A ship class is a group of ships of a similar design. This is distinct from a ship type, which might reflect a similarity of tonnage or intended use. For example, USS Carl Vinson is a nuclear aircraft carrier (ship type) of the Nimitz class (ship class).
203-1003: The Iowa class was a class of six fast battleships ordered by the United States Navy in 1939 and 1940. They were initially intended to intercept fast capital ships such as the Japanese Kongō class and serve as the "fast wing" of the U.S. battle line . The Iowa class was designed to meet the Second London Naval Treaty 's "escalator clause" limit of 45,000-long-ton (45,700 t) standard displacement. Beginning in August 1942, four vessels, Iowa , New Jersey , Missouri , and Wisconsin , were completed; two more, Illinois and Kentucky , were 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
406-560: A broadside of all nine. The fire control was performed by the Mark 38 Gun Fire Control System (GFCS); the firing solutions were computed with the Mark 8 rangekeeper, an analog computer that automatically receives information from the director and Mark 8/13 fire control radar, stable vertical, ship pitometer log and gyrocompass, and anemometer. The GFCS uses remote power control ( RPC ) for automatic gun laying . The large-caliber guns were designed to fire two different conventional 16-inch shells:
609-411: A dual-purpose gun (DP); that is, it was able to fire at both surface and air targets with a reasonable degree of success. However, this did not mean that it possessed inferior anti-air abilities. As proven during 1941 gunnery tests conducted aboard North Carolina the gun could consistently shoot down aircraft flying at 12,000–13,000 feet (2.3–2.5 mi; 3.7–4.0 km), twice the effective range of
812-529: A standard displacement of 35,000 long tons (36,000 t) and a maximum gun caliber of 16 inches. It also decreed that the five countries could not construct another capital ship for ten years and could not replace any ship that survived the treaty until it was at least twenty years old. The 1936 Second London Naval Treaty kept many of the Washington treaty's requirements but restricted gun size on new warships to 14 inches. The treaties heavily influenced
1015-519: A 15-inch (380 mm) belt and 5.25-inch (133 mm) deck , giving it a 19,000–30,000 yd (9.4–14.8 nmi; 17–27 km) immune zone against the United States' super-heavy 14-inch shell. While "K" was liked by the naval constructors, its designed standard displacement of 35,000 tons left little room for error, modifications, or improvements. The final two designs, "L" and "M," would use quadruple turrets to save weight (similar to
1218-504: A 1935 empirical formula for predicting a ship's maximum speed based on scale-model studies in flumes of various hull forms and propellers 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 108 ft 2 in (32.97 m) which, when multiplied by 7.96, produced a waterline length of 860 ft (262 m). The Navy also called for
1421-451: A SG surface search radar added. The normal battleship configuration was present aboard North Carolina in April 1944, with SK and SG radars (air and surface search, respectively), a backup SG, and Mark 8s to direct its main battery. All of the Mark 4s remained for the secondary battery, and one of the older Mark 3s was still present, possibly as a backup for the Mark 8s. An SK-2 dish replaced
1624-402: A SK-2 air-search, a Mark 38 main battery fire control system with Mark 13 and 27 radars, a Mark 37 secondary battery fire control system with Mark 12, 22 and 32 radars, and a Mark 57 smaller weaponry fire control system, with a Mark 34 radar. In March 1946, Washington had a SK fore and a SR aft, a SG both fore and aft, and a TDY jammer (which could scramble radar on other ships). The ships in
1827-416: A bore length of 190 in (4,800 mm), and had a rifling length of 157.2 in (3,990 mm). The gun could fire shells at about 2,500–2,600 ft/s (760–790 m/s); about 4,600 could be fired before the barrel needed to be replaced. Minimum and maximum elevations were −15 and 85 degrees, respectively. The guns' elevation could be raised or lowered at about 15 degrees per second. Loading
2030-447: A brand-new gun, the heavy shell would be expelled at a muzzle velocity of 2,300 ft/s (700 m/s). At a reduced charge, the same shell would be fired at 1,800 ft/s (550 m/s). Barrel life—the approximate number of rounds a gun could fire before needing to be relined or replaced—was 395 shells when using AP, although if only practice shells were used this figure was significantly higher: 2,860. Turning at 4 degrees
2233-410: A class often have names linked by a common factor: e.g. Trafalgar -class submarines ' names all begin with T ( Turbulent , Tireless , Torbay ); and Ticonderoga -class cruisers are named after American battles ( Yorktown , Bunker Hill , Gettysburg , Anzio ). Ships of the same class may be referred to as sister ships . The name of a naval ship class is most commonly the name of
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#17327872806302436-475: A detached wing with aircraft carrier or cruiser commerce raiding groups. However, one member of the Board, Admiral Joseph Reeves —one of the principal developers of the United States' aircraft carrier strategy—disliked "XVI-C" because he believed that it was not fast enough to work with the 33-knot (61 km/h; 38 mph) fast carriers, and it was not powerful enough to justify its cost. Instead, he advocated
2639-438: A development of the previously rejected "XVI", adding additional underwater protection and patches of armor within the ship to make the magazines immune to above- and below-water shell hits from 19,000 yd (9.4 nmi; 17 km) and beyond. The immune zone's outer limit was increased from 28,200 yd (13.9 nmi; 25.8 km) to 30,000 yd (15 nmi; 27 km). After further revisions, Reeves went to Standley,
2842-420: A displacement greater than that of most battleships, its armor would have protected it only against the 8-inch (200 mm) weapons carried by heavy cruisers . Three improved plans – "A", "B", and "C" – were designed at the end of January. An increase in draft , vast additions to the armor, and the substitution of twelve 6-inch (152 mm) guns in the secondary battery were common among the three designs. "A"
3045-487: A fifteenth mount was added on top of the third main turret that November. Washington retained its six 1.1 in quads until the middle of 1943, when ten quad 40 mm guns replaced them. By August, it had fifteen. The two ships carried these through to the close of the war. The .50 caliber machine guns did not have the range or power needed to combat modern aircraft and were scheduled for replacement by equal numbers of 20 mm guns, but nothing immediately came of
3248-401: A high-tensile structural steel with armor properties comparable to Class B, was extensively used in the hull plating to increase protection. The citadel consisting of the magazines and engine rooms was protected by an STS outer hull plating 1.5 inches (38 mm) thick and a Class A armor belt 12.1 inches (307 mm) thick mounted on 0.875-inch (22.2 mm) STS backing plate; the armor belt
3451-493: A large anti-torpedo bulge that ran the length of the "armored raft". The outer two compartments, the innermost compartment and the bulge would remain empty, while the third and fourth compartments would be filled with liquid. The system was reduced in depth at either end by the forward and rear gun turrets. In these areas, the fifth compartment was deleted; instead, there was an outer empty compartment and two liquid-filled spaces, backed by another empty compartment. To compensate for
3654-480: A lower maximum speed and mount heavier guns, but fitting in adequate protection against newer 16-inch guns would be extremely difficult. The Preliminary Design section drew up five more studies in October, based upon "A" with additional armor or a scaled-down "B"; all used 14-inch guns and called for at least 30 knots. Two called for four turrets, but they would be too heavy and mount less armor. Another, "K," would have
3857-443: A main armored belt of Class A armor that was 12-inch (305 mm) thick amidships, inclined at 15°, and backed by 0.75-inch (19 mm) Special Treatment Steel (STS). This tapered down to 6-inch (152 mm) on the lower edge of the belt. The ships had three armored decks; their main deck was 1.45-inch (37 mm) thick. The second, thickest deck was 3.6-inch (91 mm) of Class B armor laminated on 1.4-inch (36 mm) STS for
4060-614: A maximum superheater outlet temperature of 850 °F (454 °C). The double-expansion engines consist of a high-pressure (HP) turbine and a low-pressure (LP) turbine. The steam is first passed through the HP turbine which turns at up to 2,100 rpm. The steam, largely depleted at this point, is then passed through a large conduit to the LP turbine. By the time it reaches the LP turbine, it has no more than 50 psi (340 kPa) of pressure left. The LP turbine increases efficiency and power by extracting
4263-502: A multitude of roles. However, the acting Secretary of the Navy authorized a modified version of a different design, which in its original form had been rejected by the General Board. This called for a 27-knot (50 km/h; 31 mph) ship with twelve 14-inch guns in quadruple turrets and protection against guns of the same caliber. In a major departure from traditional American design practices, this design prioritized firepower at
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#17327872806304466-557: A quadruple mount, and North Carolina had fifty-three by March 1944. In April 1945, North Carolina was assigned to have fifty-six 20 mm, while Washington was assigned seventy-five. In August 1945, the ships both had eight twin 20 mm mounts; North Carolina also carried twenty single, while Washington carried one quad and sixty-three single. Both North Carolina and Washington , designed prior to radar , were originally fitted with many fire-control and navigational optical range-finders. The former lasted until 1944, when it
4669-501: A second, each turret could train to 150 degrees on either side of the ship. The guns could be elevated to a maximum inclination of 45 degrees; turrets one and three could depress to −2 degrees, but due to its superfiring position, the guns on turret two could only depress to 0 degrees. Each gun was 736 in (18,700 mm) long overall; its bore and rifling length were 715.2-inch (18,170 mm) and 616.9-inch (15,670 mm), respectively. Maximum range with
4872-719: A ship that sacrificed both speed and protection for firepower, a combination unprecedented in American capital ship development. —Naval historian Norman Friedman Although the Second London Naval Treaty stipulated that warship guns could be no larger than 14 inches, a so-called "escalator clause" was included at the urging of American negotiators in case any country that had signed the Washington Naval Treaty refused to adhere to this new limit. The provision allowed signatory countries of
