“You only write well with an eraser”, stated an unknown author. This quest for essentials and the refusal of anything superfluous was also the guiding principle for Blancpain watchmakers in developing the new base Calibre 13R0. The simplest constructions are those that ensure maximum reliability, while also facilitating maintenance. However, in both watchmaking and literature, simplicity is often the culmination of lengthy research. Blancpain meticulously studied all components of mechanical movements in order to choose the most effective solutions. The result is an efficient, accurate and reliable “motor” that once again takes the art of watchmaking to new heights. A creation that is both a model of restraint and highly prestigious – exactly like Blancpain’s splendid timepieces.


Blancpain first focused on the sprung balance – the regulating organ of the watch – and on its adjustment system. Most mechanical movements are equipped with a mobile organ named an “index” that enables one to adjust the active length of the balance-spring, and thus the oscillating speed of the balance. Some brands opt for a swan’s neck system with a more decorative appearance. Control of the rate is thus achieved by means of regulating screws placed on the balance rim or felly. Tightening the screws inwards reduces the active diameter of the balance, thereby increasing the speed of the oscillations – and vice versa. This system features several advantages compared with most existing devices. It takes less space than an index or a swan’s neck. The balance maintains concentric oscillations, since no organ presses against one of its ends (which would inevitably modify its shape). Nor is there any risk that a shock might modify the position of the index or the swan’s neck and thus be detrimental to the rate of the watch. Nonetheless, the supreme advantage is the precision and the effectiveness of the adjustment. There is no need to seek the correct adjustment empirically by small backward or forward pushes. The regulating screw system enables one to anticipate changes in rate. On Calibre 13R0, a quarter-turn of the two diametrically opposite screws results in a modification of thirty seconds per day. Once the rate of the watch has been verified on a chronoscope, the watchmaker knows exactly by how many fractions of a turn he must tighten or loosen the screws. To facilitate this task, Blancpain has equipped the gold micrometric screws with square heads, which mean the watchmaker can more easily visualise the corrections he is performing.


Due consideration was then given to the diameter of the balance. The goal was in particular to achieve the best possible ratio between mass and inertia, thanks to a larger-diameter balance, which accordingly reduces differences in rate between horizontal and vertical positions. In order to optimise rating regularity, Blancpain chose a titanium alloy. While it is very hard to work with, this avant-garde material features several decisive advantages. It is far less sensitive to variations in temperature than glucydur, which is used in most modern balances. It is anti-magnetic and it is also distinguished by its amazing lightness. The lighter a balance, the less energy is consumed by its to-and-fro motion; the less the force of gravity affects the regularity of its oscillations in its various positions; and the less infl uence is exercised on its tiny pivot measuring a mere 6.5/100th of a millimetre, equivalent to a hair’s breadth! Consequently, the balance-spring which serves to compensate for the expansion of the balance had to be adapted to the titanium balance.


A flat balance-spring on a single plane cannot develop in a perfectly concentric manner. To guarantee the sprung balance a maximum of isochronism (regular oscillations whatever the amplitude), Blancpain has opted for a so-called “Breguet” overcoil balance-spring with the outer coil raised and slightly tilted towards the centre on a plane running parallel to the spring; this astute device enables the balance-spring to maintain its round shape at all times (whether in contraction or expansion phases). Producing a Breguet overcoil balance-spring calls for a great deal of extra work. In the absence of machines capable of producing a correct result, each extremely slim terminal curve must be patiently shaped by hand, an approach requiring considerable experience and incomparable dexterity. Nonetheless, this demanding choice contributes to giving the movement greater rating regularity, and hence improved accuracy.


In developing Calibre 13R0, the Blancpain watchmakers also strove to find the most effective solutions in terms of energy. The main goal was to give the movement optimal operating autonomy, while guaranteeing energy of the finest “quality” at all times. The new Calibre 13R0 (in its current hours / minutes / seconds / date version) has an exceptional 8-day power reserve (192 hours). To achieve this feat, Blancpain has equipped it with three series-coupled barrels. Watchmakers made sophisticated calculations to precisely define the size and torque required for each spring. The three springs wind up and wind down in turn, but the second takes over from the first before its strength diminishes, and the same goes for the third. This system guarantees constant energy throughout the duration of the 8-day power reserve. The two springs closest to the winding spring are equipped with slipping springs, an added security feature that avoids any damage to the movement if the springs were to be overwound (by forcing the crown).


Another technical improvement lies in the fact that the date change at midnight and the fast correction may be done in either direction. On most watches, it is impossible to move the hour and minutes back past midnight, since this might damage the date change mechanism. On the new Calibre 13R0, the fingerpiece driving the date disc simply slides backward over the teeth and thus runs no risk of being damaged itself or of impairing the disc.

Decorative features worthy of a noble tradition