MB&F presents HM9-SV, or Horological Machine N°9 Sapphire Vision. Conceptualised by MB&F founder Maximilian Büsser and designed by Eric Giroud, HM9-SV features five sapphire crystals treated with anti-reflective coating: three complex crystals for the main components of the case, one crystal covering the dial, and one crystal for the dial itself.
The HM9-SV comes in four editions, each limited to only five pieces. Two editions feature 18K 5N+ red gold frame, combined with a NAC-coated black or PVD-coated blue engine. The other two editions have 18K white gold frames, with a PVD-coated purple or red gold-plated engine.
MB&F, the world’s first and only “horological concept laboratory” was founded in 2005 by its Creative Director Maximilian Büsser, after a 15-year career managing prestigious watch brands. MB&F – Maximilian Büsser & Friends – brings together talented horological professionals, artists, designers and manufacturers to produce small series of radical concept watches and “Performance Art” pieces.
MB&F presents its wristwatches under two collections. The Legacy Machine collection comprises, by MB&F standards, more classical or conservative timepieces. The Horological Machine collection, first unveiled in 2007, comprises the more radical, idiosyncratic designs. HM1, with its sculptured, three-dimensional case and beautifully finished engine, set the standard for the others to follow. Thus far, the collection has explored space (HM2, HM3, HM6), the sky (HM4, HM9), the road (HM5, HMX, HM8) and the animal kingdom (HM7, HM10).
First presented in 2018, Horological Machine N°9 – HM9 ‘Flow’ – was a tribute to the extraordinary automotive and aeronautic designs of the 1940s and 50s. The standout case design echoed that period’s flowing and exaggerated aerodynamic lines. The newest addition to the collection, the HM9-SV model, explores the depths of the ocean; inspired by “an exploratory vessel from Atlantis,” with all-round visibility.
MB&F, we are told, took two years to develop the HM9 case’s sapphire crystal components. The reason for this prolonged period of development? Because “it was theoretically impossible,” says MB&F’s Arnaud Légeret. “Other sapphire cases are essentially composed of two flat slabs screwed together. The HM9 case is anything but flat – it’s all about curves and bubbles. Thanks to our many years of experience with complex sapphire crystals – and with the precious help of our specialised Friends – we were finally able to crack the conception, machining and polishing of a transparent HM9 case that stayed true to its flowing lines.”
Sapphire crystal, or Corundum, is one of the hardest minerals known to man. Diamond rates a ten on Moh’s scale of hardness, while Corundum is rated at 9. This means it is virtually scratch-proof and offers unparalleled legibility and material integrity over the long term. This also means that sapphire is extremely challenging to machine in complex three-dimensional shapes, a challenge that is compounded by the small machining tolerances required in watchmaking.
Over the years, MB&F has produced sapphire crystal components with ever-increasingly complexity. The HM2 ‘Sapphire Vision,’ the double-arched crystals of HM4 ‘Thunderbolt,’ the recent HM3 FrogX and the hallucinatory body of HM6 ‘Alien Nation’ are prime examples. Although extremely hard, sapphire can fracture sharply under pressure whereas a metal would merely deform. According to MB&F, preparing the crystals for a single case of HM9-SV requires approximately 350 hours of careful machining and polishing.
The external lines of HM9-SV largely follow the blueprint of its predecessors. However, a more lenient approach to the sharp inward angles and parabolic curves had to be adopted to account for the material properties of sapphire crystal. The smoother lines of HM9-SV minimise potential areas of mechanical vulnerability, while also reinforcing its submarine aesthetic.
The outer “hull” of the HM9-SV combines sapphire crystal components and precious metal precisely, fitted together in three parts. The seams between the sapphire components and the minimalistic gold frame are practically invisible thanks to a patented in-house process. The 3-D gasket from the original HM9 remains in HM9-SV, but the sapphire crystals are fused with the metallic frame using to a high-tech bonding compound, along with a process that involves vacuum and high temperature. The resulting seal is resistant to 3ATM (30m) of water pressure.
Despite its dramatic external appearance, Büsser has described the engine inside the HM9 as “the most beautiful movement we’ve created to date.” This perhaps being the motivation for a sapphire crystal case. The result of three years of development, the HM9’s three-dimensional engine is assembled entirely in-house.
The movement’s twin and fully independent cantilevered balances channel pulse into a differential – the movement’s gearbox – which then averages them into a single coherent time-pulse. Statistically speaking, two identically calibrated systems offer a better-averaged reading than one system on its own. The ultra-precise conical gears efficiently turn the movement’s energy through a 90° angle to feed the time display on a sapphire crystal dial, with Super-LumiNova markings. On the reverse, beneath each of the balances, are propellers – twin turbines that spin freely as an element of pure visual interest.
The HM9-SV feature a new shock-absorbing system: helicoidal springs placed between the movement and the case. The springs are crafted by laser from a solid tube of polished stainless steel, offering excellent elasticity and limited lateral displacement.
The HM9-SV is fastened with a hand-stitched brown or black alligator strap, with red or white gold folding buckle matching the case.