5075-526: A significant accuracy advantage over earlier ships with optical rangefinders; this was demonstrated off Truk Atoll on 16 February 1944, when the New Jersey engaged the Japanese destroyer Nowaki at a range of 35,700 yards (32.6 km; 17.6 nmi) and straddled her, setting the record for the longest-ranged straddle in history. In World War II, the electronic countermeasures (ECM) included
5278-458: A single letter suffix. After the reunification of Germany the German Navy ( Deutsche Marine ) kept the system. Informally, classes are also traditionally named after their lead ships. The Indonesian Navy has a traditional naming system for its ships. In addition, the ship's type and missions can be identified by the first number on the ship's three-digit hull number , which is placed on
5481-425: A slight advantage over the 16-inch/50 caliber Mark 7 gun when hitting deck armor – a shell from a 45 cal gun would be slower, meaning that it would have a steeper trajectory as it descended. At 35,000 yards (20 mi; 32 km), a shell from a 45 cal would strike a ship at an angle of 45.2 degrees, as opposed to 36 degrees with the 50 cal. The Mark 7 had a greater maximum range over
5684-404: A standard displacement between 31,500 and 40,500 long tons (32,000 and 41,100 t). Designs "D" and "E" were attempts at fast battleships with 16-inch guns and protections against the same, but their displacement was greater than the Washington Naval Treaty allowed. Design "F" was a radical attempt at a hybrid battleship-carrier, with three catapults mounted fore and eight 14-inch guns aft . It
5887-484: A thin 10.1-inch (260 mm) belt. Another gun could be traded for a 13.5-inch (342.9 mm) belt, and yet another could be swapped for more speed and an extra tenth of an inch of belt armor; this became design "XVI-C". The General Board liked "XVI-C" very much, seeing in it a ship that had enough protection to fight—and survive—in a battle line formed with the US' older battleships while also having enough speed to operate in
6090-443: A top speed of 28 knots (52 km/h; 32 mph), though by 1945, with the addition of other equipment, such as anti-aircraft weaponry, their maximum speed was reduced to 26.8 knots (49.6 km/h; 30.8 mph). The increases in weight also reduced the ships' cruising range. In 1941, the ships could steam for 17,450 nautical miles (32,320 km; 20,080 mi) at a cruising speed of 15 knots (28 km/h; 17 mph); by 1945,
6293-402: A top speed of 35 knots (65 km/h; 40 mph) and a range of 20,000 nautical miles (37,000 km; 23,000 mi) when traveling at the more economical speed of 15 knots (28 km/h; 17 mph). Their plan fulfilled these requirements with a ship of 50,940 long tons (51,760 t) standard displacement, but Chantry believed that more could be done if the ship were to be this large; with
Iowa-class battleship - Misplaced Pages Continue
6496-417: A total of 5-inch (127 mm). In the outboard sections of the hull the plating was 4.1-inch (104 mm) Class B laminated on 1.4-inch (36 mm) STS. The third and thinnest deck was 0.62-inch (16 mm) thick inboard, and .75-inch (19 mm) outboard. The first deck was designed to cause delay-fuzed projectiles to detonate, while the thicker second deck would protect the ships' internals. The third deck
6699-410: A total of forty, but five were removed—along with all of the .50 caliber guns—shortly thereafter when two quadruple sets of 1.1 in guns were added. In its refit after being torpedoed, North Carolina had an additional six 20 mm guns added and all of its .50 caliber weapons removed. Washington had sixty-four 20 mm weapons by April 1943, prior to one single mount being replaced by
6902-469: Is sloped at 19 degrees, equivalent to 17.3 in (439 mm) of vertical class B armor at 19,000 yards. The armor belt extends to the triple bottom, where the Class B lower portion tapers to 1.62 inches (41 mm). The ends of the armored citadel are closed by 11.3-inch (287 mm) vertical Class A transverse bulkheads for Iowa and New Jersey . The transverse bulkhead armor on Missouri and Wisconsin
7105-473: Is that, although one might see the North Carolina s [as actually built] in several of these designs, that was not in fact so. The General Board was never entirely sure of what it was willing to give up to achieve some kind of ship within the treaty-limited displacement. [...] The fast capital ship with nine guns, and a speed of 30 knots, yet having good protection, was ultimately rejected in favor of
7308-493: The AN/SPY-1 Aegis Combat System radar on the battleships – were suggested in 1962, 1974, and 1977, but as before, these proposals failed to gain the needed authorization. This was due, in part, to the possibility that sensitive electronics within 200 ft (61 m) of any 16-inch gun muzzle may be damaged from overpressure. In 1980, Ronald Reagan was elected president on a promise to build up
7511-643: The Battle of the Philippine Sea , and conducted shore bombardments. Washington also participated in a surface engagement, the Naval Battle of Guadalcanal , where its radar-directed main batteries fatally damaged the Japanese battleship Kirishima . Both battleships were damaged during the war, with North Carolina taking a torpedo hit in 1942 and Washington colliding with Indiana in 1944. After
7714-481: The Bureau of Construction and Repair . However, the General Board finally decided to use faster ships, which "G" and "H" were not. These studies demonstrated the difficulty the designers faced with a displacement of 35,000 tons. They could choose a faster ship, able to steam at 30 knots, but that would force them to mount a lighter armament and armor than contemporary foreign battleships. Alternatively, they could choose
7917-526: The Confederate States Navy . Generally accepted by military historians and widely used in the more recent books, webpages and papers on the subject matter (most notably the releases of Osprey Publishing ), these latter-day classifications are sometimes considered "semi-official" (although they are not). Contemporary records, such as the " Official Records of the Union and Confederate Navies in
8120-677: The Fast Carrier Task Force and also shelled Japanese positions. During the Korean War , the battleships provided naval gunfire support (NGFS) for 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 missiles during
8323-450: The Iowa class was to consist of only four battleships with hull numbers BB-61 to BB-64: Iowa , New Jersey , Missouri , and Wisconsin . However, changing priorities during World War II resulted in the battleship hull numbers BB-65 Montana and BB-66 Ohio being reordered as Illinois and Kentucky , respectively; Montana and Ohio were reassigned to hull numbers BB-67 and BB-68. At
Iowa-class battleship - Misplaced Pages Continue
8526-578: The Iowa s have a double bottom hull that becomes a triple bottom under the armored citadel and armored skegs around the inboard shafts. 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 U.S. Navy moved quickly to develop a 45,000-ton-standard battleship that would pass through the 110 ft (34 m) wide Panama Canal . Drawing on
8729-548: The Mark 7 , that was both lighter and smaller in outside diameter; this allowed it to be placed in a turret that would fit in the smaller barbette. The redesigned 3-gun turret, equipped as it was with the Mark 7 naval gun, provided an overall weight saving of nearly 850 long tons (864 t) to the overall design of the Iowa class. The contract design displacement subsequently stood at 45,155 long tons (45,880 t) standard and 56,088 long tons (56,988 t) full load. In May 1938,
8932-830: The New Jersey was reactivated in 1968 for the Vietnam War, she was outfitted with the ULQ-6 ECM system. Like all battleships, the Iowa s carried heavy armor protection against shellfire and bombs with significant underwater protection against torpedoes. The Iowa s' " all-or-nothing " armor scheme was largely modeled on that of the preceding South Dakota class, and designed to give a zone of immunity against fire from 16-inch/45-caliber guns between 18,000 and 30,000 yards (16,000 and 27,000 m; 10 and 17 mi) away. The protection system consists of Class A face-hardened Krupp cemented (K.C.) armor and Class B homogeneous Krupp-type armor; furthermore, special treatment steel (STS),
9135-478: The New York Naval Shipyard and Philadelphia Naval Shipyard , were run by the government. When bids were reviewed, the privately run shipyards' submissions ranged from $ 46 to 50 million, while their government counterparts came in at $ 37 million. Newport News was unique among these in refusing any fixed monetary value in favor of a "cost-plus 3 + 1 ⁄ 2 %" price, but this led to
9338-500: 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-inch (27.9 mm)/75-caliber guns that were to be used for anti-aircraft (AA) work with 20 mm (0.79 in)/70 caliber Oerlikon cannons and 40 mm (1.57 in)/56 caliber Bofors guns , and moving the combat information center into
9541-507: The North Carolina class and the follow-up South Dakota class , the nine 16 in/45 were improved versions of the guns mounted on the Colorado -class battleships , hence the designation of "Mark 6". A major alteration from the older guns was the Mark 6's ability to fire a new 2,700-pound (1,200-kilogram) armor-piercing (AP) shell developed by the Bureau of Ordnance. At full charge with
9744-446: The North Carolina class were equipped with four General Electric geared turbines and eight Babcock & Wilcox three-drum express type boilers. The ships' powerplant incorporated several recent developments in turbine equipment, including double helical reduction gears and high-pressure steam technology. North Carolina ' s boilers supplied steam at 575 psi (3,960 kPa ) and as hot as 850 °F (454 °C). To meet
9947-491: The Pacific Theater of World War II , and accounted for roughly half of all Japanese aircraft shot down between 1 October 1944 and 1 February 1945. Although successful in this role against WWII aircraft, the 40 mm guns were stripped from the battleships in the jet age – initially from New Jersey when reactivated in 1968 and later from Iowa , Missouri, and Wisconsin when they were reactivated for service in
10150-636: The RIM-2 Terrier missile after World War II. One such proposal came from Rear Admiral W.K. Mendenhall, Chairman of the Ship Characteristics Board (SCB) ; Mendenhall proposed a plan that called for $ 15–30 million to be spent to allow Kentucky to be completed as a guided-missile battleship (BBG) carrying eight SSM-N-8 Regulus II guided missiles with a range of 1,000 nautical miles (1,900 km; 1,200 mi). He also suggested Terrier or RIM-8 Talos launchers to supplement
