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A large warship with guns pointed to the left, fire and smoke can be seen emanating from the gun barrels. Below the ship the dark blue water has taken on a white color owing to the disturbance in wind pressure from the firing of the guns.
USS Iowa (BB-61) fires a full broadside on 15 August 1984 during a firepower demonstration after her recommissioning.
Class overview
Name: Iowa class battleship
Builders: New York Naval Shipyard
(BB-61 & BB-63)
Philadelphia Naval Shipyard
(BB-62, BB-64, & BB-65)[A 1]
Norfolk Naval Shipyard
(BB-66)[A 2]
Operators:  United States Navy
Preceded by: South Dakota class battleship
Succeeded by: Montana class battleship
In service: 22 February 1943 – 17 March 2006[A 3]
In commission: 22 February 1943 – 31 March 1992[A 4]
Planned: 6
Completed: 4
Cancelled: Illinois[1]
Retired: 4
Preserved: Iowa[3][A 5]
New Jersey[4]
General characteristics
Type: Battleship[A 6]
Displacement: 45,000 tons (Standard);[8]
52,000 tons (mean war service);
58,000 tons (full load)[8]
Length: 861¼ ft (262.5 m) between perpendiculars
890 ft (271 m) overall[citation needed]
Beam: 108 ft (33 m)[8]
Draft: 36 ft (11 m) maximum[citation needed]
Propulsion: 4 screws;[8] General Electric geared turbines;[8] 8 Babcock & Wilcox Boilers; G.E. (BB-61;BB-63); West. (BB-62; BB-64; BB-66); 212,000 shp (158,000 kW)[8]
Speed: 31 knots (57 km/h) normal operating[9]
35 knots (65 km/h) theoretical maximum (light displacement)[9]
Range: 9,600 miles (15,000 km) @ 25 knots (46 km/h);
16,600 miles (27,000 km) @ 15 knots (28 km/h)
  • World War II, Korea and Vietnam
    2,700 officers and men[8]
  • During the 1980s
    1,800 officers and men[8]
Electronic warfare
and decoys:
Armor: Belt: 12.1 in (310 mm),[10]
Bulkheads: 11.3 in (290 mm),[10]
Barbettes: 11.6 to 17.3 in (295 to 439 mm),[10]
Turrets: 19.7 in (500 mm),[10]
Decks: 7.5 in (190 mm)[10]
Aircraft carried:
Notes: Final battleship class completed by U.S. Navy, only remaining battleship class currently in existence that can be reactivated

The Iowa class battleships were a class of six U.S. Navy fast battleships commissioned in 1939 and 1940 to escort the Fast Carrier Task Forces, which operated in the Pacific Theater of World War II. Four were completed in the early- to mid-1940s; two more were laid down, but they were canceled prior to completion and eventually scrapped. The Iowa class was the final class of U.S. battleships to be built.[A 7]

The Iowa-class battleships served in every major U.S. war of the mid and latter half of the 20th century. In World War II, they defended aircraft carriers and shelled Japanese positions before being placed in reserve at the end of the war. Recalled for action during the Korean War, the battleships provided artillery support for UN forces against North Korea. In 1968, New Jersey was recalled for action in the Vietnam War and shelled Communist targets near the Vietnamese Demilitarized Zone. All four were reactivated and armed with missiles during the 1980s as part of the 600-ship Navy. In 1991, Missouri and Wisconsin fired missiles and 16-inch (406 mm) guns at Iraqi targets during the Gulf War. All four battleships were decommissioned in the early 1990s as the Cold War drew to a close, and were initially removed from the Naval Vessel Register; however, at the insistence of the United States Congress, two were reinstated to the Naval Vessel Register for maintenance in the mothball fleet in 1995. These last two battleships were removed from the Naval Vessel Register in 2006.





After the end of the First World War, many navies—including those of the United States, the United Kingdom, and Imperial Japan—continued and expanded construction programs that had begun during the conflict. The enormous costs associated with these programs pressured their government leaders to begin a disarmament conference. On 8 July 1921, the United States' Secretary of State Charles Evans Hughes did just that when he invited delegations from the major maritime powers—France, Italy, Japan, and the United Kingdom—to come together in Washington, D.C. and discuss a possible end to the naval arms race. The subsequent Washington Naval Conference resulted in the Washington Naval Treaty. Along with many other provisions, it limited all future battleships to a standard displacement of 35,000 long tons (36,000 t; 39,000 ST) and a maximum gun caliber of 16 inches (406 mm). It also agreed that the five countries would not construct more capital ships for ten years and would not replace any ship that survived the treaty until it was at least twenty years old. The Second London Naval Treaty, while superseding the 1922 agreement, nonetheless kept many of the same requirements, including the 35,000 long ton limit. This last requirement, in particular, heavily influenced the design of the Iowa class' predecessors, the North Carolina and South Dakota classes.[11][12]

A so-called "escalator clause" of the Second London Treaty allowed the ships to carry 16-inch (406 mm) guns, as opposed to 14-inch (356 mm) ones. This benefited the North Carolina, South Dakota, and the Iowa classes; the last also made use of a different provision, the "tonnage escalator" clause. Beginning in November 1937, intelligence agencies heard rumors of "super-battleships" being built by Japan, though the specifications of these ships varied depending on the source of information. Six months later (31 March 1938), the United States, United Kingdom, and France all approved a new maximum tonnage limit of 45,000 long tons (46,000 t).[13]

27-knot battleships and "A"–"C"

Due to these political developments, the Navy was able to continue with 45,000 long ton design studies. Work began on the first study in early 1938 at the direction of Admiral Thomas C. Hart, head of the General Board. It was an expanded South Dakota carrying either twelve 16-inch/45 caliber Mark 6 guns or nine 18-inch (460 mm) guns (the latter armament being dropped after the 31 March agreement), with more armor and a power plant powerful enough to drive the larger ship through the water at the same speed as the South Dakotas, 27 knots (31 mph; 50 km/h). These studies had no further impact on the design of the Iowa class, instead being developed alongside as the future "standard" battleship. Eventually, the plans evolved into the Montana class.[14]

