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172-565: USS Illinois (BB-65) was the fifth Iowa -class fast battleship that was laid down for the United States Navy during World War II in the 1940s, although she would not be completed. The Navy had initially planned on building four of the Iowa s and then developing a new, more powerful ship for what was to be BB-65. The pressing need for more warships at the outbreak of World War II in Europe led

344-557: 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:

516-528: A parts hulk until she was broken up in 1958. The Iowa class of fast battleships was designed in the late 1930s in response to the US Navy 's expectations for a future war with the Empire of Japan . American officers preferred comparatively slow but heavily armed and armored battleships, but Navy planners determined that such a fleet would have difficulty in bringing the faster Japanese fleet to battle, particularly

688-425: A superfiring pair forward, with the third aft. The planned secondary battery consisted of twenty 5 in (127 mm) /38 caliber dual purpose guns mounted in twin turrets clustered amidships , five turrets on either side. As designed, the ship was to be equipped with an anti-aircraft battery of eighty 40 mm (1.6 in) guns and forty-nine 20 mm (0.79 in) auto-cannon . The main armor belt

860-467: A weed hatch over the propeller, and once the narrowboat is stationary, the hatch may be opened to give access to the propeller, enabling debris to be cleared. Yachts and river boats rarely have weed hatches; instead they may fit a rope cutter that fits around the prop shaft and rotates with the propeller. These cutters clear the debris and obviate the need for divers to attend manually to the fouling. Several forms of rope cutters are available: A cleaver

1032-502: 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

1204-419: A better match of angle of attack to the wake velocity over the blades. A warped helicoid is described by specifying the shape of the radial reference line and the pitch angle in terms of radial distance. The traditional propeller drawing includes four parts: a side elevation, which defines the rake, the variation of blade thickness from root to tip, a longitudinal section through the hub, and a projected outline of

1376-434: A blade onto a longitudinal centreline plane. The expanded blade view shows the section shapes at their various radii, with their pitch faces drawn parallel to the base line, and thickness parallel to the axis. The outline indicated by a line connecting the leading and trailing tips of the sections depicts the expanded blade outline. The pitch diagram shows variation of pitch with radius from root to tip. The transverse view shows

1548-424: 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 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

1720-435: A combination riveted/welded hull used on the four completed Iowa -class ships. The ship was to have been powered by four General Electric steam turbines , each driving one screw propeller , using steam provided by eight oil-fired Babcock & Wilcox boilers . Rated at 212,000 shaft horsepower (158,000  kW ), the turbines were intended to give a top speed of 32.5 knots (60.2 km/h; 37.4 mph). The ship had

1892-399: 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

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2064-508: A ducted propeller. The cylindrical duct acts as the stator, while the tips of the blades act as the rotor. They typically provide high torque and operate at low RPMs, producing less noise. The system does not require a shaft, reducing weight. Units can be placed at various locations around the hull and operated independently, e.g., to aid in maneuvering. The absence of a shaft allows alternative rear hull designs. Twisted- toroid (ring-shaped) propellers, first invented over 120 years ago, replace

2236-402: 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

2408-400: A marine screw propeller is based on a helicoidal surface. This may form the face of the blade, or the faces of the blades may be described by offsets from this surface. The back of the blade is described by offsets from the helicoid surface in the same way that an aerofoil may be described by offsets from the chord line. The pitch surface may be a true helicoid or one having a warp to provide

2580-610: 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

2752-408: A planned cruising range of 15,000 nautical miles (28,000 km; 17,000 mi) at a speed of 15 knots (28 km/h; 17 mph). Her projected crew numbered 117 officers and 1,804 enlisted men. The ship was to have been armed with a main battery of nine 16 in (406 mm) /50 caliber Mark 7 guns guns in three triple- gun turrets on the centerline, two of which were placed in

2924-501: A propeller's forward thrust as being a reaction proportionate to the mass of fluid sent backward per time and the speed the propeller adds to that mass, and in practice there is more loss associated with producing a fast jet than with creating a heavier, slower jet. (The same applies in aircraft, in which larger-diameter turbofan engines tend to be more efficient than earlier, smaller-diameter turbofans, and even smaller turbojets , which eject less mass at greater speeds.) The geometry of

