The Original IWC Doppelchronograph Pilot’s Watch

Wei Koh, on Revolution, April 28, 2012 — Available in the Shop: IWC GST Chrono Rattrapante

Logan Baker, on Hodinkee, July 27, 2021 — It’s Complicated Inside An A. Lange & Söhne Split-Seconds Chronograph

Tim Mosso, on Quill and Pad, March 29, 2024 — Review of Parmigiani Fleurier Tonda PF Split-Seconds Chronograph

My posting, Introducing the Monaco Split-Seconds Chronograph — Of Hands, Heritage and Halos, covers Heuer’s history of producing split-second chronographs, including pocket split-second chronographs and TAG Heuer’s first split-second wrist chronograph.

Jeff Stein
December 22, 2024