Montana class battleship
Encyclopedia
The Montana-class battleships of the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 were planned as successors to the , being slower but larger, better armored, and having superior firepower. Five were approved for construction during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, but changes in wartime building priorities resulted in their cancellation in favor of the s before any
Montana-class keels were laid.

With an intended armament of 12 16 inches (406 mm) guns and a greater anti-aircraft capability than the preceding
Iowa-class, as well as a thicker armor belt, the Montanas would have been the largest, the best-protected, and the most heavily-armed battleships put to sea by the United States. They would have been the only US Navy battleship class to have rivaled the Empire of Japan
Empire of Japan
The Empire of Japan is the name of the state of Japan that existed from the Meiji Restoration on 3 January 1868 to the enactment of the post-World War II Constitution of...

's s in terms of armor
Vehicle armour
Military vehicles are commonly armoured to withstand the impact of shrapnel, bullets, missiles, or shells, protecting the personnel inside from enemy fire. Such vehicles include tanks, aircraft, and ships....

, weaponry, and displacement
Displacement (ship)
A ship's displacement is its weight at any given time, generally expressed in metric tons or long tons. The term is often used to mean the ship's weight when it is loaded to its maximum capacity. A number of synonymous terms exist for this maximum weight, such as loaded displacement, full load...

.

Preliminary design work for the
Montanas began before the US entry into World War II. The first two vessels were approved by Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....

 in 1939 following the passage of the Second Vinson Act
Second Vinson Act
The Second Vinson Act was an Act of Congress, passed in May 1938, 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...

. The Japanese attack on Pearl Harbor
Attack on Pearl Harbor
The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...

 delayed construction of the
Montana class. The success of carrier combat at the Battle of Coral Sea and, to a greater extent, the Battle of Midway
Battle of Midway
The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...

, diminished the value of the battleship. Consequently, the US Navy chose to cancel the
Montana-class in favor of more urgently needed aircraft carriers, amphibious and anti-submarine vessels; though orders for the Iowas were retained as they were fast enough to escort the new s. The Montana class was the last US Navy battleship to be designed but their keels were never laid; the four completed Iowa-class battleships were the last to be commissioned
Ship commissioning
Ship commissioning is the act or ceremony of placing a ship in active service, and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to the placing of a warship in active duty with its country's military...

.

History

As the political situation in Europe and Asia worsened in the prelude to World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, Carl Vinson
Carl Vinson
Carl Vinson was a United States Representative from Georgia. He was a Democrat and the first person to serve for more than 50 years in the United States House of Representatives...

, the chairman of the House
United States House of Representatives
The United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...

 Committee on Naval Affairs, instituted the Vinson Naval Plan, which aimed to get the Navy into fighting shape after the cutbacks imposed by the depression and the naval treaties of the 1930s. As part of the overall plan Congress passed the Second Vinson Act
Second Vinson Act
The Second Vinson Act was an Act of Congress, passed in May 1938, 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...

 in 1938, which cleared the way for construction of the four South Dakota-class
South Dakota class battleship (1939)
The South Dakota-class was a group of four fast battleships built by the United States Navy. They were the second class of battleships to be named after the 40th State; the first class was designed in the 1920s and canceled under the terms of the Washington Naval Treaty. The class comprised four...

 fast battleship
Fast battleship
Historically, a fast battleship was a battleship which emphasized speed without - in concept - undo compromise of either armor or armament. The term is especially appropriate when applied to a design which was not only faster than the preceding battleship class, but faster than subsequent classes...

s and the first two
Iowa-class battleships (hull numbers BB-61 and BB-62). Four additional battleships (with hull numbers BB-63, BB-64, BB-65, and BB-66) were approved for construction in 1940, with the last two intended to be the first ships of the Montana class. By 1942, it was apparent to the US Navy high command that they needed as many fast battleships as possible, and hull numbers BB-65 and BB-66 were allocated to fast battleships and .

