The Battle of the Power Reserves Commences

As the previous article Power Trip explains, not everyone is convinced of the need for running times longer than required for, say, a weekend, when one’s regular watch might not be in use from Friday until Monday morning. With the increasing popularity of watch-winders, the issue only concerns rarely wound timepieces: an automatic in regular, daily use precludes any concerns about power reserve.

With reference to Thomas Tompion’s year-going table clock, ‘The Mostyn’, now residing in the British Museum, watchmaker Peter Roberts says: “There was a period in the late-19th century when quite a few ‘one-year-running’ duration power-reserve clocks were made and the clockmakers explored all the possibilities for achieving this: heavier weights, a lightweight train, high count pinions, as low friction as possible and a very slow-frequency oscillator, or pendulum.

“In a watch, you can use a powerful mainspring with a single large barrel or multiple barrels, you can reduce the friction by possibly using new materials, you can fit lightweight components, a high-count lightweight train and – the most difficult to achieve – you can have a very low-speed escapement oscillator system.”

Roberts warns, however, that, “most of these practices work directly against achieving good timekeeping”. He adds, wryly: “Of course, a self-winding automatic mechanism fitted to a modern wristwatch with a running time of 72 hours makes the whole idea unnecessary.” Here are eight of the world’s current super-powers.

A. Lange & Söhne 31

How Teutonic can you get? A. Lange & Söhne’s 31 doesn’t merely advertise the presence of a one-month power reserve with its name, it adorns the dial with the legend “monats-werk”, quirkily translating into “months factory” opposite what must be the largest-ever power reserve indicator.

Then again, this is the company that invented the much-copied “big date”, which features here, too. If the 31 looks like a regulator, it’s thanks to that massive, nearly 300-degree circle surrounding the power reserve hand, taking up a full quarter of the dial. At 45.9mm, the 31 is enormous for a dress watch, but never seems ungainly.

Its spectacular power reserve is the by-product of two stacked, 25mm diameter mainspring barrels, which occupy three-quarters of the movement’s real estate. Each spring measures an impressive 1,850mm in length. This inspired Lange to supply a key winding mechanism with torque limiter to assist in what would be an inconvenient experience via a crown. The crown sets the time, and a pusher advances the date. Lange also uses a constant force escapement to ensure that the 31 enjoys continuous rate stability.

Lange points out that, thanks to the 31 “the horological year is now subdivided into 12 winding sessions.” They might add that this watch’s legibility is so clear that it’s perfect for ageing Baby Boomers with failing eyesight – who might forget to wind their watches on a daily basis.

Blancpain Tourbillon Volant Un Minute

There they are, just above the 6 o’clock point, the words proclaiming this handsome timepiece’s right to membership in the 10-Day’s-Plus Club: “12 Jours”. Powered by Blancpain’s in-house Calibre 242, the Tourbillon Volant Un Minute – despite the one-minute flying tourbillon enjoying pride-of-place in an aperture at 12 o’clock – is among the most discreet examples of haute horlogerie.

Blancpain has set out to improve upon the performance of the Calibre 25 unveiled in 1998, the world’s first self-winding tourbillon with 8-day power reserve. Here the new Calibre 242 enjoys a 12-day power reserve from only a single barrel. Comprising 243 parts in a movement that’s only 6.1mm thick, it enjoys the benefits of the Swatch Group research capabilities in its silicon balance-spring and pallet-fork horns, which alleviate the effects of magnetism.

Through the back’s sapphire crystal, one can examine the semi-skeletonised movement with automatic winding mechanism and power reserve integrated to ensure the movement’s thinness. The rotor has also been entirely open-worked as to be barely visible, while the bridges and power-reserve disc are decorated with a guilloché motif.

But, oh, that dial! Sure, there’s a perfect view of the tourbillon, but the most arresting aspect is its adherence to the Villeret collection aesthetic: the dial and the painted Roman numerals are realised in exquisite grand feu enamel, enhanced by hollowed sage leaf-shaped hands.

Jacob & Co. Quenttin

Jacob & Co.’s power reserve champion has that Cabestan-y look of a lot of inter-related cylinders – actually, it reminds me more of a Reuge music box – and it features a one-minute vertical tourbillon. Here, the power reserve is a respectable 31 days, which places the Quenttin among the Top Five in this round-up.

Powered by the manually wound Jacob & Co. Calibre JCBM04, the Quenttin’s movement apes the cylindrical form of the revolutionary Parmigiani Fleurier Bugatti Type 370 of 2002 (which, incidentally, had a 10-day power reserve), but departs slightly from it in that the wheels are positioned around additional axles lined up in a horizontal position. This recalls the layout of a car’s gearbox, rather than featuring a central axle, and the works are visible through a transparent dial.

Its fold-down winder and the one-minute vertical tourbillon are positioned on the right-hand side of the case, the latter visible through a window. Seven spring barrels provide the 31-day power reserve, and the displays include revolving cylindrical drums with Super-LumiNova Arabic numerals, with the hours on the main cylinder, the minutes to the right and the power reserve indication on the left-hand cylinder. This fits in a curved, chunky rose-gold or titanium case measuring 56x47x21.55mm, with domed sapphire crystal; the case back is also fitted with a sapphire crystal.

Jaeger-LeCoultre Master Grande Tradition Minute Repeater

Even if the Jaeger-LeCoultre Master Grande Tradition Minute Repeater lacked its eponymous function – and there are those who say that the minute repeater is the toughest complication to manufacture – this gorgeous skeleton would garner acclaim because it provides a substantial 15-day power reserve thanks to two barrels. While that’s a half, or even a third of this group’s champions, we’re talking two weeks and a day! C’mon!
That’s impressive.