Another design, pursued by the Design Division section of the Bureau of Construction and Repair, was a "cruiser-killer." Beginning on 17 January 1938 under Captain A.J. Chantry, the group drew up plans for ships with twelve 16-inch and twenty 5-inch guns, Panamax capability but otherwise unlimited displacement, a top speed of 35 knots (40 mph; 65 km/h), and a range of 20,000 nautical miles (23,000 mi; 37,000 km) when traveling at the more economical speed of 15 knots (17 mph; 28 km/h). Their plan fulfilled these requirements with a ship of 50,940 long tons (51,760 t), but Chantry believed that more could be done if the ship were to be this large; with a displacement greater than that of most battleships, its armor would only have protected it against the 8-inch (203 mm) weapons carried by heavy cruisers.[13][A 8]

Three improved plans, "A"–"C", were designed at the end of January. An increase in draft, vast additions of all armor,[A 9] and the substitution of twelve 6-inch (150 mm) in the secondary battery was common between the three designs. "A" was the largest, at 59,060 long tons (60,010 t), and it was the only one to still carry the twelve 16-inch guns in four triple turrets. It required 277,000 shaft horsepower (shp) to make 32.5 knots (37.4 mph; 60.2 km/h). "B" was the smallest at 52,707 long tons (53,553 t); like "A", it had a top speed of 32.5 knots, but "B" only required 225,000 shp to make this speed. It also carried only nine 16-inch guns in three triple turrets. "C" was similar, but it added 75,000 shp (for a total of 300,000 shp) to make the original requirement of 35 knots. The weight required for this and a longer belt (512 feet (156 m) compared with 496 feet (151 m) for "B") meant that the ship was 55,771 long tons (56,666 t).[15]

Fast battleship

In March 1938, the General Board took note of the recommendations made by the Battleship Design Advisory Board, which was composed of the naval architect William Francis Gibbs, William Hovgaard (then-president of New York Shipbuilding), John Metten, Joseph W. Powell), and the long-retired Admiral and former Chief of the Bureau of Ordnance Joseph Strauss. The board asked for an entirely new design study focusing on an upsizing of the 35,000 long ton South Dakota class. The first plans made for this indicated that 30 knots (35 mph; 56 km/h) was possible on a displacement of about 37,600 long tons (38,200 t); 33 knots (38 mph; 61 km/h) could be bought with 220,000 shaft horsepower and a displacement of around 39,230 long tons (39,860 t), which was well below the treaty's maximum limit of 45,000 long tons.[16]

These designs were able to convince the General Board that a reasonably well-designed and balanced 33-knot battleship was possible within the terms of the "escalator clause". However, further studies revealed major problems with the estimates. The speed of the ships meant that more freeboard would be needed both fore and amidships, the latter of which would require an additional foot of armored freeboard. Along with this came the associated weights in supporting these new strains: the structure of the ship had to be reinforced, and the power plant had to be made more powerful to avoid a drop in speed. In all, about 24,000 long tons (24,000 t) had to be added, and the large margin the navy designers had previously thought they had—roughly 5,000 long tons (5,100 t)—was suddenly vanishing.[17]

With the additional displacement, the General Board was incredulous that a tonnage increase of 10,000 long tons (10,000 t) would only allow the addition of 6 knots (6.9 mph; 11 km/h) over the South Dakotas. They ordered that future studies would have to include the more powerful, but heavier, 16"/50 caliber Mark 2 guns left over from the canceled Lexington-class battlecruisers and South Dakota-class battleships of the early 1920s. It also allowed the draft of the ships to be deepened, meaning that the ships could be shortened (saving weight) and the power reduced (as the changing ratio of beam to draft is one of the principal determinants in how must resistance the hull offers to waves).[18]

The 50 caliber gun weighed some 400 long tons (410 t) more than the 45 caliber; in addition, the barbette size had to be increased, so the total weight gain was about 2,000 long tons (2,000 t), putting the ship at a total of 46,551 long tons (47,298 t)—well over the 45,000 long ton limit. However, the Bureau of Ordnance had a preliminary design of a turret that could carry the 50 caliber guns in a smaller barbette, leading to substantial weight savings. This breakthrough was shown to the General Board on 2 June 1938.[19]

However, the Bureau of Ordnance continued the design for the larger barbette design, while the Bureau of Construction and Repair began final planning of the ships with the smaller barbettes. As the two were independent of one another, the two bureaus did not realize that their plans could not go together until November, when the planning for both was moving into the final stages. The redesigned ship simply could not use the larger barbette, as it would require massive alterations to the design and large weight penalties as a result. The General Board could not believe this; one asked the Bureau of Ordnance's head if it had possibly occurred to him "as a matter of common sense" that Construction and Repair would have wanted to know what turret his subordinates were working on. Luckily for all involved, designers within the Bureau of Ordnance were able to come up with a new 50 caliber gun, the Mark 7, that was both lighter and smaller in outside diameter, allowing it to be placed in a turret with the smaller barbette.[20]

With 1938 drawing to a close, the design of the Iowas was nearly completed, with only minor details to be worked out. The internal subdivision of the machinery rooms was greatly modified by the New York Navy Yard in November 1939, as tests had demonstrated that the underwater protection in this area was most unsatisfactory. The results of this were clearly beneficial: "[t]he 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 added weight and 1 foot (0.30 m) in beam, this was no longer a major issue; the United Kingdom and France had renounced the Second London Naval Treaty soon after the beginning of the Second World War.[21]

Service history

A black and white photograph showing four ships at various distances sailing from the right to the left.
All four Iowa-class battleships together for the first and only time, 1954

