Patek Philippe: Grande Sonnerie Ref. 6301P

Patek Philippe has leveraged this momentum to enrich its regular collection with a masterpiece of miniaturization and acoustic perfection: the Ref. 6301P Grande Sonnerie. This grand complication is the manufacture’s first wristwatch that presents the grande sonnerie complemented with a petite sonnerie that does not strike the quarter hours and a minute repeater that strikes on demand.

To implement the grande sonnerie as envisioned, Patek Philippe developed a new movement as a spin-off of the caliber 300 of the Grandmaster Chime. The caliber GS 36-750 PS IRM is remarkably compact for such a complex mechanism, diameter: 37 mm; height: 7.5 mm. One of the traditionally greatest difficulties for the engineers of grande sonneries is mastering energy flows and power reserves. Unlike in minute repeaters which must be triggered on demand by actuating a slide or a pusher, the grande sonnerie needs to have sufficient reserve power to automatically sound the required number of time strikes with uniform acoustic quality. 

Patek Philippe endowed the caliber GS 36-750 PS IRM with two tandem-connected twin mainspring barrels, one for the going train and the other for the chiming mechanism. This configuration delivers a power reserve of 72 hours for the movement and of 24 hours for the strikework. The 24-hour power reserve for the strikework allows the watch to strike the full hours and the quarter hours during an entire day and thanks to a uniform torque characteristic to assure optimized sound intensity. The two twin mainspring barrels are wound with the crown pushed in and rotated clockwise to wind the going train and counter clockwise to wind the strikework. 

A STRIKEWORK WITH THREE GONG

As regards the strikework, Patek Philippe opted for three classic gongs – low, medium, high. This technical option requires more energy than systems with two gongs. Attached to the movement, the three gongs must not touch one another nor other parts of the case or movement despite the compact space in which they hover. Three hammers of identical size and mass guarantee a uniform strike for all three pitches. 

The hours are struck on a low-pitched gong, the quarter hours with a three-strike high-low- medium sequence. The melody for the first quarter hour (15 minutes) sounds once, for the second quarter hour (30 minutes) twice and for the third quarter hour (45 minutes) three times. Each quarter-hour sequence is automatically preceded by the number of elapsed hours, and followed by the number of quarter hours. Thanks to the energy stored in the twin mainspring barrel of the strikework, this adds up to an impressive total of 1056 strikes in 24 hours. The owner can also select the strikework mode petite sonnerie; it strikes the full hours but omits the repetition of the hours when striking the quarter hours. In the silence mode, the automatic time strike is switched off altogether. 

The selection of the strikework mode is performed with a slide switch in the caseband at 6 o’clock. The petite sonnerie mode is on the left adjoining the grande sonnerie mode in the middle and silence on the right. This special feature is the subject of a patent that was already developed for the Patek Philippe Grandmaster Chime. On request, the minute repeater can be triggered by pressing the pusher in the crown at 3 o’clock. In response, it strikes the number of hours with low tones, the quarters with three-strike sequences (as in the grande sonnerie mode), and, on the higher-pitched gong, the number of minutes that have elapsed since the last quarter hour. The minute repeater can be triggered at any time, even if the slide is set to the silence mode.

THE JUMPING SECONDS

When they reworked the caliber 300 from the Patek Philippe Grandmaster Chime, the engineers and designers at the manufacture added a small jumping seconds display. Its system does not rely on jumper springs as usual but instead with wheels and a release lever that instantaneously unblocks the wheel train every second, making energy consumption easier to regulate and control. Thus, the new Ref. 6301P chiming watch presents a novel face characterized by the subsidiary seconds hand at 6 o’clock. With the blink of an eye, it jumps along the railway track minute scale from one second to the next, recalling the regulator clocks that were used in old watchmaking ateliers to synchronize the time. 

Patek Philippe demonstrates all its savoir-faire also in the workmanship of the black grand feu enamel dial with the “glacé” finish, applied Breguet numerals, and leaf-shaped hands in luminescent white gold. The displays for the hours, minutes, and subsidiary seconds at 6 o’clock are well proportioned alongside two power-reserve indicators for the movement and the strikework at 3 and 9 o’clock with semicircular scales identified with the inscriptions MOUVEMENT and SONNERIE.

Like all Patek Philippe platinum cases, it sports a small diamond set in this instance at 12 o’clock because the usual 6 o’clock position is occupied by the slide switch for selecting the strikework mode. 

The timepiece is combined with a black Alligator strap and a fold-over clasp in platinum.