One of the first modern manufacturers to place an eight-day movement in a wristwatch was Eberhard, whose long power reserve watch (simply known as the Eberhard 8 Jours watch), introduced in 1997, is based on a Peseux 7001 hand wound movement which has been extensively modified in order to give it a prolonged running time and a power reserve indication. The Peseux 7001 normally has a running time of around 42 hours (with some variation depending on the watch in which it’s used) and to modify this rather flat movement (in unmodified form, it’s only 2.5 mm thick) to run for an additional 150 hours is a significant challenge. Since the layout and height of the movement do not facilitate the installation of a second barrel, Eberhard’s solution was to install two very thin, overlapping mainsprings as well as the additional gearing for the power reserve indication, both of which are visible when viewing the top plate of the movement under two gold colored cover plates.

Manufacturers are particularly fond of enhancing tourbillons with long power reserves, and of the long power reserve tourbillons currently available, perhaps one of the most seductively attractive is the Patek Philippe 10 Day Tourbillon. In considering an extended power reserve tourbillon, it’s interesting to remember that the tourbillon can produce a significant additional drain on the mainspring: in addition to driving the power train and escapement, the mass of the cage has to be propelled as well, adding dramatically to the burden shouldered by the unsung hero of such a watch — the mainspring. The result is that ensuring lightness of the cage, always important in a tourbillon, becomes even more necessary in order to achieve an extended power reserve, and correct adjustment and poising of the cage and balance become even more critical. The Patek 10 Day Tourbillon achieves its extremely long power reserve through the use of two mainspring barrels, which run in tandem, and is based on Patek’s ten-day time-only wristwatch, ref. 5100, launched in 2000. At the time it was launched, ref. 5100 held the record for power reserve — there had never been a ten-day wristwatch before — and although there are now watches with longer power reserves, there are few, if any, that exude the sense of completeness, wholeness and clarity of design shown by the 10 Day wristwatch and tourbillon. It’s a significant achievement not only for the sheer length of the power reserve, but also for the care with which it has been implemented: the large crown, in combination with reduction gearing, allow the owner to wind 240 hours of power into the two mainspring barrels without undue physical strain — though it still requires about 100 turns of the crown to fully wind the watch from a powered-down state. The 10 Day Tourbillon, ref. 5101P, is not only a showpiece for extended power reserve, but is also an officially certified chronometer; this is not an “all show, no go” piece of marginally functional wrist jewelry. In addition to the COSC certification, it is also tested chronometrically in-house by Patek, to standards twice as rigorous as those imposed by COSC.

The 10 Day Tourbillon was announced in 2003 and held the record for three years. In 2006, Bovet presented a tourbillon with a running time of 22 days. Rather remarkably, the Bovet tourbillon is comparable in size to the Patek 10 Day Tourbillon, — the Bovet having a diameter of 44 mm in a round case, and the Patek having a length of 51.7 mm at its longest dimension (though the Patek is just a hair over 29 mm in width and at just over 12 mm in height, it is flatter than the Bovet which, at 15.75 mm, is a very thick watch). Nonetheless, it is undoubtedly an exceptional accomplishment to have wrung 22 days of running time out of the Bovet tourbillon’s two mainspring barrels, which must drive not only the tourbillon and escapement, but also a retrograde date indication and second time zone indicator. Retrograde indicators of any kind suck progressively more power from the train as they approach the point of snapping back, as this is usually achieved through the expedient of a spiral spring attached to the retrograde hand, which is released to spring back by a snail cam. The steadily increasing pressure of the spring represents an additional load that would seem to militate against the achievement of an extended power reserve, yet Bovet has done it. Each movement is hand-engraved, with a design unique to each piece; and the case, with its crown and bow at 12 o’clock, references the earliest wristwatch designs of the early 20th century, many of which were pocket watch conversions. With its recent acquisition of tourbillon specialist STT (formerly Progress Watch), Bovet has also acquired the ability to make its own movements and hairsprings. Thus, the continued introduction of not only aesthetically unique, but also technically significant watches seems assured.
One cannot leave the subject of long power reserve tourbillon watches without mentioning one that represents perhaps the epitome of the challenge posed by trying to drive a tourbillon cage with a long power reserve movement: the Gyrotourbillon by Jaeger-LeCoultre. This remarkable watch was the crowd’s darling when it was introduced at SIHH 2004 and it is a fascinating exercise in pushing the complexity of the tourbillon, and the capacity of an extended power reserve, to their limits. The Gyrotourbillon would be a remarkable watch even without the extended power reserve; it is a veritable catalogue of esoteric complications — a tourbillon wristwatch displaying the equation of time, with a perpetual calendar that has a retrograde hand for the date and month, would be sufficient to excite interest and admiration under any circumstances. The remarkable Gyrotourbillon is much more than that — it is not only an extended power reserve watch with 150 hours of running time, but it is also a multi-axis tourbillon, with not one, but two tourbillon cages rotating one inside the other. Out of necessity, to achieve a long power reserve with so many complications and a double-axis tourbillon, the cages must be as light as possible and JLC has opted for aluminum and titanium for the cage construction. Jaeger-LeCoultre is, of course, no stranger to constructing long power reserve watches, having introduced an eight-day watch in 1931, the twin barreled cal. 124; and in 2002, the eight-day cal. 879 used in the Reverso Septantieme created to honor the beginning of the manufacture’s eighth decade of production, as well as the JLC cal. 877, which is used in the Master Eight Days watch.

