A Rolex watch is designed, engineered, produced, tested and, in most cases, purchased for life. Today, there are myriads of things that Rolex does in its own, unique ways to ensure that all the watches it puts out into the real world will serve as prized possessions through time. All these Rolex specialties we shall, over the course of upcoming articles, discover in great detail. Now, however, we will begin by learning about big one among all these bespoke methods, a method that affirms Rolex’s unmatched position in modern watchmaking: the Rolex Superlative Chronometer certificate.
As such, today we will discover the basics of the Rolex Superlative Chronometer, a certification received by every Rolex watch that passes some of the most stringent in-house and external quality assurance and performance tests.
The testing of every Rolex Superlative Chronometer watch begins with the movement’s initial testing in-house, immediately after the movement’s assembly is finalized. Once this first, base level testing is performed, every uncased movement is shipped over to the independent Swiss Official Chronometer Testing Institute (COSC). Here, in COSC’s Saint-Imier facilities, the uncased movements will be rigorously tested for accuracy under a variety of circumstances. A total of fifteen days they spend enjoying the hospitality of COSC, where the movements are held in a total of five different positions and are submitted to three different temperatures. During these tests, the watches are checked to run within a maximum average deviation between -4 and +6 seconds per day. Those movements that pass this long and thorough tests become COSC Officially Certified Chronometers.
It is here that we should note, that a chronometer – not to be confused with the chronograph, which is another word for stopwatches – has traditionally been a synonym for some of the most accurate and reliable wrist and pocket watches ever made. Even in today’s luxury watch industry, COSC Officially Certified Chronometers are few and far between, as it requires considerable additional effort and fine-tuning in both engineering, execution and testing, to produce watches capable of passing these 15-day-long COSC procedures. Once they receive their COSC chronometer certifications, the uncased movements are transferred back to Rolex.
Once they are back at Rolex’s facility in Bienne, where the entire production of all movements is performed in a single complex. The 92,000 square-meter, state of the art manufacture in Bienne was inaugurated in 2012; this facility, the size of 13 football fields spread out over 4 above - and 3 underground floors. We shall take a more in-depth look at it in a dedicated article.
The returned, COSC-certified movements are taken into stock and, once their time comes, are transferred to the Rolex’s facilities in Geneva, where the final assembly of watches happens from components sent in by the various facilities of the brand. It is also here, in the Genevan manufacture, that final quality control takes place. The movements, case, dial and bracelet are all assembled into one complete watch that can, at last, begin its Superlative Chronometer tests, performed in-house, by Rolex.
After casing the movement, Rolex first tests the precision of each watch over a 24-hour cycle in seven static positions as well as a rotating rack, in accordance with an exclusive methodology that simulates real-life wear. The tolerance criteria at this point are much stricter than the those for the official certification when it comes to the average rate deviation – that is watchmaker’s speak for the daily precision as perceived by the wearer. The deviation for all Rolex Superlative Chronometers must not exceed -2 to +2 seconds per day after casing.
Waterproofness of each watch is tested a first time by subject it to high internal air pressure and then immersing it into water in a hyperbaric tank. Watches guaranteed to a depth of 100 meters are tested at a water pressure present at 10% greater than the rated depth, while divers’ watches – waterproof to 300, 1,220 and 3,900 meters – are tested with an additional safety margin of 25 percent. What this means is that if you are the proud owner of a modern Submariner for example, that is rated water resistant for a depth of 300 meters, then your watch has actually been tested for 375 meters – and, needless to say, the watch has passed even this excessive torment.
Self-winding, i.e. the efficiency of the automatic winding feature is also tested by exclusive means to ensure that all components work together optimally, without excessive friction or any other issues. Irrespective of the length of power reserve, the self-winding functionality is relied upon by every Rolex wearer around the world.
Last, but certainly not least, the cased-up watches are tested for their power reserve capacities to ensure that they reach the extent of autonomy that Rolex engineered into the respective caliber.
The final watch that has passed all of these rigorous external and internal tests emerges as a Rolex Superlative Chronometer, an achievement testified to by the Superlative Chronometer text on its dial, as well as the green-gold hangtag that comes with every Rolex watch in its box. For over the last hundred years, Rolex has been on a quest of infinitely refining what a timepiece is capable of in an effort to create watches that perform to design reliably and exceptionally over decades and more to come. The Superlative Chronometer certification is the latest great chapter in this quest.