3096-411: 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 the earlier single-purpose 5-inch/25 caliber AA gun. As Japanese airplanes became faster,

3268-530: A row boat across Yarmouth Harbour and a small coastal schooner at Saint John, New Brunswick , but his patent application in the United States was rejected until 1849 because he was not an American citizen. His efficient design drew praise in American scientific circles but by then he faced multiple competitors. Despite experimentation with screw propulsion before the 1830s, few of these inventions were pursued to

3440-416: A rubber bushing can be replaced or repaired depends upon the propeller; some cannot. Some can, but need special equipment to insert the oversized bushing for an interference fit . Others can be replaced easily. The "special equipment" usually consists of a funnel, a press and rubber lubricant (soap). If one does not have access to a lathe, an improvised funnel can be made from steel tube and car body filler; as

3612-408: A screw propeller is derived from stern sculling . In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the water at the effective angle. The innovation introduced with the screw propeller was the extension of that arc through more than 360° by attaching the blade to a rotating shaft. Propellers can have a single blade , but in practice there

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3784-516: 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

3956-426: 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

4128-534: 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

4300-507: A speed of 4 mph (6.4 km/h), but Stevens abandoned propellers due to the inherent danger in using the high-pressure steam engines. His subsequent vessels were paddle-wheeled boats. By 1827, Czech inventor Josef Ressel had invented a screw propeller with multiple blades on a conical base. He tested it in February 1826 on a manually-driven ship and successfully used it on a steamboat in 1829. His 48-ton ship Civetta reached 6 knots. This

4472-402: 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

4644-445: Is a type of propeller design especially used for boat racing. Its leading edge is formed round, while the trailing edge is cut straight. It provides little bow lift, so that it can be used on boats that do not need much bow lift, for instance hydroplanes , that naturally have enough hydrodynamic bow lift. To compensate for the lack of bow lift, a hydrofoil may be installed on the lower unit. Hydrofoils reduce bow lift and help to get

4816-479: Is an opportunity to only change the pitch or the damaged blades. Being able to adjust pitch will allow for boaters to have better performance while in different altitudes, water sports, or cruising. Voith Schneider propellers use four untwisted straight blades turning around a vertical axis instead of helical blades and can provide thrust in any direction at any time, at the cost of higher mechanical complexity. A rim-driven thruster integrates an electric motor into

4988-531: Is modelled as an infinitely thin disc, inducing a constant velocity along the axis of rotation and creating a flow around the propeller. A screw turning through a solid will have zero "slip"; but as a propeller screw operates in a fluid (either air or water), there will be some losses. The most efficient propellers are large-diameter, slow-turning screws, such as on large ships; the least efficient are small-diameter and fast-turning (such as on an outboard motor). Using Newton's laws of motion, one may usefully think of

5160-493: Is nearly always more than one so as to balance the forces involved. The origin of the screw propeller starts at least as early as Archimedes (c. 287 – c. 212 BC), who used a screw to lift water for irrigation and bailing boats, so famously that it became known as Archimedes' screw . It was probably an application of spiral movement in space (spirals were a special study of Archimedes) to a hollow segmented water-wheel used for irrigation by Egyptians for centuries. A flying toy,

5332-465: 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

USS Illinois (BB-65) - Misplaced Pages Continue

5504-482: Is the tangential offset of the line of maximum thickness to a radius The propeller characteristics are commonly expressed as dimensionless ratios: Cavitation is the formation of vapor bubbles in water near a moving propeller blade in regions of very low pressure. It can occur if an attempt is made to transmit too much power through the screw, or if the propeller is operating at a very high speed. Cavitation can waste power, create vibration and wear, and cause damage to

5676-572: The Kongō -class battlecruisers and the aircraft carriers of the 1st Air Fleet . Design studies prepared during the development of the earlier North Carolina and South Dakota classes demonstrated the difficulty in resolving the desires of fleet officers with those of the planning staff in the displacement limits imposed by the Washington Naval Treaty system, which had governed capital ship construction since 1923. An escalator clause in