IWC PORTUGUESE AUTOMATIC The JLC, Bovet and Patek tourbillons must be wound by hand which, depending on one’s disposition to the task, may be either a soothing ritual of engagement between man and machine, or a tedious necessity — at the end of which, one might want to scream along with Ringo Starr at the end of ‘Helter Skelter’, “I’ve got blisters on my fingers!” A number of long power reserve watches nowadays, however, are automatically wound and will repay the owner for wrist time by keeping the mainspring powered up without necessitating either a trip to the hardware store for protective gloves, or a letter of referral to an orthopedic hand specialist. Of the automatic movements, one with a notably extended power reserve is the IWC cal. 5000 and its immediate descendant, cal. 50010, in which a single large mainspring barrel carries an extremely long Nivaflex mainspring. Eschewing the relatively baroque complexity of multiple barrels, the IWC cal. 50010, found in the recently introduced Portuguese Automatic ref. 5001, is a large watch with powerful, deceptively simple lines that, rather than shying away from the pocket watch idiom, chooses to specifically quote aspects of pocket watch design, albeit in a more understated fashion than the Bovet. IWC has stated clearly that the goal in fashioning the Portuguese Automatic ref. 5001 was to create a “pocket watch for the wrist” and in this particular circumstance, the decision to do so has a clear historical continuity. The original Portuguese wristwatches were, as many aficionados of the brand from Schaffhausen are aware, quite literally recased pocket watches, created at the special request of two Portuguese businessmen (Rodriguez and Teixeira), who desired wristwatches with the chronometric performance of pocket watches and for whom the original “Portuguese” watches were created in the 1930s.
One of the great delights of cal. 50010 is the way in which it keeps its huge mainspring wound: for the cal. 5000 series of watches, IWC revived the famous Pellaton winding system, in which a heart-shaped cam attached to the rotor moves a lever with two ruby rollers back and forth. The action of the Pellaton winding system is hypnotically beautiful and an ingenious solution to the problem of bi-directional winding. Its simplicity and efficiency helps to assure that a full power reserve can be maintained in the watch with ease, so that a watch set down on a Sunday night has an excellent chance of still being found in running order a week later, on the following Saturday morning.
One of the most refined of all the manufacturers of eight-day wristwatches is Parmigiani Fleurier, which has eschewed the flamboyant, pyrotechnic self-promotion of which many brands are guilty and which, as a result, is something of an insider’s brand — less frequently discussed than even some AHCI members, Parmigiani Fleurier has nonetheless staked out a position for itself as the reclusive, yet fascinating, mandarin of modern haute horlogerie — the Mycroft Holmes of watchmaking. Parmigiani Fleurier is, in a sense, the younger brother to Bovet as both were fathered by the same sire: master watchmaker Michel Parmigiani, a native of Fleurier who made a name for himself first as a restorer of complicated vintage watches and who purchased the rights to the Bovet name in 1989 (though Bovet did not actually introduce new wristwatches until 1997, seven years after Michel Parmigiani sold the trademark). It is a testimony to the sophistication and seriousness of Parmigiani’s approach to watchmaking that he has had among his clients, Bovet itself as well as Chopard, for whom Parmigiani designed the L.U.C 1.96 micro-rotor automatic movement (itself a somewhat long power reserve movement at 70 hours of running time, with two overlapping mainspring barrels running in series). Parmigiani Fleurier began production with ebauches from third-party suppliers, but has for some time been working towards complete independence and vertical integration of production, and is now one of the very few essentially completely independent manufactures, even producing their own hairsprings — a small select group indeed. Parmigiani has made something of an in-house specialty of long power reserve movements: their cal. PF 110, introduced in 1997, is a shaped caliber designed for a tonneau case and has two mainspring barrels. It is used almost exclusively in Parmigiani watches (though cal. PF 110 has been sold, in very small numbers, to one or two other manufacturers). Since the introduction of cal. PF 110, Parmigiani Fleurier has progressively expanded its range, which now includes five separately designated calibers, many of which feature extended power reserves. The Parmigiani Fleurier Hebdomadaire, in the Kalpa line, is an eight-day watch in a tonneau case with an eight-day power reserve indicator, and whose name harks back to the turn-of-the-century premier maker of eight-day watches, Hebdomas.
Two recent watches by Parmigiani Fleurier deserve special mention. The first of these is an eight-day tourbillon, which was announced in 2006 to celebrate 30 years of horological endeavor. The Kalpa XL Tourbillon Chiaroscuro is a manually-wound eight-day, 30-second tourbillon, which uses a new movement based on the eight-day PF 110. Cal. PF 501, however, represents a significant departure in most respects from the Hebdomadaire line and from cal. PF 110 — not only is it mechanically very different, but it is also aesthetically unique. The plates and bridges have been pierced to afford a better view of the movement, which has been treated to an elaborate PVD coating process that has resulted in a subtle, but varied, palette of colors that lend the Chiaroscuro its name (“chiaroscuro” refers to the use of dark and light shading to create the illusion of dimensionality in two-dimensional art.)
The second is a watch that is as seldom seen in the flesh — or “in the metal”, as connoisseurs say — as the car for which it is named: the Bugatti. The Bugatti watch was designed as a companion piece to the Bugatti Veyron – the first series produced car made with the Bugatti marque since the company sputtered out of business after the death of Ettore Bugatti in 1947. The Veyron is the fastest, most expensive and most powerful street legal production car in the world, a 16-cylinder supercar, and the Bugatti watch is no less exclusive and elaborate (and expensive — don’t ask). The profile of the watch is instantly recognizable to the enthusiast as it has been one of the most talked about, argued about and disagreed over watches of the last few years, and has a unique in-line movement reminiscent of a car engine (or perhaps a jet turbine) that places the dial perfectly in line with the vision of the driver when his hands are on the wheel (presumably of a Veyron; you might as well get the car if you’re going to get the watch, why deprive yourself?). The Bugatti watch’s cal. 370 movement is completely unique, with a production run limited to 150 watches, and has a power reserve of ten days, at which time the owner has the pleasure of winding the watch not with a crown (too pedestrian by far for this watch), but rather with a pen-shaped tool especially designed for both winding and timesetting. The first Bugatti watch was delivered in 2005 to automotive enthusiast and fashion legend Ralph Lauren.

