Girard-Perregaux has unveiled the new in-house Calibre GP4800, an automatic movement that boasts advanced technical features.
“Entirely developed in-house, it represents a clean-slate approach, free of technical constraints and creative compromise. A movement that encapsulates the enduring ethos of the brand: design and performance, innovation, and heritage, all united in perfect harmony.”
Key Features
Diameter: 25.60 mm or 11 ½ lignes. Thickness: 4.28 mm. Jewels: 19. Frequency: 28,800 vph or 4 Hz. Power reserve: 55 hours (minimum). Functions: Hours, minutes, and seconds with a stop-seconds function.
Image: The calibre features compact dimensions given the recent trend in smaller case sizes. Its design allows it to be used a base calibre for additional complications. For example, a date wheel, moon phase display, chronograph, perpetual calendar, etc.
Silicon Escapement and a Stop-Seconds Function.
Image: The escapement components – escape wheel, pallet lever, and roller – are crafted from silicon (or silicium), a lightweight material. On the image, the escapement is hidden by the variable-inertia balance wheel and skeletonised balance bridge (top of the calibre). The stop-seconds function allows precise setting of the time.
“Silicium is exceptionally smooth, non-magnetic and highly resistant to wear, attributes that make it ideal for precision watchmaking. Moreover, the hardness of silicium, its low coefficient of friction and its resistance to wear significantly enhance the reliability and longevity of the mechanism.”
Variable-Inertia or Free-Sprung Balance Wheel.
Image: Notice the variable-inertia balance wheel and balance spring. It beats at a rate of 28,800 vph or 4 Hz – a modern beat rate. While a lower beat rate of 21,600 vph or 3 Hz might be considered “luxurious” and a tad more difficult to regulate, Girard-Perregaux will be crafting this calibre at scale, hence the choice of 4 Hz.
“The GP4800 features a superior variable inertia balance. With most watches, the rate is adjusted using a ‘raquette’. This device alters the effective length of the balance spring, making the watch run faster or slower. With the new variable-inertia balance, the length of the balance spring is fixed, and the rate is altered by adjusting four white gold timing screws mounted on the rim of the balance wheel, ensuring that the rate can be set more precisely. A powerful barrel plays host to the mainspring that delivers significant torque. The balance wheel has an inertia of 8 mg per cm which, together with the variable-inertia balance, mitigates the influence of shocks. Moreover, the increased torque confers better stability, thereby enhancing precision.”
Improved Winding System.
Image: The skeletonised automatic winding rotor is made from 18K gold and provides an unobstructed view of the movement. Below the rotor sit three bridges – the balance bridge, gear train bridge, and barrel bridge. These are inspired by the brand’s 1867 pocket watch, “one of the oldest brand signatures in watchmaking.”
“The Calibre GP4800 incorporates an upgraded winding system and features an oscillating mass mounted on a ball bearing. The ball bearing is set with ceramic balls and equipped with a shock absorber system that reduces winding noise and counters shocks, delivering long-term durability. The motion of the rotor is transmitted to a ball-bearing clutch system, which winds the mainspring barrel in a unidirectional manner.”
Movement Finishing.
Image: The movement features at least 10 different types of finishing. I reckon the finishing will be a combination of hand and machine finishing, similar to that practised by the Holy Trinity (at least where their base movements are concerned). This is not artisanal independent watchmaking, so excessive hand finishing would not be possible and cost prohibitive.
“The rhodium-plated bridges are engraved with golden inscriptions, including the eagle emblem. They are adorned with straight Côtes de Genève engraving, feature diamond-bevelled edges and incorporate mirror-polished screw heads. The visible areas of the main plate feature a refined sandblasted texture, complemented by the words ‘SILICIUM ESCAPEMENT’ positioned near the balance.”
“Even the hidden surfaces are not overlooked with circular graining adorning the underside of the main plate, exemplifying the Maison’s dedication to detail. The oscillating weight incorporates polished arrow-shaped motifs, a tribute to the original bridges of 1867, while a combination of sandblasting, snailing, and traits tirés grace its flanks. Additional elements, such as the sunray-finished ball-bearing clutch, snailed barrel drum and circular satin-finished wheels further underscore the blend of innovation and heritage.”
Our Thoughts
Image: New movement means new watches. I cannot wait to see the models this calibre will power.
Today’s watch industry is different. The thought process, hard work, and innovation of independent and micro watch brands can blow one’s mind away. Established historical brands cannot afford to be lazy and use the same movements for decades. Girard-Perregaux’s Calibre GP4800 is much needed and will ensure they remain competitive. We look forward to the models the brand will launch that will be powered by Calibre GP4800.
Please click here and here to read our earlier coverage on the brand. Girard-Perregaux’s sister brand Ulysse Nardin (both are owned by the Sowind Group) is a pioneer in silicon technology. Please click here and here to read more.
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