5848-484: 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

6020-594: The Essex -class, that more Essex -class carriers could be built in the same amount of time to convert the battleships, and that the project would be significantly more expensive than building new Essex -class carriers. Instead, Illinois and Kentucky were to be completed as battleships, but their construction was given very low priority. Illinois ' s keel was laid down at the Philadelphia Naval Shipyard , on 6 December 1942; her projected completion date

6192-645: 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

6364-400: 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

6536-708: The Iowa s carried 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

6708-561: 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

6880-545: 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,

7052-820: 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),

USS Illinois (BB-65) - Misplaced Pages Continue

7224-492: 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

7396-545: The Norden bombsight further fueled these concerns. While 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,

7568-488: 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

7740-484: The Paddington Canal from November 1836 to September 1837. By a fortuitous accident, the wooden propeller of two turns was damaged during a voyage in February 1837, and to Smith's surprise the broken propeller, which now consisted of only a single turn, doubled the boat's previous speed, from about four miles an hour to eight. Smith would subsequently file a revised patent in keeping with this accidental discovery. In

7912-619: 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

8084-565: The Second London Naval Treaty of 1936 that allowed an increase from 35,000 long tons (36,000  t ) to 45,000 long tons (46,000 t) in the event that any member nation refused to sign the treaty, which Japan refused to do. The passage of the Second Vinson Act in 1938 cleared the way for construction of the four South Dakota –class battleships and the first two Iowa -class battleships ( Iowa and New Jersey ) for

8256-505: The United States Navy . Two more vessels, Missouri and Wisconsin , were ordered in June 1940, and were to have been the final members of the Iowa class. The Navy initially planned to develop a new, more powerful design for the next battleship, designated "BB-65", which would eventually become the Montana class . But the need to adopt industrial mobilization as the threat of war loomed forced

8428-452: The bamboo-copter , was enjoyed in China beginning around 320 AD. Later, Leonardo da Vinci adopted the screw principle to drive his theoretical helicopter, sketches of which involved a large canvas screw overhead. In 1661, Toogood and Hays proposed using screws for waterjet propulsion, though not as a propeller. Robert Hooke in 1681 designed a horizontal watermill which was remarkably similar to

8600-417: The vapor pressure of the water, resulting in the formation of a vapor pocket. Under such conditions, the change in pressure between the downstream surface of the blade (the "pressure side") and the suction side is limited, and eventually reduced as the extent of cavitation is increased. When most of the blade surface is covered by cavitation, the pressure difference between the pressure side and suction side of

8772-418: 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

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8944-508: 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

9116-454: 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

9288-414: The 1880s. The Wright brothers pioneered the twisted aerofoil shape of modern aircraft propellers. They realized an air propeller was similar to a wing. They verified this using wind tunnel experiments. They introduced a twist in their blades to keep the angle of attack constant. Their blades were only 5% less efficient than those used 100 years later. Understanding of low-speed propeller aerodynamics

9460-471: 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

9632-467: 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

9804-470: 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

9976-408: 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

10148-424: 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

10320-602: 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,

10492-582: 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

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10664-509: 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

10836-736: 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,

11008-491: 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

11180-579: The Kirsten-Boeing vertical axis propeller designed almost two and a half centuries later in 1928; two years later Hooke modified the design to provide motive power for ships through water. In 1693 a Frenchman by the name of Du Quet invented a screw propeller which was tried in 1693 but later abandoned. In 1752, the Academie des Sciences in Paris granted Burnelli a prize for a design of a propeller-wheel. At about

11352-547: 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,

11524-490: 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

11696-525: 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

11868-507: The Navy to conclude that new designs would have to be placed on hold to allow the shipbuilding industry to standardize on a small number of designs. As a result, BB-65 was ordered to the Iowa design in 1940. Illinois was laid down in December 1942, but work was given a low priority, and was still under construction at the end of World War II. She was canceled in August 1945, but her hull remained as