10353-496: The United States Navy in the late 1930s and early 1940s. In planning a new battleship class in the 1930s, the US Navy was heavily constrained by international treaty limitations, which included a requirement that all new capital ships have a standard displacement of under 35,000 LT (35,600 t ). This restriction meant that the navy could not construct a ship with the firepower, armor, and speed that they desired, and
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#173278728063010556-715: The Vought OS2U Kingfisher and Curtiss SC Seahawk , both of which were employed to spot for the battleship's main gun batteries – and, in a secondary capacity, perform search-and-rescue missions. By the time of the Korean War, helicopters had replaced floatplanes and the Sikorsky HO3S-1 helicopter was employed. New Jersey made use of the Gyrodyne QH-50 DASH drone for her Vietnam War deployment in 1968–69. The Iowa class were
10759-519: The War Plans Division , although at least one officer believed that an aerial attack would also be capable of sinking the Kongō s. With the above recommendations, the General Board selected "K" to undergo further development. At least 35 different final designs were proposed. All numbered with Roman numerals ("I" through "XVI-D"), the first five were completed on 15 November 1935. They were
10962-415: The bridge ; capable of 30 knots; and armored against 14-inch shells. "B" and "C" would both be over 36,000 long tons (37,000 t), able to reach 30.5 kn (56.5 km/h; 35.1 mph), and armored against 14-inch shells. The major difference between the two was the planned main battery , as "B" had twelve 14-inch guns in triple turrets, while "C" had eight 16-inch/45-caliber guns in dual turrets. "A"
11165-474: The lead ship , the first ship commissioned or built of its design. However, other systems can be used without confusion or conflict. A descriptive name may be used; for example it was decided to group destroyers made to the same design as HMS Tomahawk , all named after weapons, as the Weapon rather than Tomahawk class. In European navies, a class is named after the first ship commissioned regardless of when it
11368-418: The "escalator clause" that would permit maximum standard capital ship displacement of 45,000 long tons (45,700 t). Using the additional 10,000 long tons (10,200 t) over previous designs, the studies included schemes for 27-knot (50 km/h; 31 mph) "slow" battleships that increased armament and protection as well as "fast" battleships capable of 33 knots (61 km/h; 38 mph) or more. One of
11571-513: The "slow" designs was an expanded South Dakota class carrying either twelve 16-inch/45 caliber Mark 6 guns or nine 18-inch (457 mm)/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. 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
11774-471: The 16-inch gun's significantly greater armor penetration was of paramount importance, drawing examples from the First World War 's Battle of Jutland , where some battleships were able to survive ten or twenty hits from large guns, but other battlecruisers were blown up in three to seven hits because the shells were able to cut through the armor protecting magazines and turrets. Reeves also argued that
11977-453: The 16-inch guns and a quartet of 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. The range estimation of these gunfire control systems provided
12180-473: The 16-inch would be able to break through. In a final vain attempt, Roosevelt's Secretary of State Cordell Hull sent a telegram on 4 June to the Ambassador to Japan Joseph Grew instructing him that the United States would still accept a cap of 14-inch guns if he could get Japan to as well. The Japanese replied that they could not accept this unless the number of battleships was also limited; they wanted
12383-587: The 1930s, these guns were so successful that they were added to a myriad of American ships during the Second World War, including every major ship type and many smaller warships constructed between 1934 and 1945. They were considered to be "highly reliable, robust and accurate" by the Navy's Bureau of Ordnance. The 5-inch/38 functioned as a dual purpose gun . However, this did not mean that it possessed inferior anti-air abilities; as established during 1941 gunnery tests conducted on board North Carolina ,
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#173278728063012586-480: The 1980s, as part of the 600-ship Navy initiative. During Operation Desert Storm in 1991, Missouri and Wisconsin fired missiles and 16-inch (406 mm) guns at Iraqi targets. Costly to maintain, the battleships were decommissioned during the post- Cold War drawdown in the early 1990s. All four were initially removed from the Naval Vessel Register , but the United States Congress compelled
12789-464: The 1980s. The powerplant of the Iowa s consists of eight Babcock & Wilcox boilers and four sets of double reduction cross-compound geared turbines , with each turbine set driving a single shaft. Specifically, the geared turbines on Iowa and Missouri were provided by General Electric , while the equivalent machinery on New Jersey and Wisconsin was provided by Westinghouse . The plant produced 212,000 shp (158,000 kW) and propelled
12992-413: The 2,700-pound (1,225 kg) Mk 8 "Super-heavy" APC (Armor Piercing, Capped) shell for anti-ship and anti-structure work, and the 1,900-pound (862 kg) Mk 13 high-explosive round designed for use against unarmored targets and shore bombardment. When firing the same conventional shell, the 16-inch/45 caliber Mark 6 used by the fast battleships of the North Carolina and South Dakota classes had
13195-408: The 35,000-long-ton (36,000 t) South Dakota class. The first plans made for this indicated that 30 knots (56 km/h; 35 mph) was possible on a standard displacement of about 37,600 long tons (38,200 t). 33 knots (61 km/h; 38 mph) could be bought with 220,000 shp (160,000 kW) and a standard displacement of around 39,230 long tons (39,860 t), which was well below
13398-424: The 45,000-long-ton (46,000 t) limit. An apparent savior appeared in a Bureau of Ordnance preliminary design for a turret that could carry the 50-caliber guns and also fit in the smaller barbette of the 45-caliber gun turret. Other weight savings were achieved by thinning some armor elements and substituting construction steel with armor-grade Special Treatment Steel (STS) in certain areas. The net savings reduced
13601-621: The AA guns and proposed nuclear (instead of conventional) shells for the 16-inch guns. This never materialized, and Kentucky was ultimately sold for scrap in 1958, although her bow was used to repair her sister Wisconsin after a collision on 6 May 1956, earning her the nickname WisKy . In 1954, the Long Range Objectives Group of the United States Navy suggested converting the Iowa -class ships to BBGs. In 1958,
13804-536: The Bureau of Ships offered a proposal based on this idea. This replaced the 5- and 16-inch gun batteries with "two Talos twin missile systems, two RIM-24 Tartar twin missile systems, an RUR-5 ASROC antisubmarine missile launcher, and a Regulus II installation with four missiles", as well as flagship facilities, sonar, helicopters, and fire-control systems for the Talos and Tartar missiles. In addition to these upgrades, 8,600 long tons (8,700 t) of additional fuel oil
14007-480: The Chief of Naval Operations, who approved "XVI" in its newly modified form over the hopes of the General Board, who still thought that "XVI-C" should be built. Standley's only addition to the characteristics was to be able to switch from quadruple 14-inch to triple 16 in (406 mm) turrets if the "escalator clause" in the Second London Naval Treaty was invoked. With these parameters now set, "XVI" would become
14210-671: The French Dunkerque ) while still mounting 12 guns. Many officers in the United States Navy supported the construction of three or four fast battleships for carrier escorts and to counter Japan's Kongō class . These included the acting Secretary of the Navy and Chief of Naval Operations Admiral William Standley , the president of the Naval War College Admiral William S. Pye , a small majority (9–7) of senior officers at sea, and five of six line officers engaged in strategic planning as part of
14413-516: The Japanese Kamikaze attacks used during the latter half of World War II and were subsequently phased out in favor of the heavier Bofors 40-millimeter (1.6 in) AA gun. When the Iowa -class battleships were commissioned in 1943 and 1944, they carried twenty quad 40 mm AA gun mounts, which they used for defense against enemy aircraft. These heavy AA guns were also employed in the protection of Allied aircraft carriers operating in
14616-649: 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. For "fast" battleships, one such 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 (127 mm) guns, Panamax capability but otherwise unlimited displacement,
14819-489: The Japanese fleet into battle. Even the new standard battle line speed of 27 knots, as the preceding North Carolina -class and South Dakota -class 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. At the same time, a special strike force consisting of fast battleships operating alongside carriers and destroyers
15022-497: The London Treaty's "escalator clause" maximum limit of 45,000 long tons (45,700 t). These designs were able to convince the General Board that a reasonably well-designed and balanced 33-knot "fast" 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,
15225-564: The Mark 6: 23.64 miles (38.04 km) vs 22.829 miles (36.740 km). In the 1950s, the W23, an adaptation of the W19 nuclear artillery shell , was developed specifically for the 16-inch guns. The shell weighed 1,900 pounds (862 kg), had an estimated yield of 15 to 20 kilotons of TNT (63,000 to 84,000 GJ), and its introduction made the Iowa -class battleships' 16-inch guns the world's largest nuclear artillery and made these four battleships
15428-527: The Mk 8 armor-piercing shell due to the weapon's increased muzzle velocity and improved shell penetration; increasing the armor would have increased weight and reduced speed, a compromise that the General Board was not willing to make. The Iowa s' torpedo defense was based on the South Dakota s' design, with modifications to address shortcomings discovered during caisson tests. The system is an internal "bulge" that consists of four longitudinal torpedo bulkheads behind
15631-479: The Navy to reinstate two of them on the grounds that existing shore bombardment capability would be inadequate for amphibious operations . This resulted in 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 ships part of non-profit maritime museums across
