Iowa-class battleship: Difference between revisions

| Class after = {{sclass|Montana|battleship|4}} (planned, never built)

* [[AN/SLQ-32 Electronic Warfare Suite|AN/SLQ-32(V)3]] [[electronic warfare]] system

* 9 × 16 in/50 cal guns (3 Mounts x3)

* 12 × 5 in/38 cal guns (6 Mounts x2)

* 32 × [[Tomahawk (missile family)|BGM-109 Tomahawk]] launchers (8 Launchers x4)

* 16 × [[Harpoon (missile)|RGM-84 Harpoon]] launchers (4 Mounts x4)

The '''''Iowa'' class''' was a [[ship class|class]] of six [[fast battleship]]s ordered by the [[United States Navy]] in 1939 and 1940. They were initially intended to intercept fast [[capital ships]] such as the [[Imperial Japanese Navy|Japanese]] {{sclass|Kongō|battlecruiser|4}} whileand alsoserve beingas capablethe of"fast servingwing" inof athe traditionalU.S. [[battle line]] alongside slower battleships and act as its "fast wing".{{sfn|Hough|1964|pp=214–216}}{{sfn|Sumrall|1988|p=41}} The ''Iowa'' class was designed to meet the [[Second London Naval Treaty]]'s "escalator clause" limit of {{convert|45000|LT|-2|adj=on}} standard displacement. Beginning in August 1942, four vessels, {{USS|Iowa|BB-61|2}}, {{USS|New Jersey|BB-62|2}}, {{USS|Missouri|BB-63|2}}, and {{USS|Wisconsin|BB-64|2}}, were completed; two more, {{USS|Illinois|BB-65|2}} and {{USS|Kentucky|BB-66|2}}, were [[Keel laying|laid down]] but canceled in 1945 and 1958, respectively, before completion, and both hulls were scrapped in 1958–1959.

The four ''Iowa''-class ships were the last battleships commissioned in the USU.S. Navy. All older USU.S. battleships were [[Decommissioned (ship)|decommissioned]] by 1947 and stricken from the ''[[Naval Vessel Register]]'' (NVR) by 1963. Between the mid-1940s and the early 1990s, the ''Iowa''-class battleships fought in four major USU.S. wars. In the [[Pacific War|Pacific Theater]] of World War II, they served primarily as fast [[Ocean escort|escorts]] for {{sclass|Essex|aircraft carrier|}}s of the [[Fast Carrier Task Force]] and also shelled Japanese positions. During the [[Korean War]], the battleships provided [[naval gunfire support]] (NGFS) for [[United Nations Command|United Nations forces]], and in 1968, ''New Jersey'' shelled [[Viet Cong]] and [[Vietnam People's Army]] forces in the [[Vietnam War]]. All four were reactivated and modernized at the direction of the [[United States Congress]] in 1981, and armed with [[missile]]s during the 1980s, as part of the [[600-ship Navy]] initiative. During [[Operation Desert Storm]] in 1991, ''Missouri'' and ''Wisconsin'' fired missiles and {{convert|16|in|0|adj=on}} guns at [[Iraq]]i targets.

Costly to maintain, the battleships were decommissioned during the post-[[Cold War (1985–1991)|Cold War]] drawdown in the early 1990s. All four were initially removed from the ''Naval Vessel Register'', but the United States Congress compelled the Navy to reinstate two of them on the grounds that existing NGFSshore bombardment capability would be inadequate for [[Amphibious warfare|amphibious operations]]. This resulted in [[United States battleship retirement debate|a lengthy debate]] over whether battleships should have a role in the modern navy. Ultimately, all four ships were stricken from the ''Naval Vessel Register'' and released for donation to non-profit organizations. With the transfer of ''Iowa'' in 2012, all four are [[museum ship]]s part of non-profit [[maritime museum]]s across the US.