12040-824: The Navy to place new designs on hold, and as a result, BB-65 and a second ship were ordered to the Iowa design. The last battleships to be built by the United States, the Iowa -class ships were also the US Navy's largest and fastest vessels of the type. Illinois was 887 feet 3 inches (270.4 m) long overall and had a beam of 108 ft 2 in (33 m) and a draft of 36 ft 2.25 in (11 m). Her standard displacement as completed would have amounted to 48,110 long tons (48,880 t) and increased to 57,540 long tons (58,460 t) at full combat load . Illinois differed from her earlier sisters in that her design called for an all-welded construction, which would have saved weight due to increased strength over

12212-479: 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

12384-452: The Royal Navy's view that screw propellers would prove unsuitable for seagoing service, Smith determined to prove this assumption wrong. In September 1837, he took his small vessel (now fitted with an iron propeller of a single turn) to sea, steaming from Blackwall, London to Hythe, Kent , with stops at Ramsgate , Dover and Folkestone . On the way back to London on the 25th, Smith's craft

12556-536: 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

12728-477: 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

12900-579: 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

13072-473: 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. 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

13244-496: 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

13416-480: 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

13588-409: 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

13760-651: 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. Screw propeller The principle employed in using

13932-460: 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

14104-597: 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

14276-463: The United States unilaterally withdrew all of its nuclear artillery shells from service, and the dismantling of the US nuclear artillery inventory is said to have been completed in 2004. 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

14448-528: The absence of lengthwise twist made them less efficient than the Wright propellers. Even so, this may have been the first use of aluminium in the construction of an airscrew. In the nineteenth century, several theories concerning propellers were proposed. The momentum theory or disk actuator theory – a theory describing a mathematical model of an ideal propeller – was developed by W.J.M. Rankine (1865), A.G. Greenhill (1888) and R.E. Froude (1889). The propeller

14620-409: 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

14792-510: The adoption of screw propulsion by the Royal Navy , in addition to her influence on commercial vessels. Trials with Smith's Archimedes led to a tug-of-war competition in 1845 between HMS  Rattler and HMS  Alecto with the screw-driven Rattler pulling the paddle steamer Alecto backward at 2.5 knots (4.6 km/h). The Archimedes also influenced the design of Isambard Kingdom Brunel 's SS  Great Britain in 1843, then

14964-539: 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

15136-466: 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

15308-419: The blade drops considerably, as does the thrust produced by the propeller. This condition is called "thrust breakdown". Operating the propeller under these conditions wastes energy, generates considerable noise, and as the vapor bubbles collapse it rapidly erodes the screw's surface due to localized shock waves against the blade surface. Tip vortex cavitation is caused by the extremely low pressures formed at

15480-400: The blades with a-circular rings. They are significantly quieter (particularly at audible frequencies) and more efficient than traditional propellers for both air and water applications. The design distributes vortices generated by the propeller across the entire shape, causing them to dissipate faster in the atmosphere. For smaller engines, such as outboards, where the propeller is exposed to

15652-406: 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 a dual-purpose gun (DP); that is, it was able to fire at both surface and air targets with

15824-400: The brass and moving parts on Turtle , was crafted by Issac Doolittle of New Haven. In 1785, Joseph Bramah of England proposed a propeller solution of a rod going through the underwater aft of a boat attached to a bladed propeller, though he never built it. In February 1800, Edward Shorter of London proposed using a similar propeller attached to a rod angled down temporarily deployed from

15996-453: The bushing in the hub is overcome and the rotating propeller slips on the shaft, preventing overloading of the engine's components. After such an event the rubber bushing may be damaged. If so, it may continue to transmit reduced power at low revolutions, but may provide no power, due to reduced friction, at high revolutions. Also, the rubber bushing may perish over time leading to its failure under loads below its designed failure load. Whether

16168-588: 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

16340-430: 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,

16512-475: 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

16684-460: The converted Illinois flight deck would have been 864 feet (263 m) long by 108 feet (33 m) wide, with an armament identical to the carriers of the Essex -class 's four twin 5-inch gun mounts and four more 5-inch guns in single mounts, along with six 40 mm quadruple mounts. The conversion was abandoned after the design team decided that the converted carriers would carry fewer aircraft than

