Ein Flugzeug der 40er Jahre am Handgelenk: die MB&F Horological Machine No. 9 'Flow' - Sammler-Uhren

A 1940s airplane on your wrist: the MB&F Horological Machine No. 9 'Flow'

MB&F's Horological Machines, the ninth of which is the ninth, are as far removed from conventional clocks and watchmaking as one can imagine. Since the release of the first machine (HM1 debuted in 2007), the Horological Machines have appeared in a bewildering variety of forms and inspirations, from the bulbous convexity of the HM3 "Frog" to the saucer-shaped HM7 "Aquapod" to the latest, automotive-inspired HM8 "Can Am."

Each of the machines is essentially an act of horological deconstruction and re-creation—reengineering the elements of a traditional wristwatch to create a new kind of time-telling device that also serves as wearable art.

MB&F produces high-quality watchmaking, but its machines are also deliberately playful, designed to evoke a certain nostalgic reverence for a child's imagination. The latest Horological Machine, the "Flow," celebrates the visual poetry of streamlined cars and airplanes of the 1940s and 1950s, a time, as MB&F says, "long before wind tunnels and CAD software imposed their harsh logic and limited creativity."

Basic idea and concept:


MB&F's design language has reached a certain maturity over the past 20 years, and the HM9's variety of forms exudes a certain confidence that will be familiar to long-time observers of MB&F's work. The watch machines have always had a touch of science fiction flair, and the HM9 is no exception: Its two side capsules are somewhat reminiscent (for Star Wars fans) of the legendary twin-pod cloud cars that zip around the flying city of Bespin in "The Empire Strikes Back."

The HM9's main source of inspiration, however, is the automotive world—science fiction fans may find echoes of Star Wars in the HM9, but automotive enthusiasts will also be heavily inspired by early streamlining attempts, such as Buckminster Fuller's Dymaxion car (designed to represent the "rolling" phase of a land-to-air vehicle) or more conventional, now-classic automobiles like Pontiac's Streamliner, which debuted in 1942.

One expects all watchmaking to be symbolically ambiguous, so to speak, and the HM9 certainly evokes countless designs from the real and fictional world, but it is also one of the most mechanically sophisticated watches. Each of the two side nacelles houses a separate balance wheel and escapement, while the central nacelle houses the mainspring barrel and a differential that averages the rate of the two independent balance staffs and generates a single signal for the time display.

This mechanism was first developed in wristwatches by Philippe Dufour in his Duality wristwatch. MB&F first used a variant of this mechanism (in which the tendency of the two balance wheels to balance each other is intended to achieve greater accuracy) in the Legacy Machine 2. However, this is the first time it has been used in a horological machine.

The HM9 will be available in two versions: the Air version features a dark movement and a cockpit-style dial, while the Road version features a rose gold-plated movement and a speedometer-style dial.

The MB&F Horological Machine No. 9 "Flow" (HM9) is a watch like no other—a fusion of Art Deco, 1940s aviation, and futuristic micromechanics. It looks like a space shuttle, functions like a high-end timepiece, and feels like wearable sculpture.

MB&F HM9 "Flow" – Technical Overview

Movement & Complications

  • Movement: Manufacture hand-wound, 301 components

  • Complications:

    • Dual, independent flying balancing system

    • Differential to synchronize both inhibitions

    • Horizontal time display via prism gear

  • Power reserve: approx. 45 hours

  • Frequency: 2 × 2.5 Hz (18,000 A/h)

  • Limitation: Depending on the version 33–50 pieces

Design – “Flow” = sculpture in motion

  • Shape: Inspired by the flow lines of old airplanes and cars (e.g. Mercedes W196, Art Deco airplanes)

  • Case materials: Grade 5 titanium (polished or sandblasted)

  • Sapphire crystal: Three large glass domes – at the front for the time display, at the side for the balance wheels

  • Dimensions: 57 mm wide, 47 mm long, 23 mm high – massive, but ergonomic

🛩️ Two “turbine housings” left and right = the two balance wheels, connected via central body with time module.

Mechanics of double force

  • Two completely independent regulating organs (one balance wheel with escapement each)

  • Coupled via a mechanical differential that averages the gear ratios

  • Idea: Improvement of gait stability through redundancy + averaging

Time display

  • The time is read horizontally on a small cylinder with a rotating number ring

  • Time module is connected to the movement via a conical gear

Price & Availability

  • Original price: approx. €170,000–190,000

  • Limited Editions:

    • "Flow Air" → with a distinctly technical look

    • "Flow Road" → with "bonnet" over a fake tourbillon

    • Sapphire crystal editions (HM9 Sapphire Vision / SV) → approx. €400,000

  • Extremely limited and sought after by collectors

Quote from MB&F founder Maximilian Büsser:

“The HM9 was like a crazy project from my childhood: airplanes, cars, technology—all in one living object.”

Source: AI, WatchWiki, hodinkee.com

Back to blog

Leave a comment