Launched in 1997 around the concept of wandering hours, a complication that dates back to the mid-17th century, Urwerk has spent nearly three decades evolving it with increasingly advanced displays, from wandering discs to rotating cubes.

But all this time, the basis of the concept has remained the same: rotating symmetrical arms carrying discs or cubes.

The new UR-300 in titanium

Now, however, Urwerk has come up with a different approach. Instead of symmetrical arms, the UR-300 Time Quantum introduces two bars forming a T-shaped frame that rearranges itself in a single jump every hour.

A new concept

Some things haven’t changed. The hour still wanders across the minute track, a 108-degree arc at six o’clock, and the hour numeral itself acts as the pointer. What’s entirely new is how the hours get there.

The hour display is now built on what Urwerk calls a T-frame. Instead of cubes, it uses four three-sided prisms, with the 12 hours shared between them. The T looks like a single fixed piece, but it is actually two separate bars, each holding a prism at both ends: a vertical bar pointing down at the minute track, and a horizontal bar across the top. The bars keep swapping roles.

The T-frame at a glance

During the hour, the prism at the bottom of the vertical bar travels slowly along the minute track. When it reaches the 60-minute mark, three things happen at once.

First, the two bars swap places. Each pivots on its own centre, so the vertical bar turns to lie horizontally across the top, while the horizontal bar turns to become the new vertical bar.

At the same time, the carousel carrying both bars jumps forward 72 degrees, bringing the new vertical bar into place at the start of the minute track.

Finally, all four prisms turn to their next face, so the correct hour is shown at the bottom.

Exploded view of the mechanism

The clever maths behind it

The numbers are arranged with neat logic. The four prisms take turns being at the bottom of the T, so each prism shows the time once every four hours. That’s why each prism carries hours that are four apart: one prism has 1, 5 and 9, another has 2, 6 and 10, and so on.

Every prism turns one face at every jump, so by the time a prism comes back to the bottom, it has turned four times. With only three faces, three turns bring it back to where it started, and the fourth moves it on by one. Take the prism showing 1: it turns to 5, then 9, then back to 1, and the fourth turn lands on 5, exactly four hours later.

As an aside, the clean, industrial finishing fits the theme well

Unlike Urwerk’s earlier watches, where only the incoming disc or cube turned, all four prisms here turn together. That’s because the prisms on each bar are geared to a shared wheel at its centre, so when the mechanism fires at the end of the hour, every prism is forced to turn. Fortunately, as explained above, the clever numbering ensures the right hour always lands at the bottom. The extra movement likely uses more energy, and the 44-hour power reserve is a few hours short of many recent Urwerks.

The rest of the watch

While recent Urwerk watches with satellite hours have become more compact, the UR-300 packs a complex jumping T-frame into a 45.2 mm case, though at 18.25 mm thick it is a substantial watch. It also introduces a new case design not seen on previous Urwerk watches, offered in titanium with two finishes: bare metal or black, the latter achieved through plasma-enhanced chemical vapour deposition (PECVD).

With black coating

Inside is an automatic movement topped by Urwerk’s own module, which carries the T-frame. Tucked beside the minute track is a discreet seconds display, with three hands each covering 20 seconds across a 120-degree arc. The movement also incorporates Urwerk’s patented Dual Flow Turbine, which regulates the speed of the automatic rotor to reduce wear and tear.

A specially designed rotor completes the look

Tech Specs: Urwerk UR-300 Time Quantum

Reference UR-300-TQ
Movement UR-30.01V; automatic; 44 hours power reserve; 28,800 vibrations per hour (4 Hz)
Functions Wandering hours with jumping T-frame, minutes and seconds
Case 45.2 mm x 58.8 mm x 18.25 mm; Grade 5 titanium; water resistant to 30 m
Strap Nato strap
Limited edition 25 pieces in titanium and 25 pieces in black-coated titanium, 50 pieces in total
Price CHF 168,000 (excluding taxes)