The Navy, mindful of the ongoing construction of Japan's battleships, had been working on a 58,000-ton "super battleship" concept since 1938. This new class, with twelve 16 inches (406 mm) guns, was assigned the name Montana and cleared for construction by the United States Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....

 under the Two-Ocean Navy Act
Two-Ocean Navy Act
The Two-Ocean Navy Act, was an American Act of Congress passed on July 19, 1940, to increase the size of the United States Navy by 70%, making it the largest naval procurement bill in U.S...

 in 1940; funding for the new ships was approved in 1941. These ships, the last battleships to be ordered by the Navy, were to be designated BB-67 through BB-71.

Completion of the
Montana-class, and the last two Iowa-class battleships, was intended to give the US Navy a considerable advantage over any other nation, or probable combination of nations, with a total of 17 new battleships by the late 1940s. The Montanas also would have been the only American ships to come close to equaling Japan's massive Yamato and her sister Musashi in terms of size and firepower.

Design

Preliminary planning for the
Montana-class battleships took place in 1939, when the aircraft carrier was still considered inferior to the battleship. The Navy began designing a 65,000-ton battleship to counter the threat posed by the s of the Imperial Japanese Navy
Imperial Japanese Navy
The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

. Although the Navy knew little about the
Yamato-class, the new Japanese battleships were rumored to have a main gun battery of 18 inches (457 mm). Initially, plans were drawn for a 45,000-ton (46,000-metric-ton) US battleship, but after evaluation, the Battleship Design Advisory Board increased the displacement of the planned ship to 58,000 tons (59,000 metric tons).

At the time, the design board issued a basic outline for the
Montana class that called for it to be free of beam restrictions imposed by the Panama Canal
Panamax
Panamax and New Panamax are popular terms for the size limits for ships traveling through the Panama Canal. Formally, the limits and requirements are published by the Panama Canal Authority titled "Vessel Requirements"...

, be 25% stronger offensively and defensively than any other battleship completed or under construction, and be capable of withstanding the "super heavy" 2700 lb (1,224.7 kg) shells used by US battleships equipped with either the 16"/45 caliber guns or 16 inches (406 mm)/50 cal Mark 7 guns. Although freed of the restriction of fitting through the Panama Canal, the length and height of the Montana-class were limited by one of the shipyards at which they were to be built: the New York Navy Yard
Brooklyn Navy Yard
The United States Navy Yard, New York–better known as the Brooklyn Navy Yard or the New York Naval Shipyard –was an American shipyard located in Brooklyn, northeast of the Battery on the East River in Wallabout Basin, a semicircular bend of the river across from Corlear's Hook in Manhattan...

 could not handle the construction of a 58,000-ton (59,000-metric-ton) ship, and vessels built there had to be low enough to clear the Brooklyn Bridge
Brooklyn Bridge
The Brooklyn Bridge is one of the oldest suspension bridges in the United States. Completed in 1883, it connects the New York City boroughs of Manhattan and Brooklyn by spanning the East River...

 at low tide.

After debate at the design board about whether the
Montana-class should be fast, achieving the high 33 kn (40.2 mph; 64.7 km/h) speed of the , or up-gunned and up-armored, firepower was selected over speed. By returning the Montana class to the slower 28 kn (34.1 mph; 54.9 km/h) maximum speed of the North Carolina
North Carolina class battleship
The North Carolina class was a group of two fast battleships, North Carolina and Washington, built for the United States Navy in the late 1930s and early 1940s...

- and
South Dakota
South Dakota class battleship (1939)
The South Dakota-class was a group of four fast battleships built by the United States Navy. They were the second class of battleships to be named after the 40th State; the first class was designed in the 1920s and canceled under the terms of the Washington Naval Treaty. The class comprised four...

- class ships, naval architects were able to increase armor protection for the
Montanas, enabling the ships to withstand enemy fire equivalent to their own guns' ammunition. This limited the Montanas ability to escort and defend the Pacific-based Allied aircraft carrier fleet, as the class was to be powered by eight Babcock & Wilcox boilers which would have enabled them to steam at approximately 27 kn (32.9 mph; 52.9 km/h).

