The Saxonia Lange 31 has a very long power reserve

01 January 2019 | A.Lange & Söhne , Did You Know

A wristwatch's power reserve is one of the most debated topics among enthusiasts and is one of the most highlighted features by those brands that design their mechanical movements in-house. IWC is for example known for its big calibers that guarantee up to seven days of power reserve, Panerai revolutionized some years ago its collections by introducing a series of calibers running for eight days, Blancpain produces beautifully finished automatic movements that run for a full five days. Finally, Oris introduced the caliber 110, designed to guarantee up to ten days of power reserve, that I'll analyze in-depth in a separate post in the coming days. Designing a caliber capable of providing a long power reserve is all but trivial but making one that can guarantee up to 31 days of power reserve, as did A.Lange & Söhne when it launched the Saxonia Lange 31, is a staggering achievement.

The Saxonia Lange 31 was the first watch ever to run no stop for a total 744 hours when fully wound, as it's clearly written on the dial (Monats-werk = operating for a month) and still is the watch to boast the most extended power reserve in the world, among those that abide by the rules of traditional "Haute-Horlogerie". It was beaten by the Hublot MP-05 LaFerrari which offers an innovative and disruptive design that allowed the engineers to achieve an incredible 50 days power reserve, whereas the timepiece introduced by A.Lange & Söhne blends traditional excellent watchmaking criteria with innovative technical solutions.

The Saxon master watchmakers have equipped the movement with two long mainsprings, each measuring 1850mm, and have mounted a constant force device to help equalize the release of energy from the barrel to the gear train. It is a solution that luxury brands usually adopt on high-end watches with a power reserve of fewer than ten days, you can therefore easily understand how relevant it is when the days of power reserve are 31. The power reserve indicator is broad and takes center stage on the white gold dial. Considering the amount of torque needed to fully wind the Lange 31, whose white gold case is 45.9mm wide and 15.9mm thick, the Saxon engineers designed a particular device that must be screwed in into a hole placed on the bottom of the case, thus replacing the winding crown.