Vintage watch experience 古董手錶: Bovet Mono-Rattrapante Chonograph Watch (first series) using Valjoux caliber 84

This is a Bovet Mono Rattrapante Chronograph, stainless steel, manual wind watch using Valjoux caliber 84, 30-minute rattrapante and split-seconds chronograph. There are many Bovet chronograph that look alike. However, this 1950s Bovet chronograph is special as its Mono-Rattrapante which is a technically remarkable and rare wristwatch. The term "mono-rattrapante" means "single split-seconds". A rattrapante chronograph makes it possible to read off split times - a function that was particularly useful in motorsport for timing laps.

A traditional split seconds chronograph has two second hands, with the split-seconds hand being stopped to read off a split time, while the other hand keeps on running. A mono rattrapante, on the other hand, has a single second hand. The overall condition is nice with nice dial and hands, telemeter and tachymeter track, diameter: 36mm, thickness: 13.3mm and the watch is from circa 1940. While all the rattrapantes ( split seconds ) have two hands to measure the seconds of two events, the mono rattrapante has only one. With the upper pusher, you start the Chrono, while when pushing on the pusher at 4 o clock, you make a pause, and when you release this pusher, the seconds hand jumps till the time it was supposed to measure without stop.

The enthralling Valjoux 84 caliber first production was in 1936, with the discontinuation in 1950. Interestingly, this specific caliber was made solely for the brand Bovet Frères & Co. Other brands later adopted the same caliber, but it was Bovet that propelled Valjoux to innovate a completely new construction in the form of caliber 84.

The top button is used to start, stop and reset the chronograph hand. The purpose of the rattrapante chronograph is to allow you to time two concurrent events – for example two cars crossing the finish line at different times.

The chronograph hand, whilst running, can be ‘paused’ by holding the lower chronograph pusher. When released, the hand will jump to where it woud have been, allowing the operator of the chronograph to measure multiple intervals.

To be specific, the mono-rattrapante works like this: when the first car crosses the line, you hold down the bottom pusher, which stops the seconds hand; you can then record the time. When you release the pusher, the seconds hand jumps forward instantly to the position it would have been in if you hadn’t stopped it, and keeps running, letting you stop it when the second car crosses the line. This complication is less suitable for recording two elapsed times that are very close together, but it will do much, even most, of what a traditional rattrapante will do.

I have always wanted to find a Bovet Chronograph but there are wide range of variations. The complication was something of a specialty for Bovet in the 1940s and they capitalized on the innovation with many versions. There are two versions of this wristwatch exist:

. The first, features a round, flat push-piece at 2 and an olive-shaped push-piece at 4.

· The second version has either a square or a round water-resistant push-piece at 2 and at 4.

This model is the first series of the Bovet Mono Rattrapante Chronograph which is well kept. There are other Bovet chronograph using Landeron caliber 51. With this first generation Bovet Mono Rattrapante, I have decided to expand my collection and look for another ref 5347, which is slighly bigger versions.

This is the first model for the Bovet Mono-Rattrapante Chonograph Watch where the two pushers are not identical. More often then not, the pushers are either all suare pushers or all button pushers.

It comes with a few variations with photos from the internet

This is the first model for the Bovet Mono-Rattrapante Chonograph Watch where the two pushers are not identical. Source : https://www.europeanwatch.com/watch/22519

There is a simlar watch from the following site: