Last week, Patek Philippe unveiled a brand premiere representing its first chronograph wristwatch with the ability to time events with the precision of 1/10th of a second.

Presented in a luxurious 41 mm x 13.68 mm 950 platinum case, the Patek Philippe Ref. 5470P-001 1/10th Second Monopusher Chronograph is a tour de force — showing off the Geneva-based watchmaker’s mechanical prowess. Not only does the watch possess the ability to record elapsed times down to a tenth of a second, but it’s also a monopusher, meaning you control the start/stop/reset functions — with just one pusher.

Patek Philippe Ref. 5470P-001 1/10th Second Monopusher Chronograph pusher

Some of the well-known watchmakers that produce high-beat 5Hz calibers are Zenith, Grand Seiko, Chopard, and Blancpain. Above the 5Hz rate, Chopard makes an 8Hz movement, Breguet makes a 10Hz movement, and TAG Heuer has movements that are 50Hz, 500Hz, and even 1,000Hz. Quartz, of course, runs at an even higher rate, of 32,768 Hz, but as far as mechanicals go, anything 5Hz (36,000 vph) or higher is considered a “high beat” movement.

Even considering all the formidable high beat offerings mentioned above, none are as intuitive and easy to read as Patek Philippe’s configuration, which uses two separate chronograph mechanisms and sweep hands. Central chronograph seconds are displayed via the white hand the 60 pearl marks on the ring that surrounds the hour markers, the traditional way — while tenths of seconds are simultaneously displayed via the red lacquered hand in conjunction with the twelve red hash marks. You simply stop the chronograph and read the railway scale to count how many marks from the last red mark the red hand stopped out to determine what fraction of a second was recorded. For instance, six marks is 6/10ths of a second.

Patek Philippe Ref. 5470P-001 1/10th Second Monopusher Chronograph

The visual simplicity of the dial belies the amount of technology that’s underneath the dial. Case in point: the caliber CH29-535 PS 1/10 utilizes intellectual property from 31 Patek Philippe patents (all developed in the first twenty years of the 21st century). This timepiece was not given the “Advanced Research” moniker (although it seems to more than qualify), numerous of the patents come from the Advanced Research department. Moreover, seven of the new patents are specific to this new caliber.

The seven patents of the new caliber CH 29-535 PS 1/10 movement are as follows:

1- Concentric display (Patent WO2012104688A1) This display mode based on two sweep hands assures simple, swift, and safe legibility of seconds and fractions of a second.

2- Notch in the barrel arbor (Patent WO2017005394A1) The addition of this notch reduces the tension exerted by the spring hook while the mainspring is being wound. It also allows a smaller diameter of the barrel arbor, increasing the energy stored in the mainspring by further spring coils.

3- 1/10 driving wheel with anti-backlash feature (European patent application EP3042250A1) This design on two levels (an upper wheel with flexible spokes and a lower one with rigid spokes) allows the creation of an anti-backlash wheel that is compact and consumes little energy.

4- Chronograph with a shock-absorber hook (Patent WO2015173372A2) In the event of a shock, this system securely holds the clutch rocker of the operating chronograph mechanism to prevent disruptions of the ongoing short-time measurement.

5- Pendulum shock absorber (Swiss Patent CH713473A2) This system utilizes the acceleration forces of shocks on the watch to keep the components of a mechanism in the desired position and thus to assure correct functionality.

6- A surface primer for the silicon hand (European patent application EP3764167A1) With a fine primer coating (e.g. PVD or CVD), this process improves the adhesion of lacquer on a silicon-oxide surface (Silinvar®).

7- Assembly process for watch components (European patent EP 3309624 B1) Thanks to a multi-layer metal coating, this process for joining two base materials, one of which is non-metallic, allows the pipe of a Silinvar® hand to be brazed.

Patek Philippe Ref. 5470P-001 1/10th Second Monopusher Chronograph

Naturally, there were many challenges in creating the Ref. 5470P-001 and these are best described by Patek Philippe.

