“Naval Architecture is concerned with ship safety, ship performance and ship geometry.” (Basic Ship Theory, K.J. Rawson & E.C. Tupper)

Ship Safety

One important focus area for Naval Architects is Ship Safety. Ship safety ensures that the ship does not capsize in the following conditions:

  • Rough weather and sea conditions.
  • When the ship is damaged.
  • When the ship is being maltreated by the crew or owner operators.

The Naval Architect must also ensure that the ship is sufficiently strong to prevent break up or fracture locally, and that the crew and passengers onboard the ship has a good chance of survival in case of an accident, or if damaged.

Ship Performance

Another focus area for the Naval Architect is Ship Performance.  A lot of the aspects regarding a ship’s performance has been addressed in previous Chapters.  The performance of a ship is mostly always dictated by two aspects. These are “trade” and “war”.

The important performance characteristics that must be considered by the Naval Architect for Naval Vessel are as follows:

  • War Fighting Capability:  Is the vessel a destroyer, frigate, aircraft carrier, troop and helicopter carrier, inshore patrol vessel, offshore patrol vessel, minelayer, minesweeper or a replenishment ship? Does it operate in blue waters only, or is it also required to operate in brown water? Does it engage targets from a large distance or in close quarters? Does the ship stand off or immediately engage enemies or vessels of interest? As you can hear, there is various aspects of operation that determines the vessel in question’s capability.
  • Weapons Payload: What does the Navy in question need? Do they require ICBM’s with nuclear warheads, guns and below deck magazines, are they crew served or rogues, surface-to-air and/or surface-to-surface missiles, jet fighters and interception craft or do they only require various small arms with storage space?
  • Speed: Generally, warships loiter in an area of interest or of patrol. Cruising speed is only reached during transit, and full speed is only employed during evasive manoeuvres or when required as part of engaging an enemy.
  • Endurance: Naval ships generally spend a long time at sea without any replenishment requirements. This must be taken into consideration.
  • Resistance.
  • Propulsion: Does the vessel require more than two propulsion diesels and perhaps a gas turbine to reach higher speeds in certain operational situations?
  • Ship Motion: Ship motions must be considered to ensure that crew do not get sea-sick and that the vessel is not put under unnecessary stress in rough seas. In the case of aircraft carries, ship motions determine when an aircraft can land or not.
  • Manoeuvrability: Naval vessels are generally highly manoeuvrable.


The important performance characteristics that must be considered by the NA for Merchant Vessels are as follows:

  • Profitability: Is the operational cost and life cycle cost of the vessel low enough to allow for enough profit to be generated.
  • Cargo: What type of cargo will the vessel be carrying and what quantity and volume.
  • Speed: What vessel speed is required to meet schedules and for operations to run as efficiently as possible.
  • Endurance: Is the vessel’s endurance enough to travel been all the ports it serves.  Should endurance considerations be included to address possible resale of the vessel.
  • Resistance: Total resistance must be as little as possible in terms of the vessel usage to reduce fuel costs and increase efficiency.
  • Propulsion.
  • Ship Motion: Motions must be such that the crew’s safety and comfort is not compromised and that the safety of the carried cargo is not compromised.
  • Manoeuvrability

Ship Geometry

Another focus area for the Naval Architect is the Ship’s Geometry.  Aspects that need to be considered when designing any ship is as follows:

  • The interrelation of compartments as well as the spatial design of each.
  • The build economy.
  • Is it aesthetically pleasing? For example, people will shy away from a cruise ship that is not pleasing to the eye.


Next topic Ship Stability »