15834-437: The Navy's Bureau of Ordnance. Each 5-inch/38 gun weighed almost 4,000 pounds (1,800 kg) without the breech; the entire mount weighed 156,295 pounds (70,894 kg). It was 223.8 inches (5,680 mm) long overall, had a bore length of 190 inches (4,800 mm), and a rifling length of 157.2 inches (3,990 mm). The gun could fire shells at about 2,500–2,600 ft/s (760–790 m/s); about 4,600 could be fired before
16037-546: The SK-2 air-search radar and SG surface-search radar; the Iowa class was updated to make use of these systems between 1945 and 1952. At the same time, the ships' radar systems were augmented with the installation of the SP height finder on the main mast. In 1952, AN/SPS-10 surface-search radar and AN/SPS-6 air-search radar replaced the SK and SG radar systems, respectively. Two years later
16240-481: The SP height finder was replaced by the AN/SPS-8 height finder, which was installed on the main mast of the battleships. In addition to these search and navigational radars, the Iowa class were also outfitted with a variety of fire control radars for their gun systems. Beginning with their commissioning, the battleships made use of a pair of Mk 38 gun fire control systems with Mark 8 fire control radar to direct
16443-592: The SPT-1 and SPT-4 equipment; passive electronic support measures (ESM) were a pair of DBM radar direction finders and three intercept receiving antennas, while the active components were the TDY-1 jammers located on the sides of the fire control tower. The ships were also equipped with the identification, friend or foe (IFF) Mark III system, which was replaced by the IFF Mark X when the ships were overhauled in 1955. When
16646-603: The Second London Treaty—France, the United Kingdom and the United States—to raise the limit from 14 to 16 inches if Japan or Italy still refused to sign after 1 April 1937. When figuring potential configurations for the North Carolina s, designers focused most of their planning on 14-inch weaponry; Standley's requirement meant that a switch from 14- to 16-inch, even after the ships' keels had been laid,
16849-487: The U.S. Navy's traditional 21-knot battle line of "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 Kongō -class battlecruisers, which had been upgraded in the 1930s to fast battleships . As a result, the U.S. Navy envisioned a fast detachment of the battle line that could bring
17052-409: The US Navy had consistently advocated armor and firepower at the expense of speed. Even in adopting fast battleships of the North Carolina class, it had preferred the slower of two alternative designs. Great and expensive improvements in machinery design had been used to minimize the increased power on the designs rather than make extraordinary powerful machinery (hence much higher speed) practical. Yet
17255-586: The US military as a response to the increasing military power of the Soviet Union . The Soviet Navy was commissioning the Kirov class of missile cruisers, the largest type of surface combatant since World War II . As part of Reagan's 600-ship Navy policy and as a counter to the Kirov class, the US Navy began reactivating the four Iowa -class units and modernizing them for service. Ship class In
17458-467: The US. The vessels that eventually became the Iowa -class battleships were born from the U.S. Navy's War Plan Orange , a Pacific war plan against Japan. War planners anticipated that the U.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
17661-685: The United States Congress passed the Second Vinson Act , which "mandated a 20% increase in strength of the United States Navy ". The act was sponsored by Carl Vinson , a Democratic Congressman from Georgia who was Chairman of the House Naval Affairs and Armed Services Committee. The Second Vinson Act updated the provisions of the Vinson-Trammell Act of 1934 and the Naval Act of 1936, which had "authorized
17864-414: The United States and the United Kingdom to agree to having an equal number of battleships with Japan, but this was a condition that the two countries refused to accept. On 24 June, the two North Carolina s were ordered with the 14-inch weapons, but on 10 July, Roosevelt directed that they be armed with triple 16-inch instead. The North Carolina was 713 feet 5.25 inches (217.456 m) long at
18067-586: The War of the Rebellion " (Series 2, Volume 1, Part 1), show that the modern nomenclature was not in use at the time. The unofficial retro-applying of ship classes can occasionally lead to confusion. For example, while American works consistently adhere to the City - and Columbia -class monikers, works of British origin refer to the same classes as Cairo class and Tennessee class respectively, in compliance with
18270-582: The accepted European convention, some classes have been named after a common theme in the included ships' names, e.g., Tribal-class destroyers , and some classes were implemented as an organizational tool, making traditional methods of naming inefficient. For instance, the Amphion class is also known as the A class. Most destroyer classes were known by the initial letter used in naming the vessels, e.g., V and W-class destroyers . Classification by letter also helped to conflate similar smaller classes of ships as in
18473-409: The addition of 6 knots (11 km/h; 6.9 mph) over the South Dakota s. Rather than retaining the 16-inch/45 caliber Mark 6 guns used in the South Dakota s, they ordered that the preliminary design would have to include the more powerful but significantly heavier 16-inch/50 caliber Mark 2 guns left over from the canceled Lexington -class battlecruisers and South Dakota -class battleships of
18676-407: The administration of President Woodrow Wilson called for building an additional ten battleships and six battlecruisers. The 1919–1920 General Board proposals planned for slightly smaller, but still significant, acquisitions beyond the 1916 plan: two battleships and a battlecruiser for the fiscal year 1921, and three battleships, a battlecruiser, four aircraft carriers and thirty destroyers between
18879-647: The aft main battery director, which required additional reinforcing braces due to the vibrations. Nevertheless, skegs would be improved and incorporated in the designs of all subsequent American battleships, with vibration problems largely eliminated on the Iowa class battleships. North Carolina and Washington were principally armed with nine 16-inch (406 mm)/45 caliber (cal) Mark 6 guns and twenty 5-inch (127 mm)/38 cal Mark 12 guns. Their lighter armament consisted of varying numbers of 1.1-inch (28 mm)/75 caliber , .50 caliber machine guns, Bofors 40 mm and Oerlikon 20 mm . Mounted on both
19082-551: The armored hull. 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
19285-510: The balancing uncertainty that resulted meant that the navy considered fifty widely varying designs. Eventually, the General Board of the United States Navy declared its preference for a battleship with a speed of 30 knots (56 km/h; 35 mph), faster than any in US service, with a main battery of nine 14-inch (356 mm)/50 caliber Mark B guns . The board believed that these ships would be balanced enough to effectively take on
19488-464: The barbettes. These guns fire high explosive- and armor-piercing shells and can fire a 16-inch shell approximately 23.4 nautical miles (43.3 km; 26.9 mi). The guns are housed in three 3-gun turrets: two forward of the battleship's superstructure and one aft, in a configuration known as "2-A-1". The guns are 66 feet (20 m) long (50 times their 16-inch bore, or 50 calibers from breechface to muzzle ). About 43 feet (13 m) protrudes from
19691-527: The barrel needed to be replaced. Minimum and maximum elevations were −15 and 85 degrees, respectively. The guns' elevation could be raised or lowered at about 15 degrees per second. The mounts closest to the bow and stern could aim from −150 to 150 degrees; the others were restricted to −80 to 80 degrees. They could be turned at about 25 degrees per second. The mounts were directed by four Mark 37 fire control systems primarily through remote power control (RPC). The 5-inch/38 gun functioned as
19894-478: The basis of the North Carolina class' as-built design despite additional back and forth over the design's final particulars. These included an increase in armor; something allowed by the finding of more on-paper weight savings; the armor's slope was increased from 10° to 13°, and eventually settled at 15°; a months-long debate on the propulsion machinery's layout was finally concluded, and other minor changes. The point of this rather long and erratic design history
20097-589: The battleships. Since each battleship carried a small detachment of Marines aboard, the Marines would man one of the 5-inch gun mounts. At the time of their commissioning, all four of the Iowa -class battleships were equipped with 20 quad 40 mm mounts and 49 single 20 mm mounts. These guns were respectively augmented with the Mk ;14 range sight and Mk 51 fire control system to improve accuracy. The Oerlikon 20-millimeter (0.8 in) gun, one of
20300-525: The case of the A-class destroyers of 1913 whose names spread across the alphabet. Since the end of the Second World War , Royal Navy ship classes have also been known by their type number (e.g. Type 45 destroyer .) For the United States Navy , the first ship in a class to be authorized by Congress is the designated class leader and gives the name to the class, regardless of the order in which
20503-586: The centerline, extending down to the main armor deck. The conning tower armor is Class B with 17.3 inches (439 mm) on all sides and 7.25 inches (184 mm) on the roof. The secondary battery turrets and handling spaces were protected by 2.5 inches (64 mm) of STS. The propulsion shafts and steering gear compartment behind the citadel had considerable protection, with 13.5-inch (343 mm) Class A side strake and 5.6–6.2-inch (142–157 mm) roof. The armor's immunity zone shrank considerably against guns equivalent to their own 16-inch/50-caliber guns armed with
20706-428: The class to have a lengthened forecastle and amidship, which would increase speed, and a bulbous bow . The Iowa s exhibit good stability, making them steady gun platforms. At design combat displacement, the ships' (GM) metacentric height was 9.26 ft (2.82 m). They also have excellent maneuverability in the open water for their size, while seakeeping is described as good, but not outstanding. In particular,
20909-565: The class, Illinois and Kentucky , by eliminating knuckles along certain bulkheads; this was estimated to improve the strength of the system by as much as 20%. Based on costly lessons in the Pacific theater, concerns were raised about the ability of the armor on these battleships to withstand aerial bombing, particularly high-altitude bombing using armor-piercing bombs. Developments such as the Norden bombsight further fueled these concerns. While