When brought into service during the final years of World War II, the Iowa-class battleships were assigned to operate in the Pacific, primarily to provide anti-aircraft screening for U.S. aircraft carriers and perform shore bombardment.[citation needed] At the end of the war, Iowa, New Jersey and Wisconsin were decommissioned and placed in the mothball fleet;[A 10] construction was halted on the two incomplete ships, Illinois [1] and Kentucky.[2]

The Iowas were recalled in 1950 with the outbreak of the Korean War, and provided naval artillery support for U.N. forces for the entire duration of the war before being returned to mothballs in 1955 after hostilities had ceased. In 1968, to help alleviate US air losses over North Vietnam[22] as well as delivering the ordnance necessary for the escalating war in Vietnam, New Jersey was recommissioned, and as the only active battleship in the world in 1968, departed for the gunline off the Vietnamese coast. From approximately 6 April 1968 until 17 December 1969, New Jersey operated in the waters off the Vietnamese Demilitarized Zone, firing nearly 6,000 16-inch (406 mm) shells and well over 14,000 rounds of 5-inch (127 mm) shells at communist targets, before departing the gunline;[23] she was decommissioned the following year.[24]

In the 1980s, all of the Iowas were recommissioned as part of President Ronald Reagan's plan to rebuild the U.S. military and create a 600-ship Navy. The ships provided a counter to the new Soviet Orlan-class large missile cruisers, better known in the West as the Kirov-class battlecruisers.[25][26][27] Each battleship was modernized to carry electronic warfare suites, CIWS self-defense systems, and missiles.[A 11][28] They became the centerpieces of their own battleship battle groups (BBBGs).[A 12] Their missions in the 1980s and early 1990s included the U.S. intervention in the Lebanese Civil War following the 1983 Beirut barracks bombing and Desert Storm in 1991, first as part of Operation Desert Shield in 1990 and then as part of Operation Desert Storm in January through February 1991. Decommissioned for the last time due to budgetary restraints[A 13] in the early 1990s, the Iowas were split into two groups: those retained in the United States Navy reserve fleets (better known as the "mothball fleet") and those donated for use as museum ships.[29]

In 1996, the National Defense Authorization Act led Iowa and Missouri to be struck from the Naval Vessel Register. Missouri was donated to the Missouri Memorial Association of Pearl Harbor, Hawaii, for use as a museum ship. Iowa was set to be donated with Missouri, but was reinstated to the Naval Vessel Register after the Strom Thurmond National Defense Authorization Act of 1999 allowed New Jersey to be donated as a museum ship.[30] The last two Iowa-class battleships were removed from the mothball fleet in 2006; Wisconsin has been formally donated for use as a museum ship,[6] while Iowa remains stricken and available for donation.[3]


USS Iowa (BB-61)

A large ship resting on the ocean, with smoke visible from the back of the vessel.
USS Iowa during the Korean War

Iowa was ordered 1 July 1939, laid down 27 June 1940, launched 27 August 1942, and commissioned 22 February 1943. Iowa conducted a shakedown cruise in the Chesapeake Bay before sailing to Naval Station Argentia, Newfoundland to counter the German battleship Tirpitz. Transferred to the Pacific Fleet in 1944, Iowa made her combat debut in the campaign for the Marshall Islands. The ship escorted U.S. aircraft carriers conducting air raids in the Marianas campaign, then was present at the Battle of Leyte Gulf. During the Korean War, Iowa bombarded enemy targets at Songjin, Hungnam, and Kojo, North Korea. Iowa returned to the U.S. for operational and training exercises before being decommissioned.[31] Reactivated in the early 1980s, Iowa made several operation cruises in European waters. On 19 April 1989, an explosion of undetermined origin ripped through her No. 2 turret, killing 47 sailors. The turret remained inoperable when Iowa was decommissioned for the last time in 1990.[32] In 1999, Iowa was placed in the mothball fleet as a replacement for sister ship New Jersey.[33] Stricken from the Naval Vessel Register on 17 March 2006, Iowa is currently berthed at Suisun Bay in San Francisco, California.[3]

USS New Jersey (BB-62)

A large ship partially obscured by fire emanating from gun barrels pointed to the left.
USS New Jersey fires a broadside of 16-inch (406 mm) guns.

New Jersey was ordered 1 July 1939, laid down 16 September 1940, launched 7 December 1942, and commissioned 23 May 1943. New Jersey completed fitting out and trained her initial crew in the Western Atlantic and Caribbean before transferring to the Pacific Theatre in advance of the planned assault on the Marshall Islands, where she screened the U.S. fleet of aircraft carriers from enemy air raids. At the Battle of Leyte Gulf, the ship protected carriers with her anti-aircraft guns. New Jersey then bombarded Iwo Jima and Okinawa. During the Korean War, the ship pounded targets at Wonsan, Yangyang, and Kansong. Following the ceasefire, New Jersey conducted training and operation cruises until she was decommissioned. Recalled to duty in 1968, New Jersey reported to the gunline[23] off the Vietnamese coast; delivering nearly 6,000 rounds of 16-inch (406 mm) gunfire and over 14,000 rounds of 5-inch (127 mm) shells before departing the line in December 1968.[23] She was decommissioned the following year.[A 14][24] Reactivated in 1982 under the 600-ship Navy program,[34] New Jersey was sent to Lebanon to protect U.S. interests and U.S. Marines, firing her main guns at Druze and Syrian positions in the Bekaa Valley east of Beirut.[35] Decommissioned for the last time 8 February 1991, New Jersey was briefly retained on the Naval Vessel Register before being donated to the Home Port Alliance of Camden, New Jersey, for use as a museum ship.[4]

USS Missouri (BB-63)

A large ship sailing on the ocean, with white tipped waves in the foreground.
USS Missouri in her 1980s configuration

