Blancpain Calibres: In-House Movements from Le Sentier

Blancpain's movement manufacture is one of the most technically diverse in the Swiss watch industry. The calibre family spans ultra-thin automatic movements of 2.6mm, the Calibre 595 micro-rotor for the Ladybird, the Calibre 1315 for the Fifty Fathoms with its five-day reserve, and the Calibre 2585 perpetual split-seconds chronograph with approximately 650 components. The breadth of in-house production reflects a brand committed to mechanical watchmaking at every level of complexity.

The Manufacture — Le Sentier and Paudex

Blancpain's primary movement manufacture is in Le Sentier , in the Vallée de Joux — the same valley where Audemars Piguet and Jaeger-LeCoultre are located. The Le Sentier facility handles movement design, component production, and base calibre assembly.

A secondary facility in Paudex (near Lausanne) handles casing, quality control, and some complication assembly for the most complex references. Between the two sites, Blancpain employs approximately 400 people.

The manufacture's origins are in Frédéric Piguet — the independent movement maker that supplied Blancpain from the 1983 revival. Frédéric Piguet was acquired by Blancpain (and through it, Swatch Group) in 1992, becoming the technical core of the current Blancpain manufacture. The Frédéric Piguet name still appears on certain movement components and in historical references.

Calibre 1150 and 1151 — The Foundation

The Calibre 1150 (manual-wind) and Calibre 1151 (automatic) are the foundation movements of the Villeret dress watch collection:

The 2.6mm height of the Cal. 1150 makes it one of the thinnest manual-wind movements in production. The thinness is achieved through a construction that minimises plate heights and uses a large-diameter barrel (providing reserve) within the constraints of the small movement height.

Calibre 1315 — The Fifty Fathoms Five-Day Reserve

The Calibre 1315 is the movement powering the Fifty Fathoms range — a robustly constructed automatic designed for water resistance and extended power reserve:

The silicon balance spring is the Cal. 1315's key technical advancement over the earlier Fifty Fathoms movements. Silicon is non-magnetic (the standard Nivarox alloy balance spring can be affected by magnetic fields), dimensionally stable across temperature ranges, and self-lubricating at the hairspring-stud contact — improving long-term accuracy without the degradation of lubricant that affects metal springs.

The five-day reserve is achieved through three series-coupled mainspring barrels — three times the standard single-barrel capacity. The barrel arrangement requires precise engineering to ensure equal draw-off across the three barrels, preventing uneven mainspring torque across the power reserve.

Calibre 5954P — The Villeret Perpetual Calendar

The Calibre 5954P powers the Villeret Quantième Perpétuel (perpetual calendar) references:

The retrograde date display — in which the date hand sweeps forward across an arc scale and snaps back at month end — is mechanically more complex than a standard rotating date disc but provides a more dramatic and legible display.

Calibre 25 — The Tourbillon

The Calibre 25 is the direct descendant of the original 1983 Blancpain tourbillon calibre:

The eight-day reserve is achieved through a large single barrel with an extended mainspring. The tourbillon cage is assembled by a single watchmaker who is responsible for the entire cage build, including the balance wheel adjustment.

Calibre 2585 — The Perpetual Split-Seconds Chronograph

The most complex production Blancpain calibre is the Calibre 2585 :

The split-seconds chronograph uses two superimposed seconds hands: the main chronograph hand and a secondary hand that can be stopped independently to record an intermediate time. Releasing the split hand causes it to snap back to the position of the main chronograph hand — hence "rattrapante" (catching up).

Combining this with a perpetual calendar in a single movement requires the component count of a small clock movement to be compressed into a 13.1mm height — wearable on the wrist.