The main principle of side shell-doors operations consists of a hydraulic cylinder powered by a hydraulic power pack, with which it is possible to obtain:

1. Door maneuvering (open-close)
2. Door cleating and blocking through a leverism system:
3. With this application it is possible to obtain the water tightness through a neoprene gasket crushed on the hull structure

The main local signaling of door locked is provided through a limit switch which is assembled close to the cleating device. The signal is provided to the wheelhouse through the automation system.

The state of the art on side shell-door equipment is that it consists of two macro elements: the first one is the hydraulic system consisting of hydraulic power pack, cylinders, pipes, flexiblecomponents and conduits, valves, quick coupling for emergency maneuvering, where a fluidcomposed of mineral oil, poliglicol or ester-based oil is basically used.

Hydraulic power pack of side shell-doors

The hydraulic power pack can be of two types:

• mini-power pack: HPP for the operation of only one door (“dedicated”)
• centralized power pack: for the operation of many shell-doors trough the pipes network construction.

The second macro area is the electric system composed of cables, limit switch and HPP electric supply elements.