Missouri was ordered 12 June 1940, laid down 6 January 1941, launched 29 January 1944, and commissioned 11 June 1944. Missouri conducted her trials off New York and shakedown and battle practice in the Chesapeake Bay before transferring to the Pacific Fleet, where she screened U.S. aircraft carriers involved in offensive operations against the Japanese before reporting to Okinawa to shell the island in advance of the planned landings. Following the bombardment of Okinawa Missouri turned her attention to Honshū and Hokkaidō, shelling the islands and screening U.S. carriers involved in combat operations against the Japanese positions. She garnered international attention in September 1945 when representatives of the Empire of Japan boarded the battleship to sign the documents of unconditional surrender to the Allied powers. After World War II Missouri turned her attention to conducting training and operational cruises before being dispatched to Korea at the outbreak of the Korean War. Missouri served two tours of duty in Korea before being decommissioned in 1956. Reactivated 1984 as part of the 600-ship Navy plan, Missouri was sent on operational cruises until being assigned to Operation Earnest Will in 1988. In 1991, Missouri participated in Operation Desert Storm by firing 28 Tomahawk Missiles at Iraqi targets and firing 759 sixteen-inch (406 mm) shells[36] at Iraqi positions along the coast. Decommissioned for the last time in 1992, Missouri was donated to the USS Missouri Memorial Association (MMA) of Pearl Harbor, Hawaii, for use as a museum ship in 1998.[37][5]

USS Wisconsin (BB-64)

A forward view of a ship with large gun barrels pointing forward. To the left, a missile is flying away from the ship.
Wisconsin fires a Tomahawk missile.

Wisconsin was ordered 12 June 1940, laid down 25 January 1942, launched 7 December 1943, and commissioned 16 April 1944. After trials and initial training in Chesapeake Bay, she transferred to the Pacific Fleet in 1944 and was assigned to protect the U.S. fleet of aircraft carriers involved in operations in the Philippines until summoned to Iwo Jima to bombard the island in advance of the Marine landings. Afterward, she proceeded to Okinawa, bombarding the island in advance of the allied amphibious assault. In mid-1945 Wisconsin turned her attention to bombarding the Japanese home islands, until the surrender of Japan in August. Reactivated in 1950 for the Korean War, Wisconsin served two tours of duty assisting South Korean and UN forces by providing call fire support and shelling targets. In 1956, the bow of the uncompleted USS Kentucky was removed and grafted on Wisconsin, which had collided with the destroyer USS Eaton. Decommissioned in 1958, Wisconsin was placed in the reserve fleet at the Philadelphia Naval Yard[7] until reactivated in 1986 as part of the 600-ship Navy plan. In 1991, Wisconsin participated in Operation Desert Storm, firing 24 Tomahawk Missiles at Iraqi targets, and expending 319 16-inch (406 mm) shells[23] at Iraqi troop formations along the coast. Decommissioned for the last time 30 September 1991 Wisconsin was placed in the reserve fleet until struck from the Naval Vessel Register 17 March 2006 so she could be transferred for use as a museum ship. Wisconsin is currently berthed at the Nauticus maritime museum in Norfolk, Virginia.[6]

Illinois (BB-65)

A large hull being pushed through a shipyard by tugboats.
Kentucky (pictured) and Illinois were never finished, and both ultimately scrapped.

Illinois was ordered 9 September 1940 and laid down 15 January 1945. Construction was canceled 11 August 1945 when Illinois was 22% complete. She was sold for scrap in September 1958.[38][1]

Kentucky (BB-66)

Kentucky was ordered 9 September 1940 and laid down on 6 December 1944. Construction was suspended 17 February 1947 when Kentucky was 72% complete. She was informally launched 20 January 1950 to clear a dry-dock for repairs to Missouri, which had run aground. In 1956, Kentucky’s bow was removed and shipped in one piece across Hampton Roads, where it was grafted on the battleship Wisconsin, which had collided with the destroyer Eaton. Later, Kentucky’s engines were salvaged and installed on the fast combat support ships Sacramento[39] and Camden. Ultimately, Kentucky was sold to Boston Metals Co. for scrap on 31 October 1958.[40][2]


Main battery

An overhead view of a large ship with a teardrop shape firing guns toward the top of the image.
USS Iowa fires a full broadside of nine 16-inch (406 mm) / 50-caliber and six 5-inch (127 mm) / 38-caliber guns during a target exercise. Note concussion effects on the water surface.

The primary armament of an Iowa-class battleship is nine 16-inch (406 mm)/50-caliber Mark 7 naval guns, which are housed in three three-gun turrets, two forward and one aft. The guns fire projectiles weighing from 1,900 to 2,700 pounds (860 to 1,200 kg) at a muzzle velocity of 2,690 ft/s (820 m/s) to a maximum range of 42,345 yards (38,720 m) (24.06 mi) using an armor-piercing shell. At maximum range the projectile spends almost 1½ minutes in flight. The maximum firing rate for each gun is two rounds per minute.[41] The turrets are "three-gun", not "triple", because each barrel can be elevated independently; they can also be fired independently. The ship could fire any combination of its guns, including a broadside of all nine.

Radar range estimation provided a significant accuracy advantage over earlier ships with optical rangefinders. Off Truk Atoll on 16 February 1944 Iowa engaged the Japanese destroyer Nowaki at a range of 35,700 yards (32.6 km). While she did not hit the destroyer she did straddle her, setting a record for the longest ranged straddle in history.[42]

Secondary battery

A grey turret with two gun barrels pointing forward. A black eagle, globe, and anchor insignia has been painted on the side of the turret.
A 5-inch (127 mm) gun mount emblazoned with the Eagle, Globe, and Anchor of the United States Marine Corps aboard the battleship New Jersey. In keeping with tradition, a 5-inch gun mount on each Iowa class battleship was manned by the ship's Marine Detachment (MARDET).