21112-482: The construction of the first American battleships in 17 years", based on the provisions of the London Naval Treaty of 1930; this act was quickly signed by President Franklin D. Roosevelt and provided the funding to build the Iowa class. Each ship cost approximately US$ 100 million. As 1938 drew to a close, the contract design of the Iowa s was nearly complete, but it would continuously evolve as
21315-468: The cost of speed and protection. After construction had begun, the United States invoked a so-called "escalator clause" in the international treaty to increase the class' main armament to nine 16-inch (406 mm)/45 caliber Mark 6 guns . Both North Carolina and Washington saw extensive service during the Second World War in a variety of roles, primarily in the Pacific Theater where they escorted fast carrier task forces , such as during
21518-413: The course of building a class of ships, design changes might be implemented. In such a case, the ships of different design might not be considered of the same class; each variation would either be its own class, or a subclass of the original class (see County-class cruiser for an example). If ships are built of a class whose production had been discontinued, a similar distinction might be made. Ships in
21721-673: The current convention to historical naval vessels sharing similarities, such as those of the American Civil War , where the Union Navy built several vessels in series, which can be termed "classes" as presently understood. Common examples include the Passaic -class monitor and the City-class ironclad , among many others, for the Union side, and Columbia class or Richmond class , for those ironclads in service with
21924-520: The design called for only 50,000 shp (37,000 kW ) and a length of only 640 ft (200 m). Most other plans called for 710 ft (220 m) or 725 ft (221 m), although a few had lengths between 660 ft (200 m) and 690 ft (210 m). Several different gun mountings were examined, including eight, nine, ten, eleven, and twelve 14-inch guns; eight 14-inch guns in two quadruple turrets, and even one design with two quadruple 16-inch guns. One specific design, "XVI,"
22127-470: The design for the 60,500-long-ton (61,500 t) Montana class after all treaty restrictions were removed following the start of World War II. Priority was given to the "fast" design in order to counter and defeat Japan's 30-knot (56 km/h; 35 mph) Kongō -class fast battleships, whose higher speed advantage over existing U.S. battleships might let them "penetrate U.S. cruisers, thereby making it 'open season' on U.S. supply ships", and then overwhelm
22330-406: The design of the Iowa s was too far along to adequately address this issue, experience in the Pacific theater eventually demonstrated that high-altitude unguided bombing was ineffective against maneuvering warships. When they were commissioned during World War II, the Iowa -class battleships came equipped with two aircraft catapults designed to launch floatplanes . Initially, the Iowa s carried
22533-588: The design of the North Carolina class, as can be attested to in the long quest to find a ship that incorporated everything the US Navy considered necessary while remaining under 35,000 long tons. With the end of the capital ship construction "holiday" approaching, the General Board began preparations for a new class of battleships in May–July 1935, and three design studies were submitted to them. "A" would be 32,150 long tons (32,666 t) armed with nine 14-inch (356 mm) guns in triple turrets , all forward of
22736-470: The design process of the Montana -class battleship would indicate an increase in drag. The skegs improved the structural strength of the stern by acting as girders and also provided structural continuity for the torpedo bulkheads. However, the skegs also contributed to severe vibration problems with the class that required extensive testing and modifications to mitigate. The problem was particularly acute near
22939-489: The design proposal to rebuild these two ships as aircraft carriers and they were cleared for construction as fast battleships to conform to the Iowa -class design, though they differed from the earlier four that were built. Eventually, the Cleveland -class light cruisers were selected for the aircraft-carrier conversion. Nine of these light cruisers would be rebuilt as Independence -class light aircraft carriers. After
23142-476: The design requirement of 27 kn (50 km/h; 31 mph), the engine system was originally designed to supply 115,000 shp (85,755 kW), but the new technologies increased this output to 121,000 shp (90,000 kW). Despite this increase, the maximum speed for the ships did not change, since the modifications to the powerplant were incorporated later in the design process. The turbines that had already been installed could not fully take advantage of
23345-554: The dismantling of the US nuclear artillery inventory is said to have been completed in 2004. The Iowa s carried twenty 5-inch (127 mm)/38 caliber Mark 12 guns in ten Mark 28 Mod 2 enclosed base ring mounts. Originally designed to be mounted upon destroyers built in the 1930s, these guns were so successful that they were added to many American ships during the Second World War, including every major ship type and many smaller warships constructed between 1934 and 1945. They were considered to be "highly reliable, robust and accurate" by
23548-473: The earlier single-purpose 5-inch/25 caliber AA gun. As Japanese airplanes became faster, the gun lost some of its effectiveness in the anti-aircraft role; however, toward the end of the war, its usefulness as an anti-aircraft weapon increased again because of an upgrade to the Mark ;37 Fire Control System, Mark 1A computer, and proximity-fused shells. The 5-inch/38 gun would remain on the battleships for
23751-439: The early 1920s. The 16"/50 turret weighed some 400 long tons (406 t) more than the 16"/45 turret already in use and also had a larger barbette diameter of 39 feet 4 inches (11.99 m) compared to the latter's barbette diameter of 37 feet 3 inches (11.35 m), so the total weight gain was about 2,000 long tons (2,030 t). This put the ship at a total of 46,551 long tons (47,298 t) – well over
23954-419: The effects, the third deck and triple bottom structure behind the lower armor belt were reinforced and the placement of brackets was changed. Iowa s' system was also improved over the South Dakota s' through closer spacing of the transverse bulkheads, greater thickness of the lower belt at the triple bottom joint, and increased total volume of the "bulge". The system was further modified for the last two ships of
24157-422: The empty compartment behind it absorb any remaining energy. However, the Navy discovered in caisson tests in 1939 that the initial design for this torpedo defense system was actually less effective than the previous design used on the North Carolina s due to the rigidity of the lower armor belt causing the explosion to significantly displace the final holding bulkhead inwards despite remaining watertight. To mitigate
24360-441: The end of World War II, the crew complement was reduced to 1,774. The North Carolina class hull feature a bulbous bow and had an unusual stern design for the time by placing the two inboard propulsion shafts in skegs. This was theorized to improve flow conditions to the propellers. Initial model basin testing for various stern configurations suggested that the skeg arrangement could reduce resistance, although later testing during
24563-602: The end of the war, both ships remained in commission for a brief time before being laid up in reserve. In the early 1960s, North Carolina was sold to the state of North Carolina as a museum ship , and Washington was broken up for scrap. After the end of the First World War , several navies continued and expanded naval construction programs that they had started during the conflict. The United States' 1916 program called for six Lexington -class battlecruisers and five South Dakota -class battleships ; in December 1918,
24766-418: The explosive magazines, and the Bureau believed that hits around this part of the hull were easily possible when fighting at ranges between 20,000 and 30,000 yd (9.9 and 14.8 nmi; 18 and 27 km). Other problems included the design's defense against aircraft-dropped bombs, as the Bureau thought the formula used to calculate its effectiveness was not realistic, and the tapering of a fore bulkhead below
24969-525: The first to employ so-called "paper" weight reductions: not counting certain weights towards the ship's 35,000 long ton treaty limit that were not specifically part of the definition of standard displacement . In this case, even though there was designed storage room for 100 shells per main battery gun and an extra 100 rounds, the weight of the rounds did not figure toward the treaty-mandated limit. These final designs varied greatly in everything but their standard displacements and speeds. Just one
25172-621: The fiscal years 1922 and 1924. The United Kingdom was in the final stages of ordering eight capital ships (the G3 battlecruisers , with the first's keel laying in 1921, and N3-class battleships , to be laid down beginning in 1922). Imperial Japan was, by 1920, attempting to build up to an 8-8 standard of eight battleships and eight battlecruisers or cruisers with the Nagato , Tosa , Amagi , Kii and Number 13 classes. Two ships from these designs were to be laid down per year until 1928. With
25375-553: The four largest battleships the US Navy produced were not much more than 33-knot versions of the 27-knot, 35,000 tonners that had preceded them. The Iowa s showed no advance at all in protection over the South Dakota s. The principal armament improvement was a more powerful 16-inch gun, 5 calibers longer. Ten thousand tons was a very great deal to pay for 6 knots. Norman Friedman , U.S. Battleships: An Illustrated Design History , p. 307. The Iowa -class battleships are 860 ft 0 in (262.13 m) long at
25578-788: The front bows and the back of the stern. The naming convention is: Russian (and Soviet ) ship classes are formally named by the numbered project that designed them. That project sometimes, but not always, had a metaphorical name, and almost always had a NATO reporting name . In addition, the ships of the class would have a number prefixed by a letter indicating the role of that type of vessel. For example, Project 641 had no name, though NATO referred to its members as Foxtrot-class submarines . The ship classification does not completely correspond common designation, particularly for destroyers, frigates and corvettes. Russia has its own classification system for these ships: The British Royal Navy (RN) has used several methods of naming classes. In addition to
