Hull and Propulsion

• Modern naval warship hull design focuses on high speed, low fuel consumption and stability as weapons platforms. Most warship hulls tend to be long and slender to boost speed, with a sharp, tapered bow to improve fuel economy and reduce noise.
  
  Similarly, propulsion systems are designed to maximize fuel economy and speed while reducing noise and heat emission -- either of which could betray the ship's location to an enemy. Propulsion systems include the ship's engine, propellers and their shafts and housings.
  
  

Offensive Weapons

• A naval warship's primary suite of offensive weapons is designed around the vessel's primary mission. An attack submarine, for example, will be armed with torpedoes but not missiles. A ballistic missile submarine will be armed with torpedoes for defense, but her primary weapons will be nuclear missiles. Most modern naval warships are equipped with secondary weapons batteries as well. These weapons are generally smaller than those in the primary battery, but allow the vessel to engage targets outside of her primary mission.
  
  

Active Defensive Systems

• All modern naval warships are armed with an array of active defensive systems. These systems include weapons, such as anti-aircraft guns, missiles and torpedoes to destroy incoming enemy missiles, aircraft or ships. Other defensive systems are designed to confuse and defeat an enemy's ability to target the vessel. Radio and radar jamming equipment confuse an enemy's electronic systems while smoke generators make it difficult for an attacking pilot to find the ship. Chaff ejectors fire metal strips in the air to confuse the radar of an attacking missile.
  
  

Passive Defenses

• Modern naval warship hulls and superstructures are designed to minimize and distort the ship's radar profile to help it hide from potential enemies. Designers are constantly striving to reduce the ship's exhaust signature in an effort to protect the ship from heat-seeking missile attacks. The shape of a submarine's hull and the design of her propeller are also passive defensive systems engineered to help the boat move as silently as possible through the water.
  
  

Aircraft Facilities

• Ships in the frigate classes and larger classifications generally carry some facility to launch and recover helicopters. This facility usually involves a flat landing pad and a hanger structure adjacent to it. Aircraft carriers, of course, are capable of handling fixed-wing aircraft as well.
  
  

Command, Control and Communications

• The upper structures of most modern naval warships are festooned with all manner of communications antennae. Modern sea battle tactics often require a high degree of contact between each element of the fleet, with headquarters and with any aircraft that may be aloft. Included in that antenna array are the dishes for surface and air search radars. Ships use radar as navigation aids, as part of their defense against a surprise attack and as a method by which to guide their weapons towards a target. Hiding below the waterline, but equally important, is the bulbous fairing at the forefoot of the bow, at the very forward bottom edge of the ship, that houses the sonar antenna. Sonar is used to give accurate depth readings for navigation and to aid in the detection of enemy submarines and mines.
  
  

The Critical Component

• Ships of previous generations were most often designed around a single weapon system, such as the large guns on battleships. As weapon systems advanced, these single-purpose ships quickly became obsolete. Modern naval warships are designed in a component fashion -- weapons, propulsive, electronic, even communications systems -- which can be removed and upgraded as technology advances. As such, modern naval vessels are considered 'open' design platforms -- upgrades are expected and accommodated in the initial design.