The secondary battery of the ship consists of 5-inch (127 mm) Mark 12 guns in 10 twin mounts, five each to port and starboard, and four Mark 37 Gun Fire Control Systems. These guns were introduced on destroyers in 1934, but by World War II had been installed on nearly every major U.S. warship.[43] The secondary battery was intended to fight off aircraft. Its effectiveness soon declined as Japanese airplanes became faster, then rose again toward the end of the war because of an upgrade to the Mark 37 Fire Control System and the proximity-fused 5-inch (130 mm) shells. During the 1980s modernization, four twin mounts were removed to make room for missiles, the two farthest aft and the two at mid-ship on each side.[44]

Anti-aircraft batteries

All four Iowa-class battleships were outfitted with Oerlikon 20 mm and Bofors 40 mm, both of which were among the most heavily produced anti-aircraft guns of World War II. The Oerlikon 20 mm AA gun remained the primary anti-aircraft weapon of the United States Navy until the introduction of the Bofors 40 mm gun in 1943,[45] while the Bofors 40 mm gun accounted for roughly half of all Japanese aircraft shot down between 1 October 1944 and 1 February 1945.[46] Both of these batteries were replaced with Phalanx CIWS mounts when the battleships were modernized in the 1980s.[47][48]


During the modernization in the 1980s each of the Iowa-class battleships received a complement of BGM-109 Tomahawk Land Attack Missiles (TLAMs) for use against enemy targets on land and a complement of RGM-84 Harpoon anti-ship missiles for use against enemy ships. Both missile systems have a greater range than the gun batteries aboard the battleships.[49] At one point, the NATO Sea Sparrow was to be installed on the reactivated battleships; however, it was determined that the system could not withstand the overpressure effects from firing the main battery.[28][50]


The rear deck of ship, with a large partially erect net visible near the center of the image. Many men in orange suits are working to free a white drone entangled in the net.
Crewmen recover an RQ-2 Pioneer Unmanned Aerial Vehicle aboard Iowa.

During their service careers the Iowas have carried a number of different aircraft, beginning with the Vought OS2U Kingfisher[51] and Curtiss SC Seahawk,[52] both of which were employed to spot for the battleship's main gun batteries, and in a secondary capacity, perform search and rescue missions.[51]

By the time of the Korean War, helicopters had replaced floatplanes on the Iowa class. They added a logistics role to gunnery spotting and search-and-rescue; helicopters ferried troops and supplies between ships and to and from land bases. Like the seaplanes before them, the helicopters had no hangar facilities, but the Iowas did have support facilities for five types of helicopters: the UH-1 Iroquois, SH-2 Seasprites, CH-46 Sea Knight, CH-53 Sea Stallion and the LAMPS III SH-60B Seahawk.[51]

By the 1980s the helicopters had given way to unmanned aerial vehicle (UAVs), the first of which was the RQ-2 Pioneer.[53] Pioneer UAVs carried a video camera in a pod under the belly of the aircraft, which transmitted live video back to the ship so that the operators could observe enemy actions or fall of shot during naval gunnery.[53] Pioneer garnered international attention for its use during the 1991 Gulf War, when it saw extensive use from Missouri and Wisconsin. The latter became the first ship to have enemy forces surrender to one of its remotely controlled observation drones.[53]

Engineering plant

A large panel with many dials. A man works a wheel at the far right end of the image.
A crewman operates the ship's throttle in the main engine room aboard New Jersey.

The Iowa-class battleships are the fastest battleships ever launched, theoretically capable of sustained speeds of 35 knots (65 km/h) or better.[A 15] This is due in part to the use of an empirical formula for predicting a ship's maximum speed that was originally developed for 12-meter (39 ft) yachts. The formula was on scale-model studies in flumes of various hull forms and propellers, and was adopted after various tests at the David Taylor Model Basin. It quickly became apparent that propeller cavitation caused a drop in efficiency at speeds over 30 knots (56 km/h). Propeller design therefore took on new importance.[54][A 16]

The engineering plant on Iowa and Missouri consists of four General Electric cross-compound steam turbine engines, each driving a single shaft that turns one screw. The two outboard screws on the Iowa class have four blades and are just over 18 feet (5.5 m) in diameter. The two inboard screws have five blades and are about 17.5 feet (5.3 m) in diameter.[8] The equivalent machinery on New Jersey and Wisconsin was provided by Westinghouse. Eight Babcock and Wilcox M-Type boilers operate at 600 pounds per square inch (4,100 kPa) with a maximum superheater outlet temperature of 875 °F (468 °C). In normal steaming four boilers were operated; this was sufficient to power the ships at speeds up to 27 knots. For higher speeds all eight boilers were lit.[55]

Electricity drives many systems aboard ship, including rotating the turrets and elevating the guns. Each of the four engine rooms has a pair of Ship's Service Turbine Generators (SSTGs)[56] manufactured by Westinghouse. Each SSTG generates 1.25 MW for a total of 10 MW of electricity. The SSTGs are powered by steam from the same boilers that feed the engines. For backup, the ship also has a pair of 250-kW diesel generators.[8] To allow battle-damaged electrical circuits to be repaired or bypassed, the lower decks of the ship have a Casualty Power System whose large three-wire cables and wall outlets called "biscuits" can be used to re-route power.[57]

Radar and electronic warfare systems

A monitor with a circular appearance is visible. A large man is seated in front of the monitor, and is watching the display with care.
AN/SPS-67 radar operator aboard USS Missouri

Each of the four Iowa-class battleships are equipped with the AN/SPS-49 Radar Set, an L-band, long-range, two-dimensional, air-search radar system that provides automatic detection and reporting of targets within its surveillance volume. The AN/SPS-49 performs accurate centroiding of target range, azimuth, amplitude, ECM level background, and radial velocity with an associated confidence factor to produce contact data for command and control systems. Additionally, the contact range and bearing information is provided for display on standard plan position indicator consoles.[58]

