Ship gun fire-control system
Lockheed Electronics produced a prototype with AN/SPQ-9 radar fire control in 1965. An air defense requirement delayed production with the AN/SPG-60 until 1971. The Mark 86 did not enter service until when the nuclear-powered missile cruiser was commissioned in February 1974, and subsequently installed on US cruisers and amphibious assault ships. The last US ship to receive the system, USS Port Royal was commissioned in July 1994.
The Mark 86 on Aegis-class ships controls the ship's 5"/54 caliber Mark 45 gun mounts, and can engage up to two targets at a time. It also uses a Remote Optical Sighting system which uses a TV camera with a telephoto zoom lens mounted on the mast and each of the illuminating radars.

Mark 34 Gun Weapon System (GWS): The Mark 34 Gun Weapon System comes in various versions. It is an integral part of the Aegis combat weapon system on Arleigh Burke-class guided missile destroyers and modified Ticonderoga-class cruisers. It combines the Mark 45 5"/54 or 5"/62 Caliber Gun Mount, Mark 46 Optical Sight System or Mark 20 Electro-Optical Sight System and the Mark 160 Mod 4–11 Gunfire Control System / Gun Computer System. Other versions of the Mark 34 GWS are used by foreign navies as well as the US Coast Guard, with each configuration having its own unique camera and/or gun system. It can be used against surface ship and close hostile aircraft, and as in Naval Gunfire Support (NGFS) against shore targets.

Mark 92 Fire Control System (FCS): The Mark 92 fire control system, an Americanized version of the WM-25 system designed in The Netherlands, was approved for service use in 1975. It is deployed on board the relatively small and austere Oliver Hazard Perry-class frigate to control the Mark 75 Naval Gun and the Mark 13 Guided Missile Launching System (missiles have since been removed since retirement of its version of the Standard missile). The Mod 1 system used in PHMs (retired) and the US Coast Guard's WMEC and WHEC ships can track one air or surface target using the monopulse tracker and two surface or shore targets. Oliver Hazard Perry-class frigates with the Mod 2 system can track an additional air or surface target using the Separate Track Illuminating Radar (STIR).

Mark 160 Gun Computing System: Used in the Mark 34 Gun Weapon System, the Mark 160 Gun Computing System (GCS) contains a gun console computer (GCC), a computer display console (CDC), a magnetic tape recorder-reproducer, a watertight cabinet housing the signal data converter and gun mount microprocessor, a gun mount control panel (GMCP), and a velocimeter.

See also: Close-in weapon system
Director (military)
Fire-control system Ground, sea and air based systems
Mathematical discussion of rangekeeping
Rangekeeper shipboard analog fire-control computer

Notes: 

Citations: 

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Fairfield, A.P. (1921). Naval Ordnance. The Lord Baltimore Press.
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Frieden, David R. (1985). Principles of Naval Weapons Systems. Naval Institute Press. ISBN 0-87021-537-X.
Friedman, Norman (2008). Naval Firepower: Battleship Guns and Gunnery in the Dreadnought Era. Seaforth. ISBN 978-1-84415-701-3.
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Pollen, Antony (1980). The Great Gunnery Scandal – The Mystery of Jutland. Collins. ISBN 0-00-216298-9.
Schleihauf, William (2001). "The Dumaresq and the Dreyer". Warship International. XXXVIII (1). International Naval Research Organization: 6–29. ISSN 0043-0374.
Schleihauf, William (2001). "The Dumaresq and the Dreyer, Part II". Warship International. XXXVIII (2). International Naval Research Organization: 164–201. ISSN 0043-0374.
Schleihauf, William (2001). "The Dumaresq and the Dreyer, Part III". Warship International. XXXVIII (3). International Naval Research Organization: 221–233. ISSN 0043-0374.
Friedman, Norman (2004). US Destroyers: An Illustrated Design History (Revised ed.). Annapolis: Naval Institute Press. ISBN 1-55750-442-3.
Friedman, Norman (1986). U.S. Battleships: An Illustrated Design History. Annapolis, Maryland: Naval Institute Press. ISBN 0870217151. OCLC 12214729.
Friedman, Norman (1984). U.S. Cruisers: An Illustrated Design History. Annapolis, Maryland: U.S. Naval Institute Press. ISBN 9780870217180.
Stille, Mark (2014). Us Heavy Cruisers 1941-45: Pre-War Classes. OSPREY PUB INC. ISBN 9781782006299.
 This article incorporates public domain material from websites or documents of the United States Navy.

External links: The British High Angle Control System (HACS)
Best Battleship Fire control – Comparison of World War II battleship systems
Appendix one, Classification of Director Instruments
HACS III Operating manual Part 1
HACS III Operating manual Part 2
USS Enterprise Action Log
The RN Pocket Gunnery Book
Fire Control Fundamentals
Manual for the Mark 1 and Mark 1a Computer
Maintenance Manual for the Mark 1 Computer
Manual for the Mark 6 Stable Element
Gun Fire Control System Mark 37 Operating Instructions at ibiblio.org
Director section of Mark 1 Mod 1 computer operations at NavSource.org
Naval Ordnance and Gunnery, Vol. 2, Chapter 25, AA Fire Control Systems