“With this tenth-of-a-second monopusher chronograph produced in small series — it is just as difficult to craft as a tourbillon, a minute repeater, or a split-seconds chronograph — Patek Philippe is delighting connoisseurs and enthusiasts with a new attraction in the domain of grand complications.

The challenge began with a single mainspring that was needed to provide energy for the whole movement. Patek Philippe reworked this component and increased its efficiency to preserve the amplitude of the balance spring as much as possible and to assure optimized rate stability. To increase the available energy and boost the power reserve, the diameter of the barrel arbor was reduced and the number of mainspring coils increased. A patented notch reduces the tension of the slip bridle during the winding process, thus eliminating the risk of damage due to the increased force.

To handle the three challenges – efficiency, reliability, and rate accuracy – Patek Philippe decided to use its Oscillomax® ensemble that had been developed by the ‘Patek Philippe Advanced Research’ department. This high-tech regulator mechanism was presented in 2011, was granted 17 patents, and has three innovative components that rely on all advantages of the Silinvar® technology – it is based on a derivative of silicon with extraordinary physical and mechanical characteristics (lightweight, rugged, antimagnetic, etc.). The ensemble operates with a Spiromax® balance spring with a patented terminal curve and an inner boss (patent granted in 2017, Ref. 5650), a Pulsomax® escapement consisting of a lever and escape wheel with extensively reworked geometries as well as a Gyromax® balance in Silinvar® with gold inlays. This is the first time since the launch of the perpetual calendar “Patek Philippe Advanced Research Ref. 5550P“ (2011) that Patek Philippe has added the Oscillomax® ensemble in its current collection. But this decision plays a decisive role for the exceptional performance of the new caliber CH 29-535 PS 1/10 movement. And it enables the high rate accuracy with a maximum deviation of -3/+2 seconds per day specified by the Patek Philippe Seal – despite the clearly higher energy consumption of the movement.

Another big challenge arose during the development of the caliber CH 29-535 PS 1/10 regarding the quality of the display, particularly of the tenths of a second. The two chronograph displays must be perfectly synchronized. Despite the high speed of rotation, the tenth-of-a-second hand must move fluidly without jumps or vibrations. Here, too, the manufacture’s engineers developed and implemented innovative solutions.

The mechanism for displaying the tenths of a second receives its energy via a driving wheel from the fourth wheel of the base movement. Patek Philippe designed the driving wheel in a novel two-part arrangement: the upper wheel with flexible spokes, the lower one with rigid spokes. Thanks to this patented anti-backlash principle that is both compact and energy-saving, the teeth of the driving wheel exert an elastic force on the clutch wheel, eliminating any risk of hand vibration.

As soon as the chronograph is started, the tenth-of-a-second driving wheel (with one revolution per minute) engages with the tenth-of-a-second pinion that performs one revolution in 12 seconds (turning five times faster). To enable this ‘acceleration,’ Patek Philippe provided the tenth-of-a-second pinion with microtoothing: 136 teeth on a pinion diameter of 1.469 mm and with a tooth height of 30 μm. The pretensioning force exerted by the clutch wheel on the pinion suppresses tooth backlash. Many individual measures maximize the accuracy of the display.

The watch should not only be able to measure and display tenths of a second but also retain this precision during a 30-minute run of the chronograph. Additionally, the caliber CH 29-535 PS 1/10 had to be built as compactly as possible while retaining the diameter of the base caliber (29.6 mm) and allowing only a slight height increase (from 5.35 mm to 6.96 mm) – despite the two chronograph mechanisms and a total of 396 parts. As a true accomplishment in miniaturization, this new movement is even shorter than the rattrapante caliber CHR 29-535 PS (7.1 mm).

