A traditional wristwatch has a relatively straightforward role: to tell the time. All that is needed is a hand for the hours, another for the minutes and perhaps a power reserve indicator to keep track of running time. Horological Machine No4 has a hand for the hours, another for the minutes and a power reserve indicator. HM4 tells the time.
HM4 is not a traditional wristwatch.
The aviation-inspired case and engine of the HM4 are one. Neither would, nor could, exist without the other, yet each is so transcendental as to be able to stand alone as a work of art in its own right.
The HM4 engine is the culmination of three long years of development. Each of the 300-plus components – including the regulator and even the screws – was developed specifically for this anarchistic calibre. Horizontally configured dual mainspring barrels drive two vertical gear trains, transferring power to the twin pods indicating hours/minutes and power reserve.
But describing HM4's engine through its mechanical functionality is like describing Renoir's work through the chemical composition of his paint. Only careful contemplation enables full appreciation, and the sapphire case section and display panels top and bottom allow full access to the flawless fine finishing of HM4's intricate and vibrant micro-mechanics.
The sleek aerodynamic form of Horological Machine No4’s envelope has its roots in Maximilian Büsser's childhood passion for assembling model plane kits, though none looked remotely as futuristic as these. The striking transparent sapphire section of the case requires over 185 hours of machining and polishing to transform an opaque solid block of crystal into a complex, exquisitely curved panel allowing the light to come in and the beauty of the HM4 engine to stand out. Every component and form has a technical purpose; nothing is superfluous and every line and curve is in poetic harmony. Articulated lugs ensure supreme comfort. Highly legible time is a fringe benefit.
The HM4 series:
HM4 Thunderbolt: launched in 2010, nicknamed after the A-10 Thunderbolt aircraft; case in titanium/sapphire.
HM4 ‘Razzle Dazzle’ & ‘Double Trouble’: presented in 2011, these limited editions of 8 pieces each take the aviation theme even further with real rivets in their titanium fuselages and hand painted nose art, inspired by the rebellious paintings on WWII aircraft.
HM4 RT: launched in 2012, a limited edition of 18 pieces in red gold, titanium and sapphire.
The HM4 Final Edition closes the HM4 series in 2013 with a limited edition of 8 pieces in blackened titanium and sapphire.
Inspiration and Realisation
A long childhood passion for assembling model aircraft had Maximilian Büsser's walls, cupboards and ceiling covered in small aircraft of every description. Planes were what he saw last thing at night and planes were what he saw first thing each morning.
Many boys sketch supercars and fast planes, but few have the drive and determination to make their dreams come true. Büsser created MB&F to do just that. The HM4 Thunderbolt is born of the child's fantasy and the man's tenacity.
HM4's engine was entirely designed and developed by MB&F over three years of intensive work with Laurent Besse and Beranger Reynard. Each of the 311 components were developed specifically for HM4, no off-the-shelf mechanisms or parts were used at all due to the extreme nature of its architecture.
Two mainspring barrels connected in parallel provide 72 hours of energy, and they transfer their power to the dual jet-turbine-like indication pods (one displaying the hours and minutes, the other the power reserve) via vertical gear trains.
Visible through a shaped sapphire display panel on the top of the case, a distinctive streamlined cock supports the balance, its centre cut away to reveal as much of the oscillating wheel as possible and validating the "kinetic" in MB&F's "kinetic art".
A work of art rewards when viewed from different angles and the HM4 is no exception. Turning the machine over reveals a veritable panorama of meticulously finished micro-engineering through the sapphire sections. In a playful trompe l'oeil, what at first glance appears to be a micro-rotor in the form of MB&F's iconic battle-axe is actually a bridge.
For a timepiece not developed specifically to tell the time, HM4 performs that role superbly. In fact, with its highly legible dials perpendicular to the wearer's wrist, Horological Machine No4 might be described as the perfect pilot's or driver's watch.
On the left pod, the power reserve is clearly indicated by a skeletonised hand echoing MB&F's battle-axe motif. On the right, hours and minutes are displayed by bold, arrow-tipped Super-LumiNova filled hands. Each of the two aviation instrument-styled dials is directly controlled by its own crown, one to wind and re-fuel the tanks, the other to set the time, which provides direct and instantaneous feedback of the action performed.
Inspired by aviation, more specifically the model aircraft kits of Maximilian Büsser's childhood, the case of HM4 imparts speed, power, technology and refinement in equal measure. Visually, the case is composed of three parts: two streamlined jet-turbine-styled pods supported by a horizontal section housing the engine, which is clearly visible through transparent sapphire display panels and the central section of the case itself.
Technically there are also three main sections, but these comprise a fore section in titanium (red gold/titanium for HM4 RT), which includes the dials and articulated front lugs; a central section in sapphire offering unprecedented 360° access to the superbly finished engine; and an aft section tapering down to the dual crowns and framing the animated balance, which is supported by an aerodynamic cock. Methods borrowed from aeronautic engineering are visible in the externally mounted screws, which provide both rigidity and watch resistance to hold the case’s three sections solidly and elegantly together.
Beginning with a solid piece of sapphire, more than 185 hours of intricate machining and meticulous polishing are required to turn an opaque block of crystal into the clear, light-filled atrium of the central case section, which reveals part of the HM4 engine and engineering details. The metal case sections are milled from solid blocks of high-tech grade 5 titanium (red gold for HM4 RT), which undergoes hundreds of hours of machining before polishing, masking and finally satin-finishing of the surfaces. The results speak for themselves.
The contrasts of matte with highly polished surfaces, metal with sapphire, straight lines with seductive curves and rigid forms with articulated arms endows Horological Machine No4 with a life and vibrancy that sets it apart from anything that has ever gone before.
HM4 is the quintessential machine as three-dimensional kinetic art.
HM4 Thunderbolt: grade 5 titanium and sapphire
HM4 ‘Razzle Dazzle’ / ‘Double Trouble’: grade 5 titanium and sapphire, hand painted nose art
HM4 RT: 5N red gold, grade 5 titanium and sapphire
HM4 Final Edition: grade 5 titanium with black PVD and sapphire, angular dial shades
54mm wide x 52mm long x 24mm high
Number of components: 65 (67 for HM4 Final Edition)
Articulation of lugs: 3°
Five sapphire crystals: 2 x dials, 1 x central case section, 2 x display panels (top and bottom)
Strap & Buckle:
Hand-stitched calfskin strap with titanium/white gold or red gold custom-designed folding buckle attached to articulated lugs.
Razzle Dazzle and Double Trouble: authentic vintage leather strap crafted from Swiss military bags with contrasting white hand stitching. Titanium/white gold custom designed deployment buckle.