Based on an open-circuit “Eiffel style” layout, the womb-like main chamber stretched more than 88 feet long. The engine room, extending another 32 feet, housed a 900-hp, military surplus Fiat V-12. (Moto Guzzi later upgraded to a larger closed-circuit configuration with an electric motor.) Rider and motorcycle were suspended on a pendulum, like a proto Space Age trapeze act, facing 120-mph winds. Fergus Anderson was among the first racers to test inside the tunnel. He compared the sensation to flying.