The first watch made by the Glashütte-based firm of Moritz Grossmann that I saw in person was the Benu wristwatch, which the company debuted –in one of the most low-key launches I can remember –in 2010. The Benu was a watch very much to my personal tastes: discreet, very precisely made, with a sober beauty and just enough idiosyncratic touches (such as the heat colored hands, which were not the usual cornflower blue, but instead, a lovely brown-violet color, which I can’t recall seeing on any other modern watch and which up until then I’d only seen on high grade American railroad chronometers) to give it an immediate identity of its own.
My first impression was of a company that wasn’t going to expend a lot of energy on high profile marketing, but rather, one that was going to try –as much as possible –to devote its resources to making very well made watches, and to let the quality of its products speak for itself. It’s a risky strategy –particularly with the memory of the Crash of 2009 still fresh in everyone’s mind, it seemed a dicey time to start anything new, much less an all-steak-no-sizzle watch company that focused on quality.
Fortunately there still seems to be room for such an approach from a relative newcomer (Grossmann is named after the Glashütte watchmaker Moritz Grossmann –1826-1885 –who specialized in high precision chronometry and is considered one of the founding fathers of Glashütte watchmaking. Refreshingly, Grossmann sensibly avoids any hand-waving unsubstantiated claims about continuity of descent; rather, the name’s a statement of intent.) In the the last three years, Grossmann has released a spare handful of carefully thought out new models, and it’s only this year (well, late last year, to be exact) that it released its first high complication: the Benu Tourbillon.
This is Grossmann showing a somewhat more lyrical face than in its time-only Benu and Atum watches –we’d have expected the firm (which has recently moved into spacious new quarters of its own, after starting out in leased space; the company’s factory is on the site of a former Urofa factory in Glashütte, overlooking the Müglitz River) to make a tourbillon with a closed dial but instead it’s chosen to make one that shows the complication off. In this case, there’s actually something worth seeing. The Grossmann tourbillon is a three-minute, flying tourbillon, with a large (16.2mm) cage. The dial is a regulator-style arrangement, with the running seconds at 9:00 (an indirect sub-seconds display, about which more in a minute) and the hours at 3:00.
In order to ease read-off of the minutes past the hour, the minutes hand –heated to the characteristic Grossmann brown-violet –is double-ended. The shorter of the two ends passes across an arc on the dial showing the minutes past the hour from 24 to 26 –filling in the gap created by the aperture for viewing the tourbillon (Grossmann has a patent pending for the display.)
The tourbillon uses a side-lever configuration, but a somewhat unusual one. The lever is a rather elaborate construction, in two parts: a lower, which holds the sapphire pallet-stones, and an upper arm, with the fork on one end, and a curved tail that holds the banking-pin. In a conventional side-lever tourbillon, the lever banks (stops at the limit of each oscillation) against two pins fixed to the cage. In the Grossmann lever, the banking-pin on the end of the lever banks against the walls of a rhomboid-shaped cut-out in the cage; this is a similar strategy to that used in the Glashütte lever, which uses a banking-pin on the shorter of the two arms of the anchor, and which banks against the walls of a small hole drilled in the plate. One of the claimed advantages for the Glashütte lever is that it’s better poised than a standard Swiss lever and the same is asserted as an advantage by Grossmann for their tourbillon lever.
Grossmann tourbillon calibre 103.0, three-minute tourbillon with stop-seconds.
The setting mechanism is the same as that first used by Grossmann in the Atum models –pull out the crown and release it, and it drops back into its usual position while an internal clutch engages the hand-setting train. You set the hands as you normally would, and then press a small button in the case-band to re-start the watch. This prevents the jumping motion of the hands sometimes seen thanks to the backlash sometimes present in a conventional hand-setting mechanism (I can testify first-hand to how irritating it is for the temporally persnickity amongst us to have the minutes hand jump forwards or backwards when pushing in the crown, especially after waiting patiently for a time reference to match the position of the hands.)
There are a couple of fascinatingly anachronistic elements in the Grossmann tourbillon as well. The first is the mechanism for the tourbillon stop-seconds. The problem with putting a stop-seconds mechanism in a tourbillon is that they generally work by causing a small brake to press lightly on the balance when the crown’s pulled out; such a system won’t work in a tourbillon because the pillars of the carriage may block the brake from falling. Grossmann’s adopted a very unusual system –there is a brake, but instead of using a metal blade, it uses a brush made of human hair. The pillars of the carriage have a triangular profile, so that if the brush falls when blocked by one of the pillars, the hairs of the brush are parted by the angle of the metal, allowing the bristles to fall completely onto the tourbillon. Other than the use, hundreds of years ago, of stiff hog’s bristle to control the rate of pre-balance spring verge watches, I’m unaware of any other such use of hair in the mechanism of a watch.
Dial side: stop-seconds brush to the right of the tourbillon; hour wheel train above; arbor for the small seconds visible at 9:00.
The indirect seconds mechanism also has an unusual detail. In a one minute tourbillon, the running seconds hand is generally just mounted on the arbor of the tourbillon; in a three minute tourbillon, you could mark off three minutes –180 seconds –but the seconds markers would be so close to each other as to be illegible without a loupe. Grossmann’s opted for a sub-seconds dial at nine o’clock, whose pinion is driven by the first wheel in the going train (via an intermediate wheel.) Indirect seconds systems are so called because the seconds hand is not in the direct line of power flow to the escapement, and such systems usually require some sort of retaining spring on the pivot of the sub-seconds wheel to help prevent flutter of the seconds hand due to backlash (some backlash has to be present or the gear teeth won’t be able to roll in and out of engagement with each other; in the going train the backlash is simply taken up by the side pressure between teeth caused by the mainspring tension.)
Movement plate removed; tension spring and lignum vitae roller visible below mainspring barrel.
Grossmann uses a flat spring that presses against a small roller mounted on the small seconds gear arbor. The roller is made of a material once very important in clock-making but which today is almost unknown –wood from a tree of the genus Guaiacum, which may be better known to antiquarian horologists under the name lignum vitae, which name can refer to the hard heartwood of several trees of the genus. This extremely hard wood has natural oils which make it self-lubricating and thanks to its tribological properties, it was much used at one time as a bearing material both in horology and other applications (John Harrison made use of it for the anti-friction rollers of one of his marine chronometers.) Restorers sometimes find that even when metal bushings are worn out in centuries-old clocks, bearings made of lignum vitae are still in good running order. It’s a material with a fascinating history even outside tribology –the name lignum vitae was given to it because of its use in medicine (in the Renaissance its gum was used as a treatment for syphilis) and was famously described by the Elizabethan satirist Nashe with the grotesquely long Medieval Latin term, “honorificabilitudinitatibus” (“able to achieve” or “worthy of achieving” honor.) The word is a hapax legomenon (word appearing only once in a certain body of writing) in the works of Shakespeare (Love’s Labours Lost, Act V, Scene i.)
A word which, despite its unwieldy length and un-euphonious pronunciation, could apply very well to the Grossmann Benu Tourbillon as well.