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Rolex’s Calibre 3255 - A New Benchmark For Chronometric Precision

Rolex doesn’t launch a new movement very often. But when it does, one had to be sure to sit up and take heed. At Baselworld 2015, we were awed by the new Calibre 3255, Rolex’s first new movement since 2012’s Calibre 9001, which drives the SkyDweller.

The Calibre 3255 represents a significant enhancement in precision, power reserve and resistance to magnetic fields and shocks. The key here is Rolex’s new Chronergy escapement. It’s essentially an improved Swiss lever escapement, with redesigned escape wheel teeth and a lighter escape wheel (which has a cut-out design to reduce its inertia) that makes the escapement 15 per cent more energy efficient.

Together with a new barrel construction, this gives the watch 10 more hours of power reserve. Precision-wise, the escapement registers a daily rate variation of -2/+2 seconds a day – twice as exacting as the COSC standard of -4/+6 seconds day, and more accurate than even Rolex’s current self-imposed tolerance of -1/+5 s/day. It redefines the term ‘Superlative Chronometer’, a phrase coined by Rolex in the 1950s. In addition, the pallet fork and escape wheel are made of nickel-phosphorus, making these sensitive parts immune to the effects of magnetism – an increasing threat, given the number of electronic devices that govern our daily lives.

What about the hairspring? Well, Rolex has opted to use its trusty Parachrom, and not the Syloxi, as some might expect. To recap, the latter – Rolex’s first silicon hairspring – debuted in Calibre 2236 last year, housed in the Datejust Pearlmaster 34. It’s useful to note that the Syloxi offers no performance advantage over the Parachrom; rather, there’s a manufacturing advantage in that it can be mass-produced using DRIE (Deep Reactive-Ion Etching) technology, thus ‘freeing up’ the Parachrom production line.


Of course, Rolex wouldn’t be Rolex if it didn’t develop new high-tech equipment and techniques to test the precision of Calibre 3255 according to the new tolerances. These chronometric tests are designed to simulate wear and tear sustained during the user’s day-to-day existence. In typical Rolex fashion, the tests are conducted over and above the official COSC tests (which all Rollies are subject to), and are performed not just on the movements, but also after final assembly when the movements have been cased.


Doing Better Than Before


Could Rolex manufacture a minute repeater or tourbillon if it wanted? We believe so. There’s such a thing as diversifying one’s portfolio and, conversely, spreading oneself too thin, and Rolex has hitherto managed to strike the right balance without losing its essence.


Of course, maintaining one’s position at the top of the heap isn’t easy. Rolex relies on a tried-and-tested formula: the continuous refinement of its movements and their constituent parts; the development of its own tools and lubricants; and stringent tests and inspections at virtually every stage of the manufacturing process.


The quest for precision is so deeply rooted in the brand’s DNA that as early as 1910 – just five years after its founding – a Rolex wristwatch bagged the Swiss Certificate of Chronometric Precision (pictured), making it the first wristwatch in the world to do so. The award had previously only been granted to marine chronometers.


In 1931, Rolex perfected the design of the world’s first self-winding wristwatch, invented by British watchmaker John Harwood eight years earlier. While Harwood’s movement had an oscillating weight that could rotate 300 degrees, Rolex’s version went all the way, a full 360. This allowed the mainspring to store more energy, and became the basis of the company’s Oyster Perpetual movement.


The last 15 years have seen giant leaps in Rolex’s in-house technics. Parachrom was the first of the major inventions to be launched post-vertical integration (pictured). Debuting in 2000, the distinctive blue hairspring is an alloy of niobium, zirconium and a small percentage of oxygen. Besides being amagnetic, another key characteristic is its elasticity, which allows it to be 10 times as impervious to shocks compared to normal hairsprings.


Building on this robustness, 2005’s Paraflex shock absorbers set out to improve shock resistance on the balance by 50 per cent. It does so by virtue of its design: the springs, placed on the balance bridge, boast a geometry optimised by computer modelling. Together, Parachrom and Paraflex mean that even if you, dear wearer, get banged up, your Rollie will still keep good time.


It would be an understatement to say that Rolex is obsessive about quality control. During a rare visit to the manufacture (spread across four sites), we observed first-hand just how deep this obsession was. Components were tested, checked, and then re-tested and re-checked. For instance, during final assembly – one of the last stages in production – the dials, hands and Perpetual rotor are fitted onto the movement before being cased up. Technicians diligently check for any discrepancies. If they discover any error, the watch is disassembled (in reverse order) and sent back to the individual responsible to make the necessary corrections.


After casing, the watches are subject to a set of three draconian tests simulating wear before they’re sent out to retailers. This stage, known as final control, focuses on power reserve, waterproofness and chronometric precision. They are performed using highly sophisticated, fully automated equipment developed specifically by Rolex, and take a total of about one-and-a-half days.


We’re curious to see what plans are in store for the 3255, beyond the new Day-Date. Will the Chronergy escapement be applied across Rolex’s portfolio of movements? Hard to say, though it’s a logical assumption. What’s certain, though, is that the Calibre 3255 is destined to be a future icon alongside the 3135, the 4130 and all the other Rolex greats.




Ex Editor-In Chief

Alvin promises not to be a douche when talking about watches. He may have scoured the Basel and Geneva watch fairs for the past 15 years, and played an instrumental role to the growth of Singapore's pioneering horological and men's lifestyle publications, but the intrepid scribe seeks to learn something new with each story he writes.