Another indispensable measure needed for a user-centric solution relates to the shock absorber. The new caliber CH 29-535 PS 1/10 had to handle all requirements and risks to which it would be exposed in daily use. For this purpose, Patek Philippe developed two patented mechanisms. One of them is a shock absorber hook that would secure the clutch rocker during the entire short-time measurement process. The second one uses the “unbalances” (centers of gravity, not to be confused with centers of rotation) of components of the mechanism for the tenths-of-a-second chronograph. In the event of a shock, the acceleration values of the components exposed to it are compensated instead of being cumulated. The result is that all components remain in the desired positions, eliminating any impact on the correct function of the watch.

The last notable feature: The chronograph has a single pusher at 2 o’clock that successively executes the start, stop, and reset commands. This monopusher arrangement recalls the classic chronographs and will delight the aficionados of technical timepieces. In addition to the patented special features of the caliber CH 29-535 PS 1/10, the new watch embodies the seamless pairing of tradition and innovation that constitutes the core of the Patek philosophy.”

Viewed through a sapphire crystal exhibition caseback (interchangeable with an included solid platinum caseback), you can view the CH 29-535 PS 1/10 in all its glory, including the incredible chamfered and polished edges of the bridges and components, as well as Geneva stripes, flat polished screw heads, perlage on the mainplate, and straight graining on the top of most components. Engraved, gilt inscriptions “Oscillomax 5 Hz” and “GyromaxSi” on the bridges refer to the innovative movement components.

Patek Philippe caliber CH 29-535 PS 1/10

The platinum case has the same design as the manually wound Ref. 5370 Split Seconds Chronograph launched in 2015. Distinguished by a concave bezel that transitions between a slightly domed sapphire crystal and the middle case. The case flanks are slightly recessed and have been satin-finished. The lugs are curved and feature decorative cabochons at the ends of the spring bars. Like all of Patek Philippe’s platinum models, the Ref. 5470P-001 is adorned with a flawless brilliant-cut diamond (Top Wesselton) between the lugs at 6 o’clock. 

Patek Philippe Ref. 5470P-001 1/10th Second Monopusher Chronograph diamond between lugs

The dial is crafted from brass, and given a lacquered blue finish. Hand-applied to the brass dial are Breguet numerals in 18K white gold, and 18K white gold minute/chronograph second pearl markers. The railway track scale was printed in white and red, while the slightly recessed snailed small seconds (at 9 o’clock) and snailed 30-minute chronograph counter (at 3 o’clock) are surrounded by printed white railway style scales. The leaf-shaped hour and minute hands are in 18K white gold with a luminous. Small seconds and the instantaneous 30-minute chronograph display are indicated with 18K white leaf-shaped hands.  The traditional chronograph seconds hand is crafted in sandblasted steel, that has been rhodium-plated and the tenths-of-a-second chronograph hand is in red lacquered Silinvar®.

Patek Philippe Ref. 5470P-001 1/10th Second Monopusher Chronograph

Perhaps the best feature of all is that even with the plethora of patents and mechanical innovations — the manually wound 396 components, 38-jewel, 48-hour power reserve caliber CH 29-535 PS 1/10 with a column wheel, horizontal dual-clutch with wheels, the balance Gyromax® in Silinvar® with inlays in 99.9% gold, balance spring Spiromax® in Silinvar®, Pulsomax® with lever and escape wheel in Silinvar® — the movement measures 29.6 mm x 6.96 mm, adding very little thickness to the base caliber from which they started, resulting in a case that’s just 13.68 mm thick.

Patek Philippe Ref. 5470P-001 Monopusher Chronograph case flank


The Patek Philippe debuts 1/10th Second Monopusher Chronograph (Ref. 5470P-001) is depth rated to 30 meters and is paired with a blue calfskin leather strap with an embossed fabric pattern, hand-stitched with red contrasting thread, and secured with a fold-over clasp in 950 platinum. 


Photos by Patek Philippe.

Posted by:Jason Pitsch

Jason is the founder of Professional Watches and specializes in writing, product photography, and digital marketing.