Stand before the Éolienne Bollée and witness a unique intersection of hydraulic engineering and wind power. Unlike traditional windmills that rely solely on a rotor, this distinctive machine functions as a true turbine. You are looking at a design first patented in 1868 by Ernest Sylvain Bollée, a hydraulic engineer from Le Mans. Its defining characteristic is the presence of a stator—a set of fixed blades through which the wind must pass before reaching the rotating rotor.
Witnessing the Mechanics of the Stator and Rotor
When you observe the Éolienne Bollée, notice the two distinct rings that form the heart of the machine. The inner ring is the rotor, while the outer ring is the stator, which features more blades than its inner counterpart. In models following the 1885 patent, a funnel was added to the stator to capture wind from a wider area and increase its velocity through the turbine. This design allowed for various sizes of construction; depending on the model, you might see between 24 and 44 blades on the stator and between 18 and 32 on the rotor. If the machine is mounted on one of the signature cast-iron columns, it features a spiral staircase made of wrought iron steps wrapping around a segmented tower.
The Engineering of Wind Management
The design of the Éolienne Bollée was as much about safety as it was about efficiency. You can see how the system manages varying weather conditions through several mechanical features:
- A small fantail located upwind of the rotor uses a system of gears to turn the turbine toward the wind.
- A counterweight system automatically turns the turbine out of the wind when speeds increase, protecting the structure from damage during heavy gusts.
- The internal mechanics translate the rotation into power through a bevel wheel and a gearbox, which was traditionally used to drive three throw pumps for water supply.
Planning Your Visit
To appreciate the historical significance of this engineering feat, allow yourself enough time to study the intricate blade arrangements and the unique structural transition from the stator to the rotor. The most striking feature not to miss is the sheer complexity of the 1885 patent improvements—specifically how the funnel and counterweight systems work in tandem to maximize wind capture while ensuring durability. While you explore this piece of mechanical history, you can also find other points of interest in Le Mans, such as the Saint Julian stone, L'Envol, Général Leclerc de Hautecloque, Rabbit Hole, or Retour à la vie.
Begin your journey by tracing the legacy of Ernest Sylvain Bollée and his quest to perfect the hydraulic wind engine. Planning a visit allows you to see how these machines were once exported as far as Morocco and Brazil, making it a world-renowned piece of French industrial history.