Stay on top of all watchmaking news ! OK

This search is sponsored by Cyrus

Search in :
Watches and Wonders
Patek Philippe - In The Fast Lane With Patek Philippe (Part 1/3)

Patek Philippe In The Fast Lane With Patek Philippe (Part 1/3)

We look at why the new ref. 5470 means so much for Patek Philippe, and how to actually read its chronograph display


People tend to imagine that the minute repeater poses the greatest mechanical challenge in traditional watchmaking, and they’re right, but only to a certain extent. Chiming watches, especially those towards the more elevated end of the spectrum, such as grandes sonneries, are usually held up as the ultimate demonstration of a watchmaker’s skill. This is why the minute repeater (and its other chiming relatives) is considered the most prestigious horological complication in the traditional watchmaking canon.

I don’t really subscribe to this thinking, myself. First of all, I don’t believe in ranking complications in this way. It’s reductive and not very useful, except when making snap judgements about watches — which is something I particularly wish to discourage. Secondly, context is important. For an individual watchmaker, I can readily accept that creating a chiming watch from scratch represents the Mt Everest of their professional career, drawing on the widest range of skills and experience they have. It’s not the same thing at all for a watch company.

For a watch company, one of the clearest signs of strength and longevity is an in-house chronograph. There are numerous (long and complex) reasons for this, but I’m just going to give one illustration to prove my point. There are a number of watch brands today that offer (or that have offered in recent years) minute repeaters in their product range. These include successful brands as well as struggling brands.

On the other hand, you won’t be able to name a single brand with an in-house chronograph who isn’t doing well. This is not necessarily a causal relationship. Successful brands are successful not just because they have an in-house chronograph. It’s not a one-to-one correlation either; not all successful brands have an in-house chronograph. But empirically, watch brands with in-house chronograph movements do extremely well, in terms of both product quality and business performance.



Which leads us to the in-house chronograph cal. CH 29-535 PS of Patek Philippe, launched in 2009.

Patek Philippe ref. 5470

The Patek Philippe cal. CH 29-535 PS was first presented in 2009 © Patek Philippe

 We first saw this in 2012 with the ref. 5204, where the optimised construction of the CH 29-535 PS made possible the addition of a rattrapante function and perpetual calendar whilst still maintaining 65 hours of power reserve.

Patek Philippe ref. 5470

The Patek Philippe ref. 5204 Split-Seconds Chronograph Perpetual Calendar, presented in 2012 © Patek Philippe

Patek Philippe ref. 5470

The Patek Philippe cal. CHR 29-535 PS Q proved that the CH 29-535 PS could carry various high complications without compromising performance © Patek Philippe

The more perceptive among the Patek Philippe enthusiast community quickly noted that the ref. 5204 was launched the year following the 2011 announcement of the silicon-based Patek Philippe Oscillomax assortment, consisting of the Spiromax hairspring, the GyromaxSi balance and the Pulsomax escape wheel and anchor assembly. One of the many advantages of a silicon assortment is its energy efficiency and low inertia, allowing for higher balance frequencies. And while a high-frequency balance is sufficiently interesting in any timepiece, its utility increases exponentially in a chronograph, making the CH 29-535 PS the natural choice for the next home of the Oscillomax. Those wondering what lay in the future for the CH 29-535 PS didn’t have to fatigue their imaginations too much in order to draw the right conclusion.

Patek Philippe ref. 5470

The silicon-based Patek Philippe Oscillomax, consisting of the GyromaxSi (top left), the Pulsomax escapement (centre) and Spiromax hairspring (bottom right) © Patek Philippe

The ref. 5470 1/10th Second Monopusher Chronograph was presented the day after Watches And Wonders 2022, providing the final grand note to a weeklong symphony of horological news. Its 5Hz (36,000vph) beat rate marked the first high-frequency wristwatch from Patek Philippe, and the long-awaited union of two of the maison’s greatest creations in the third millennium — the Oscillomax assortment and the in-house chronograph cal. CH 29-535 PS.