The Iowa-class battleships are also equipped with the Radar Set AN/SPS-67, a short-range, two-dimensional, surface-search/navigation radar system that provides highly accurate surface and limited low-flyer detection and tracking capabilities. The AN/SPS-67 is a solid-state replacement for the AN/SPS-10 radar, using a more reliable antenna and incorporating standard electronic module technology for simpler repair and maintenance. The AN/SPS-67 provides excellent performance in rain and sea clutter, and is useful in harbor navigation, since the AN/SPS-67 is capable of detecting buoys and small obstructions without difficulty.[59]

Reactivation potential

"In summary, the committee is concerned that the Navy has foregone the long-range fire support capability of the battleship, has given little cause for optimism with respect to meeting near-term developmental objectives, and appears unrealistic in planning to support expeditionary warfare in the mid-term. The committee views the Navy’s strategy for providing naval surface fire support as 'high risk,' and will continue to monitor progress accordingly."
Evaluation of the United States Navy's naval surface fire support program in the National Defense Authorization Act of 2007[60]

After World War II, the United States maintained the four Iowa-class battleships in the United States Navy reserve fleets, better known as the "mothball fleet", and on several occasions reactivated these battleships for naval gunfire support. The U.S. Navy has held onto its battleships long after the expense and the arrival of aircraft and precision guided munitions led other nations to scrap their big-gun fleets.[61] The United States Congress is largely responsible for this. The lawmakers argue that the battleships' large-caliber guns have a militarily useful destructive power lacking in the smaller, cheaper, and faster guns mounted by U.S. cruisers and destroyers.[62]

In response, the Navy has pointed to the cost of reactivating the two Iowa class battleships to their decommissioned capability. The Navy estimates costs in excess of $500 million,[63][64] but this does not include an additional $110 million needed to replenish the gunpowder for the 16-inch (406 mm) guns because a survey found the powder to be unsafe. In terms of schedule, the Navy's program management office estimates that reactivation would take 20 to 40 months, given the loss of corporate memory and the shipyard industrial base.[62]

Reactivating the battleships would require a wide range of battleship modernization improvements, according to the Navy's program management office. At a minimum, these modernization improvements include command and control, communications, computers, and intelligence equipment; environmental protection (including ozone-depleting substances); a plastic-waste processor; pulper/shredder and wastewater alterations; firefighting/fire safety and women-at-sea alterations; a modernized sensor suite (air and surface search radar); and new combat and self-defense systems.[62] The Navy's program management office also identified other issues that would strongly discourage the Navy from reactivating and modernizing the battleships. For example, personnel needed to operate the battleships would be extensive, and the skills needed may not be available or easily reconstituted.[65] Other issues include the age and unreliability of the battleships' propulsion systems and the fact that the Navy no longer maintains the capability to manufacture their 16-inch (410 mm) gun system components and ordnance.[62]

Although the Navy firmly believes that the battleships are no longer needed, members of the United States Congress remain skeptical about the Navy's plan to replace its battleships with specially designed destroyers.[66] Partially as a consequence the US House of Representatives have asked that the battleships be kept in a state of readiness should they ever be needed again.[67]


