First Came the Ludwig
In 1996, Ulysse Nardin introduced the revolutionary Perpetual Ludwig, named for the man who designed the movement, Dr. Ludwig Oechslin. The "Ludwig" became the new standard for practicality among perpetual calenders. Unlike other perpetual calender watches, the Ludwig's displays can be set forward or backward quickly with the winding crown. The design of the Ludwig's movement solves three problems usually associated with perpetual calender watches: the inability to set the day and date back when traveling westward across midnight, the inability to adjust all of the displays quickly via the crown, and inability to fully account for the peculiarities of the Gregorian calender's leap year formula, necessitating re-setting at the factory. The Ludwig also addresses another shortcoming of most perpetual calender watches - poor legibility.
As one might expect, the Ludwig breaks with traditional perpetual calender movement design. Dr. Oechslin's goal is to find the most direct, reliable and functional design. The Ludwig's heart is the "program wheel", shown right (above, labeled "A", detail below). The program wheel is a multi-tiered assembly of 9 wheels and pinions that permit the movement to account for months of 28, 29, 30 and 31 days. The program wheel is activated once each day by the unique tooth of the lower 24 hour wheel (4 in diagram below left). The differing aspects or angles of the long 24 hour wheel teeth (1, 2, 3 in diagram below left) activate the program wheel by means of satellite wheels within the program wheel.
Above, both sides of the 24 hour wheel are shown. Referring to the diagram above left, in non-leap years, tooth 1 engages the program wheel at 9 p.m. on February 28th, advancing the 28th to the 29th, then at 10 p.m. tooth 2 engages to advance the date from February 29th to the 30th. In leap years, there is no tooth to advance February 29 to the 30th. Tooth 3 engages at 11 p.m. on each 30th day of in the months without 31 days, advancing the date to the 31st. In all cases, tooth 4 then advances the date by one day at 00.00 a.m. each day.
The GMT ± Perpetual
Never a company that rests on its laurels, in 1999 Ulysse Nardin introduced the GMT ± Perpetual, which combined the Ludwig's unique perpetual calender mechanism with another of Dr. Oechslin's inventions: a GMT or second time zone complication that incorporates pushers to move the local time hour hand ahead and back in one-hour increments. The GMT ± Perpetual was awarded the 2000 Chronos Innovations Prize by German Chronos Magazine, finishing first in voting by both readers and a panel of experts. The GMT ± Perpetual finished ahead of such notable watches as the Lange Datograph, Omega Daniels Co-Axial, Journe Chronometer Resonance, Blancpain Tourbillon Chronograph, Girard-Perregaux Three Bridges Tourbillon, and the Audemars Piguet Jules Audemars Tourbillon.
The GMT ± Perpetual's Three Patents
Quick setting, patent number CH 680 630. The GMT ± Perpetual allows the calender functions to be set quickly, forward or backward, from the winding crown. Everything from the minute hand to the year is synchronized. This allows the GMT ± Perpetual to be set by the owner when other perpetual calender watches must be sent to the factory, due to their inability to account for the complex leap year calculations Gregorian calender.
Pusher-adjusted GMT complication, patent number CH 685 965. This system allows the owner to re-set the local time hour hand via two pushers, + to advance, and - to set back. The pushers allow the local time to be adjusted while the watch remains on the wrist, and without interfering with normal timekeeping.
|| Oversized Date Display, patent number CH 688 671. Dr. Oechslin developed a double disk date display that places both disks on the same level. This device provides easy reading, superior aesthetics compared with two-tier big date systems, and instant date changes at midnight. The date changes automatically when the local time is adjusted via the pushers, and the date will change backward should you pass midnight headed west.
Above, a diagram of the GMT ± Perpetual movement. The numbered parts are the program wheel assembly (1), inner date disk (2), outer date disk (3), 24 hour wheels (4), month disk (5), left year disk (6), right year disk (7).
New for 2000
This year, Ulysse Nardin is introducing a new Limited Edition GMT ± Perpetual, and I recently spent a few days photographing one. The images are below. The LEs have a new, larger case, measuring 40 mm in diameter without the crown. The Limited Editions are also set apart by a deeply textured guilloché dial. Another distinction: the Limited Editions are COSC certified chronometers. Like regular GMT ± Perpetuals, the LEs have a solid gold rotors, are water resistant to 30 meters, and have a power reserve of 48 hours. Production numbers and prices for the GMT ± Perpetual Limited Editions are as follows: 500 pieces in red gold, priced at $29,800, and 500 pieces in platinum with silver dial, priced at $34,800.
*Dial side of Perpetual Ludwig movement, program wheel, and 24 hour wheel Ulysse Nardin images, provided by Hans Zbinden, used with permission.
*White gold GMT ± Perpetual with silver dial and GMT ± Perpetual movement diagram courtesy Ulysse Nardin, used with permission.
*Red gold GMT ± Perpetual Limited Edition images by the Author, taken with Sony DSC-S70 digital camera.