Naval architecture

"Naval engineering" redirects here. For the wider engineering discipline, see marine engineering.

Naval architecture also known as naval engineering, is an engineering discipline dealing with the engineering design process, shipbuilding, maintenance, and operation of marine vessels and structures. [1] [2] Naval architecture involves basic and applied research, design, development, design evaluation and calculations during all stages of the life of a marine vehicle. Preliminary design of the vessel, its detailed design, construction, trials, operation and maintenance, launching and dry-docking are the main activities involved. Ship design calculations are also required for ships being modified (by means of conversion, rebuilding, modernization, or repair). Naval architecture also involves formulation of safety regulations and damage control rules and the approval and certification of ship designs to meet statutory and non-statutory requirements.

The hull of a racing yacht being lifted from the water for maintenance

Main subjects

The word "vessel" includes every description of watercraft, including non-displacement craft, WIG craft and seaplanes, used or capable of being used as a means of transportation on water. [3] The principal elements of naval architecture are: [4]

Hydrostatics

Body plan of a ship showing the hull form

Hydrostatics concerns the conditions to which the vessel is subjected to while at rest in water and its ability to remain afloat. This involves computing buoyancy, ( displacement) and other hydrostatic properties, such as trim (the measure of the longitudinal inclination of the vessel) and stability (the ability of a vessel to restore itself to an upright position after being inclined by wind, sea, or loading conditions). [5]

Hydrodynamics

Hydrodynamics concerns the flow of water around the ship's hull, bow, and stern, and over bodies such as propeller blades or rudder, or through thruster tunnels. Resistance – resistance towards motion in water primarily caused due to flow of water around the hull. Powering calculation is done based on this. Propulsion – to move the vessel through water using propellers, thrusters, water jets, sails etc. Engine types are mainly internal combustion. Some vessels are electrically powered using nuclear or solar energy. Ship motions – involves motions of the vessel in seaway and its responses in waves and wind. Controllability (maneuvering) – involves controlling and maintaining position and direction of the vessel

Deck of an oil tanker, looking aft.

Structures

Structures involves selection of material of construction, structural analysis of global and local strength of the vessel, vibration of the structural components and structural responses of the vessel during motions in seaway.

Arrangements

Arrangements involves concept design, layout and access, fire protection, allocation of spaces, ergonomics and capacity.

Construction

Construction depends on the material used. When steel or aluminium is used this involves welding of the plates and profiles after rolling, marking, cutting and bending as per the structural design drawings or models, followed by erection and launching. Other joining techniques are used for other materials like fibre reinforced plastic and glass-reinforced plastic.