Fate

By January 1941, the design limit for the 58,000-ton (59,000-metric-ton) battleship plan had been reached, and consensus among those designing the battleship class was to increase the displacement to support the armor and weaponry on the ships. At the same time, planners decided to adopt a slightly greater length and reduce power for a better machinery arrangement, as well as improving internal subdivisions, and selecting as the secondary armament several dual-mounted 5 inches (127 mm)/54 cal guns instead of the 5 inches (127 mm)/38 cal guns used on the Iowas. At this point, the net design for the Montana-class somewhat resembled the Iowa-class since they would be equipped with the same caliber main guns and similar caliber secondary guns; however, Montana and her sisters had more armor, mounted three more main guns, and were 22 ft (6.7 m) longer and 13 ft (4 m) wider than the Iowa class.

By April 1942, the Montana-class design had been approved; construction was authorized by the United States Congress and the projected date of completion was estimated to be somewhere between 1 July and 1 November 1945. The Navy ordered the ships in May 1942, but the Montana class were placed on hold because the Iowa-class battleships and the Essex-class aircraft carriers were under construction in the shipyards intended to build the Montanas. Unfortunately for the Montana class, both the Iowa and Essex classes had been given higher priorities: the Iowas due to their ability to defend the Essex-class carriers with 20 mm and 40 mm guns, and the Essexes because of their ability to launch aircraft to gain and maintain air supremacy
Air supremacy
Air supremacy is the complete dominance of the air power of one side's air forces over the other side's, during a military campaign. It is the most favorable state of control of the air...

 over the islands in the Pacific and intercept warships of the Imperial Japanese Navy. Because of this, the entire Montana class was suspended in May 1942, before any of their keels had been laid. In July 1943, the construction of the Montana class was canceled following the Battle of Midway
Battle of Midway
The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...

, and the corresponding shift in naval warfare from surface engagements to air supremacy, and, thus, a shift from battleships to aircraft carriers.

Ships

Five ships of the Montana class were authorized on 19 July 1940, but they were suspended indefinitely until being canceled 21 July 1943. The ships were to be built at the New York Navy Yard, Philadelphia Navy Yard, and Norfolk Navy Yard.

USS Montana (BB-67)

Montana was planned to be the lead ship
Lead ship
The lead ship or class leader is the first of a series or class of ships all constructed according to the same general design. The term is applicable military ships and larger civilian craft.-Overview:...

 of the class. She was the third ship
USS Montana
USS Montana may refer to:, was a that provided convoy escort duty during World War I, and was eventually renamed and reclassified Missoula , was a cargo ship during World War I and sunk by torpedo in August 1918...

 to be named
Ship naming and launching
The ceremonies involved in naming and launching naval ships are based in traditions thousands of years old.-Methods of launch:There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching." The oldest, most familiar, and most widely...

 in honor of the 41st state
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

, and was assigned to the Philadelphia Navy Yard. Both the earlier battleship, , and BB-67 were canceled, so Montana is the only one of the US states never to have had a battleship with a "BB" hull classification completed in its honor.

USS Ohio (BB-68)

Ohio was to be the second Montana-class battleship. She was to be named in honor of the 17th state
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...

, and was assigned to the Philadelphia Navy Yard for construction. Ohio would have been the fourth ship
USS Ohio
Five ships of the United States Navy have borne the name USS Ohio: was a schooner on Lake Erie during the War of 1812 in commission from 1813 to 1814. was a ship-of-the-line, launched in 1820 and in commission as a warship from 1838 to 1840 and from 1846 to 1850, then later used as a receiving...

 to bear that name had she been commissioned
Ship commissioning
Ship commissioning is the act or ceremony of placing a ship in active service, and may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most commonly applied to the placing of a warship in active duty with its country's military...

.

USS Maine (BB-69)

Maine was to be the third Montana-class battleship. She was to be named in honor of the 23rd state
Maine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...

