This is one of fewer than 25 examples of the Chronomtre 27*, a watch that Kari Voutilainen designed around the small batch of new old stock examples of the legendary observatory-grade Longines 360 bauche calibre he came upon. The calibre has been extensively redesigned and finished to high horology standards. It is paired with a white gold case and a regulator dial layout laid out on a white gold base.

The Calibre 360 is rightly held in high regard. Created to definitively establish Longines dominance in accuracy competitions in Neuchtel and Geneva, an arena the brand had already been preeminent in for much of the early 20th century, the calibre was never destined for mass production. In fact, during its production run between 1959 and 1963, only 200 examples of the bauche were manufactured. However, in those years, it commanded an almost unassailable position in chronometric competitions in Neuchtel.

Its accuracy is due to the high-frequency escapement and large balance wheel. The calibres beats at a rapid 36,000 vibrations per hour. To achieve this, instead of outfitting it with an escape wheel with more teeth (thereby increasing the speed of rotation), Longines design of the Calibre 360 included an additional wheel between the fourth and escape wheels. However, this arrangement would have meant the escape wheel would rotate counter to its natural direction. To address this, in the Calibre 360, the escape wheel is flipped.

The fast-rotating escape wheel and pallet fork were made small and light and mounted as close as possible to the balance wheel. This was paired with the then-established practice of including a large balance wheel in the pursuit of improved chronometry. In fact, the large, 11.5mm diameter balance and the 18.3mm diameter mainspring barrel influenced the rectangular form of the Calibre 360. Such a vertical layout allowed for both of these aspects, whereas the theoretical maximum that a typical 30mm round calibre could accommodate would have been a 15mm mainspring barrel (due to the 15mm radius of the calibre).

As previously noted, the Calibre 360, which was never destined to be fitted to wristwatches, made its way to less than a handful of examples, one of which is displayed at the brands museum in St-Imier, Switzerland.

Voutilainen went about disassembling the small batch of Calibre 360 he chanced upon, redesigning bridges, and refinishing components of the industrially produced bauche. The balance is free-sprung, and the brass bridges bear Voutilainens signature aesthetic. They have a frosted appearance, and their edges are finished with fine anglage. The balance cock has a rounded form and is mirror polished. The baseplate, visible under the balance wheel, bears fine perlage. The bridge anchoring the third and fourth wheels of the going train features engravings of the brand mark and the location of Voutilainens workshop, Mtiers. Those of the 21 jewels seen on the movement side feature mirror-polished countersinks, while the visible screws are black polished.

The case, 31.5mm wide and 44mm tall, has a polygon appearance thanks to its many details. It is a monocoque arrangement that is evenly high polished. The midcase is concave, its scalloped form serving to minimise the overall profile. The teardrop lugs, Voutilainens visual hallmark, have been artfully included, their form contiguous to that of the case. The vertically satinated caseback features the oversized brand mark, engraved at 6 oclock, as well as the precious metal hallmarks.

The dial, made of solid gold, features Clous de Paris engine turning with four visible screws. Normally blued, the dial screws are black polished in this example. The regulator layout is vertically oriented, with the hours followed by the minutes and seconds. The hours register is sunken, with a brushed rim furnished with a quarter chapter of applied Roman indices, and slim printed batons denoting the other hours. The central portion of this register is also adorned with Clous de Paris guilloch.

Overlapping the hour and second registers is the sapphire disc displaying the minutes. It is underpinned by a frosted bridge, in the shape of a battle axe, that serves to elevate its form. The four screws that hold the sapphire display in place are black-polished. The disc itself has printed minutes graduations. The seconds register has a chapter of printed Arabic minutes at intervals of five, with a larger central portion with guilloch. The hours and minutes hands are simple batons, while the second hand is thinner in weight. The overall monochrome appearance is satisfying, while the logical deployment of finishes serves to aid quick-time reading.

The watch comes with its original warranty paperwork from 2009, as well as the box it retailed with. It is a rare instance of a milestone of historical calibre being overhauled and improved upon by one of the finest independent watchmakers of the modern era. As such, theChronomtre 27is singular in both its provenance and its place in Voutilainens body of work.

If sold within the United Kingdom, this Voutilainen Chronomtre 27 will be subject to 20% VAT

Closer look

Condition

This Voutilainen Chronomtre 27 is in excellent overall condition. The case and lugs show light superficial marks consistent with minimal wear over time. More specifically, light marks on the upper right lug. The dial, hands, sapphire disc, and movement have been well preserved without any signs of imperfections. The hallmarks/engravings on the caseback and buckle are crisp and well defined.

Warranty

The watch comes with a two-year warranty from A Collected Man, alongside a lifetime guarantee of authenticity.