16856-600: The core of the tip vortex. The tip vortex is caused by fluid wrapping around the tip of the propeller; from the pressure side to the suction side. This video demonstrates tip vortex cavitation. Tip vortex cavitation typically occurs before suction side surface cavitation and is less damaging to the blade, since this type of cavitation doesn't collapse on the blade, but some distance downstream. Variable-pitch propellers may be either controllable ( controllable-pitch propellers ) or automatically feathering ( folding propellers ). Variable-pitch propellers have significant advantages over

17028-412: The deck above the waterline and thus requiring no water seal, and intended only to assist becalmed sailing vessels. He tested it on the transport ship Doncaster at Gibraltar and Malta, achieving a speed of 1.5 mph (2.4 km/h). In 1802, American lawyer and inventor John Stevens built a 25-foot (7.6 m) boat with a rotary steam engine coupled to a four-bladed propeller. The craft achieved

17200-473: 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

17372-485: 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

17544-441: The distinction of being the first submarine used in battle. Bushnell later described the propeller in an October 1787 letter to Thomas Jefferson : "An oar formed upon the principle of the screw was fixed in the forepart of the vessel its axis entered the vessel and being turned one way rowed the vessel forward but being turned the other way rowed it backward. It was made to be turned by the hand or foot." The brass propeller, like all

17716-440: 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

17888-401: 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

18060-422: 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

18232-409: The engine at normal loads. The pin is designed to shear when the propeller is put under a load that could damage the engine. After the pin is sheared the engine is unable to provide propulsive power to the boat until a new shear pin is fitted. In larger and more modern engines, a rubber bushing transmits the torque of the drive shaft to the propeller's hub. Under a damaging load the friction of

18404-399: The filler is only subject to compressive forces it is able to do a good job. Often, the bushing can be drawn into place with nothing more complex than a couple of nuts, washers and a threaded rod. A more serious problem with this type of propeller is a "frozen-on" spline bushing, which makes propeller removal impossible. In such cases the propeller must be heated in order to deliberately destroy

18576-535: The fixed-pitch variety, namely: An advanced type of propeller used on the American Los Angeles-class submarine as well as the German Type 212 submarine is called a skewback propeller . As in the scimitar blades used on some aircraft, the blade tips of a skewback propeller are swept back against the direction of rotation. In addition, the blades are tilted rearward along the longitudinal axis, giving

18748-553: 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

18920-420: 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,

19092-459: 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 the ships' entire service life; however, the total number of guns and gun mounts

19264-401: 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

19436-462: 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

19608-484: 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

19780-421: The last two ships of 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

19952-416: 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) –

20124-424: 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

20296-616: The meantime, Ericsson built a 45-foot (14 m) screw-propelled steamboat, Francis B. Ogden in 1837, and demonstrated his boat on the River Thames to senior members of the British Admiralty , including Surveyor of the Navy Sir William Symonds . In spite of the boat achieving a speed of 10 miles an hour, comparable with that of existing paddle steamers , Symonds and his entourage were unimpressed. The Admiralty maintained

20468-413: 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

20640-412: 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

20812-470: 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,

20984-417: 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

21156-623: The plan was abandoned. She remained in the dockyard until September 1958, when she was broken up on the slipway . The ship's bell , inscribed "USS Illinois 1946", is now at Memorial Stadium at the University of Illinois at Urbana–Champaign . The bell is on loan from the Naval History and Heritage Command (Accession #70-399-A), Washington Navy Yard , Washington DC, to the Naval Reserve Officers Training Corps (NROTC) at

21328-428: 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

21500-401: 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

21672-401: 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

21844-447: The propeller an overall cup-shaped appearance. This design preserves thrust efficiency while reducing cavitation, and thus makes for a quiet, stealthy design. A small number of ships use propellers with winglets similar to those on some airplane wings, reducing tip vortices and improving efficiency. A modular propeller provides more control over the boat's performance. There is no need to change an entire propeller when there

