Main propulsion is via two propellers, each driven by a electric motor. They ran with single deck electric motor cars. It is propelled by a pump jet driven by an electric motor. The petrol engine produces at 7,200 rpm with an additional from the electric motor. Main propulsion is via two ABB Azipods, each driven by a electric motor. The exact characteristics vary greatly with the type of electric motor. Carbon brushes are one of the least costly parts in an electric motor. Later machines use a gear box driven by a dedicated electric motor. The controls also include the switchgear required to control the electric motor. This is the reason for torque in an electric motor. A wide variety of electric motor technologies are in use. The turret was moved with an electric motor. One degree is governed by the electric motor. Some scooters use batteries and an electric motor. Mechanical sirens driven by an electric motor are often called "electromechanical".