Retractable auxiliary thruster

Submarine - Mobility

This auxiliary thruster is located underneath the submarine in the aft section. It is retractable through doors which open & close during deployment & retraction phase.
This system acts as a back-up thruster in case of failure of the main electric propulsion system, to prevent the submarine from drifting. Additionally, this thruster has the capacity to rotate around its vertical axis which eases the maneuvers in port.
The system is composed of a main electrical motor which drives the propeller at up to 600 rpm in any directions. The propeller gyration is driven by another electrical motor and gives the propeller a 360° degree rotation capability. The deployment is driven by hydraulic jacks, both for the tip-up of the propeller but also for opening / closing of the doors. The entire system is controlled by a control cabinet equipped with Programmable Logic Controller which drives the electro-hydraulic servo valves which drive the jacks. The system is equipped with sensors to detect that the retraction / deployment has been performed as expected, but also check that the propeller is maneuvering as instructed (position, rotation angle, speed, axis, etc…).