Skeletonizing a watch is no easy feat. And it is doubly hard for an ultra-thin motion, mainly because the motion is already so thin that removing any more material is likely to affect structural rigidity. As a result, the A&S8200 calibre from the Arnold & Son UTTE Skeleton watch had to be thoroughly redesigned and re-engineered. The outcome is that the A&S8220 calibre, which measures 3.3mm thick. The extra thickness, according to Arnold & Son, is necessary to ensure rigidity as they hunted to skeletonized the movement. However, let’s face it, 3.3mm for a tourbillon movement with two barrels and a power reserve of 90 hours is badly impressive.The brand new A&S8220 calibre boasts a few significant revisions. For instance, the principal plate has been heavily modified to reveal as much as you can of the internal workings. But maybe what’s most visible to owners is that the tourbillon cage has been completely reworked to show off more of this mechanism when retaining the three-dimensional design which has become a signature of the sooner Arnold & Son UTTE watch. In addition, the tourbillon cage is relatively large as compared to this movement. It measures 14mm across, while the movement itself is 32mm. This implies it’s the single most dominating component of the dial, and in addition to this is the fact that the crate is fully hand-polished and chamfered, which makes it a real visual treat for owners.And because you would expect, the A&S8220 calibre can also be treated to the best haute horlogerie finishing: The main plate and bridges have been constructed using nickel silver and completed with C?tes de Genève rayonnantes; The edges are also polished and chamfered; The steel components, gears, and ratchets are satin-finished with their borders polished and chamfered; The screws have bevelled and polished heads, and ultimately, the jewels are placed in polished countersinks; exploring of the period is performed off a sapphire disk with printed numerals at 12 o’clock; The hour and minute hands are golden and feature white lacquered tips.
One of the most important issues when it comes to accuracy is moderating the source of power to the regulating organ of the timepiece (in this case, the tourbillon featured in the lower right quadrant of the dial). The mainspring, for example every part of this size, is vulnerable to particular molecular inconsistencies acquired during the creation procedure. Any internal or external inconsistency could result in a fluctuation of power delivered to the equipment train. And that is before one even considers the extreme drop-off in torque when the mainspring sufficiently uncoils. Since the mainspring winds down, the amount of power delivered to the escapement dips. This can potentially play havoc with all the timekeeping, therefore Arnold & Son have attempted to remove this mistake by installing a “constant-force” mechanism. The modern incarnation of the business that lay dormant for more than a century is doing what it is to reconnect with the source of its inspiration.Practically speaking, this component takes the place of a fuseé, which is an old-fashioned constant force complication we’ve seen on aBlogtoWatch very recently in the new Zenith Academy Georges Favre-Jacot Anniversary piece (read the review), for example. To compensate for the inevitable drop-off in electricity generated with a single barrel in a standard setup, Arnold & Son have started out with two symmetrical barrels in series. The first barrel powers the gear train, while the next barrel tops up the torque of the first whenever it drops below an optimal level. But their innovation doesn’t end there.
Arnold & Son will present an interesting watch at Baselworld 2012, the TB88. “TB” stands for “true beat”, referring to the dead beat seconds at eight o’clock. Additionally the calibre has twin barrels providing 100 hours of power reserve.
This is simple yet interesting. It’s a welcome departure from the Arnold & Son watches of recent vintage which were bizarrely complicated astronomical and longitude watches. I remember one year the brand unveiled a watch that I found nearly impossible to comprehend. The A&S 5003 movement has been inverted and has no dial, so everything of interest – barrels, escapement, gear train – is revealed. This is reminiscent of the ultra high-beat 43,200 bph Audemars Piguet ChronAP. Furthemore the movement design is quite interesting. It has hints of vintage English pocket watches evident in the bridge shapes and regulator index, but that is combined the very modern ruthenium coated bridges and base plate. The watch case is 46 mm in diameter, in rose gold or steel. Retail is CHF49,000 in gold and CHF33,500 in steel, exclusive of tax.
I believe the movement is created by La Joux-Perret, which is the owner of Arnold & Son. Arnold & Son used to be sister companies with Graham in The British Masters, but since last year the two brands parted company. – SJX