Patek Philippe ref. 5470

The new Patek Philippe ref. 5470 1/10th Second Monopusher Chronograph, displaying a chronograph reading of 1 minute and 20 seconds exactly © Patek Philippe

On first glance, the ref. 5470 appears to be a traditional split-seconds chronograph. Official photography of the timepiece features two chronograph seconds hands, one with a polished rhodium surface and another coated in red lacquer, posed in a configuration that we associate with split-seconds chronographs. Although superficially misleading, these images give us a fundamental insight into the development of the ref. 5470 — that it was built along the same principles of construction as the ref. 5204 and ref. 5370, benefiting from the experience gained in layering mechanisms on top of the CH 29-535 PS.

Instead of indicating a split-seconds (or rattrapante) function, both chronograph seconds hands are dedicated to the same display of elapsed time. The polished and rhodinated hand indicates elapsed seconds, and the red hand indicates elapsed tenths of a second. This level of timing precision is all thanks to the 5Hz (36,000vph) balance, and adds one decimal place to the display of elapsed time in the ref. 5470.



What may take a little getting used to at first is the reading of elapsed tenths of a second. We normally assume that on an analogue timepiece, time-display hands make one complete turn around the dial to indicate a full complement of the units of time that they display. For example, seconds are counted in blocks of 60, and therefore the seconds hand goes around the dial once every 60 seconds. Minutes are counted in blocks of 60 and the minute hand goes around the dial once every 60 minutes. Hours are counted up to 12, so the hour hand goes around the dial once every 12 hours.

But the tenths-of-a-second hand of the ref. 5470 doesn’t go around the dial once every 10 decimals of a second. It goes around the dial once every 12 seconds. The 30° arc between two consecutive hour markers, which is also the same angle traversed by the minute hand between two consecutive multiples of 5 minutes (and the seconds hand between two consecutive multiples of 5 seconds) is therefore used to indicate 10 decimals of a second by the red chronograph hand.

Patek Philippe ref. 5470

The 30° arc between two red lacquer dial markings (or two hour markers) indicates the 10 decimals of a second when associated with the red chronograph hand. In this image, the red hand is directly above a red marker (parallax error notwithstanding) and hence the chronograph reading is in complete units of a second with no decimals. © Patek Philippe

Rather than being read from an absolute position (which, for virtually every display hand in every timepiece, is the 12 o’clock position), the red tenths-of-a-second hand is read from its relative position between two consecutive hour markers, which are further demarcated by red lacquer dial accents.

The chronograph reading is therefore given in the following way. The jumping elapsed minutes, up to a maximum of 30, are displayed on a totaliser at the 3 o’clock position on the dial. The elapsed seconds are read in the conventional way, according to the 60 divisions marked around the dial. The elapsed tenths of a second are then read in a dual-step approach — first determining where the red hand is and then reading its position in the 10 decimal divisions within its current 30° arc segment (as defined by two consecutive hour markers or two consecutive red lacquer dial markings).

Patek Philippe ref. 5470

The cal. CH 29-535 PS 1/10, as seen through the transparent caseback of the ref. 5470 1/10th Second Monopusher Chronograph © Patek Philippe

This is for a combination of reasons both aesthetic and technical. First of all, implementing a true foudroyante display for the tenths-of-a-second hand, where the hand makes one turn around the dial in one second, would dramatically increase the energy consumption of the chronograph. As the cal. PS 29-535 PS is a manual-winding movement, power management needs to be carefully regulated and a foudroyante tenths-of-a-second display could be considered an unnecessary energy expenditure. Secondly, the time divisions marked on the periphery of the dial are in base-12 format, and overlaying a base-10 (or decimal) scale would hinder readability. The solution that the ref. 5470 finally arrived at is therefore the most pragmatic approach to incorporating an additional precision chronograph reading.


NEXT: How the Patek Philippe ref. 5470 1/10th Second Monopusher Chronograph makes precision its absolute priority



Recommended reading

The brand

Patek Philippe enjoys outstanding renown and rare prestige, due to the constancy with which the Manufacture has applied its philosophy of excellence ever since it was founded.

Find out more >

All the news >

Contact brand >

All the watches >