I’m not only a fan of the outside of a watch, but the inside and all its moving parts are what makes every watch tick. Fascinated by the countless innovations and improvements for watch movements, I picked out one. The improvement of having more power reserve and the distribution by a double barrel in this case.double barrel movement by watches and pencils Double barrel movements feature more than one mainspring and barrel. This way the movement has an increased power reserve and sometimes more efficient distribution. The actual power reserve depends on several things. For example:

  • The complications of the movement (e.g. chronograph).
  • Whether the double barrels are linked in parallel or paired serially.
  • Multiple or a single gear train (more on this, later on).
  • For older watches, the technical condition of the movement (Has it been serviced or not?)
  • The age of the watch. Newer watches have technical improvements like high-tech materials to increase the power reserve.

Even More Barrels

While you might think that 2 barrels is the max, you’re wrong. Some movements house up to 4 barrels! Blancpain has several movements that feature more than 2 barrels. For example, the Blancpain movement with reference number 1315 has 3 barrels. King of the hill is Vacheron Constantin with its Patrimony Traditionnelle Tourbillon (reference 89000/000R-9655). It features 2 stacks of 2 barrels and has a power reserve of 14 days!

Dual Time Resonance

Two barrels per movement and a longer power reserve on the Dual Time Resonance by Armin Strom (ref. ARF17)

Need Or Nice-To-Have?

Watches with a lot of complications need more power. Therefore a double barrel is more like a necessity than a nice-to-have. In these cases, one barrel can serve the time indication, while the other barrel serves the chronograph and/or other complications. Besides this, more power reserve was also useful in times when watches were purely functional. As an example, I take the first Panerai watches. Since they were created for (military) frogmen, it was best to include as much power reserve as possible. This way, the winding interval was stretched and the chance of water coming into the watch was kept to a minimum. Nowadays, most of the watches with double barrels serve our laziness.

The MSH01 has a power reserve of five days

Two Barrels on the Meistersinger Caliber MSH01

One BIG Barrel or more than one?

Instead of creating an extra barrel some brands also increase the power reserve by increasing the size of the barrel and mainspring. There are some differences compared to multiple barrels. Besides the accuracy, it also has a lot to do with the available space in the movement. With some movements, you can’t just keep increasing the size of the barrel. With two barrels they are more flexible in the placement of the barrels.

Oris Caliber 111 with one massive barrel, good for 10 days of power reserve

Names And Branding

While ‘double barrel movement’ is the term mostly used, some brands use a unique name to indicate the double barrel concept. To name some:

  • Jaeger-LeCoultre: Duomètre or ‘Dual Wing’
  • Favre-Leuba: Twin-power calibre 253
  • Multiple brands: twin barrel

JLC Duomètre Quantième Lunaire (ref. 1701195081)

Aesthetics

The double barrel movement might have increased power reserve as primary goal there is another interesting benefit to this concept. For me as a designer, a double barrel also can create more balance in the overall design of a movement. Most of the double barrel movements are more symmetric and therefore look nicer in my opinion.

Verdict

Barrels are interesting parts of the movement. Together with the mainspring, they provide the essence: energy. What makes them especially interesting is fact that there are many variations. What do you like or dislike about a double barrel movement? Maybe you own a double barrel movement? We’d like to hear from you.

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