WatchTime Exclusive: Inside Rolex Bienne

Rolex Bienne building On a rare tour of Rolex’s movement-manufacturing complex in Bienne, Switzerland, WatchTime’s Joe Thompson and Norma Buchanan witnessed the making of the Cosmograph Daytona Caliber 4130. Buchanan reported on it in this feature from our March-April 2010 issue.

The first thing that strikes you is its sheer size. The Rolex movement-making complex, on the outskirts of Bienne, Switzerland, is a study in gigantism. It consists of four monolithic buildings, occupying 170,000 cubic meters of space. It’s imposing, and, with its air of impregnability, a little mysterious.

We ride out there one February afternoon because Rolex has agreed to give us, two WatchTime editors, a tour of the facility, a mainplate-to-hairspring view of how it makes its movements, 750,000-plus of them per year.

Before the tour, we receive a background briefing, a combination of live presentation and film. It takes place in a proportionately large auditorium attached to what is surely the biggest watch-company reception area we’ve ever been in: a two-story-high, light-filled atrium with a Rolex-green marble floor.

This complex, Manufacture des Montres Rolex SA, located in an industrial zone called Champs-de-Boujean, is the sister of Rolex SA in Geneva, which makes cases, bracelets and dials; assembles the watches; and does the company’s gem-setting. Rolex corporate headquarters are also in Geneva.

Rolex Daytona Caliber 4130

The Cosmograph Daytona Caliber 4130, introduced in 2000

Here in Bienne, about 2,000 employees make movement components, 50 million of them per year, assemble the movements, and send them to Switzerland’s chronometer-testing agency, COSC (Contrôle Officiel Suisse des Chronomètres) to receive chronometer certification. (All Rolex-made movements receive certification except for most in the Cellini collection — although Cellini Prince models are COSC-certified.) Rolex Bienne then ships the movements to Rolex Geneva for casing. The four Bienne buildings, set against the backdrop of the Jura mountains, are called Rolex III, IV, V and VI. (Rolex I and II are old, former factory buildings near the center of Bienne. Rolex no longer owns them.) The company also has a factory in the town of Le Locle, employing 150 people, where some movement assembly takes place.

Until 2004, Rolex Bienne and Rolex Geneva had different owners. The former belonged to the descendants of Jean Aegler, whose Aegler SA factory in Bienne provided movements to Rolex founder Hans Wilsdorf starting in 1905. Rolex Geneva was, and still is, owned by the Hans Wilsdorf Foundation, which Wilsdorf established in 1945.

Six years ago, Rolex Geneva bought the Bienne facility and the two were merged. That move, along with Rolex’s long-term project of acquiring many of its suppliers of components and equipment, has transformed the company into a vertically integrated manufacture.

Class over, we set out on the tour. It will have a theme, says François Paschoud, one of the facility’s technical directors: We will be following the manufacturing steps of Rolex’s famous Caliber 4130, the chronograph movement that Rolex launched in 2000 to replace the Zenith El Primero caliber it had been using in its Cosmograph Daytona models. That introduction was a major event for Rolex; it meant that from that point on all movements used in the Rolex brand were made in-house (watches in Rolex’s sister brand, Tudor, have ETA movements).


Rolex V is one of the four big buildings in the Bienne complex.

Besides Paschoud, our guides on the tour are the facility’s top manager, Raymond Kerrison, and Jacques Baur, head of research at Rolex. We start in Rolex V, in the department where the movement’s plates and bridges are made. There, in a huge room filled with the roar of toiling machines, we see something — or rather some things — we’ve never seen before. They look like giant, round, glass pods, or maybe spaceships, nearly as high as the ceiling and 12 feet or so in diameter. The Rolex officials call them “modules.” There are a dozen of them, some connected at the top to an adjacent module by metal rails, which, we soon learn, are a kind of monorail transit system for carrying components from one module to the next. Four of the modules are dedicated to the 4130. Inside each one, a cluster of CNC machines are stamping, drilling, milling, turning and polishing the plates, the rough forms of which were produced, by the stamping process, in another department. We can see almost none of the actual work from outside the modules; the machines have their backs turned to us, as it were, and are facing inside. What we do see is oil, gallons and gallons of it, which is squirted on the plates and bridges to lubricate them during manufacturing and to rinse off metal shavings.

To see the actual processes, such as milling and stamping holes in the plates, we watch a movie on a video monitor. There are more than 50 tools working simultaneously in the four modules. Humans are far scarcer in this room: just one or two are needed to keep the noisy machines humming.

The modules are made exclusively for Rolex by a Rolex-owned company. They serve several purposes. Most obviously, they contain the oil that would otherwise be knee-deep on the factory floor. They also protect the components and machinery from dust. Thirdly, they keep the components at the same precise temperature throughout the manufacturing process so they will neither shrink nor expand. Any such change, however small, would have disastrous consequences given the tolerances involved: two microns, that is, two thousandths of a millimeter, or, as Paschoud says, a few hundredths of the diameter of a human hair.


