Ship Systems

All ship's systems are designed for maximum survivability to operate without interruption under battle conditions. Survivability features include segregation, duplication, flexibility, adaptability, remote operation, shock resistance and special protection. When the crew understands how systems function, why they are important and how they help the ship survive, isolation can be effected and repairs can be made quickly.

The combat systems provide the means for fighting the ship. Restoration of combat systems is given the highest priority and is dependent on maintenance and/or restoration of engineering plant operations.

Sensors provide detection capability for air, surface and subsurface threats. Command and control provides for command direction and coordination of forces and weapons utilizing communications, com-puters and weapons control systems. Weapons include the direction and control of ordnance delivery for AAW, ASUW and antisubmarine warfare ASW systems.

Navigation capability provides ship positioning and targeting direction for weapons systems through the utilization of onboard electronics (receiving signals generated from satellites or shore-based transmitters) and depth-sounding equipment and systems. External communications are provided by radio transceivers, terminal equipment and antennas.

Support services/systems are those auxiliary support services essential to the operation and maintenance of combat systems. These services consist of electrical power, chilled water, cooling water, compressed air, hydraulic services and HVAC facilities.

Electronic warfare and intelligence-gathering capability consist of receivers for signal intercept, source analysis and active/passive deception devices. Monitoring and control equipment provides the capability for casualty detection, equip-ment testing, configuration control, status displays and switching facilities.

Electrical Power is supplied throughout the ship to combat systems, sensors, propulsion systems, navigation systems, communications, damage control and many other systems. Electrical systems are built with alternate power sources, segregation features and multiple routes from sources to equipment. Without power a ship is unable to take offensive action or to defend itself, and may not be able to use its survivability systems. Personnel must know the systems' capabilities well enough to make sound decisions in the selection of circuits to be restored and to coordinate restoration to other equipment. It is essential that vital electronics supporting the combat systems resume operation as quickly as possible after damage.

Seawater is provided throughout the ship in the firemain system. The firemain is designed and constructed to use pumps located throughout the ship and is laid out in loops with valves that allow isolation of small sections. Firemains are built to absorb damage and remain operable. Additionally, seawater, either from the firemain or another independent system, is used to cool combat systems' equipment and auxiliary machinery. Restoration of seawater systems should have the highest priority in damage control actions. Personnel must have a thorough understanding of, and the ability to provide repairs and/or alternate service to the seawater systems to ensure maintenance of warfighting capability.

Compressed air systems are vital to combat capability, providing dry air to weapons and combat systems' electronic equipment, propulsion equipment and emergency generators. A thorough knowledge of the capabilities and limitations of this system and the impact on combat capability is essential to repair or provide alternate service to affected equipment. Care must be exercised during the repair of compressed air lines to avoid the escape of air. Escaped air can fuel fires. It is imperative that a thorough inspection for system integrity be ensured prior to restoration of compressed air lines. Dangerous environments can be created when flammable liquid lines and air lines rupture in the same area.

On all combat ships and some auxiliary ships, chilled water is designated a vital system because of its essential support of weapons, surveillance and communications systems operations. The chilled water system removes the heat generated by electronic equipment. An interruption to the chilled water supply even for a few minutes may cause some systems to shut down from high temperature or even fail. The chilled water system must be maintained in good working order and the plants segregated during battle conditions in order to provide alternate service in the event of a casualty. In the event of piping damage, the chilled water plant in the same segregated zone as the damaged piping should be secured as soon as feasible until the damage is either isolated or repaired.

On all combat and some auxiliary ships, Electronic Cooling Water Systems [ECWS] are vital systems essential to the operation of weapons, surveillance and communications systems. ECWS removes the heat generated by electronic equipment. Usually electronic equipment will not operate if the ECWS is interrupted or degraded. In the event of damage to piping, systems serviced by the ECWS must be secured until alternate service is provided or the damage is repaired.

The purpose of the ventilation system is to maintain a standard of air quality in temperature and humidity for personnel habitation and for the removal of equipment-generated heat. Areas requiring critical temperature control are supported by heating and/or air conditioning, essential to the equipment's operation. Normal operations of the ventilation system are necessary to remove internally-generated contaminants, fumes and humidity.

Ventilation may be accomplished by either natural draft or by electrically driven blowers. Ventilation systems are designated as supply, exhaust or recirculating systems. Individual ventilation systems between the main transverse bulkheads are large piping systems which can provide an impediment to watertight or fumetight integrity. To overcome this impediment, ventilation closures are installed in fire and flooding boundary bulkheads where penetrations are necessary. To minimize the number of holes in bulkheads and decks and improve resistance to damage, ventilation systems are not installed to serve spaces infrequently entered, such as storerooms and voids. Wherever ventilation systems cross fire-zone boundaries, fire dampers are installed at the bulkhead penetration.

Portable ventilation systems consisting of electric driven, air driven and water driven blowers with attached flexible trunks are available for emergency applications where the installed ventilation is inoperative. Portable ventilation systems are available as a means of smoke and gas removal during post fire conditions. While the installed supply and exhaust ventilation systems can be used for desmoking operations, permission must be obtained from the ship's engineer officer prior to such application.

Drainage Systems consist of the main and secondary drainage piping. The main drain line (a loop in large ships, a single line in smaller ones) traverses the main machinery and principal auxiliary spaces, utilizing eductors to remove water. The secondary drainage system traverses remote engineering spaces and other ship's compartments that have water removal requirements. These drainage systems are the means of maintaining ship's buoyancy and stability through control and removal of water. The drainage system is useful in removal of water accumulated in firefighting. Such removal may require directing firefighting water by emergency or temporary means to drainage suction points. Those charged with direction of firefighters should plan for water removal taking into consideration the approximate one-ton per minute accumulation from each 2½-inch nozzle.