In case you had a sick note on the day they taught molecular chemistry in school, C3H5N3O9 is both the molecular formula for nitroglycerine and, unknown to many, a horological experiment.Many of the most reactive chemical reactions derive from combining seemingly innocuous ingredients. The watch known simply as Experiment ZR012, all started when Felix Baumgartner and Maximilian Büsser shared a pleasant, and no doubt expensive lunch on a Geneva terrace in the summer of 2008. It set in motion a horological chain reaction that four years later has manifested itself as C3H5N3O9.
URWERK founders, Felix Baumgartner and Martin Frei had a concept featuring Wankel engine inspired indications that they had not yet developed, and they wanted to see if constructor Cyrano Devanthey could develop and produce a movement based on the Wankel principles.
What is a Wankel engine?
In 1919, a 17-year-old German boy called Felix Wankel dreamt of a new type of engine. Despite no formal training, Wankel believed that he could design an engine in which the four stages of intake, compression, combustion and exhaust-took place in one rotation, rather than four separate reciprocations of a piston as in a normal engine.
Interrupted by his work for the German war effort, it wasn’t until 1954 that Wankel first tested his motor. Nine years later, German manufacturer NSU revealed the Wankel Spider with a production version of the all-new engine, a 50-hp rotary capable of pushing the car to a top speed of 93 mph.
One of the main reasons development took so long is that Wankel’s orbital engine was based on a convex-triangle rotor rotating inside a epitrochoid combustion chamber. An epitrochoid is a very complex shape traced by a point on a small circle rotating around the perimeter of a larger circle and plotting that shape involves seriously complex mathematics. From over 800 shapes considered, Wankel investigated nearly 150 configurations and variations – in a time long before computers – before settling on a fat figure-eight form.
Wankel was the first to use an epicyloid in an internal combustion engine; Experiment ZR012 is the first to use an epicyloid indications in a wristwatch. So, Experiment ZR012 by C3H5N3O9, features a Wankel engine adapted to a watch movement, with hour and minute indications in an asymmetrical zirconium case with articulated and compound lugs.
MB&F partners Maximilian Büsser and Serge Kriknoff teamed up with independent watch designer Eric Giroud to design and produce the case, and Experiment ZR012 was born!
At first glance, the time appears to be indicated by centrally rotating triangular rotors; however, the triangles are what are known as Releaux polygons which rotate eccentrically rather than centrally and track complex epitrochroid curves rather than circles. The system was inspired by the Wankel engine, which features orbital Releaux polygon rotors rather than the reciprocating pistons that power the majority of our cars and machines today.
C3H5N3O9 is an experimental platform, not a luxury brand and will retail for CHF110,000 (approx US$115,600). There will be no marketing to promote this experimental watch. Instead a few select bloggers were informed of C3H5N3O9’s website on launch day. The question is, can blogs alone market and sell high-end wrist watches, simply by reputation alone. We will soon find out. The watch is only available through the contact form on the website. As there are only 12 of them being made in zirconium and 12 in red gold, the time to start ordering one is NOW.
Case: Dimensions without lugs: 59mm long x 44mm wide x 17mm high
Dimensions with lugs: 71mm long x 47mm wide x 25mm high
Case and lugs: Zirconium case with titanium lugs
Number of case components: 60
Articulated front lug, compound rear lug
Sapphire crystal with anti-reflective treatment both side
Water resistance: 30m/ 100’ / 3atm
Strap and buckle: Brown calf leather strap. Titanium and white gold (palladium 150 alloy) folding buckle.
Experiment ZR012: Movement
Movement dimensions: 41.35mm long x 32.65mm wide x 11.55 mm high
Number of components: 328
Number of jewels: 42
Power reserve: 39h
Balance frequency: 28’800
Finishing: satin finishing, sandblasted, circular graining on movement, black PVD treated components, black ruthenium treated components
Number of plots to create epitrochoids for hours and minutes: 180
Tolerance between hour and minute indication rotors and inside of epitrochoids: 0.20mm
Via: mingthein, google