Mark 63 Gun Fire Control System (Mk.63 GFCS) is a gun fire-control system made up of AN/SPG-34

radar tracker A radar tracker is a component of a radar system, or an associated command and control (C2) system, that associates consecutive radar observations of the same target into Track (navigation), tracks. It is particularly useful when the radar system ...

and the Mark 29

gun sight A sight is an aiming device used to assist in visually aligning ranged weapons, surveying instruments or optical illumination equipments with the intended target. Sights can be a simple set or system of physical markers that have to be aligne ...

. They were usually equipped for the control of twin QF 4-inch naval gun Mk XVI and Mk.33 twin 3"/50 cal guns.

Overview

Conventionally, the US Navy has used Mark 51 GFCS on their gun of medium caliber guns and cannons, but it was based on visual aiming and tracking by human, and it does not have

anti-aircraft Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, ...

range measuring means, etc. It was rather limited. For this reason, Mark 63 was developed as a new generation GFCS with a particular focus on attack

countermeasures A countermeasure is a measure or action taken to counter or offset another one. As a general concept, it implies precision and is any technological or tactical solution or system designed to prevent an undesirable outcome in the process. The fi ...

Mark 29 Gun Sight

During development, the Navy Weapons Agency aimed to achieve blind shooting and high-precision interception capabilities for targets that take evasive action within 4,000

yards The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3 feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly 0.914 ...

(3,700 m). Similar to the late model of Mk.51, it is a human-operated GFCS centered on the disturbed-line-of-sight systems Mk.15 (later improved Mk.29) gun sight. Equipped with a radar, the radar spot appears within the field of view of the Mk.29, so blind shooting was also possible. Initially,

S-band The S band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a part of the microwave band of the electromagnetic spectrum covering frequencies from 2 to 4 gigahertz (GHz). Thus it crosses the conventional ...

Mk.28 and later X-band Mk.34 were used as radars, and they were installed on turrets and mounts, but the beam width was too narrow and it was difficult to capture targets. By moving the antenna up and down 20 degrees to make it easier to capture the target by swinging the beam (notting mechanism), measures were taken. The first test was conducted in June 1944, and the deployment started with the installation on an

aircraft carrier An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...

in November of the same year, and it was put into actual battle in the

Battle of Okinawa The , codenamed Operation Iceberg, was a major battle of the Pacific War fought on the island of Okinawa by United States Army (USA) and United States Marine Corps (USMC) forces against the Imperial Japanese Army (IJA). The initial invasion of ...

AN/SPG-34 Radar Tracker

In 1953, the formal name was changed from Mk.34 to AN/SPG-34 based on the naming convention for military electronic devices after completing certain improvements such as increasing the antenna diameter and increasing radar transmission output. In AN/SPG-34, the knotting mechanism was removed due to the improved target acquisition capability, and instead, like

AN/SPG-35 Mark 56 Gun Fire Control System (Mk.56 GFCS) is a gun fire-control system made up of AN/SPG-35 radar tracker and the Mark 42 ballistic computer. Overview The directional board is maneuverable, equipped with an X-band radar Mk.35 (later ren ...

in Mk.56 GFCS, conical scanning that quickly measures and distances with a narrow beam width. It was supposed to track the target by (

conical scan A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines co ...

). In 1956, AN/SPG-34 was modified by using a slightly higher

frequency Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...

(8,600–9,600

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...

), narrowing the

pulse width The pulse width is a measure of the elapsed time between the leading and trailing edges of a single pulse of energy. The measure is typically used with electrical signals and is widely used in the fields of radar and power supplies. There are two c ...

(0.25

microsecond A microsecond is a unit of time in the International System of Units (SI) equal to one millionth (0.000001 or 10−6 or ) of a second. Its symbol is μs, sometimes simplified to us when Unicode is not available. A microsecond is equal to 1000 n ...

s), and increasing the

pulse repetition frequency The pulse repetition frequency (PRF) is the number of pulses of a repeating signal in a specific time unit. The term is used within a number of technical disciplines, notably radar. In radar, a radio signal of a particular carrier frequency is tu ...

(2,000/200 pps). On the other hand, Mk.57 was also developed as a direct-view system that uses the AN/SPG-34 radar and eliminates the complicated optical system due to the perspective type of Mk.63. This was because the computer Mk.17 on the directional board detects the

angular velocity In physics, angular velocity or rotational velocity ( or ), also known as angular frequency vector,(UP1) is a pseudovector representation of how fast the angular position or orientation of an object changes with time (i.e. how quickly an objec ...

etc. with the built-in

gyroscope A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rota ...

by looking directly at the aiming

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe ...

of the directional board or manually tracking the target on the radar scope, and the computer placed inside the ship. The shooting specifications were calculated by .16. However, unlike Mk.63, the fire-control radar was installed on the directional board rather than on the gun side. Of AN/SPG-34, Mk.63 adopted mod.1 and mod.2 while Mk.57 adopted mod.3 and mod.4. Later, based on the Mk.63, the Mk.70 was also developed as a derivative of the

Ku-band The Ku band () is the portion of the electromagnetic spectrum in the microwave range of frequencies from 12 to 18 gigahertz (GHz). The symbol is short for "K-under" (originally german: Kurz-unten), because it is the lower part of the ori ...

AN/SPG-52 range-finding radar.

