There has been a lot of talk about movements of late, so I thought I would bring this watch to your attention.
The watch itself is typical A Lange & Sohne:
But that's not what makes this watch special.
It is (I think) just the third wristwatch ever to contain a chain and fusee movement, and that's what I wanted to point out.
Many of you know that one of the problems with mechanical movements is that they tend to run faster when the mainspring is fully wound and slower when the mainspring is almost fully unwound - it's logical when you think about it.
This is a much more significant time impact than the positioning issue and yet all of the work goes into tourbillons that do nothing for this problem. That's in part because tourbillons look cool, and partly because chain and fusee is extremely difficult to do.
In a regular watch the mainspring transmits power directly to the gear train, in a chain and fusee movement the mainspring barrel and the geartrain are connected via a chain - in the Lange & Sohne it has over 600 parts.
In addition to the chain there are two 'blocks' that address the two extremes - fully wound and fully unwound to prevent the excessive torque changes at the fully wound and fully unwound states. Finally the chain has a pretensioner which adds or decreases tension at the mainspring and allows for adjustment of each individual movement to balance the chain and the spring.
Does it make a practical difference to the everyday wearer - not in the slightest, but its an amazing piece of technology, will doubtless have an amazing price, and results in a movement for a watch that has over 900 parts.
It's also pretty damn cool!
