Retractable bow stabilizers trim control system

Submarine - Mobility

Some submarine are equiped with stabilizers on the aft part of these; some are retractable, some are not. In both case, their aim is to help for the navigation, in particular when close to the sea surface to compensate from the swell movements.
The system described below is controlling the deployment & retract phases of the aft stabilizers, but also controls the angle of these stabilizers which commands come from the piloting console.
This system is composed of control cabinets equipped with Programmable Logic Controllers which receive orders to deploy, retract, & control the angle of the stabilizers. This control cabinet is itself connected to servovalves which utilizes the hydraulic pressure to activate the jacks which themselves unlock the stabilizers, open doors, deploy/retract the stabilizers & control their angle.
The motions of these jacks are controlled by sensors which are then sending the information back to the control cabinet which control this information & react to adjust the command on the electro-hydraulic valves if necessary.
In that manner, the angle of the stabilizers is controlled in real time in order that the jacks give the right angle & motion to these so that the submarine navigates as expected by the sailor using the piloting console.