Patent ID: 9725135
Date: 2017-08-08
CPC Classifications: B63B,B63H

Claim:
1. A method for maintenance of a ship or platform propulsion assembly while floating, comprising the steps of: providing a hull insert, or trunk, forming a housing, or propeller case, located within a hull of a ship; providing for said housing to be watertight with respect to the hull in all walls thereof, except for an opening externally to the ship hull; arranging a motor in said hull externally to said housing without changing position of the motor with respect to the hull; providing a thruster, which is suitable to be arranged externally to said hull to generate a propulsion thrust; providing a telescopic driving shaft passing sealingly through one of the walls of said housing operatively connecting said motor and said thruster, to transmit movement from the motor to the thruster for the movement of said thruster; retracting said thruster within said housing passing through said opening; lowering externally to the hull a submersible movable hatch in a separate piece and completely disconnected from said thruster and from said housing, by removable hanging cables; associating said submersible movable hatch externally to said housing and sealingly closing said opening of said housing, closing said housing and forming a watertight closed chamber with respect to outside of said hull containing said thruster; evacuating possible fluid, which is present within said closed chamber even when the hull or platform are floating and partially submersed, to arrange said thruster at least partially in air.