Rotary drives for civil engineering

A multiple rotary drive arrangement for driving drilling and/or mixing tools for civil engineering, comprising

• a first rotation gearbox comprising at least one first gearbox input for introducing a first input torque and configured to provide the first input torque as a first output torque at a first gearbox output for driving a first drilling and/or mixing civil engineering tool or, in the case of more than one first gearbox inputs, configured to add the first input torques of the more than one first gearbox inputs together to make a first total input torque and to provide the first total input torque as a first total output torque at the first gearbox output for driving the first drilling and/or mixing civil engineering tool, and
• a second rotation gearbox comprising at least one second gearbox input for introducing a second input torque and configured to provide the second input torque as a second output torque at a second gearbox output for driving a second drilling and/or mixing civil engineering tool or, in the case of more than one second gearbox inputs, configured to add the second input torques of the more than one second gearbox inputs together to make a second total input torque and to provide the second total input torque as a second total output torque at the second gearbox output for driving the second drilling and/or mixing civil engineering tool,
• wherein a drive motor unit for generating and providing a motor torque is mounted on each of the first and second gearbox inputs of the first and second rotation gearboxes,
• wherein at least one drive motor unit of the first rotation gearbox comprises a hydraulic motor, and
• wherein each and every drive motor unit of the second rotation gearbox comprises an electric motor.