We already told about how in Czechoslovakia solves the problem of increasing the stability of the boat on the course by synchronizing the rotation of the propeller shafts in a twin-engine, twin-shaft scheme of the propulsion system. But the student of 7th class from the city of Tyumen Eugene Shein uses for double-shaft scheme engine of a single engine. Typically, such a transfer requires the installation of gear-distributor, Eugene is used to drive both propeller shafts rotating in opposite directions flexible shafts, springs. Gear now you do not need, springs are placed directly on the protruding ends of the motor shaft. Not a single unnecessary detail, and the desired effect achieved!