The vessels that eventually became the ''Iowa''-class battleships were born from the USU.S. Navy's [[War Plan Orange]], a Pacific war plan against Japan. War planners anticipated that the USU.S. fleet would engage and advance in the Central Pacific, with a long line of communication and logistics that would be vulnerable to high-speed Japanese cruisers and capital ships. The chief concern was that the USU.S. Navy's traditional 21-knot battle line of [[Standard-type battleship|"Standard-type"]] battleships would be too slow to force these Japanese task forces into battle, while faster aircraft carriers and their cruiser escorts would be outmatched by the Japanese {{sclass|Kongō|battlecruiser|0}} battlecruisers, which had been upgraded in the 1930s to [[fast battleship]]s. As a result, the USU.S. Navy envisioned a fast detachment of the battle line that could bring the Japanese fleet into battle. Even during the developmentnew processstandard battle line speed of 27 knots, as the preceding {{sclass|North Carolina|battleship|0}} and {{sclass|South Dakota|battleship (1939)|0}} battleships were designed for, was not considered enough and during their development processes, designs that could achieve over 30 knots in order to counter the threat of fast "big gun" ships were seriously considered.{{sfn|Garzke|Dulin|1995|p=107}}{{sfn|Friedman|1986|p=307}} At the same time, a special strike force consisting of fast battleships operating alongside carriers and destroyers was being envisaged; such a force could operate independently in advance areas and act as scouts. This concept eventually evolved into the [[Fast Carrier Task Force]], though initially the carriers were believed to be subordinate to the battleship.{{sfn|Sumrall|1988|p=41}}

Another factor was the "escalator clause" of the [[Second London Naval Treaty]], which reverted the gun caliber limit from {{convert|14|in|0}} to {{convert|16|in|0}}. Japan had refused to sign the treaty and in particular refused to accept the 14-inch gun caliber limit or the 5:5:3 ratio of warship tonnage limits for Britain, the United States, and Japan, respectively. This resulted in the three treaty powers, the United States, Britain, and France, invoking the caliber escalator clause after April 1937. Circulation of intelligence evidence in November 1937 of Japanese capital ships violating naval treaties caused the treaty powers to expand the escalator clause in June 1938, which amended the [[Displacement (ship)#Standard displacement|standard displacement]]{{refn|Standard displacement, also known as "Washington displacement", is a specific term defined by the Washington Naval Treaty of 1922. It is the displacement of the ship complete, fully manned, engined, and equipped ready for sea, including all armament and ammunition, equipment, outfit, provisions and fresh water for crew, miscellaneous stores, and implements of every description that are intended to be carried in war, but without fuel or reserve boiler feed water on board.<ref>''Conference on the Limitation of Armament, 1922''. Ch II, Part 4.</ref>|group=N}} limit of battleships from {{convert|35000|LT|-2}} to {{convert|45000|LT|-2}}.{{sfn|Friedman|1986|pp=307–309}}

Work on what would eventually become the ''Iowa''-class battleship began on the first studies in early 1938, at the direction of Admiral [[Thomas C. Hart]], head of the [[General Board of the United States Navy|General Board]], following the planned invocation of the "escalator clause" that would permit maximum standard capital ship displacement of {{convert|45000|LT|-2}}. Using the additional {{convert|10000|LT|-2}} over previous designs, the studies included schemes for {{convert|27|knot|adj=on}} "slow" battleships that increased armament and protection as well as "fast" battleships capable of {{convert|33|knot}} or more. One of the "slow" designs was an expanded ''South Dakota'' class carrying either twelve [[16"/45 caliber Mark 6 gun|16-inch/45]] [[Caliber (artillery)|caliber]] Mark 6 guns or nine [[18"/48 caliber Mark 1 gun|{{convert|18|in|0|adj=on}}/48]] guns and with more armor and a power plant large enough to drive the larger ship through the water at the same 27-knot maximum speed as the ''South Dakota''s.{{refn|Also considered was the 16-inch/56 caliber gun, but this was dropped in March 1938 due to the weapon's weight.{{sfn|Garzke|Dulin|1995|pp=107–110}}|group=N}} While the "fast" studies would result in the ''Iowa'' class, the "slow" design studies would eventually settle on twelve 16-inch guns and evolve into the design for the {{convert|60500|LT|adj=on}} {{sclass|Montana|battleship|4}} after all treaty restrictions were removed following the start of World War II.{{sfn|Friedman|1986|pp=309, 311}} Priority was given to the "fast" design in order to counter and defeat Japan's {{convert|30|knot|adj=on}}{{sfn|Burr|2010|p=5}} ''Kongō''-class battlecruisersfast battleships, whose higher speed advantage over existing USU.S. battleships might let them "penetrate USU.S. cruisers, thereby making it 'open season' on USU.S. supply ships",<ref>{{cite web |url=https://www.warhistoryonline.com/instant-articles/built-to-last-iowa-class.html |title=Built To Last: Five Decades for the Iowa Class Battleship |author=Winston, George |date=15 September 2018 |website=War History Online |publisher=Timera Inc |access-date=12 January 2019 }}</ref> and then overwhelm the Japanese battle line was therefore a major driving force in setting the design criteria for the new ships, as was the restricting width of the Panama Canal.{{sfn|Burr|2010|p=5}}

