THE IWC SCHAFFHAUSEN INGENIEUR PERPETUAL CALENDAR 41 IN STAINLESS STEEL

In 1976, IWC introduced the Ingenieur SL, Reference 1832, spearheading its SL collection of luxury sports watches in stainless steel. Less than a decade later, in 1985, the now legendary perpetual calendar developed by Kurt Klaus premiered in the Da Vinci Perpetual Calendar Chronograph. Forty years later, IWC now presents the first stainless steel model to combine the emblematic Ingenieur design inspired by Gérald Genta with Kurt Klaus’ crown-operated perpetual calendar.

The Ingenieur Perpetual Calendar 41 (Ref. IW344903) features a stainless steel case with a diameter of 41 millimetres. The proportions of each case component have been reworked and adapted to accommodate the perpetual calendar movement while offering perfect ergonomics. Seamlessly integrated into the case via a middle-link attachment, the H-link bracelet with a butterfly clasp ensures high wearing comfort. The characteristic bezel, a hallmark feature of Gérald Genta’s design, is secured to the case with five functional screws. The detailed finishing further accentuates the sculptural quality and timelessness of the Ingenieur design. The case, bezel and crown protection feature a combination of satin-finished and polished surfaces. The H-links of the bracelet are satin-finished with polished outer edges, while the middle links are polished. The case back ring, which encloses the sapphire glass case back, is polished.

A COMPLEX DIAL WITH “GRID” STRUCTURE AND THREE COUNTERS

Another highlight is the dial, which is manufactured in a highly complex process. In a first step, the characteristic “Grid” and the subdials are applied to the dial base. Consisting of small lines and squares, this unique structure adds additional depth to the dial and reflects the light exquisitely. The counters are treated with a sunray finish, while the outer edges feature a refined azurage. After colouring, the subdials are pad-printed with the calendar display information. The single moon disc, which is visible in the subdial at 6 o’clock, features an intricate azurage finish. Finally, the metal markers are filled with Super-LumiNova® and applied individually by hand. The rhodium-plated hours and minutes hands are also filled with luminescent material.

PERPETUAL CALENDAR WITH HIGH-PRECISION MOON PHASE

The three perpetual calendar subdials have been carefully integrated into the Ingenieur dial to create a balanced layout. The calendar information is displayed at 3 o’clock, 6 o’clock and 9 o’clock. The subdial at the 3 o’clock position indicates the date, while the one at 6 o’clock combines the month with the perpetual moon phase. Thanks to a reduction gear train using two intermediate wheels, the moon phase display will only deviate by one day after 577.5 years. In addition to showing the day of the week, the subdial at 9 o’clock features a small leap year indicator, which counts down the years to the next leap year. In case of a leap year, the calendar will automatically insert a 29th day at the end of February. All these displays are perfectly synchronised with each other and can be advanced simply by turning the crown.

PELLATON WINDING SYSTEM WITH CERAMIC COMPONENTS

The Ingenieur Perpetual Calendar 41 is powered by the IWC-manufactured 82600 calibre. The automatic Pellaton winding system uses movements of the oscillating mass in both directions to efficiently convert movements on the wearer’s arm into potential energy for the mainspring, thereby building up a power reserve of 60 hours. Components that are subject to high stress are made of virtually wear-free zirconium oxide ceramic, one of the hardest materials on Earth. The automatic wheel and the clicks are made of black ceramic, while the rotor bearing is made of white ceramic. The balance wheel oscillates at 28,800 vibrations per hour, ensuring accurate timekeeping. Featuring an elaborate finishing with circular graining, Geneva stripes and blued screws, the movement is visible through the sapphire glass case back.