25781-418: The gun house. Each gun weighs about 239,000 pounds (108,000 kg) without the breech, or 267,900 pounds (121,500 kg) with the breech. They fired 2,700-pound (1,225 kg) armor-piercing projectiles at a muzzle velocity of 2,500 ft/s (762 m/s ), or 1,900-pound (862 kg) high-capacity projectiles at 2,690 ft/s (820 m/s), up to 24 miles (21 nmi; 39 km). At maximum range,
25984-431: The gun possessed the ability to consistently shoot down aircraft flying at 12,000–13,000 feet (2.3–2.5 miles; 3.7–4.0 kilometres), which was twice as far as the effective range of the earlier single purpose 5-inch/25 anti-air gun. Each 5-inch/38 weighed almost 4,000 lb (1,800 kg) without the breech. The entire mount weighed 156,295 pounds (70,894 kilograms). It was 223.8 in (5,680 mm) long overall, had
26187-460: The heavy AP shell was obtained at an inclination of 45 degrees: 36,900 yd (33,700 m). At the same elevation a lighter 1,900-pound (860-kilogram) high capacity (HC) shell would travel 40,180 yards (20 nautical miles; 37 kilometres). The guns weighed 85.85 long tons (192,300 lb; 87,230 kg) not including the breech; the turrets weighed 1,403–1,437 long tons (3,143,000–3,219,000 lb; 1,426,000–1,460,000 kg). When firing
26390-422: The higher pressure and temperature steam, and so the level of efficiency was not as high as it should have been. When going astern, the engines provided 32,000 shp (24,000 kW). The engine system was divided into four engine rooms, all on the centerline. Each room contained a turbine and two boilers, without any division between the boilers and turbines. This was done to limit the risk of capsizing should
26593-401: The inboard pair consisting of five-bladed propellers 17 ft (5.18 m) in diameter. The propeller designs were adopted after earlier testing had determined that propeller cavitation caused a drop in efficiency at speeds over 30 kn (56 km/h; 35 mph). The two inner shafts were housed in skegs to smooth the flow of water to the propellers and improve the structural strength of
26796-486: The international importance of the United States not being the first to change the principles laid down in the Washington and London Treaties, it seems to me that the plans for the two new battleships should contemplate the ... 14-inch gun. Admiral Reeves also came out strongly in favor of the larger weapon. In a two-page letter to Secretary of the Navy Claude A. Swanson and indirectly to Roosevelt, Reeves argued that
26999-456: The larger gun would favor the "indirect method" of shooting then being developed, where airplanes would be used to relay targeting information to allied battleships so that they could bombard targets that were out of their sight or over the horizon, because new battleships being built by foreign powers would have more armor. Reeves believed that if the 14-inch gun was adopted, it would not be able to penetrate this larger amount of protection, whereas
27202-471: The last battleships commissioned in the U.S. Navy. All older U.S. battleships were 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 U.S. wars. In the Pacific Theater of World War II, they served primarily as fast escorts for Essex -class aircraft carriers of
27405-484: The last little bit of energy from the steam. After leaving the LP turbine, the exhaust steam passes into a condenser and is then returned as feed water to the boilers. Water lost in the process is replaced by three evaporators, which can make a total of 60,000 US gallons per day (3 liters per second) of fresh water. After the boilers have had their fill, the remaining fresh water is fed to the ship's potable water systems for drinking, showers, hand washing, cooking, etc. All of
27608-416: The latter requiring an additional foot of armored freeboard. Along with this came the associated weight in supporting these new strains: the structure of the ship had to be reinforced and the power plant enlarged to avoid a drop in speed. In all, about 2,400 long tons (2,440 t) had to be added, and the large margin the navy designers had previously thought they had – roughly 5,000 long tons (5,080 t) –
27811-422: The long fine bow and sudden widening of the hull just in front of the foremost turret contributed to the ships being rather wet for their size. This hull form also resulted in very intense spray formations, which led to some difficulty refueling escorting destroyers. The primary guns used on these battleships are the nine 16-inch (406 mm)/50-caliber Mark 7 naval guns, a compromise design developed to fit inside
28014-414: The main system be damaged. Total electrical output was 8,400 kilowatts, not including the emergency generators, at 450 volts on an alternating current . The North Carolina class incorporated " all or nothing " armor which weighed 41% of the total displacement; it consisted of an "armored raft" that extended from just forward of the first gun turret to just aft of the rear gun turret. They had
28217-598: The modern Royal Navy naming conventions. By the time the United States entered World War II, the current naming convention was in place, though it remains unclear as to exactly how and when the practice originated. Merchant ships are almost always classed by a classification society . These vessels are said to be in class when their hull, structures, machinery, and equipment conform to International Maritime Organization and MARPOL standards. Vessels out of class may be uninsurable and/or not permitted to sail by other agencies. A vessel's class may include endorsements for
28420-413: The most heavily produced anti-aircraft guns of the Second World War, entered service in 1941 and replaced the 0.50-inch (12.7 mm) M2 Browning MG on a one-for-one basis. Between December 1941 and September 1944, 32% of all Japanese aircraft downed were credited to this weapon, with the high point being 48.3% for the second half of 1942; however, the 20 mm guns were found to be ineffective against
28623-413: The new battleships. The private shipyards, however, had their own labor problems, so much so that one author described the navy's issues as "minimal" compared to their shipbuilding counterparts. This increased the price of the battleships to $ 60 million each, so the Bureau of Steam Engineering and Bureau of Construction and Repair recommended to their superiors that the $ 37 million tenders from
28826-412: The new battleships. As the bureaus were independent of one another, they did not realize that the two plans could not go together until November 1938, when the contract design was in the final stages of refinement. By this time, the ships could not use the larger barbette, as it would require extensive alterations to the design and would result in substantial weight penalties. Reverting to the 45-caliber gun
29029-475: The older SK radar and Mark 12s and 22s superseded the Mark 4s in September of that year. Aside from never receiving an SK-2, Washington was the recipient of similar upgrades. Both ships underwent extensive refits near the end or after the war. North Carolina received a secondary air search set (SR) and a SCR-720 zenith search radar on the forward funnel. At the end of the war, it had an SP surface-search,
29232-444: The only US Navy ships ever to have nuclear shells for naval guns. 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. In 1991, the United States unilaterally withdrew all of its nuclear artillery shells from service, and
29435-467: The only battleships with the speed required for post-war operations based around fast aircraft carrier task forces. There were several proposals in the early Cold War to convert the class to take into account changes in technology and doctrine. These included plans to equip the class with nuclear missiles, add aircraft capability, and – in the case of Illinois and Kentucky – a proposal to rebuild both as aircraft carriers instead of battleships. Initially,
29638-417: The outer hull plating with a system depth of 17.9 feet (5.46 m) to absorb the energy of a torpedo warhead. The extension of the armor belt to the triple bottom, where it tapers to a thickness of 1.62 inches (41 mm), serves as one of the torpedo bulkheads and was hoped to add to protection; the belt's lower edge was welded to the triple bottom structure and the joint was reinforced with buttstraps due to
29841-426: The powder bags used to fire them. Each turret required a crew of between 85 and 110 men to operate. The original cost for each turret was US$ 1.4 million, but this figure does not take into account the cost of the guns themselves. The turrets are "three-gun", not "triple", because each barrel is individually sleeved and can be elevated and fired independently. The ship could fire any combination of its guns, including
30044-400: The preliminary design displacement to 44,560 long tons (45,280 t) standard, though the margin remained tight. This breakthrough was shown to the General Board as part of a series of designs on 2 June 1938. However, the Bureau of Ordnance continued working on the turret with the larger barbette, while the Bureau of Construction and Repair used the smaller barbettes in the contract design of
30247-400: The projectile spends almost 1 + 1 ⁄ 2 minutes in flight. The maximum firing rate for each gun is two rounds per minute. Each gun rests within an armored turret, but only the top of the turret protrudes above the main deck. The turret extends either four decks (Turrets 1 and 3) or five decks (Turret 2) down. The lower spaces contain rooms for handling the projectiles and storing
30450-416: The proposal. In fact, both North Carolina and Washington carried 20 mm and .50 caliber guns for most of 1942. In April, North Carolina had, respectively, forty and twelve, while Washington had twenty and twelve. Two months later, the number of 20 mm guns remained the same, but twelve .50 caliber guns had been added. By September, Washington had twenty more 20 mm guns added, for
30653-535: The range at that speed was reduced to 16,320 nmi (30,220 km; 18,780 mi). At 25 knots (46 km/h; 29 mph), the range was considerably lower, at 5,740 nmi (10,630 km; 6,610 mi). Electrical power was supplied by eight generators. Four were turbo-generators designed for naval use; these provided 1,250 kilowatts each. The other four were diesel generators that supplied 850 kilowatts each. Two smaller diesel generators—each provided 200 kilowatts—supplied emergency power should
30856-495: The recommendations of 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 requested an entirely new design study, again focusing on increasing the size of
31059-418: The reduced underwater protection system, these sections received additional armor plating, up to 3.75-inch (95 mm) in thickness. The complete system was 18.5 ft (5.64 m) deep and designed to withstand warheads of up to 700 lb (320 kg) of TNT . Underwater protection was rounded out by a triple bottom that was 5.75 ft (2 m) deep. The bottom layer was 3 ft (1 m) thick and
