The chronograph is one of the most common complications in watch making, which also makes it one of the most overlooked and misunderstood. Often seen as a simple stopwatch, its functions and subdials can be used for calculating speeds to measuring heart rates. And this is even before we get to the seriously complex stuff. You have flyback chronographs designed for accuracy, split second chronographs for timing multiple events and even lap timers named after F1 drivers. Overall, the chronograph has a lot more to offer than you might think, which is why this beginner’s guide to chronographs should prove handy!
The long history of the chronograph can be traced back to Louis Moinet who in 1816 created the world’s first chronograph pocket watch. Mr Moinet however, had to wait until 2013 to receive the credit he deserved as its inventor. Until this point Nicolas Mathieu Rieussec was heralded as the chronographs creator thanks to his 1821 device which was used to time horse racing in France. It was only on discovery of Louis Moinet’s pocket watch in 2013 that watch historians had to rethink their textbooks.
The watch that confirmed Louis Moinet as the inventor of the chronograph
It wasn’t until 1969 that the first automatic chronograph watches arrived with brands from Zenith to Breitling and Tag Heuer all jumping to release their automatic chrono movements.
Fast forward to today and when we think of a chronograph, we tend to envisage the traditional 3 subdial layout with two pushers. One each at the two and four o’clock positions. This is the look we’ve become accustomed to in modern icons such as the Omega Speedmaster and Rolex Daytona. However, this is only scratching the surface of this complication. In fact the chronograph is far more versatile and complex than you might imagine, so if you’re itching to find out more about the different types and functions then you’re in the right place.
Simple Chronograph
Tag Heuer Monaco Chronograph Night Driver, a perfect example of a simple chronograph
In short, all chronographs are stopwatches with varying levels of complexity and time measuring functionality. The simple chronograph is the most basic of stopwatches and gives you the ability to time a given event using start, stop and reset pushers. A simple chrono will typically include a central chronograph seconds hand and a set of subdials. The central chronograph hand replaces what on a traditional time only watch would be your seconds hand. The difference with the central chronograph hand is that it remains motionless pointing at 12 o’clock until you start the chrono.
On many chronographs this relegates your running seconds hand to a subdial most commonly housed on the left hand side of the dial. There are then two other common subdials you may be familiar with. The minute register and hour register. Once the central seconds hand has recorded 60 seconds the minute register will move to indicate how many minutes have elapsed. The hour register follows suit measuring how many hours have passed.
Vacheron Constantin Overseas Chronograph Panda
In some specialist chronographs the central seconds hand will complete a full rotation, not in 60 seconds as you might expect, but in 10 seconds or even a single second. These high flying chronographs are for precise time measuring to a tenth or even hundredth of a second. In these instances the central seconds will complete multiple full rotations before the minute register needs to kick into gear.
The Tachymeter, Telemeter and Pulsometer
Zenith Chronomaster Sport Watches with the 3 subdial layout (tri-compax)
The common 3 subdial layout can best be seen in something like the Zenith Chronomaster Sport. Zenith chronographs are all powered by variations on their El Primero movement which has become something of a legend. The original El Primero was released by Zenith in 1969 as one of the world’s first automatic chronograph movements and it would go on to power Rolex Daytona’s until around 2000. Whilst most simple chronographs adopt the 3 subdial layout (known as tri-compax) others opt for a 2 subdial configuration (known as bi-compax).
However, as chronographs are expert timing devices there are several iterations of the chronograph with specialised functions for timing unique events, the next layer of complexity to consider in this chronograph guide. These variations may not require large mechanical changes but instead offer different visual representations of how to read a chronograph using markers or scales.
Tag Heuer Tag Heuer Carrera Chronograph Glassbox, a chronograph with a tachymeter
The most common of these is the tachymeter. Often reserved for chronographs with an automotive connection, such as the Tag Heuer Carrera, the tachymeter is a scale on the bezel, or outer edge of the dial which allows you to calculate speed. In order to operate a tachymeter you need to know the distance the object is travelling i.e 1 kilometer. Assuming you’ve then used your chronograph to time how long it takes to cover this distance you refer to the tachymeter scale to read the speed.
In the theme of speed and distance the next specialist chronograph is the telemeter. This unique scale serves to measure the distance between an event that you can both see and hear. For example, thunder and lightning. Simply start your chronograph once you see the flash of lightning and stop it once you hear the thunder. Then use the telemeter scale to determine how far away you are from being caught in the storm. The telemeter scale works using the speed of sound to determine how far the sound has travelled since you saw the flash.
