Monochrome Watches
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The New Ulysse Nardin Blast HourStriker Tourbillon (Live Pics & Price)

Ulysse Nardin’s take on the chiming watch with sound enhanced by Devialet technology.

| By Robin Nooy | 7 min read |
Ulysse Nardin Blast HourStriker Tourbillon

Before the invention of portable clocks, pocket and wristwatches, telling the time was primarily an audible exercise. In the past, almost every major city and town had a church with a tower clock. Visible from close quarters but not from afar, a system of bells and hammers chimed the time. For centuries this technique has been refined and miniaturised to fit into a mechanical wristwatch. Ulysse Nardin now takes the next step in this highly complex yet ever so romantic field of traditional mechanical watchmaking. Today we’re introducing the Ulysse Nardin Blast HourStriker Tourbillon.

Ulysse Nardin Blast HourStriker Tourbillon


In the world of watchmaking, there are a few complications regarded as ultra-complex to master. One is the integrated chronograph, even more so when fitted with a rattrapante. Then there’s the tourbillon and even double or triple-axis tourbillons. And finally, there are various striking mechanisms, whether a Sonnerie, a repeater or a striking time indication. There are only a handful of watchmakers around capable of creating such complex and magnificent movements. Incorporating levers, springs, gongs and hammers to create an audible indication of time requires the most expert knowledge and skill.

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Ulysse Nardin has been creating striking watches for close to 40 years now and has since built a reputation for its commitment to high-tech innovation. Not only in the field of materials, such as the Freak once demonstrated, but also in finding new solutions to improve existing mechanical complications. Since its first striking mechanism, Ulysse Nardin has played with the concept across a whole range of models, often inspired by historical figures and scenes, such as Alexander the Great or Hannibal. More recently, the Maison introduces this highly technical complication in more modern, contemporary watches, overcoming challenges by applying technology from other fields into watchmaking.

Ulysse Nardin Blast HourStriker Tourbillon
HiFi specialist Devialet has partially developed the construction of the case.

We first saw such an advancement in the Ulysse Nardin Hourstriker Phantom. For this unique-looking watch, Ulysse Nardin partnered up with renowned luxury speaker manufacturer, Devialet. The French masters of HiFi speakers and sound systems have once again aided Ulysse Nardin to develop a unique, striking time watch. This year, UN follows the principles learned from the Ulysse Nardin Hourstriker Phantom released in 2019. This used a never-seen-before technology that included a membrane and perforations in the caseback to allow the sound to travel beyond the confinement of the case. 

The new Ulysse Nardin Blast HourStriker Tourbillon

The ingenious system brings the striking mechanism to the watch’s dial side, and since there’s no actual dial here, it is in full view for everyone to see. When activated, the spectacle is mesmerising; you can activate the passage of time like a true ‘Sonnerie au Passage’ or trigger an on-demand chime with the pusher at 10 o’clock. The system of springs, levers, hammers and gongs is fascinating to behold. When the chiming mechanism is selected in the ‘on’ position, with the pusher at 8 o’clock, the Ulysse Nardin Blast HourStriker Tourbillon will indicate each full and half-hour. The correct number of hours (2 for 2 o’clock, 3 for 3 o’clock and so on), and a single strike every half-hour interval. 

Ulysse Nardin Blast HourStriker Tourbillon

When activated, the hammer strikes the circular steel gong, which flows around the flying tourbillon, and produces a chime. The soundwaves produced by the hammer striking the gong resonate through the case and are often partly absorbed by it, losing crispness and volume. To overcome this issue, Ulysse Nardin and Devialet have found a way to amplify the sound waves and produce a much louder, warmer sound. 

Ulysse Nardin Blast HourStriker Tourbillon

Ulysse Nardin Blast HourStriker Tourbillon

A black DLC-coated titanium membrane was developed by Devialet and is only 3 tenths of a millimetre thick. The heel of the gong is connected to the membrane with a torsion bar. This torsion bar connects the gong and gong support to the rest of the movement. The torsion bar spans the tungsten oscillating weight. The next step involves fitting the support back with cut-outs for sounds to travel through and a gasket outside. The support back helps to prevent deformation of the titanium membrane underwater. This is all covered in a solid caseback, made in gold, with X-shaped cut-outs to allow the sound waves to travel outside of the case. 

Ulysse Nardin Blast HourStriker Tourbillon

The membrane acts very similarly to the membrane in a high-quality speaker. It moves air and, as such, enhances the air’s pressure and vibrations to amplify the sounds the hammers and gong produce. In essence, it works similarly to a phonograph. This is further aided by the cut-outs in the caseback similar to the Hourstriker Phantom to allow the soundwaves to travel outside the case and be heard much clearer and louder. 

The case for the Ulysse Nardin Blast Hourstriker Tourbillon is perhaps as complex as the movement. Made from black DLC-coated titanium and 18k rose gold, it has a very contemporary design similar in style to the Blast Skeleton Tourbillon presented last year. The choice of materials in a chiming watch is essential to the quality of the sound it makes. Denser materials such as platinum and gold absorb some vibrations and, although they are often used, they are not the best for chiming watches. 

Ulysse Nardin Blast HourStriker Tourbillon

Steel is much better suited, but titanium has the best resonating properties of all these materials. Being very light, titanium is best used to resonate sound waves in a watch. Ulysse Nardin has used black DLC-coated titanium for the central part of the case, the part that matters most in a chiming watch. The titanium mid-case is capped with an 18k rose gold top case and a box sapphire crystal. This complicated construction of the case allows for 30m water-resistance despite multiple openings in the caseback.

Ulysse Nardin Blast HourStriker Tourbillon

Positioned just underneath the crystal is the hour ring and minute track to help indicate time more accurately. As mentioned, there’s no real dial here and the large, rose gold hands are aided by bold hour markers, of which four make up a stylized X-shape to keep the design coherent with the Blast collection. All in all, the 45mm wide case is bold, with multiple facets and alternating brushed and polished finishing throughout. 

In-house Calibre UN-621

The Calibre UN-621 is derived from the UN-610 calibre, with many redesigned and newly constructed parts. It is, for now at least, exclusively made for the Ulysse Nardin Blast HourStriker Tourbillon and is the first in-house movement of its kind for Ulysse Nardin. The movement is on full display, with all the parts for the striking time complication visible. The hour rack, for instance, the 12-tooth lever that, along with sensors, snail cams, and springs resets and releases the hammers, can be viewed thanks to the skeletonised construction. Along with the inertia regulator, this ensures the gong is struck at a precise speed and frequency, ensuring the individual notes are spaced evenly and sound as clear as can be.

Ulysse Nardin Blast HourStriker Tourbillon

The UN-621 is regulated by a flying tourbillon with a variable inertia balance wheel. The hairspring, anchor and escape wheel are made of silicium – as expected from UN. It features 330 parts and is self-winding (at least for the timekeeping part). The frequency of the UN-621 calibre is 4Hz or 28,800 vibrations per hour. The chiming complication has its own barrel, which is hand-wound, and in total, the movement can store up to 60 hours of power reserve. The movement is finished to the highest standards with straight and circular graining, polished surfaces, bevelled edges…

Straps, Availability & Price

The Ulysse Nardin Blast Hourstriker Tourbillon comes with a choice of three straps: one in waterproof velvet, one in alligator leather and one in rubber. The watch is priced at CHF 99,000 or EUR 91,100. There’s no word regarding limitation, but I can’t imagine this running in the hundreds of watches per year.

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1 response

  1. Looks scrappy to me. AND I`ll get several of my dream watches for that money…

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