I have spoken about chronographs before on Tick Talk, and if you read that post you will know that I love them!
In this post, I will delve deeper into chronographs and explain the different variations and types of mechanical chronographs available today.
All chronographs come with subdials. These are the little dials within the main dial of the watch.
These mini dials are used to measure different things.
Bi-Compax or Twin-Register
Bi-Compax or Twin-Register chronographs have 2 subdials.
One is used as the main seconds hand of the watch, so it is constantly running. The other is usually a 30-minute counter which is used as part of the chronograph. This hand will only run if the chronograph is in operation.
Bi-Compax Chronographs can usually measure up to 30 minutes.
Tri- Compax or Triple Register
Tri- Compax or Triple Register chronographs have 3 subdials.
One is used as the main seconds hand of the watch, the second is the chronograph minute counter, and the third is the hour counter.
The minute counter usually measures up to 30 minutes and the hour counter goes up to 12 hours (most of the time).
These chronographs can usually measure up to 12 hours.
Chronographs come with a bunch of different complications.
This is by far the most common type of chronograph.
There are 2 buttons on the side of the case. When you push the top button, the seconds hand starts running. When you push the top button a 2nd time, the chronograph stops. You can push the top button again to continue the timing, or you can push the bottom button to reset it to zero.
A few good examples are the Omega Speedmaster, Rolex Daytona and Zenith el Primero.
Monopushers are similar to the Normal/Common Chronograph, but this watch only has 1 button on the side of the case. You push that button to Start, Stop and Reset the chronograph. With a monopusher you can’t stop and then continue your timing. Once you have stopped, you can only reset to zero when pushing the button again.
Flyback Chronographs look and function in almost the same way as a Normal/Common Chronograph, but they have 1 very useful extra feature.
While the chronograph is running, you can push the bottom button (on a normal chronograph, this will break the movement). When the bottom button is pushed, the seconds hand will “fly back” to zero and keep running. So you can reset the timing to zero, and without stopping, the timing will resume.
This comes in useful if you are timing a race where there are multiple laps.
Once your car/runner/horse (whatever) crosses the line after a lap, you can use the flyback feature to start timing the next lap. If you had a normal chronograph, you would need to stop, reset and restart the chronograph. That’s 3 button pushes.
By the time you have done it all, your racer might already be well into his next lap.
With a Flyback Chronograph, this can be done with just 1 push!
Split-Second or Rattrapante Chronograph
The Split-Second Chronograph is by far the most complicated and most expensive to manufacture.
It is usually only found is very high-end and very expensive watches.
The watch will have 3 pushers. One to start/stop the chronograph, one to reset it to zero and one to engage the “split-second” feature.
When you look at the seconds hand of a split-second chronograph, it might look like a normal hand, but you are mistaken. It is actually 2 hands right on top of each other!
You use it just like any other chronograph, but when you push the button to engage the “split second” feature, one of the seconds hands will stop while the other continues to run.
This can be used if you are timing 2 cars going around a racetrack.
You can stop the one seconds hand when the first racer crosses the line and stop the 2nd one when the other races crosses the line. You will then be able to see the “split” or difference between the time when the first car crossed the line and when the 2nd one crossed.
Here is a video from A. Lange & Söhne explaining the different types of chronographs and the ways in which they can be used.