As 1938 drew to a close, the contract design of the ''Iowa''s was nearly complete, but it would continuously evolve as the [[New York Navy Yard]], the lead shipyard, conducted the final detail design. These revisions included changing the design of the foremast, replacing the original [[1.1"/75 caliber gun|{{convert|1.1|in|1|adj=on}}/75-caliber gun]]s that were to be used for [[anti-aircraft]] (AA) work with [[Oerlikon 20 mm cannon|{{cvt|20|mm|2}}/70&nbsp;caliber Oerlikon cannons]] and [[Bofors 40 mm Automatic Gun L/60|{{cvt|40|mm|2}}/56&nbsp;caliber Bofors guns]], and moving the [[Operations room|combat information center]] into the armored hull.<ref>Stillwell, p. 16.{{Incomplete short citation|date=November 2020}}<!--Ambiguous, there are two Stillwells (1986, 1996) cited in article--></ref> Additionally, in November 1939, the New York Navy Yard greatly modified the internal subdivision of the machinery rooms, as tests had shown the underwater protection in these rooms to be inadequate. The longitudinal subdivision of these rooms was doubled, and the result of this was clearly beneficial: "The prospective effect of flooding was roughly halved and the number of uptakes and hence of openings in the third deck greatly reduced." Although the changes meant extra weight and increasing the beam by {{convert|1|ft}} to {{convert|108|ft|2|in}}, this was no longer a major issue; [[United Kingdom|Britain]] and [[France]] had renounced the Second London Naval Treaty soon after the beginning of the [[Second World War]].{{sfn|Friedman|1986|pp=313–314}} The design displacement was {{convert|45873|LT}} standard, approximately 2% overweight, when ''Iowa'' and ''New Jersey'' were laid down in June and September 1940. By the time the ''Iowa''s were completed and commissioned in 1943–44, the considerable increase in anti-aircraft armament&nbsp;– along with their associated splinter protection and crew accommodations&nbsp;– and additional electronics had increased standard displacement to some {{convert|47825|LT}}, while full load displacement became {{convert|57540|LT}}.{{sfn|Friedman|1986|p=449}}{{sfn|Sumrall|1988|p=38}}{{sfn|Garzke|Dulin|1995|pp=147–149}}

