The cutting-edge Swiss watch factory where robots run things by night

Tucked away in the Jura Mountains, just on the border between France and Switzerland, and almost 1,000m above sea level, the town of Le Locle boasts wide streets lined with prosperous 19th-century buildings and ultra-modern factories that have earned it Unesco World Heritage status, all set against a backdrop of dense forest and rolling green hills.

What sets Le Locle apart is the watchmaking expertise that has been passed down through generations over 150 years, partly via the local watchmaking school, founded in 1868. The key to its horological domination lies in its ability to embrace modern production methods and technology. Rejecting the romantic narrative of the lone Swiss artisan painstakingly creating and assembling every component by hand, the resident watch brands of Le Locle remain at the forefront of industrial innovation.

Leading a manufacturing revolution is Tudor, which unveiled a state-of-the-art watchmaking facility here in 2021. The jaunty scarlet building is a 5,500sq m complex that marries advanced production techniques with traditional handmaking. Next door is the movement manufacture, Kenissi, steel grey rather than red, but nonetheless owned mostly by Tudor.

This means that, where once components had to be transported to Geneva, now Tudor’s suppliers are also its neighbours. 
Tudor is a sister brand to Rolex, but its founder, Hans Wilsdorf, wanted the new company to be able to make a timepiece ‘at a more modest price than our Rolex watches’ and yet ‘with the same standard of dependability’. Ninety-eight years later, that’s still the aim.

At the manufacture’s heart is a bespoke, fully automated stock system that borrows technology from the pharmaceutical industry. After delivery from suppliers, components are logged then loaded into special boxes that whizz through the cavernous storage area on conveyor belts. Computer-controlled robotic arms then select all the parts needed and deliver them to watchmakers on the first floor within minutes, minimising errors, improving efficiency and freeing human hands to focus on actually making the watches.

‘We harness the latest horological manufacturing technology to complement human know-how,’ says a spokesperson. ‘It’s a challenging and exciting process.’ But the technology doesn’t minimise the importance of the human element: ‘Every watch is ultimately assembled and inspected by a watchmaker; but the know-how of these makers is supercharged by the high-tech machinery and robotics.’

The climate-controlled first floor, where the air is changed three times an hour to maintain a dust-free environment, is dedicated to watch assembly. This is where people place dials, fit hands and case movements, while a fleet of advanced robots complete the more repetitive tasks.

The watchmakers in the department work in groups of between eight and 10. The small teams never change, so colleagues are exceptionally close. There is no group leader, a different person taking the role of delegate each week, giving daily team talks and raising any issues with the floor manager, who is based in the centre of the room. Everyone is trained to carry out each of the tasks. This takes a minimum of a year to learn and many more to master, and watchmakers decide between themselves who will do what, changing roles weekly if they feel like it.

Each watch is linked to a radio-frequency identification tag containing its serial numbers and a record of everyone who worked on it. When tenths of seconds are in play, of course, quality control matters. Components are randomly sampled, and if the AQL (acceptable quality limit) of 2.5 per cent is exceeded, the entire shipment is rejected.

Once assembled, the watches move to the more cybernetic second floor, dedicated to testing, and boasting 46 tons of equipment. Up here, machines work around the clock. Intelligent roaming robots, nicknamed Wall-E and EVE, after Pixar’s automatons, deliver watches to various testing stations. As the wheeled duo silently race around the floor, trays of watches between their ‘forearms’, they nimbly avoid bumping into people or objects.

With typical Swiss seriousness, Tudor has avoided over anthropomorphising these droids, but thoughts of Short Circuit’s genial Johnny 5 are never far from a visitor’s mind. By day they share the space with human colleagues, but at night the robots have the run of the floor, barring a sole maintenance person.

While all movements undergo the brand’s standard testing (TPC, for Tudor performance control), a select group of high-performance watches also undergoes Metas Master Chronometer testing. Developed by the Swiss Federal Institute of Metrology in collaboration with Omega in 2015, this is considered the most rigorous test in the industry.

The Metas process begins with accuracy testing to ensure the watch’s precision remains stable over time. This is carried out at two temperatures and six positions (dial upward, dial downward, crown to the right, crown to the left, crown upward, crown downward) both at full wind and at 33 per cent power reserve. Throughout this, the watch must maintain accuracy of between 0 and +5 seconds per day. To put this into context, Tudor’s standard tolerances are -2 to +4, while the Official Swiss Chronometer Testing Institute allows deviations of -4 to +6 seconds per day.

Next, the timepiece is subjected to a magnetic field of 15,000 gauss, roughly equivalent to an MRI scan and much stronger than anything in everyday life. The magnets in handbag clasps and phone cases and on fridges are feeble in comparison. Magnetism is the silent enemy of a watch movement: the delicate hairspring that regulates its frequency can become magnetised, causing the watch to lose or gain time. To measure resistance, both the movement and the cased watch are loaded into trays that then slide into the belly of a gigantic magnet weighing approximately 1,500kg, and there they stay for about 30 seconds. The watch must function flawlessly during and after this.

Another serious danger to the smooth running of a movement is moisture, and today all watches have to be water resistant to some degree. Metas-tested watches are put in a basket and lowered into huge drums filled with cold water. The lids are closed and the pressure is set to whatever depth is required plus 25 per cent. That means 250m for Tudor’s Master Chronometer watches. When the watches are removed from the tank, one single drop of ice-cold water lands on the crystal. If any water has leaked into the case, the glass will fog and the watch will fail the test.

In a discreet corner room, with frosted glass windows to prevent anyone peering in, is the Metas lab, and it’s kept locked. The only person allowed in is a Metas employee, who turns up unannounced and does spot checks on watches that are in line to be Master Chronometers. Five per cent of the watches in any one batch are tested; if one fails, the whole lot are rejected. Only when all tests are passed has a watch earned the right to bear the Master Chronometer legend on its dial.

‘It’s easy to make one very precise watch,’ says the spokesperson. But it’s much harder to produce thousands and maintain quality. ‘What we do here is bring traditional know-how together with the best in production and management, with the most sophisticated robotics in this industry.’