الوصف

Ship's portholes reason are designed into round, according to the principle of mechanics, circular than other shapes more under pressure, shear stress. The installation position of porthole according to insubmersibility of ship.
Classify into heavy and light type. Heavy porthole inboard hinge cover anti wave porthole. Deadlights side with rubber seals, tightly pressed by the bolt to keep watertight. Light portholes are generally not associated with deadlights. In the spaces below the freeboard deck or enclosed superstructure premises portholes were all severe side scuttle.