The ''Iowa''-class battleships are {{cvt|860|ft|0|in}} long at the waterline and {{cvt|887|ft|3|in}} long overall with a beam of {{cvt|108|ft|2|in}}.{{refn|''Iowa''{{'}}s andIndividual ship''New Jersey''{{'}}s dimensions vary slightly from design values. ''Iowa'' is {{cvt|859|ft|5+3/4|in|3}} waterline length, {{cvt|887|ft|2+3/4|in|3}} overall length, and {{cvt|108|ft|2+1/16|in|3}} beam. ''New Jersey'' is {{cvt|859|ft|10+1/4|in|3}} waterline length, {{cvt|887|ft|6+5/8|in|3}} overall length, and {{cvt|108|ft|1+3/8|in|3}} beam.{{sfn|Garzke|Dulin|1995|pp=145–146}}{{sfn|Sumrall|1988|p=157}}|group=N}} During World War II, the draft was {{cvt|37|ft|2|in}} at full load displacement of {{cvt|57540|LT}} and {{cvt|34|ft|9+1/4|in|2}} at design combat displacement of {{cvt|54889|LT}}. Like the two previous classes of American fast battleships, the ''Iowa''s featurehave a double bottom hull that becomes a triple bottom under the armored citadel and armored skegs around the inboard shafts.{{sfn|Garzke|Dulin|1995|pp=144–148}} The dimensions of the ''Iowa''s were strongly influenced by speed. When the Second Vinson Act was passed by the United States Congress in 1938, the USU.S. Navy moved quickly to develop a 45,000-ton-standard battleship that would pass through the {{cvt|110|ft}} wide [[Panama Canal]]. Drawing on a 1935 [[Empirical relationship|empirical formula]] for predicting a ship's maximum speed based on scale-model studies in flumes of various [[Hull (watercraft)|hull]] forms and [[propeller]]s{{refn|These mathematical formulas still stand today, and they have been used to design hulls for US ships and to predict the speed of those hulls for the ships when commissioned, including [[nuclear power|nuclear-power]]ed ships like the US fleet of {{sclass|Nimitz|aircraft carrier|0}} [[supercarrier]]s.{{sfn|Rogers|n.d.|p=15}}|group=N}} and a newly developed empirical theorem that related [[waterline length]] to maximum beam, the Navy drafted plans for a battleship class with a maximum beam of {{cvt|108|ft|2|in}} which, when multiplied by 7.96, produced a waterline length of {{cvt|860|ft|0}}.{{sfn|Rogers|n.d.}} The Navy also called for the class to have a lengthened [[forecastle]] and amidship, which would increase speed, and a [[bulbous bow]].{{sfn|Rogers|n.d.|p=10}}

| caption2= {{USS|Iowa|BB-61|6}} fires a full broadside of nine 16-inch and six 5-inch guns during a gunnery exercise (1984)

In the 1950s, the W23, an adaptation of the [[W19 (nuclear artillery shell)|W19 nuclear artillery shell]], was developed specifically for the 16-inch guns. The shell weighed {{convert|1900|lb|0}}, had an estimated yield of {{convert|15|to|20|ktonTNT|GJ|lk=in}},{{sfn|Yenne|2005|pp=132–133}}, and its introduction made the ''Iowa''-class battleships' 16-inch guns the world's largest [[nuclear artillery]]{{sfn|Polmar|2001|p=490}} and made these four battleships the only US Navy ships ever to have nuclear shells for naval guns.{{sfn|Polmar|2001|p=490}} Although developed for exclusive use by the battleship's guns it is not known if any of the ''Iowa''s actually carried these shells while in active service due to the United States Navy's policy of refusing to confirm or deny the presence of nuclear weaponry aboard its ships.{{sfn|Yenne|2005|pp=132–33}}{{refn|"Military members and civilian employees of the Department of the Navy shall not reveal, report to reveal, or cause to be revealed any information, rumor, or speculation with respect to the presence or absence of nuclear weapons or components aboard any specific ship, station or aircraft, either on their own initiative or in response, direct or indirect, to any inquiry. [...] The Operations Coordinating Board (part of President Eisenhower's National Security Council) established the US policy in 1958 of neither confirming nor denying (NCND) the presence or absence of nuclear weapons at any general or specific location, including aboard any US military station, ship, vehicle, or aircraft."<ref>{{cite web |last=Morgan | first=J.G. Jr. |date=3 February 2006 |title=Release of Information on Nuclear Weapons and on Nuclear Capabilities of U.S. Forces (OPNAVINST 5721.1F N5GP) |publisher=Department of the Navy&nbsp;– Office of the Chief of Naval Operations |location=Washington, DC |pages=1–2 |url=http://www.fas.org/irp/doddir/navy/opnavinst/5721_1f.pdf |access-date=2012-07-02 }}</ref>|group=N|name=Nuclear}} In 1991, the United States unilaterally withdrew all of its nuclear artillery shells from service, and the dismantling of the US nuclear artillery inventory is said to have been completed in 2004.{{sfn|DeVolpi|Minkov|Simonenko|Stanford|2005|p=VA-13}}