31262-549: The rejection of their bid out of hand. The bids from private companies were heavily influenced by the legislation of the New Deal . The Vinson–Trammell Act limited profit from a ship's construction to 10 percent, while the Walsh–Healey Public Contracts Act specified a minimum wage and required working conditions for workers. The latter act greatly affected the ability of the navy to acquire steel, as
31465-604: The same shell, the 16-inch/45 Mark 6 had a slight advantage over the 16-inch/50 Mark 7 when hitting deck armor—a shell from a 45 cal gun would be slower, meaning that it would have a steeper trajectory as it descended. At 36,000 yards (18 nautical miles; 33 kilometres), a shell from a 45 cal would strike a ship at an angle of 47.5 degrees, as opposed to 38 degrees with the 50 cal. The North Carolina s carried ten Mark 28 Mod 0 enclosed base ring mounts, each supporting twin 5-inch/38-caliber Mark 12 guns Originally designed to be mounted on destroyers built in
31668-401: The ship have a Casualty Power System whose large 3-wire cables and wall outlets called "biscuits" can be used to reroute power. The earliest search radars installed were the SK air-search radar and SG surface-search radar during World War II. They were located on the mainmast and forward fire-control tower of the battleships, respectively. As the war drew to a close, the United States introduced
31871-399: The ship sustain heavy flooding in the engine rooms. The engine rooms alternated in their layout: the first and third engine rooms were arranged with the turbine on the starboard side and its corresponding boilers on the port, this was reversed in the second and fourth rooms. The forward-most engine room powered the starboard outer shaft, the second turbine drove the outer screw on the port side,
32074-859: The ship up to a maximum speed of 32.5 kn (60.2 km/h; 37.4 mph) at full load displacement and 33 kn (61 km/h; 38 mph) at normal displacement. The ships carried 8,841 long tons (8,983 t) of fuel oil which gave a range of 15,900 nmi (29,400 km; 18,300 mi) at 17 kn (31 km/h; 20 mph). Two semi-balanced rudders gave the ships a tactical turning diameter of 814 yards (744 m) at 30 kn (56 km/h; 35 mph) and 760 yards (695 m) at 20 kn (37 km/h; 23 mph). The machinery spaces were longitudinally divided into eight compartments with alternating fire and engine rooms to ensure adequate isolation of machinery components. Four fire rooms each contained two M-Type boilers operating at 600 pounds per square inch (4,137 kPa ; 42 kgf/cm ) with
32277-459: The ships of that class are laid down, launched or commissioned. Due to numbering conventions, the lead ship often has the lowest hull number of its class. (During World War II , the award of construction contracts was not always congruent with completion, so several ships had higher hull numbers than later ships.) Before the 1920s, naval vessels were classified according to shared characteristics. However, naval historians and scholars retro-apply
32480-431: The ships were originally designed to carry only four quadruple 1.1 in and twelve .50 caliber, this was greatly increased and upgraded during the war. On both ships, two more quadruple sets of 1.1 in guns were added in place of two searchlights amidships. After it was torpedoed in 1942, North Carolina had these removed and ten quadruple sets of 40 mm guns added. Fourteen were present by June 1943, while
32683-418: The ships were still "on the way" rather than after the ships had been launched. The Iowa s had heavily protected main battery turrets, with 19.5-inch (495 mm) Class B and STS face, 9.5-inch (241 mm) Class A sides, 12-inch (305 mm) Class A rear, and 7.25-inch (184 mm) Class B roof. The turret barbettes' armor is Class A with 17.3 inches (439 mm) abeam and 11.6 inches (295 mm) facing
32886-473: The ships' entire service life; however, the total number of guns and gun mounts was reduced from twenty guns in ten mounts to twelve guns in six mounts during the 1980s' modernization of the four Iowa s. The removal of four of the gun mounts was required for the battleships to be outfitted with the armored box launchers needed to carry and fire Tomahawk missiles. At the time of the 1991 Persian Gulf War , these guns had been largely relegated to littoral defense for
33089-413: The slight knuckle causing a structural discontinuity. The torpedo bulkheads were designed to elastically deform to absorb energy and the two outer compartments were liquid loaded in order to disrupt the gas bubble and slow fragments. The outer hull was intended to detonate a torpedo, with the outer two liquid compartments absorbing the shock and slowing any splinters or debris while the lower armored belt and
33292-408: The splinter deck is replaced by a 1-inch (25 mm) STS third deck that separates the magazine from the main armored deck. The powder magazine rooms are separated from the turret platforms by a pair of 1.5-inch STS annular bulkheads under the barbettes for flashback protection. The installation of armor on the Iowa s also differed from those of earlier battleships in that the armor was installed while
33495-583: The staggering costs associated with such programs, the United States' Secretary of State Charles Evans Hughes invited delegations from the major maritime powers—France, Italy, Japan, and the United Kingdom—to come together in Washington, D.C. to discuss, and hopefully end, the naval arms race. The subsequent Washington Naval Conference resulted in the 1922 Washington Naval Treaty . Along with many other provisions, it limited all future battleships to
33698-401: The stern. Each of the four engine rooms has a pair of 1,250 kW Ship's Service Turbine Generators (SSTGs), providing the ship with a total non-emergency electrical power of 10,000 kW at 450 volts alternating current. Additionally, the vessels have a pair of 250 kW emergency diesel generators. To allow battle-damaged electrical circuits to be repaired or bypassed, the lower decks of
33901-492: The surrender of the Empire of Japan , construction on Illinois and Kentucky stopped. Illinois was eventually scrapped, but Kentucky ' s construction had advanced enough that several plans were proposed to complete Kentucky as a guided missile battleship (BBG) by removing the aft turret and installing a missile system. A similar conversion had already been performed on the battleship Mississippi (BB-41/AG-128) to test
34104-692: The text of the law caused friction between executives in the industry, who greatly disliked the forty-hour work week and minimum wage requirements, and their workers—who themselves were embroiled in a separate dispute pitting the union of the skilled workers, the American Federation of Labor , against the union of the unskilled, the Congress of Industrial Organizations . Amid the unrest, the navy ran into difficulties trying to acquire 18 million pounds of steel to build six destroyers and three submarines; many more pounds than this would be needed for
34307-547: The third deck greatly reduced." Although the changes meant extra weight and increasing the beam by 1 foot (0.30 m) to 108 feet 2 inches (32.97 m), this was no longer a major issue; Britain and France had renounced the Second London Naval Treaty soon after the beginning of the Second World War . The design displacement was 45,873 long tons (46,609 t) standard, approximately 2% overweight, when Iowa and New Jersey were laid down in June and September 1940. By
34510-403: The third engine supplied power to the inner starboard propeller, and the fourth turbine drove the port-side inner screw. All four screws had four blades; the two outer propellers were 15 ft 4 in (4.67 m) in diameter and the inner pair were 16 ft 7.5 in (5.067 m) wide. Steering was controlled by a pair of rudders . At the time of their commissioning, the ships had
34713-648: The time of the ships' design; by 1939, however, it was possible to create 18-inch (457 mm)-thick plates. These were not installed because it was estimated that the conversion would delay completion of the ships by 6 to 8 months. The barbettes that held the turrets were also strongly protected. The front portion was 14.7 inches (373 mm), the sides increased to 16 in, and the rear portion reduced to 11.5-inch (292 mm). The 5-inch gun turrets, along with their ammunition magazines, were armored with 1.95-inch (50 mm) STS plates. The side protection system incorporated five compartments divided by torpedo bulkheads and
34916-439: The time the Iowa s were completed and commissioned in 1943–44, the considerable increase in anti-aircraft armament – along with their associated splinter protection and crew accommodations – and additional electronics had increased standard displacement to some 47,825 long tons (48,592 t), while full load displacement became 57,540 long tons (58,460 t). For half a century prior to laying [the Iowa class] down,
35119-450: The time these two battleships were to be built a proposal was put forth to have them constructed as aircraft carriers rather than fast battleships. The plan called for the ships to be rebuilt to include a flight deck and an armament suite similar to that placed aboard the Essex -class aircraft carriers that were at the time under construction in the United States. Ultimately, nothing came of
35322-428: 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
35525-621: The treaty limit. Although these original three studies were all "fast" battleships , the General Board was not committed to the higher maximum speeds. It posed questions to the Naval War College , asking for their opinion as to whether the new class should be a "conventional" 23-knot (43 km/h; 26 mph) ship with an eight-nine, 16-inch main battery, or rather one akin to "A", "B" or "C". Five more design studies were produced in late September 1935, which had characteristics of 23–30.5 knots, eight or nine 14- or 16-inch guns, and
35728-420: The treaty powers to expand the escalator clause in June 1938, which amended the standard displacement limit of battleships from 35,000 long tons (35,600 t) to 45,000 long tons (45,700 t). 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 , following the planned invocation of
35931-488: The two navy yards be accepted. This was confirmed by Roosevelt, as the private shipyards' bids were seen as unjustly inflated. The contracts for North Carolina and Washington —names had been officially chosen on 3 May 1937—were sent to the New York and Philadelphia yards, respectively, on 24 June 1937. Shortly after this announcement, Roosevelt was bombarded with heavy lobbying from citizens and politicians from Camden and