  1. ^ BB-65 was canceled on 11 August 1945 when 22% complete. (Jane's Fighting Ships of World War II).
  2. ^ BB-66 was suspended for a time, but was started on 6 December 1944. Canceled 1950. "Kentucky (BB 66)". Naval Vessel Register, United States Navy. 2002-07-23. Retrieved 2010-1-17. 
  3. ^ The Iowas were maintained on the Naval Vessel Register (NVR) throughout the mid and latter half of the 20th century, this range accounts for the earliest commissioning date to the last day on NVR before being officially struck. Newhart, Max R. (2007). American Battleships: A Pictorial History of BB-1 to BB-71 with Prototypes main and Texas. Missoula, Montana: Pictorial Histories Publishing Company, Inc.. pp. 90–101. ISBN 1-57510-004-5. 
  4. ^ The Iowas were commissioned intermittently throughout the mid and latter half of the 20th century, therefore the range given here accounts for the times when they were in reserve in between conflicts. Newhart, Max R. (2007). American Battleships: A Pictorial History of BB-1 to BB-71 with Prototypes main and Texas. Missoula, Montana: Pictorial Histories Publishing Company, Inc.. pp. 90–101. ISBN 1-57510-004-5. 
  5. ^ Iowa is officially listed as avaliable for donation, however she has yet to be donated to a orginization for use as a museum ship. "Iowa (BB 61)". Naval Vessel Register, United States Navy. 2007-02-26. Retrieved 2010-01-30. 
  6. ^ The Iowa-class battleships are also frequently cited as Fast Battleships due to their 30+ knot speed. Newhart, Max R. (2007). American Battleships: A Pictorial History of BB-1 to BB-71 with Prototypes main and Texas. Missoula, Montana: Pictorial Histories Publishing Company, Inc.. pp. 90–101. ISBN 1-57510-004-5. 
  7. ^ At this time, the Montana-class battleships were being planned, but none were laid down. Newhart, Max R. (2007). American Battleships: A Pictorial History of BB-1 to BB-71 with Prototypes main and Texas. Missoula, Montana: Pictorial Histories Publishing Company, Inc.. pp. 90–101. ISBN 1-57510-004-5. 
  8. ^ Furthermore, the armor was distributed to best protect against close-in hits, as these cruiser-killers would generally fight alone and possibly in poor weather, which would hamper visibility and range (radars had not been fitted to ships by this point); on the other hand, a true battleship could be designed to only deal with long-range threats as they would be escorted by destroyers and possibly cruisers, both of which would find and engage an enemies before they approached capital ship, regardless of weather.[13]
  9. ^ The belt armor was increased from 8.1 inches (210 mm) to 12.6 inches (320 mm); the deck from 2.3 inches (58 mm) to 5 inches (130 mm); the splinter armor to 3.9 inches (99 mm); the turret armor from 9 inches (230 mm) on the front, 6 inches (150 mm) on the side, and 5 inches (130 mm) on the rear to 18 inches (460 mm), 10 inches (250 mm) and 8 inches (200 mm), respectively.[15]
  10. ^ As part of the post World War II drawdown, three of the Iowa-class battleships had been de-activated and decommissioned; however, President Truman refused to allow Missouri to be decommissioned. Against the advice of Secretary of Defense Louis Johnson, Secretary of the Navy John L. Sullivan, and Chief of Naval Operations Louis E. Denfeld, Truman ordered Missouri to be maintained with the active fleet partly because of his fondness for the battleship and partly because the battleship had been commissioned by his daughter Margaret Truman. See: Stillwell, Paul (February 1999). "USS Missouri: Served in World War II and Korean War". American History. OCLC 30148811. ISSN 1076-8866. Retrieved 2007-12-03.  Adamski, Mary (1998-08-09). "Mighty Mo anchors $500,000 donation". Honolulu Star-Bulletin. Retrieved 2007-06-14. 
  11. ^ During this reactivation, the Navy played with various ideas to remove the #3 gun turrets from the battleships and replace them with servicing facilities for 12 AV-8B Harrier STOVL jumpjets. Plans for such a conversion were dropped in 1984. See: "BB-61 Iowa-class Aviation Conversion". 2005-11-27. Retrieved 2007-05-19. 
  12. ^ A Battleship Battle Group consisted of one Ticonderoga-class cruiser, one Kidd-class destroyer or Arleigh Burke-class destroyer, one Spruance-class destroyer, three Oliver Hazard Perry-class frigate, and one support ship. Lightbody, Andy; Poyer, Joe (1990). The Complete Book of U.S. Fighting Power. New York, New York: Crown Publishers, Inc. pp. 338–339. ISBN 0517032988. 
  13. ^ A Government Accountability Office report on the operating cost for each individual Iowa-class battleship in 1991 reported that it cost the United States Navy $58 million to operate each individual battleship. Adjusted for inflation on the Consumer Price Index, each individual battleship would cost just over $88.5 million to operate in 2008 dollars. This number does not take into consideration the cost of specialty items and other unique components that may be needed to keep a battleship operational. "Defense Budget: Potential Reductions to DOD's Ammunition Budgets" (pdf). United States General Accounting Office. 17 September 1990. pp. 29. Retrieved 2009-08-08. 
  14. ^ "On 17 December 1969 New Jersey’s colors were hauled down and she entered the inactive fleet, still echoing the words of her last commanding officer: 'Rest well, yet sleep lightly; and hear the call, if again sounded, to provide fire power for freedom'." "USS New Jersey (BB 62) History". Dictionary of American Naval Fighting Ships. United States Navy. Retrieved 2010-01-30. 
  15. ^ The actual speed of the Iowa-class battleships varies from source to source. The most commonly cited figures for the battleship class are 32-33 knots, but it appears that such speeds have never actually been attained in speed tests. Theoretically, the battleships of the Iowa-class should be able to cruise at nearly 35 knots, but this speed appears to be abnormally high and does not take into account factors like ocean resistance and weight. The fastest confirmed speed for the class is just over 31 knots, a speed attained by New Jersey during tests. (Friedman, U.S. Battleships, p. 317)
  16. ^ These mathematical formulas still stand today, and have been used to design hulls for U.S. ships and to predict the speed of those hulls for the ships when commissioned, including nuclear powered ships like the U.S. fleet of Nimitz-class supercarriers. See Davis, p. 15.