| caption1= A crewman operates the ship's throttle in the main engine room aboard ''New Jersey''. (1982)

| caption2= Crewmen operate the electrical generators in the upper-level engine room aboard ''New Jersey''. (1982)

In addition to these search and navigational radars, the ''Iowa'' class were also outfitted with a variety of [[Ship gun fire-control system|fire control radars]] for their gun systems. Beginning with their commissioning, the battleships made use of a pair of [[Ship Gun Fire Control Systems#MK 38 Gun Fire Control System|Mk 38 gun fire control systems]] with Mark 8 fire control radar to direct the 16-inch guns and a quartet of [[Ship Gun Fire Control Systems#MK 37 Gun Fire Control System (GFCS)|Mk 37 gun fire control systems]] with Mark 12 fire control radar and Mark 22 height finding radar to direct the 5-inch gun batteries. These systems were upgraded over time with the Mark 13 replacing the Mark 8 and the Mark 25 replacing the Mark 12/22, but they remained the cornerstones of the combat radar systems on the ''Iowa'' class during their careers.{{sfn|Sharpe|1991|p=732}} The range estimation of these gunfire control systems provided a significant accuracy advantage over earlier ships with optical rangefinders; this was demonstrated off [[Truk Atoll]] on 16 February 1944, when the ''IowaNew Jersey'' engaged the {{ship|Japanese destroyer|Nowaki|1940|6}} at a range of {{convert|35700|yd|km nmi}} and [[Salvo|straddled]] her, setting the record for the longest-ranged straddle in history.<ref name="straddle">{{Harvardcite citationweb no|url=https://www.battleshipnewjersey.org/the-ship/full-history/ brackets|Fischertitle=Full History - USS New Jersey, The World's Greatest Basttleship |Jurensdate=28 March 2024 |2006website= Battleship New Jersey |access-date=28 March 2024 |pquote=83}}</ref>

== 1980s refitreactivation/modernization ==

The Navy considered several proposals that would have removed the aft 16-inch turret. [[Martin Marietta]] proposed to replace the turret with servicing facilities for 12 [[McDonnell Douglas AV-8B Harrier II|AV-8B Harrier]] STOVL jump jets. Charles Myers, a former Navy test pilot turned Pentagon consultant, proposed replacing the turret with [[Vertical launching system|vertical launch systems]] for missiles and a flight deck for Marine helicopters. In July 1981, the [[United States Naval Institute|US Naval Institute]]'s ''[[Proceedings (magazine)|Proceedings]]'' published a proposal by naval architect Gene Anderson for a canted flight deck with steam catapult and arrestor wires for [[McDonnell Douglas F/A-18 Hornet|F/A-18 Hornet]] fighters.<ref>{{cite magazine |last1=Anderson |first1=Gene |title=Comment and Discussion: A Sea-Based Interdiction System for Power Projection |url=https://www.usni.org/magazines/proceedings/1981/july/comment-and-discussion |magazine=Proceedings |agencypublisher=US Naval Institute |date=July 1981 |page=21 |quote=Aided by a steam catapult, a canted deck, and arresting gear, this extension of the flight deck could allow the Navy's latest fighters to operate from this ship.}}</ref> Plans for these conversions were dropped in 1984.{{sfn|Muir|1989|p=130}}