CHOPARD QUATTRO One cannot leave the subject of Michel Parmigiani’s influence on the design of long power reserve watches without mentioning Chopard again, whose base caliber L.U.C 1.96 was designed by Michel Parmigiani but which, like all subsequent Chopard movements, is an in-house product of the Chopard manufactory. From the very beginning, Chopard made it clear that its entry into the haute horlogerie ranks would be characterized by the very highest level of commitment to quality, and cal. 1.96 is designed, manufactured and finished to the very highest standards, qualifying for both the COSC chronometer certification and the Geneva Seal. In 2000, Chopard introduced a new movement, cal. 1.98, a hand-winding movement cased in the “Quattro” line of long power reserve wristwatches, which has four mainspring barrels and which provides a power reserve of 216 hours or about nine days (the power reserve indicator shows eight days of reserve — the additional hours of running time helping to ensure stability of rate over the entire unwinding of the mainspring). In 2004, a regulator-dialed variant of the Quattro was introduced, followed by the Quattro Tourbillon which, in addition to being one of the very few tourbillons to be COSC certified as a chronometer, was also the first watch produced by Chopard to incorporate their new free-sprung, variable mass balance — the ‘Variner’ balance wheel.
Like any other accomplishment, the achievement of long power reserves can be taken to the point of reductio ad absurdum and the most extreme of long power reserve watches could certainly never be accused of restraint — of any kind. The all-time record holder for length of power reserve in a wristwatch is the Jacob & Co. Quenttin watch, best known in the past for its elaborate jewelry watches, but which — more recently — has been bidding for horological legitimacy as well. The Quenttin is as un-nuanced in its pursuit of horological superlatives as its predecessors were in pursuing gemological superlatives — it has a 744-hour (or 31 days) power reserve and is powered by seven mainspring barrels, which can be wound with either an integrated key reminiscent of the film winding knob on a vintage 35 mm camera, with an external hand crank or, in the very likely event that the owner is too exhausted from carrying the sheer mass of the watch around to wind it, an electric winder in the accompanying box. The Quenttin watch is exaggerated in every respect, even by the sometimes cartoonish standards of modern horological fashions: at 56 mm in length, 47 mm in width, and a whopping 21.5 mm in height, it is — to put it mildly — not an especially forearm friendly watch. Although, it would be surprising if any wristwatch were to ever be produced that exceeds it in duration of running time. It can be had in platinum on request, in which case it’s likely to compete in weight with the turret of an M1A1 Abrams tank, but anyone who’s thinking of buying this watch at all is probably not going to be deterred by practical considerations. The Quenttin is somewhat handicapped in its resemblance to the Vianney Halter Cabestan (co-designed with Jean François Ruchonnet, who is the chief designer of the Monaco V4 concept watch, among other projects), with which it shares the features of a tourbillon regulator, digital indication of time, and vertically oriented mainspring barrels. Though the Cabestan is a watch with considerably less heft (and, at 72 hours, a shorter power reserve), at 46 mm in width, it is not a small watch by any stretch of the imagination. It probably says something about the single-mindedness with which the Quenttin has pursued its goal of exceeding considerably any previous record for power reserve that it actually succeeds in making the Cabestan look restrained.
While the achievement of a full month’s power reserve unquestionably necessitates a large watch, a diametrically opposed philosophy has informed the development of the newest timepiece from the neo-Saxon atelier of A. Lange & Söhne. Lange & Söhne has elected to produce a one-month power reserve watch that demonstrates the firm’s commitment to a certain indefinable dignity and subtlety in design, and the Lange 31 — the subject of an in-depth examination in this issue — is very much a classic Lange & Söhne design despite its muscular proportions. Using two full-case diameter mainsprings, in a 46 mm diameter round case with a height of nearly 16 mm, it is unquestionably a statement (and a presence impossible to ignore) on the wrist. And in adopting a key-winding system, it is also, like so much of Lange & Söhne’s oeuvre, a homage to the past as well as a step into the future. If the aesthetic of the Quenttin is that of deliberate overstatement, the calculated bombast of the peacock loudly proclaiming the length and iridescence of his plumes, the Lange 31 is the aesthetic of concealment and of power hidden — like a tiger growling softly in the shadows. H

