Ref. 5208P - Ron DeCorte
"Ref. 5208P" - Ron DeCorte
The Patek Philippe Ref. 5208P is an inspiration of watchmaking. With minute repeater, mono-pusher chronograph, instantaneous perpetual calendar (with apertures), moon phase, day/night indication and automatic winding it is the second most complicated in the Patek Philippe line of Grand Complication wristwatches and is the first triple complication with a chronograph. Each complication, repeater, chronograph and calendar has its own unique pleasure and value in everyday life. Cased in 950 platinum, with platinum back or sapphire back if you wish, the Ref. 5208P measures a modest 42mm diameter and 15.7 mm thickness. Keeping with the Patek Philippe tradition of “classic”.
To imagine a Grand Complication wristwatch and to conceive it with accuracy and elegance demands expert technical innovation/design, the finest manufacturing techniques, great watchmaking skills, and most importantly – dedication. The Ref. 5208P is not an afterthought with generic additions. Instead it is a superb minute repeater movement with carefully designed complications that enhance it, rather than detract from its original purpose. With this in mind Patek Philippe has developed a triple Grand Complication, which meets all the criteria demanded by the Patek Philippe Seal.
Upon inspection from the back, the Ref. 5208P is deceptive, looking like a typical Patek Philippe minute repeater with automatic winding. Visible are the striking-hammers, gongs along the perimeter, and the solid gold winding rotor. At the top we can see the Patek Philippe Calatrava cross in pierced gold that covers the repeater regulator. Unlike most repeaters this regulator is a centrifugal governor that is whisper quiet. Allowing the strike sequence to be heard with unmistakable clarity and perfect rythm.
From the opposite side the Ref. 5208P reveals its more serious and complicated nature. This is the business side of the minute repeater complication. Here we find a labyrinth of micro-components such as racks, levers, springs and three finely calibrated snails that dissect the time into hours, quarter hours and minutes which activate the hammers and via the gongs bring superbly tuned time to our ears. In terms of striking watches the minute repeater is considered the second most difficult complexity to achieve, only the grand sonnerie with minute repetition is of higher difficulty.
The chronograph mechanism was of particular challenge in terms of intergration with a minute repeater. Mixing the repeater mechanism with a chronograph within the same space would create a nightmare of confusion and compromise. The solution was to create a separate chronograph mechanism that would add a minimum of thickness, 2.4 mm, be easy to adjust, and most importantly – reliable. Many patented and unique ideas are incorporated.
The vast majority of chronographs either draw power from the movement power source when engaged, and allow extra power when disengaged, resulting in a power fluctuation to the critical escapement. In order to tame this power fluctuation, the minute and hour counter wheels of the Ref. 5208P are of two-piece construction. The main wheels of the minute and hour counters are in constant motion providing a much stabilized consumption of power while light springs act to couple the main wheels with their respective axis/hand when the chronograph is engaged, resulting in reduced power fluctuation and increased accuracy. Patented tooth profiles of the chronograph engagement wheels provide a vastly reduced prospect of seconds hand jump during the start/stop functions, and increase the efficiency of the chronograph by reducing wheel friction.
The instantaneous perpetual calendar is the king of calendar mechanisms. The brain of the perpetual calendar is a lobed cam "A" situated near the perimeter at about 1:30 which makes one revolution per year in 12 monthly jumps. The cam has nine fixed lobes with two lobes being extra long to cover those months that have consecutive 31 day lengths (July/August and December/January). This accounts for 11 of the 12 months. February is a different matter having either 28 or 29 days. In order to account for this fluctuation a small non-fixed lobe or satelite is integrated within the main cam making one revolution every four years. Three sides of the non-fixed lobe are same distance from the perimeter of the main cam, while the fourth side is longer and thus closer to the perimeter. It is the depth of the lobes that dictate the number of days the calendar automatically advances at the end of each month, 1 or 2 days for most months and 3 or 4 days in February.
Under the dial we can see the calendar disks, as they will be viewed through their apertures. Disks viewed through apertures was chosen as this is easier to read compared to hands, especially on a complicated watch such as the Ref. 5208P. Towards the top are the day and month disks. Along the perimeter is the date wheel that is suspended by ruby jewels to reduce friction.  Below is the moon phase disk flanked by two other disks that deserve our attention. To the right is the leap year indicator marked in Roman numerals I – IV, with IV being in red to designate a leap year. On the left is a disk that resembles ying/yang, this is the day/night disk which is visible through a small aperture just below the chronograph hour recording hand. These latter two disks are very useful when adjusting the calendar after periods of inactivity.
The day, date, month, and leap year indications of the Ref. 5208P are controlled via their instantaneous mechanism(s) that snaps them ahead the proper amount instantly and in complete synchronization. Assuring there is no confusion at the end/beginning of each day. Of these instantaneous mechanisms the leap year is the simplest and easy to see, so we will use it as an example.

Near the top is a gold colored wheel "A" with a snail-shaped "B" cam attached. The wheel and cam combination rotate anti-clockwise once per year while a finger "C", which is part of the operating lever "D" extending downward, is gently lifted until it reaches the apex of the cam and falls off instantly. Near the bottom we see a four tooth star wheel "G" that holds the leap year disk and the operating lever "E" with a small articulating finger "F". As the lever is slowly moved during the year, the finger gently passes over the star wheel tooth without upsetting it. But when the operating lever suddenly falls off the snail "B", the lever snaps to the left and the finger "F" indexes the leap year.
See the perpetual calendar displays, day of the week, date and month, change from February 28th to March 1st instantaneously and simultaneously in 0.02 seconds, on a prototype filmed with a high speed camera (20’000 images/second).
The Patek Philippe Ref. 5208P Grand Complication is a fitting tribute to the art of watchmaking being interrogated with technology to a serious level. There are no short cuts to making great watches. Dedication, time, and experience are the only solution. Anything else is meaningless folly.