36134-470: The type of cargo such as "oil carrier", "bulk carrier", "mixed carrier" etc. It may also include class notations denoting special abilities of the vessel. Examples of this include an ice class , fire fighting capability, oil recovery capability, automated machinery space capability, or other special ability. North Carolina-class battleship The North Carolina class were a pair of fast battleships , North Carolina and Washington , built for
36337-474: The urinals and all but one of the toilets on the Iowa class flush with salt water in order to conserve fresh water. The turbines, especially the HP turbine, can turn at 2,000 rpm; their shafts drive through reduction gearing that turns the propeller shafts at speeds up to 225 rpm, depending upon the desired speed of the ship. The Iowa s were outfitted with four screws: the outboard pair consisting of four-bladed propellers 18.25 ft (5.56 m) in diameter and
36540-418: The waterline and 728 feet 8.625 inches (222.113 m) long overall. The maximum beam was 108 feet 3.875 inches (33.017 m) while waterline beam was 104 feet 6 inches (31.85 m) due to the inclination of the armor belt. In 1942, the standard displacement was 36,600 long tons (37,200 t) while full load displacement was 44,800 long tons (45,500 t), while maximum draft
36743-440: The waterline and 887 ft 3 in (270.43 m) long overall with a beam of 108 ft 2 in (32.97 m). During World War II, the draft was 37 ft 2 in (11.33 m) at full load displacement of 57,540 long tons (58,460 t) and 34 ft 9 + 1 ⁄ 4 in (10.60 m) at design combat displacement of 54,889 long tons (55,770 t). Like the two previous classes of American fast battleships,
36946-446: The waterline could worsen underwater shell hits because the mostly unarmored bow could easily be penetrated. The proposed solutions for these issues were all impractical: added patches of armor around the magazines could neutralize the effectiveness of the ship's torpedo-defense system, and deepening the belt near the bow and stern would put the ships over the 35,000 long ton limit. The General Board detested this design, saying it
37149-510: Was "not ... a true battleship" due to its speed and armor problems. To address these problems, a final set of designs was presented by the Preliminary Design section in October 1936. Designated "XVI-B" through "XVI-D," they were all modifications of the "XVI" plan. These added an extra 11 feet (3.4 m) of length to "XVI" for greater speed, but the resulting weight increase meant that only eleven 14-inch guns could be mounted with
37352-566: Was 35 feet 6 inches (10.82 m). At design combat displacement of 42,329 long tons (43,008 t), the mean draft was 31 feet 7.313 inches (9.635 m) and (GM) metacentric height was 8.31 feet (2.53 m). As designed, the crew complement was 1,880 with 108 officers and 1,772 enlisted. By 1945, the considerable increase in anti-aircraft armament and their crew accommodations had increased full load displacement to 46,700 long tons (47,400 t), while crew complement increased to 2,339 with 144 officers and 2,195 enlisted. After
37555-406: Was 7 inches (178 mm) thick and the bottom was 3.9 inches (99 mm) thick. The main battery turrets were heavily armored: the turret faces were 16-inch (406 mm) thick, the sides were 9-inch (229 mm) thick, the rear sides were 11.8-inch (300 mm) thick, and the roofs were 7-inch (178 mm) thick. Sixteen–inch-thick armor was the maximum width factories were able to produce at
37758-444: Was a 27-knot (50 km/h), 714 ft-long (218 m) ship with twelve 14-inch guns, a 11.2-inch (284.5 mm) belt, and a deck 5.1 to 5.6-inches (129.5 to 142.2 mm) thick. Produced on 20 August 1936, the Bureau of Ordnance found many problems in it. For example, model tests showed that at high speeds, waves generated by the hull would leave certain lower parts of the ship uncovered by water or adequate armor, including around
37961-405: Was also deemed unacceptable. The General Board was astounded; one member asked the head of the Bureau of Ordnance if it had occurred to him that Construction and Repair would have wanted to know what turret his subordinates were working on "as a matter of common sense". A complete scrapping of plans was avoided only when designers within the Bureau of Ordnance were able to design a new 50-caliber gun,
38164-461: Was also suggested to serve in part as ballast for the battleships and for use in refueling destroyers and cruisers. Due to the estimated cost of the overhaul ($ 178–193 million) this proposal was rejected as too expensive; instead, the SCB suggested a design with one Talos, one Tartar, one ASROC, and two Regulus launchers and changes to the superstructure, at a cost of up to $ 85 million. This design
38367-447: 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. Another factor was the "escalator clause" of the Second London Naval Treaty , which reverted the gun caliber limit from 14 inches (356 mm) to 16 inches (406 mm). Japan had refused to sign
38570-403: Was increased to 14.5 inches (368 mm); this extra armor provided protection from raking fire directly ahead, which was considered more likely given the high speed of the Iowa s. The deck armor consists of a 1.5-inch-thick (38 mm) STS weather deck, a combined 6-inch-thick (152 mm) Class B and STS main armor deck, and a 0.63-inch-thick (16 mm) STS splinter deck. Over the magazines,
38773-422: Was intended to protect against shell splinters that might have penetrated the second deck; it also acted as the upper support for the torpedo bulkheads . The conning tower was connected to the armored citadel by a 14-inch (356 mm) thick communications tube. Armor thickness for the conning tower itself ranged from 16 inches (406 mm) on both sides to 14.7 inches (373 mm) on the front and rear. The roof
38976-556: Was kept filled with fluid, while the upper 2.75-foot (1 m) thick layer was kept empty. The triple bottom was also heavily subdivided to prevent catastrophic flooding should the upper layer be penetrated. Two ships, each to cost about $ 50 million, were authorized in January 1937. Five shipyards submitted bids to build one of the two planned ships. Three were privately run corporations: Bethlehem Shipbuilding , New York Shipbuilding and Newport News Shipbuilding . The other two,
39179-551: Was later revised to accommodate the Polaris Fleet Ballistic Missile, which in turn resulted in a study of two schemes by the SCB. In the end, none of these proposed conversions for the battleships were ever authorized. Interest in converting the Iowa s into guided-missile battleships began to deteriorate in 1960 because the hulls were considered too old and the conversion costs too high. Nonetheless, additional conversion proposals – including one to install
39382-552: Was ordered or laid down. In some cases this has resulted in different class names being used in European and U.S. references; for example, European sources record the Colorado -class battleships of the United States Navy as the " Maryland class", as USS Maryland was commissioned before USS Colorado . The West German Navy ( Bundesmarine ) used a three-digit type number for every class in service or in advanced project state. Modified versions were identified by
39585-401: Was over the treaty displacement limit; every other design called for 35,000 long tons. Only five planned for a top speed of under 27 kn (50 km/h; 31 mph); of those, only one was lower than 26.5 kn (49.1 km/h): "VII", with 22 kn (41 km/h). "VII" returned to a lower speed to obtain more firepower (twelve 14-inch guns in triple turrets) and protection; as such,
39788-429: Was possible at any elevation. The mounts closest to the bow and stern could aim from −150 to 150 degrees; the others were restricted to −80 to 80 degrees. They could be turned at about 25 degrees per second. The remaining weaponry on board the two North Carolina s was composed of differing numbers of 1.1"/75 caliber guns, .50 caliber machine guns, Bofors 40 mm and Oerlikon 20 mm cannons. Although
39991-402: Was possible. Japan formally rejected the 14-inch limit on 27 March 1937, meaning that the "escalator clause" could be invoked. There were hurdles that still needed to be overcome, though: Roosevelt was under heavy political pressure and, as a result, was reluctant to allow the 16-inch gun. I am not willing that the United States be the first naval power to adopt the 16 in. gun. ... Because of
40194-456: Was replaced by a Mark 27 microwave radar supplemented by a Mark 3 main armament fire control radar. The range-finders were removed in favor of additional 20 mm guns sometime between the end of 1941 and mid-1942. In addition, the ships were commissioned with two Mark 38 directors and were originally fitted with a CXAM air search, two Mark 3s and three Mark 4 secondary armament. By November 1942, North Carolina had an additional Mark 4 and
40397-475: Was reportedly favored by President Franklin Delano Roosevelt , but as aircraft launched from catapults were necessarily inferior to most carrier- or land-based aircraft because of the floats used to land, nothing came of the design. Designs "G" and "H" were slower 23-knot ships with nine 14-inch guns; in particular, "H" was thought to be a very well balanced design by the Preliminary Design section of
40600-409: Was similar but added 75,000 shp (56,000 kW) (for a total of 300,000 shp (220,000 kW)) to meet the original requirement of 35 knots (65 km/h; 40 mph). 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) standard. In March 1938, the General Board followed
40803-431: Was suddenly vanishing. The draft of the ships was also allowed to increase, which enabled the beam to narrow and thus reduced the required power (since a lower beam-to-draft ratio reduces wave-making resistance ). This also allowed the ships to be shortened, which reduced weight. With the additional displacement, the General Board was incredulous that a tonnage increase of 10,000 long tons (10,200 t) would allow only
41006-547: Was the largest, at 59,060 long tons (60,010 t) standard, and was the only one to still carry the twelve 16-inch guns in four triple turrets (3-gun turrets according to US Navy). It required 277,000 shp (207,000 kW ) to make 32.5 knots (60.2 km/h; 37.4 mph). "B" was the smallest at 52,707 long tons (53,553 t) standard; like "A" it had a top speed of 32.5 knots, but "B" only required 225,000 shp (168,000 kW) to make this speed. It also carried only nine 16-inch guns, in three triple turrets. "C"
41209-411: Was the only one to remain within the 35,000-ton displacement limit set in the Washington Naval Treaty and reaffirmed in the Second London Naval Treaty. When the Bureau of Ordnance introduced a "super-heavy" 16-inch shell, the ships were redesigned in an attempt to provide protection against it, but this introduced severe weight problems; two of the designs were nearly 5,000 long tons (5,100 t) over
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