22016-406: The propeller. It can occur in many ways on a propeller. The two most common types of propeller cavitation are suction side surface cavitation and tip vortex cavitation. Suction side surface cavitation forms when the propeller is operating at high rotational speeds or under heavy load (high blade lift coefficient ). The pressure on the upstream surface of the blade (the "suction side") can drop below

22188-482: 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

22360-403: The risk of collision with heavy objects, the propeller often includes a device that is designed to fail when overloaded; the device or the whole propeller is sacrificed so that the more expensive transmission and engine are not damaged. Typically in smaller (less than 10 hp or 7.5 kW) and older engines, a narrow shear pin through the drive shaft and propeller hub transmits the power of

22532-404: The rubber insert. Once the propeller is removed, the splined tube can be cut away with a grinder and a new spline bushing is then required. To prevent a recurrence of the problem, the splines can be coated with anti-seize anti-corrosion compound. In some modern propellers, a hard polymer insert called a drive sleeve replaces the rubber bushing. The splined or other non-circular cross section of

22704-585: The same date as Kentucky . Funding for the battleship was provided in part by proceeds from the auction of " King Neptune ", a Hereford swine presented across the state of Illinois as a fundraiser, ultimately helping to raise $ 19 million in war bonds . Illinois ' s construction was put on hold in 1942, after the Battles of the Coral Sea and Midway, while the Bureau of Ships considered an aircraft carrier conversion proposal for Illinois and Kentucky . As proposed,

22876-535: The same time, the French mathematician Alexis-Jean-Pierre Paucton suggested a water propulsion system based on the Archimedean screw. In 1771, steam-engine inventor James Watt in a private letter suggested using "spiral oars" to propel boats, although he did not use them with his steam engines, or ever implement the idea. One of the first practical and applied uses of a propeller was on a submarine dubbed Turtle which

23048-402: 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

23220-862: 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

23392-419: 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

23564-599: The sleeve inserted between the shaft and propeller hub transmits the engine torque to the propeller, rather than friction. The polymer is weaker than the components of the propeller and engine so it fails before they do when the propeller is overloaded. This fails completely under excessive load, but can easily be replaced. Whereas the propeller on a large ship will be immersed in deep water and free of obstacles and flotsam , yachts , barges and river boats often suffer propeller fouling by debris such as weed, ropes, cables, nets and plastics. British narrowboats invariably have

23736-413: 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

23908-410: 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

24080-403: 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

24252-442: 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

24424-495: The testing stage, and those that were proved unsatisfactory for one reason or another. In 1835, two inventors in Britain, John Ericsson and Francis Pettit Smith , began working separately on the problem. Smith was first to take out a screw propeller patent on 31 May, while Ericsson, a gifted Swedish engineer then working in Britain, filed his patent six weeks later. Smith quickly built a small model boat to test his invention, which

24596-624: 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

24768-570: The three designs. "A" 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"

24940-442: 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,

25112-402: 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

25284-452: The transverse projection of a blade and the developed outline of the blade. The blades are the foil section plates that develop thrust when the propeller is rotated The hub is the central part of the propeller, which connects the blades together and fixes the propeller to the shaft. This is called the boss in the UK. Rake is the angle of the blade to a radius perpendicular to the shaft. Skew

25456-427: The traverse bulkhead armor was increased from the original 11.3 in (287 mm) to 14.5 in (368 mm) in order to better protect against fire from frontal sectors. Tests with caissons in 1943 led to improvements for the torpedo defense system that increased its resilience to underwater damage by around twenty percent compared to the first four Iowa s. When BB-65 was redesignated an Iowa -class ship, she

25628-428: 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

25800-477: 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

25972-461: The university. The bell is traditionally rung by NROTC members when the university football team scores a touchdown or goal. Iowa-class battleship 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

26144-475: 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

26316-466: The view that screw propulsion would be ineffective in ocean-going service, while Symonds himself believed that screw propelled ships could not be steered efficiently. Following this rejection, Ericsson built a second, larger screw-propelled boat, Robert F. Stockton , and had her sailed in 1839 to the United States, where he was soon to gain fame as the designer of the U.S. Navy 's first screw-propelled warship, USS  Princeton . Apparently aware of

