Driven by the unending quest for innovation that makes it one of the most dynamic Manufactures, in 2015 Ulysse Nardin dropped a new marker buoy on the capricious ocean of fine watchmaking. An undisputed world first, the new Ulysse Anchor Tourbillon is the quintessence of avant-garde mechanical technology, timelessly arrayed in gold and enamel. The outcome of eight years of research and development, the constant Ulysse Anchor escapement, made entirely of silicium, displays hitherto unknown architecture based on the principle of flexible mechanisms exploiting the elasticity of flat springs. This device, the culmination of the development work on the prototype version presented in 2014, represents the height of timekeeping sophistication today: first, no longer constrained by a pivoting staff, the pallet fork moves entirely without friction; second, the geometrical improvements made to the pallet fork, the escape wheel and the flat springs have resulted in a constant-force escapement; and to crown all of this, this new coinage in watchmaking is brought aboard in a tourbillon cage, the peak of traditional expertise.

Ulysse Nardin has always been driven by a pioneering spirit: in 2001, the Manufacture was the first to develop an escapement made of silicium; it was the first to test a diamond balance spring in 2002; the first to use silicium for its Dual Ulysse escapement – a phenomenon in its own right – in 2005; the first to fit a watch with a diamond escapement, also in 2005; and lastly, the first to use silicium as a kernel for growing diamonds, DIAMonSIL.

In collaboration with Sigatec, a co-owned company specializing in the production of silicium micro-components, the Le Locle-based company spent no less than eight years perfecting this mechanism, which today appears to be a paradigm shift in the approach to mechanical watchmaking. Challenging the principle of the traditional Swiss anchor escapement, the new constant Ulysse Anchor escapement features a circular frame with a pallet fork fixed in the center, supported in space on two blade springs less than a tenth of the thickness of a hair in diameter. Mounted perpendicular to each other, these are subjected to a bending force that curves them and maintains them in a bi-stable state.

This complex structure, made entirely of silicium thanks to the DRIE deep etching technique, exploits the physical capacity of blade springs to become distorted along the left-right axis while remaining perfectly rigid along the up-down axis, thus reproducing the kinetic functions of a pivot. The impulse that issues from each alternation of the balance wheel thus transmits its energy to the blades, which snap from one stable state to the other, very much like a snap hair-clip. The pallet arms thus pivot backwards and forwards about a pallet staff that is purely virtual, without generating any frictional forces.

But the best is yet to come: the redesigned pallet fork now possesses an integral resetting face. As the tooth of the escape wheel slides along this surface as far as the banking face, it will bring the pallet fork back every time to within just 3° of the center line – that is, the imaginary straight line between the center of the balance wheel and the center of the escape wheel which defines the system's equilibrium limit. Thus the effort that the balance wheel has to exert to push the pallet fork as far as its tipping point is less than the effort that is restored to it immediately afterwards by the bending of the blade springs. In this way, this positive energy balance is able to maintain the oscillations of the balance wheel at a constant rate. In fact, this interplay of forces is not influenced by the motor torque injected into the escape wheel, which only starts to move once the pallet fork has switched over. 

In a final touch of artistry, this astonishing construction is housed in a 60-seconds tourbillon, whose cage comprises 35 components but weighs no more than 0.4 grams. With its constant amplitude, irrespective of how much the two series-mounted spring barrels are wound, this exceptional oscillating mechanism is a major step forward in the field of chronometric accuracy. Visible through a large opening in the dial at 6 o'clock, it is encircled by the indication of its power reserve of at least 7 days on a 140° arc. This caliber UN-178 is housed in a rose gold or white gold case in the Classico collection. A setting with traditional lines enhanced with a white Grand Feu enamel dial created by the unrivaled expertise of Donzé Cadrans, a dial-making specialist company owned by Ulysse Nardin. Available in two limited editions of 18 pieces each, the Ulysse Anchor Tourbillon will be in the retailers' display windows from May.