Omega Speedmaster Chronoscope comes equipped with a tachymeter, telemeter and pulsometer
The final scale enhancement, the pulsometer, has nothing to do with speed or distance. This very specialised type of chronograph reading is designed to help you measure a pulse or heart rate. By starting the chrono at the same time as you begin counting pulses you measure the time required to reach a set number of pulsations (usually 15 or 30). Once this many pulses has been reached you stop the chrono and read the pulsometer scale to obtain the pulse rate per minute.
These three variations on the chronograph are perhaps best represented in the Omega Speedmaster Chronoscope. A watch which contains all three of the tachymeter, telemeter and pulsometer.
Monopusher Chronograph
Patek Philippe 5470P with a monopusher at 2 o’clock
In most chronographs the controls are set on the side of the case and usually involve one or two pushers. If a single pusher is used to operate the chronograph this is referred to as a monopusher. Monopusher chronographs are an additional level of complexity over and above your usual run of the mill two pusher chrono and the reasons for a monopusher are predominantly aesthetic. You need fewer pushers protruding out and spoiling a perfectly crafted case.
Although there is a visual advantage to the monopusher it comes with a drawback. Once the chronograph has been stopped it can’t be restarted, only reset. Stopping the chrono and pressing the monopusher will send the chronograph back to zero ready to start all over again. Today monopusher’s are in the minority among chronographs and typically command a price premium. However, there was a time when they were the choice of the British Navy and Royal Air Force who during the 1940’s and 50’s issued soldiers with Lemania monopusher watches.
Flyback Chronograph
Longines Spirit Flyback Titanium
Moving on down the chronograph guide, you may have heard of a flyback chronograph but what actually is it? Imagine you need to time two separate events where event number 2 starts immediately when event number 1 finishes. In this situation you’d be grateful for having a flyback chronograph on your wrist.
In most aspects the flyback chronograph looks the same as the simple chrono with the same pusher and dial layouts. However, when you press the chronograph pusher on a flyback the hands will immediately reset to zero and start again. The chronograph function has been reset and restarted on the click of a single pusher without losing any recording time.
On the simple chronograph this action would require the press of three pushers. One to stop the timing hands, the second to reset to zero and the third to restart. At its creation the flyback was designed for pilot’s to aid navigation whereby a specific heading had to be maintained for a specific time with no margin for error. When traveling at high speeds any lost time could result in missing your destination by a considerable distance, hence the need for a flyback chronograph.
Split Seconds Chronograph
A. Lange & Söhne 1815 Rattrapante Chronograph
The most sophisticated, most complex and therefore most expensive of chronographs is the split second or rattrapante. So far, we’ve seen that simple and flyback chronographs operate with either one or two pushers, the giveaway for a split second chronograph is that they require three. The third split second pusher is often placed at the 10 o’clock position on the case.
The other big difference is the addition of a second central chronograph hand. This extra hand, when the chronograph isn’t running, can be almost impossible to see as it sits directly underneath the regular central seconds hand. Look closely at an A. Lange & Sohne 1815 Rattrapante and the two central seconds hand can just be distinguished thanks to the colours. The top hand is blue and the bottom hand is silver.
The purpose of a split second chrono is to allow you to time two events simultaneously, for example, two athletes running a race at the same time. In this scenario, you start your chronograph as normal and this sets off both the central seconds hands. Once athlete one crosses the finish line you use the split second pusher to stop one of the seconds hands (giving you the time for athlete one). Meanwhile, the other central seconds hand continues running uninterrupted allowing you to record athlete 2’s time. Essentially, what the split seconds chrono gives you is the ability to show how much quicker you are in the parents race at sports day than the guy in second place.
The Ultimate Chrono: The Laptimer
Audemars Piguet Royal Oak Concept Laptimer Michael Schumacher
This final chronograph is so complex and difficult to create that it wasn’t until 2015 when Audemars Piguet released the Royal Oak Concept Laptimer Michael Schumacher that we got to glimpse the world’s first ever lap timer watch. The laptimer takes the concept of the split second chronograph and elevates it to a new level. In the traditional split second, when you press the split second pusher one of the central seconds hands stops whilst the other continues. In the lap timer when you press the split second pusher two things happen.
Firstly, one of the seconds hands will stop (so you can take note of the lap time that’s been completed). Simultaneously, the other seconds hand will reset to zero and restart (so you can immediately start the timing of the second lap). Think of it as a flyback and split second chrono all in one. This just goes to show how the often underappreciated chronograph is one of watchmaking’s greatest and most versatile complications.