26488-441: 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,

26660-426: The world's largest nuclear artillery and made these four battleships 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,

26832-603: The world's largest ship and the first screw-propelled steamship to cross the Atlantic Ocean in August 1845. HMS  Terror and HMS  Erebus were both heavily modified to become the first Royal Navy ships to have steam-powered engines and screw propellers. Both participated in Franklin's lost expedition , last seen in July 1845 near Baffin Bay . Screw propeller design stabilized in

27004-415: Was 1 May 1945. Ultimately, the ship was canceled on 11 August 1945, when she was about 22 per cent complete. She was struck from the Naval Vessel Register on 12 August 1945. Her incomplete hulk initially was retained on the belief that it could be used as a target in nuclear weapons tests. However, the $ 30 million it would cost to complete the ship enough to be able to launch her proved too great and

27176-405: Was 12.1 in (307 mm) thick, while the main armor deck was 6 in (152 mm) thick. The main battery gun turrets had 19.5 in (495 mm) thick faces, and they were mounted atop barbettes that were protected with 17.3–11.6 in (439–295 mm) of armored steel. The conning tower had 17.3 in (439 mm) thick sides. Like the Iowa -class ships from Missouri onward,

27348-405: 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,

27520-458: 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

27692-547: Was assigned the name Illinois and reconfigured to adhere to the fast battleship designs drawn up in 1938, by the Preliminary Design Branch at the Bureau of Construction and Repair . Her funding was authorized via the passage of the Two-Ocean Navy Act by the U.S. Congress on 19 July 1940, and she would now become the fifth Iowa -class ship built for the U.S. Navy. Her contract was assigned on 9 September 1940,

27864-448: 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

28036-441: Was complete by the 1920s, although increased power and smaller diameters added design constraints. Alberto Santos Dumont , another early pioneer, applied the knowledge he gained from experiences with airships to make a propeller with a steel shaft and aluminium blades for his 14 bis biplane . Some of his designs used a bent aluminium sheet for blades, thus creating an airfoil shape. They were heavily undercambered , and this plus

28208-613: Was demonstrated first on a pond at his Hendon farm, and later at the Royal Adelaide Gallery of Practical Science in London , where it was seen by the Secretary of the Navy, Sir William Barrow. Having secured the patronage of a London banker named Wright, Smith then built a 30-foot (9.1 m), 6- horsepower (4.5 kW) canal boat of six tons burthen called Francis Smith , which was fitted with his wooden propeller and demonstrated on

28380-616: Was designed in New Haven, Connecticut , in 1775 by Yale student and inventor David Bushnell , with the help of clock maker, engraver, and brass foundryman Isaac Doolittle . Bushnell's brother Ezra Bushnell and ship's carpenter and clock maker Phineas Pratt constructed the hull in Saybrook, Connecticut . On the night of September 6, 1776, Sergeant Ezra Lee piloted Turtle in an attack on HMS  Eagle in New York Harbor . Turtle also has

28552-403: 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,

28724-540: 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

28896-435: Was observed making headway in stormy seas by officers of the Royal Navy. This revived Admiralty's interest and Smith was encouraged to build a full size ship to more conclusively demonstrate the technology. SS  Archimedes was built in 1838 by Henry Wimshurst of London, as the world's first steamship to be driven by a screw propeller . The Archimedes had considerable influence on ship development, encouraging

29068-439: 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 the battleships. Since each battleship carried

29240-410: 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

29412-433: 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

29584-526: Was the first successful Archimedes screw-propelled ship. His experiments were banned by police after a steam engine accident. Ressel, a forestry inspector, held an Austro-Hungarian patent for his propeller. The screw propeller was an improvement over paddlewheels as it wasn't affected by ship motions or draft changes. John Patch , a mariner in Yarmouth, Nova Scotia developed a two-bladed, fan-shaped propeller in 1832 and publicly demonstrated it in 1833, propelling

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