We all want more power. When we buy cold medicine, no one buys regular strength any more – it’s all about extra strength or maximum strength, or as Jerry Seinfeld once said: “Figure out what will kill me, then back it off a little bit.”
In watches, the debate about power reserve is coming to a head. As more people have multiple watches, the challenge of keeping them wound, so they don’t have to be reset every time you decide to wear a different watch, is resulting in a consumer demand for longer power reserves. This is especially true when you have sophisticated complications such as perpetual calendars, Moon phases and more. Resetting these is a challenge, often involving reading through an owner’s manual the size of a novel.
The “standard” power reserve of 38-45 hours is laughably insufficient in modern watchmaking. At the SIHH in Geneva earlier this year, one company, Vacheron Constantin, introduced a breakthrough watch that has revolutionised how people look at power reserve – the Traditionnelle Twin Beat Perpetual Calendar.
“For me, it’s thinking completely out of the box when considering long power reserve watches,” says Christian Selmoni, style and heritage director of Vacheron Constantin. “Instead of adding barrels and barrels to movements in order to increase the power reserve of the timepiece, the idea behind Twin Beat is to use different frequencies, one which is very low for standby mode. With this system, we need less energy for the watch to work, so we don’t need to put a huge number of barrels."
As a result, the watch is a wearable size – 42mm, and only 10mm thick. It is a regular watch, but it has a gargantuan 65 days of power in reserve. "It’s like cars – you can either increase the size of the gas tank, or you reduce the car’s consumption of gas,” Selmoni says.
To accomplish this, Vacheron Constantin’s engineers and watchmakers developed a system that has two separate gear trains, one that incorporates an oscillator that beats at 1.2Hz (10,800 vibrations per hour), which is very low, and the second gear train that beats at 5Hz (36,000 vibrations per hour), a normal range. The user decides which frequency he or she wants depending on the use of their watch.
“We had to make sure no matter which frequency is used, the time display will still be accurate,” Selmoni says. “When you select standby mode (1.2Hz), you still have the timekeeping and the perpetual calendar continues to operate. All the information has to remain correct, so we use several differentials in the system. In order to get 65 days of power reserve, you have to put the Twin Beat in a flat position - you can’t wear it because the chronometry will suffer if you do. It was a matter of finding the best compromise between the longest power reserve possible and great accuracy when you are wearing it.” In 5Hz mode, the power reserve is still a respectable four days.
The Vacheron Constantin Traditionnelle Twin Beat Perpetual Calendar is a huge step forward in addressing the issue of power reserve. The hope is that more companies take up this mantle and come up with other ideas that extend the power reserve of timepieces in the future, making them better suit the lifestyle of today.
This article was originally published by WIRED UK