Plates and bridges are manufactured by CNC machines inside huge, pod-like modules.

When one module completes its work, the plate or bridge moves to the next module by means of the monorail. Each component is mounted on its own small pallet. Human hands never touch the component during this phase of production. The entire process consists of about 100 different steps. (Some are performed next door, in Rolex III.) There are some 350 points of measurement for each plate.

Leaving the department, we pass the quality control section where, helped by precision measuring equipment and magnifying lenses, employees in two separate departments check the plates and bridges to be sure they have exactly the right measurements and are free of any surface flaws. They work behind a glass partition in a controlled environment. That, Paschoud tells us, is because a temperature change of as little as 1 degree can affect a component’s measurements.

If the plates and bridges pass muster, they are sent to another department for rhodium galvanic coating and decoration: circular graining, for instance.


Components are made by machine and assembled by hand.

We then walk through an underground passageway connecting Rolex V to Rolex IV, where small components such as staffs, wheels (including balance wheels), and Microstella screws, which are used to adjust the balance, are made. On the way, we pass a man riding a bicycle (another watch-factory first for us). There are more bikes, special Rolex bikes, with light-colored tires, parked at the elevator in Rolex IV. Employees use them to move quickly between the buildings.

This department’s job is to turn bars and tubes of metal, some two meters long, into pieces as small as one millimeter across. Tolerances here are as tiny as two microns. The parts are made by turning, cutting, stamping and spark erosion performed by CNC machines. As in the plates-and-bridges department, much of the work is hidden within the machines. The metal, an alloy of steel, aluminum or copper, goes in one end and, seemingly by magic, comes out the other in the form of infinitesimally small screws (the Microstella screws are made of gold) or tiny wheels. Decoration also takes place here: wheels, for instance, receive a sunray finish.

Our guides show us one machine that is making a pivot for a winding rotor, a component that is still in the testing stage and is hence being produced in a small series. Paschoud pulls out a mechanical drawing of the pivot, which is just 2.5 mm long and 2.2 mm wide, with a diameter of 0.3 mm at its end. It’s a simple thing, but the drawing is so complicated, and dotted with so many measurements, you’d think it depicted a nuclear submarine.

All these components come together in Rolex VI, our next stop, which we reach through another underground passageway. Before we go in, we don disposable white lab coats and blue plastic shoe coverings so we won’t track dirt inside. The latter are dispensed by a machine (by now we expect no less): we stick our feet, one at a time, smartly into the machine and the booties’ elastic-band tops snap shut around our ankles.

But before we get to the movement-assembly department, we’re in for a treat, a glimpse at something even inveterate watch-factory tourists seldom see. We’re going to watch hairsprings being made. And not just any hairsprings, but blue Parachrom ones, which are unique to Rolex.

The company introduced Parachrom hairsprings in the 4130 when the movement was first launched a decade ago. Since then, they have worked their way into all Rolex-brand men’s watches (the women’s models, along with the company’s Cellini collection, have hairsprings made of an alloy identical to that used by Nivarox). The advantages of Parachrom, says Jacques Baur, is that it has superior shock-resistance and anti-magnetism. There are two models of Parachrom hairsprings. One is made for the 4130 and 4160 (a relative of the 4130 used in the Yacht-Master II). The other is for the 3100-series non-chronograph men’s-watch calibers, used in the GMT-Master II, Submariner, Deepsea, Day-Date, Datejust, Explorer, and Milgauss.

Parachrom is an alloy of 85 percent niobium and 15 percent zirconium. Rolex makes it itself, by taking 30-centimeter rods of each element, two of niobium and one of zirconium, clumping them together and melting them so that they become a homogenous alloy.


Rolex balances have gold Microstella screws and Parachrom hairsprings.

The melting takes place inside an electron-beam vacuum furnace, a tall, shiny behemoth that reaches up through the ceiling and looks kind of like a rocketship, albeit a rather chubby one. Like the modules in Building V, it’s a Rolex exclusive. And, like them, it makes us gape because it’s so big and odd-looking. We’re invited to peek into the furnace. The Rolex executives warn us that the light inside it can damage our eyes if they’re unprotected, and hand us dark goggles. We climb up on a viewing platform, put on the goggles, and peer into the furnace through a porthole. There we see the soon-to-be Parachrom rod being heated by a burning stream of electrons to a temperature of 2,400 degrees Centigrade. The rod glows with fiery intensity. It is heated one section at a time: the rod will pass through the electron fire three times before the metal is completely blended. The process is entirely automatic, but a technician observes it on a video monitor to make sure nothing goes awry.

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    About Norma Buchanan

    Norma Buchanan is the executive editor of WatchTime magazine. She has been a reporter and editor for 30 years and has specialized in writing about watches and the watch industry for 18 years. She is also the author of "The Watch Buff's Book of Trivia."


    1. Reinier Lolkes De Beer on Facebook says:

      Interesting reading! tnx for the info, giving us rollies fans more insight.

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