  1. ^ a b c "Illinois (BB 65)". Naval Vessel Register, United States Navy. 2002-07-22. Retrieved 2010-01-17. 
  2. ^ a b c "Kentucky (BB 66)". Naval Vessel Register, United States Navy. 2002-07-23. Retrieved 2010-1-17. 
  3. ^ a b c "Iowa (BB 61)". Naval Vessel Register, United States Navy. 2007-02-26. Retrieved 2010-01-30. 
  4. ^ a b "New Jersey (BB 62)". Naval Vessel Register, United States Navy. 2002-07-19. Retrieved 2010-1-28. 
  5. ^ a b "Missouri (BB 63)". Naval Vessel Register, United States Navy. 2002-07-19. Retrieved 2010-01-30. 
  6. ^ a b c "Wisconsin (BB 64)". Naval Vessel Register, United States Navy. 2006-03-20. Retrieved 2010-01-30. 
  7. ^ a b Naval Historical Center. "Wisconsin". DANFS. 
  8. ^ a b c d e f g h i j k l Newhart, pp. 90–101
  9. ^ a b Friedman, U.S. Battleships, p. 317
  10. ^ a b c d e Johnston and McAuley, pp. 108–23.
  11. ^ Friedman, U.S. Battleships, 181–182, 243
  12. ^ Garzke and Dulin, Battleships: United States Battleships in World War II, 3, 6
  13. ^ a b c Friedman, U.S. Battleships, 309
  14. ^ Friedman, U.S. Battleships, 309, 311
  15. ^ a b Friedman, U.S. Battleships, 310
  16. ^ Friedman, U.S. Battleships, 271, 309
  17. ^ Friedman, U.S. Battleships, 309–310
  18. ^ Friedman, U.S. Battleships, 310–311
  19. ^ Friedman, U.S. Battleships, 311
  20. ^ Friedman, U.S. Battleships, 311–312
  21. ^ Friedman, U.S. Battleships, 313–314
  22. ^ Neubeck, p. 42
  23. ^ a b c d Polmar, p. 129
  24. ^ a b Naval Historical Center. "New Jersey". DANFS. 
  25. ^ Middleton, Drew (1981-03-13). "Pentagon likes budget proposal, but questions specifics". The New York Times: p. A14. 
  26. ^ Bishop, p. 80.
  27. ^ Miller and Miller, p. 114.
  28. ^ a b Horan, Donald J. (1981-04-20). "Update of the Issues Concerning the Proposed Reactivation of the Iowa class battleships and the Aircraft Carrier Oriskany" (PDF). United States General Accounting Office. pp. 3–18. Retrieved 2005-05-25. 
  29. ^ National Defense Authorization Act of 1996PDF (1.68 MB). 104th Congress, House of Representatives. p. 237. Retrieved on 17 December 2006.
  30. ^ 105th Congress (1998-10-17). "Strom Thurmond National Defense Authorization Act of 1999" (PDF). pp. 200–01. Retrieved 2007-03-12. 
  31. ^ "Iowa". DANFS. Retrieved 2010-02-15. 
  32. ^ Thompson, p. 261.
  33. ^ "Strom Thurmond National Defense Authorization Act of 1999 (Subtitle B-Naval Vessels and Shipyards)" (pdf). 105th Congress, United States Senate and House of Representatives. pp. 200–201. Retrieved 2007-03-12. 
  34. ^ Stillwell, p. 243-251
  35. ^ Stillwell, p.261-273
  36. ^ Polmar p. 129
  37. ^ Naval History & Heritage Command. "Missouri". DANFS. 
  38. ^ Naval History & Heritage Command. "Illinois". DANFS. 
  39. ^ "Sacramento". Dictionary of American Naval Fighting Ships. Navy Department, Naval History & Heritage Command. Retrieved 2010-02-21. 
  40. ^ Naval Historical Center. "Kentucky". DANFS. 
  41. ^ DiGiulian, Tony (22 November 2009). "United States of America 16"/50 (40.6 cm) Mark 7". Retrieved 23 January 2010. 
  42. ^ Fischer, Brad D.; Jurens, W. J. (2006). "Fast Battleship Gunnery during World War II: A Gunnery Revolution, Part II". Warship International (Toledo, OH: International Naval Research Organization) XLIII (1): 83. ISSN 0043-0374. 
  43. ^ DiGiulian, Tony (2008-03-27). "United States of America 5"/38 (12.7 cm) Mark 12". Retrieved 2008-07-25. 
  44. ^ Stillwell, Missouri p. 256
  45. ^ DiGiulian, Tony (2008-05-14). "British, Swiss and USA 20 mm/70 (0.79") Oerlikon Marks 1, 2, 3 and 4". Retrieved 2008-07-25. 
  46. ^ DiGiulian, Tony (2008-05-14). "Sweden, British, USA, German and Japanese Bofors 40 mm/56 (1.57") Model 1936". Retrieved 2008-07-25. 
  47. ^ DiGiulian, Tony (2007-11-02). "USA 20 mm Phalanx Close-in Weapon System (CIWS)". Retrieved 2008-07-25. 
  48. ^ "The USS Wisconsin (BB-64) Ship's History". USS Wisconsin Association. 2008-01-08. Retrieved 2008-07-25. 
  49. ^ "Iowa Class: Missile Battery". Iowa Class Preservation Society. Retrieved 2009-07-02. 
  50. ^ Statement by Admiral Rowden in the Department of Defense Appropriations for Fiscal Year 1982.[citation needed]
  51. ^ a b c "Iowa Class: Shipboard Aircraft". Iowa Class Preservation Association. Retrieved 2007-03-13. 
  52. ^ Bridgeman, pp. 221–22.
  53. ^ a b c Pike, John (2000-03-05). "Pioneer Short Range (SR) UAV". Federation of American Scientists. Retrieved 2007-03-02. 
  54. ^ Davis, pp. 5–6.
  55. ^ Preston, p. 259.
  56. ^ For a diagram and statistics of SSTGs, see: Hochscheidt, Mike. "Ship’s Service Turbine Generator". Retrieved 2008-07-25. 
  57. ^ Defense Technical Information Center. "Casualty power" (doc). United States Department of Defense. Retrieved 2007-03-14. 
  58. ^ "AN/SPS-49 Very Long-Range Air Surveillance Radar". 2005-04-27. Retrieved 2007-03-14. 
  59. ^ "AN/SPS-67". 2005-04-27. Retrieved 2007-03-14. 
  60. ^ "National Defense Authorization Act of 2007" (PDF). pp. 193–94. Retrieved 2007-03-12. 
  61. ^ Government Accountability Office, Naval Surface Fire Support Program Plans and Costs (NSIAD-99-91).
  62. ^ a b c d Government Accountability Office. Information on Options for Naval Surface Fire Support (GAO-05-39R).
  63. ^ This number is based on 1999 estimate with a 4% annual inflation rate. See: Government Accountability Office. Information on Options for Naval Surface Fire Support.
  64. ^ The U.S. Navy reported in the April 1987 edition of All Hands that the original cost of bringing the battleships back in the 1980s was $110 million per ship, but the actual cost after modernization and recommissioning was $455 million. See: Bureau of Naval Personnel, "Back on the battle line".
  65. ^ The U.S. Navy reported in the April 1987 edition of All Hands that while battleships have larger crews than other vessels the level of training required and the criticality of that training were less than that required of a crew aboard an Oliver Hazard Perry-class frigate. See: Bureau of Naval Personnel, "Back on the battle line".
  66. ^ Government Accountability Office, Evaluation of the Navy’s 1999 Naval Surface Fire Support Assessment (NSAID-99-225).
  67. ^ "Report 109–452. National Defense Authorization Act of 2007." 109th Congress, House of Representatives. p. 68.


Further reading

  • Butler, John A. (1995). Strike Able-Peter: The Stranding and Salvage of the USS Missouri. Annapolis, Maryland: Naval Institute Press. ISBN 1557500940. 
  • Reilly, John C., Jr. (1989). Operational Experience of Fast Battleships: World War II, Korea, Vietnam. Washington DC: Naval Historical Center. ASIN B000KZP9LA. 

External links

Redirecting to Iowa class battleship

Redirecting to Iowa class battleship


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