As part of their modernization in the 1980s, each of the ''Iowa''s received a complement of eight quad-cell [[Armored Box Launcher]]s and four "shock hardened" [[List of United States Navy Guided Missile Launching Systems|Mk 141 quad-cell launchers]]. The former was used by the battleships to carry and fire the [[Tomahawk (missile family)|BGM-109 Tomahawk Land Attack Missiles]] (TLAMs) for use against enemy targets on land, while the latter system enabled the ships to carry a complement of [[Harpoon (missile)|RGM-84 Harpoon]] anti-ship missiles for use against enemy ships. With an estimated range of {{convert|675|to|1500|nmi|lk=on}}{{sfn|Sumrall|1988|p=87}} for the Tomahawks and {{convert|64.5|to|85.5|nmi}}{{sfn|Sumrall|1988|p=87}} for the Harpoons, these two missile systems displaced the 16-inch guns and their maximum range of {{convert|42345|yd|km nmi|1}}<ref name="NavWeaps 16/50" /> to become the longest-ranged weapons on the battleships during the 1980s; the ships' complement of 32 Tomahawk missiles was the largest until the [[Mark 41 Vertical Launching System|Mk 41 VLS]]-equipped {{sclass|Ticonderoga|cruiser|0}} cruisers entered service. It has been alleged by members of the environmental group [[Greenpeace]]{{sfnm|1a1=Norris|1a2=Arkin|1y=1989|1p=48|2a1=Pugh|2y=1989|2p=194|3a1=Walsh|3a2=Arkin|3y=1991|3pp=8–9}} that the battleships carried the TLAM-A (also cited, incorrectly, as the TLAM-N) – a Tomahawk missile with a [[variable yield]] [[W80 (nuclear warhead)|W80 nuclear warhead]] – during their 1980s service with the United States Navy, but owing to the United States Navy's policy of refusing to confirm or deny the presence of nuclear weaponry aboard its ships, these claims can not be conclusively proved.{{sfn|Yenne|2005|pp=132–33}}<ref group=N name=Nuclear/> Between 2010 and 2013, the US withdrew the BGM-109A, leaving only conventional munitions packages for its Tomahawk missile inventory, though the Iowas had been withdrawn from service at that point.<ref name="FASNT">{{cite web |last= Kristensen |first= Hans M. |url= https://fas.org/blogs/security/2013/03/tomahawk/ |title=US Navy Instruction Confirms Retirement of Nuclear Tomahawk Cruise Missile |date= 18 March 2013 |publisher=[[Federation of American Scientists]] |access-date= 21 November 2020 |url-status=live |archive-url= https://web.archive.org/web/20140709001733/https://fas.org/blogs/security/2013/03/tomahawk/ |archive-date=9 July 2014 }}</ref>

During their modernization under the 600-ship Navy program, the ''Iowa''-class battleships' radar systems were again upgraded. The foremast was of a new tripod design that was considerably reinforced to allow the AN/SPS-6 air-search radar system wasto be replaced with the [[AN/SPS-49]] radar set (which also augmented the existing navigation capabilities on the battleships), and the AN/SPS-8 surface-search radar set was replaced by the [[AN/SPS-67]] search radar. The new mast also incorporates a Tactical Air Navigation System ([[TACAN]]) antenna.<ref name="Stillwell 62.1" /> The aft mast was changed to be placed in front of the aft funnel and mounts a circular SATCOM antenna while another one was mounted on the fire control mast.<ref>Miano 2021, p. 15</ref>

[[File:USS New Jersey BB-62 salvo Jan 1953.jpeg|thumb|left|''New Jersey'' fires a nine gun salvo of 16-inch shells into an enemy troop concentration near [[Kaesong]], Korea (1953)|alt=A black-and-white photograph of a large caliber gunship on the left side of the picture with the main guns pointed to the top right side of the image. Smoke and flames can be seen from the barrels of the guns as they have just been discharged. A disturbance on the water generated from the pressure of the gun's firing can be seen on the bottom right of the image.]]

* {{cite magazine |last1= Jurens |first1= W. J. |last2= Morss |first2= Strafford |date= 2016 |title= The Washington Naval Treaty and the Armor and Protective Plating of USS Massachusetts |magazine= Warship International |publisher= International Naval Research Organization |location= Toledo, Ohio |volume= 53 |issue= 4 }}