Limited to six pieces: the Grand Complication is by far the most complicated and most exclusive A. Lange & Söhne piece ever produced.
The Grand Complication brings to life the most elaborate complications which the art of haute horlogerie has to offer: chiming mechanism with grand and small strike, minute repeater, split-seconds chronograph with minute counter and jumping seconds as well as a perpetual calendar with moon-phase display.
Two carefully hand-wrought gongs produce the tones of the minute repeater and of the hour and quarter-hour strikes. The Grand Complication is endowed with a chiming mechanism that automatically indicates the time in the grand strike (grande sonnerie for hours) or small strike (petite sonnerie for quarter-hours) modes.
The chronograph of the Grand Complication is a monopusher type with a rattrapante function and jumping seconds (seconde foudroyante). This rare supplementary function makes it possible to freeze stopped times to fifths of a second. A blued-steel hand on the lower subsidiary dial performs five jumps to complete each revolution along its five-second scale while the chronograph is running. Thus, the hand precisely emulates the balance frequency of 2.5 Hz. A gold chronograph hand and a blued-steel rattrapante hand for stopping lap times sweep the main dial from the centre.
The perpetual calendar mechanism emulates the Gregorian calendar. Not only does it know how many days each month has in the course of a year, it is also aware of the fact that February has 29 days in leap years. The mechanism first needs to be corrected by one day in the year 2100. This is because of special rule in the Gregorian calendar which stipulates that the leap year is omitted if the year is divisible by 100.
The white enamel dial with Arabic numerals is characterized by a railway-track minute scale and four symmetrically arranged subsidiary dials.
The heart of the exclusive manually wound movement is a balance that beats with a frequency of 18,000 semi-oscillations per hour. As a tribute to Ferdinand A. Lange, who established Saxony's watchmaking heritage, the watch incorporates a Glashütte lever escapement based on one of his early inventions. Its lever and escape wheel are made of hardened 18-carat gold.
The exclusive collectors' item in the 50-millimetre pink gold case comes in a limited edition of six watches to be delivered in the next six years.