Onboard ships

United States Navy

Worcester-class cruiser The ''Worcester'' class was a class of light cruisers used by the United States Navy, laid down in 1945 and commissioned in 1948–49. They and their contemporaries, the heavy cruisers, were the last all-gun cruisers built for the U.S. Navy. Ten ...

* Cannon-class destroyer escort *

Dealey-class destroyer escort The ''Dealey''-class destroyer escorts were the first post-World War II escort ships built for the United States Navy. Slightly faster and larger than the escort destroyers they succeeded, the ''Dealey'' class were fitted with twin-mounted gun ...

Asheville-class gunboat The ''Asheville''-class gunboats were a class of small warships built for the United States Navy in response to the Cuban Missile Crisis. The class is named for a city in western North Carolina and the seat of Buncombe County. All ''Ashevil ...

Maritime Self-Defense Force

Ayanami-class destroyer The ''Ayanami'' class was a destroyer class built for the Japan Maritime Self-Defense Force (JMSDF) in the late 1950s. The primary purpose was anti-submarine warfare, so this class was classified as "DDK" (hunter-killer anti-submarine destroyer) u ...

Akizuki-class destroyer ''Akizuki''-class destroyer may refer to: * , the "Type B Destroyer" used by the Imperial Japanese Navy during World War II * , a developed version of the 1942 class * , a Cold War era destroyer used by the Japanese Maritime Self-Defense Force for ...

Harukaze-class destroyer The ''Harukaze''-class destroyer was the first indigenous post-World War II Japanese destroyer class. Its main mission was anti-submarine warfare. Almost all equipment was supplied from the United States according to the U.S. and Japan Mutual Def ...

* Murasame-class destroyer *

Yamagumo-class destroyer The ''Yamagumo'' class are vessels of the Japanese Maritime Self-Defense Force, usually classified as a destroyer, but due to their relatively light displacement, in other sources as a destroyer escort. This class is the successor of the . This cl ...

* JDS Amatsukaze (DDG-163) * JDS Akebono (DE-201) * JDS Wakaba *

Isuzu-class destroyer escort The ''Isuzu'' class destroyer escort was a destroyer escort (or frigate) class built for the Japan Maritime Self-Defense Force (JMSDF) in the early 1960s. The latter batch (''Kitakami'' and ''Ōi'') were quite different from the earlier two vess ...

Kamome-class submarine chaser The ''Kamome''-class submarine chaser was a class of submarine chasers of the Japan Maritime Self-Defense Force after the Second World War, in the mid-1950s. Development In the 1950s, although there were some new innovations such as the sprea ...

Kari-class submarine chaser The ''Kari''-class submarine chaser was a class of submarine chasers of the Japan Maritime Self-Defense Force after the Second World War, in the mid-1950s. Development In the 1950s, although there were some new innovations such as the spread ...

* Mizutori-class submarine chaser *

Umitaka-class submarine chaser The ''Umitaka''-class submarine chaser was a class of submarine chasers of the Japan Maritime Self-Defense Force after the Second World War, in the late 1950s. Design In this type, the navigation performance was improved and the design was r ...

Royal Canadian Navy

AN/SPG-34 were equipped on board Batch 1 and 2 Tribal-class destroyers, HMCS Algonquin (R17) and HMCS Crescent (DDE-226). A surviving example of this is equipped on

HMCS Haida (G63) HMCS ''Haida'' is a that served in the Royal Canadian Navy (RCN) from 1943 to 1963, participating in World War II and the Korean War , date = {{Ubl, 25 June 1950 – 27 July 1953 (''de facto'')({{Age in years, months, weeks and ...

. *

Tribal-class destroyer (1936) The Tribal class, or ''Afridi'' class, were a class of destroyers built for the Royal Navy, Royal Canadian Navy and Royal Australian Navy that saw service in World War II. Originally conceived during design studies for a light fleet cruiser, t ...

HMCS Algonquin (R17) HMCS ''Algonquin'' was a V-class destroyer, laid down for the Royal Navy as HMS ''Valentine'' (R17) and transferred to the Royal Canadian Navy on completion during the Second World War. She saw service in the Second World War escorting the a ...

HMCS Crescent (DDE-226) HMCS ''Crescent'' was a destroyer that was built for the Royal Navy but was transferred before completion and saw active service with the Royal Canadian Navy. She was one of 32 destroyers of that class built between 1943 and 1945 as part of th ...

{{Flagicon, Portugal Portugal

* Admiral Pereira da Silva-class frigate

Citations

References

Norman Friedman Norman Friedman (born 1946) is an American internationally known author and analyst, strategist, and historian. He has written over 30 books and numerous articles on naval and other military matters, has worked for the U.S. Navy and Marine Corps ...

(2006).
The Naval Institute Guide to World Naval Weapon Systems
'.

Naval Institute Press The United States Naval Institute (USNI) is a private non-profit military association that offers independent, nonpartisan forums for debate of national security issues. In addition to publishing magazines and books, the Naval Institute holds se ...

ISBN The International Standard Book Number (ISBN) is a numeric commercial book identifier that is intended to be unique. Publishers purchase ISBNs from an affiliate of the International ISBN Agency. An ISBN is assigned to each separate edition and ...

9781557502629 Naval radars Military radars of Japan Military equipment introduced in the 1950s