Jaeger-LeCoultre added the long power reserve to a model powered by the Jaeger-LeCoultre Calibre 947, a hand-wound movement containing 413 components, including 43 jewels. While a massive power reserve is always useful for complications that drain power, the key to a magnificent minute repeater is the sound quality.

For Jaeger-LeCoultre, the challenge was juggling the conflicting virtues of letting the sound out while keeping moisture from entering. To amplify the sound, instead of a vulnerable aperture that acts like a horn, the designers chose an unorthodox solution: they situated the gongs near the crystal, which resonates with the gongs, for clearer – and louder – sound.

Calibre 947 first appeared in 2005 for the Master Minute Repeater Antoine LeCoultre, so the neat trick of using the crystal has been  JLC technique for over a decade, while a new gong shape, with a larger surface area, was devised two years later. Combined with a sublime skeletonised movement, with barrel torque and minute repeater power-reserve indicators, this is a dream of a repeater.

Oris 112

The Oris in-house Calibre 110 didn’t merely provide the company with its first manufacture movement in some years: it gained entry into the 10-days-plus Power Reserve Club. Oris has refined it continually; with the Calibre 112, the company has added that most practical of features for those who travel: the GMT function.

Calibre 112 achieves its 10-day reserve with a single barrel. To further distinguish this from its rivals, Oris developed a clever, patented non-linear power reserve indicator. Usefully, this shows the remaining power in increasing detail as the time to wind the watch draws near. Near the end of its travel, more of the arc is allocated to the indicating hand, for more accurate readings.

Further expanding the usability for the traveller are a date function and a day-night indicator. Its second time zone occupies a subdial at 12 o’clock, showing the hours and minutes in the second zone, not just the hour. This subdial also houses the day/night indication, shown through a circular sun or a crescent moon aperture. Cleverly, a two-tone rotating disc under the dial turns the sun white during the day and the moon dark, and vice versa.

Through its sapphire case back, the user can examine this beautiful movement, taking note of the massive, single barrel. What is never apparent is that the Oris 112 starts at an international price of only SFr.6,300.

Parmigiani Fleurier Senfine

Being as manufacture as it gets, Parmigiani Fleurier is in a perfect position to develop not merely new movements for the sake of it, ever complex but ultimately the watchmaking equivalent of willy-waggling, they’re also looking to improve the breed. Parmigiani used a clean slate and went outside the industry to clear its corporate head. At Baselworld 2016, the company announced a new movement that promises a greater power reserve – as well as other benefits – by reducing the number of parts and the friction between them.

Parmigiani’s Senfine project began in 2008, headed by Genevoise engineer Pierre Genequand. This former employee of the Swiss Centre for Electronics and Microtechnology had no watchmaking background and was not constrained by the traditional methods of addressing these concerns.

With a completely fresh outlook, he addressed everything within a movement by forming all of the regulator’s components from materials of negligible friction, derived from aerospace technology; using silicon machined to micron-level, for superior elasticity, durability and low friction; devised a “monolithic oscillator” that combines in one subassembly the functions of the balance, balance-spring and pallet fork, to which it is  connected via a common attachment.

Where Senfine scores in this company is that the current workhorses promise a power reserve in excess of 70 days. Yup, over two months. Y’hear that, Hublot?

Patek Philippe ref. 5100

When Patek Philippe told us that it no longer have a model with a 10-day power reserve, we went into mourning for the ref. 5100 and its tourbillon-equipped sibling, the ref. 5101. The Gondolo-cased classic appeared in 2000, followed in 2003 by the ref. 5101. Ten years later, ref. 5200 with day and date indication replaced both, and the power reserve was reduced to 8 days.

Why the reduction? Well, refs. 5100 and 5101 feature “relatively simple mechanics that are not as power hungry as a day-date calendar”. All three feature power-reserve indicators that consume little power over the course of the power-period. Calendar mechanisms, however, have to activate the day-date indicators each day, and this requires much more mechanical energy.

Which brings us back to the discontinued model, which now features regularly in auctions, typically in the £18,000-£40,000 region depending on case material. The ref. 5100 was a limited edition series of 3,000 watches, with 1,500 made in yellow gold with white dial, 300 in platinum with black dial, 450 in white gold with blue dial (shown here) and 750 in rose gold with a brown dial. The manually wound, rectangular, COSC-certified Calibre 28-20/220 featured a power-reserve indicator positioned on the upper half of the dial, while subsidiary seconds were symmetrically placed on the lower half. Happy hunting.

Vacheron Constantin Patrimony Traditionelle 14-Day Tourbillon

Another exquisite, discreet tourbillon with a long power reserve, the Vacheron Constantin Patrimony Traditionelle 14-Day Tourbillon resembles the Blancpain on the previous spread, but in reverse. Here, the tourbillon resides at the 6 o’clock position, visible in a circular aperture that corresponds visually with the circular power reserve dial at the 12 o’clock point for ideal symmetry.

It is powered by the manually wound Calibre 2260/1, installed in a 42mm platinum case with pale grey dial and blue strap, or an pink-gold case, with white dial and dark brown strap; the platinum edition can also be ordered with 80 diamonds inset into the bezel and lugs, surrounding an anthracite dial and fitted with a black strap. The power reserve is read off with a “dragging” or “trailing” hand that displays the remaining energy with 280-degree arc, and its generous size allows the user to enjoy a display with 28 precise graduations that divide the 14 days into two
12-hour segments, for enhanced readability.

While the finish of the movement is to the usual sublime Vacheron Constantin standards, the company also offers a Métiers d’Art Mécaniques Gravées version of the Patrimony Traditionelle 14-Day Tourbillon. This edition is fully skeletonised and hand-engraved with floral motifs and acanthus leaves on its two main bridges. This level of craftsmanship requires a week’s work, to hand-engrave each movement.

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