Bovet with 22 Days Power Reserve

Jaeger-LeCoultre Skeletonized Master Perpetual with 8 Days Power Reserve

The remarkable Gyrotourbillon is not only AN equation of time watch with perpetual calendar and an extended power reserve, it is also a multi-axis tourbillon, with not one, but two tourbillon cages rotating one inside the other

Kalpa Xl Tourbillon with 7 Days Power Reserve

Chopard L.U.C Quattro Tourbillon
with 8 Days Power Reserve

The Bugatti watch’s cal. 370 movement is completely unique, with a production run limited to 150 watches, and has a power reserve of ten days, at which time the owner has the pleasure of winding the watch not with a crown, but with a pen-shaped tool especially designed for both winding and timesetting

From the very beginning, Chopard made it clear that its entry into the haute horlogerie ranks would be characterized by the very highest level of commitment to quality. its cal. 1.98 movement introduced In 2000 has four mainspring barrels, for a power reserve of about nine days

Big Ingenieur with 7 Days Power Reserve

Eberhard ‘8 Jours’

Patek Philippe Ref. 5100 with 10 Days Power Reserve

Jacob & Co. Quenttin with 31 Days Power Reserve

Parmigiani Bugatti with
10 Days Power Reserve

Lange 31 with 31 Days Power Reserve