Dr. Ito's Thorough Analysis of Mechanical Watches! Vol.8 - About A. Lange & Söhne's "Caliber" Numbers

Good evening, everyone!

This column discusses mechanical watches from an engineer's perspective. For our eighth installment, we will be discussing:

"About A. Lange & Söhne's "Cal." (Caliber) Numbers"

I will be talking about this as our main topic.

Since its revival in 1994, the new A. Lange & Söhne has quickly gained a high reputation and taken its place as one of the top luxury watch brands. It now boasts an overwhelming presence in the industry, even being counted among the world's top five watch brands.

Behind this rapid resurgence, which achieved such a revival in a short period of about 20-30 years, I believe that the unique models, born from a production-first approach where new movements are developed for new models, have captivated the hearts of watch enthusiasts who focus on machinery and mechanisms.

This time, I will focus on the movements of A. Lange & Söhne and explain the "Cal." (Caliber) numbers assigned to each. Some of you might think, "Cal. is just a number," but in fact, this number, which starts with "L," contains a variety of information.

And knowing how to decipher it can be quite interesting, as it allows you to gain a different perspective on the watch and even trace back the history of its development. So, please take this opportunity to learn about it.

If you haven't paid much attention to it before, after reading this article, you might start noticing it, and before you know it, you might find yourself deeply immersed in the world of watches! (laughs)

Let's dive right in!

"Cal." (Caliber) Number Explanation

First, I will explain using my favorite model, the "Lange 1," as an example. The "Cal." number for the first-generation "Lange 1" is "L901.0."

This breaks down as:

・L (= A. Lange & Söhne)
・90 (= Development began in 1990)
・1 (= Order of development started in that year)
・.0 (= Branch number / Indicates the number of minor changes made, original model)

Next, the "Cal." number for the second-generation "Lange 1" is "L121.1."

This breaks down as:

・L (= A. Lange & Söhne)
・12 (= Development began in 2012)
・1 (= Order of development started in that year)
・.1 (= Indicates the first movement)

This shows that it took approximately three years from development to its announcement (2015). While it can be a bit confusing when spanning across the millennium, the "Cal." number allows us to obtain information such as when the movement was developed and how many minor changes it has undergone.

Next, I will introduce an example using the "Datograph," often called the "most beautiful chronograph in the world."

The movement installed in the first-generation "Ref. 403.035" is "Cal.L951.1." And the movement installed in the latest model, "Ref. 405.028," announced at this year's Watches & Wonders Geneva, is "Cal.L951.6."

As can be seen from the identical first three digits "951," these two movements are based on "the first movement whose development began in 1995."

The "Datograph" has undergone significant evolution, such as repeatedly refining details without changing the basic design, extending the short power reserve of the first generation from approximately 36 hours to about 60 hours, and adding a power reserve indicator. However, it's clear that the basic design inherits the historic movement whose development began in 1995.

When you interpret these rules, you realize that while one might typically assume that a new model features the newest movement, this isn't always the case. For example, the "Richard Lange Jumping Seconds," a new model from 2016, has "Cal.L094.1," meaning its development began in 2009. This indicates that despite development starting three years earlier than the 2015 "Lange 1" new model, it actually took a full seven years to complete.

Summary

What did you think?

Even for items whose development began at roughly the same time, there are cases where a watch that was completed earlier is announced first, or cases where an announcement is delayed for some reason. Therefore, a different perspective, new questions, and new discoveries might arise when viewing watches, unlike simply looking at them in order of their announcement year.

I hope this article has provided useful information for everyone and sparked some interest in luxury watches! Also, if you have any questions, please feel free to ask directly, and I will be happy to answer them. We look forward to your visit and inquiries.

Look forward to the next installment! See you then!