, and was assigned to the New York Navy Yard. Maine would have been the third ship
USS Maine
Four ships of the United States Navy have borne the name USS Maine, named for the 23rd state.*The first , was a second-class pre-dreadnought battleship whose sinking by an explosion, either internal or by a mine, on February 15, 1898 at 9:40 p.m...

 to bear that name had she been commissioned.

USS New Hampshire (BB-70)

New Hampshire was to be the fourth Montana-class battleship, and was to be named in honor of the ninth state
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...

. She was assigned to the New York Navy Yard, and would have been the third ship
USS New Hampshire
USS New Hampshire may refer to one of a number of United States Navy ships named in honor of the state of New Hampshire: was one of nine ships of the line authorized in 1816, but not launched until 1864 as a storeship and destroyed by fire in 1921...

 to bear that name had she been commissioned.

USS Louisiana (BB-71)

Louisiana was to be the fifth and final Montana-class battleship. She was to be named in honor of the 18th state
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

 and assigned to the Norfolk Navy Yard, Portsmouth, Virginia
Portsmouth, Virginia
Portsmouth is located in the Hampton Roads metropolitan area of the U.S. Commonwealth of Virginia. As of 2010, the city had a total population of 95,535.The Norfolk Naval Shipyard, often called the Norfolk Navy Yard, is a historic and active U.S...

. Louisiana would have been the third ship
USS Louisiana
Five ships of the United States Navy have borne the name USS Louisiana in honor of the 18th state., was a sloop that served in the War of 1812, was a propeller-driven steamer that served in the American Civil War...

 to bear that name had she been commissioned. By hull number, Louisiana was the last American battleship authorized for construction.

Armament

The armament of the Montana-class battleships would have been similar to the preceding Iowa-class battleships, but with an increase in the number of primary and secondary guns for use against enemy surface ships and aircraft. Had they been completed, the Montanas would have been gun-for-gun the most powerful battleships the United States had constructed, and the only US battleship class that would have come close to equaling the Imperial Japanese Navy battleships Yamato and Musashi on a gun-for-gun and ton-for-ton basis.

Main battery

The primary armament of a Montana-class battleship would have been 12 16"/50 caliber Mark 7 gun, which were to be housed in four three-gun turrets: two forward and two aft. The guns, the same used to arm the Iowa-class battleships, were 66 ft (20.1 m) long — 50 times their 16 inches (406 mm) bore, or 50 calibers, from breechface
Breechface
In firearms the breech face, also breechface, is the surface of the bolt or slide that locks against the rear of the chamber so that one can fire a cartridge....

 to muzzle
Muzzle (firearm)
The muzzle of a firearm is the end of the barrel from which the projectile will exit.Precise machining of the muzzle is crucial to accuracy, because it is the last point of contact between the barrel and the projectile...

. Each gun weighed about 239000 lb (108,408.6 kg) without the breech, or 267900 lb (121,517.4 kg) with the breech. They fired projectiles weighing up to 2700 lb (1,224.7 kg) at a maximum speed of 2690 ft/s (819.9 m/s) with a range of up to 24 nmi (27.6 mi; 44.4 km). At maximum range the projectile would have spent almost 1½ minutes in flight. The addition of the #4 turret would have allowed Montana to overtake the Yamato as the battleship having heaviest broadside overall; Montana and her sisters would have had a broadside of 32400 lb (14,696.4 kg) vs. 28800 lb (13,063.5 kg) for Yamato. Each gun would have rested within an armored barbette
Barbette
A barbette is a protective circular armour feature around a cannon or heavy artillery gun. The name comes from the French phrase en barbette referring to the practice of firing a field gun over a parapet rather than through an opening . The former gives better angles of fire but less protection...

, but only the top of the barbette would have protruded above the main deck. The barbettes would have extended either four decks (turrets 1 and 4) or five decks (turrets 2 and 3) down. The lower spaces would have contained rooms for handling the projectiles and storing the powder bags used to fire them. Each turret would have required a crew of 94 men to operate. The turrets would not have been attached to the ship, but would have rested on rollers, which meant that had any of the Montana-class ships capsize
Capsize
Capsizing is an act of tipping over a boat or ship to disable it. The act of reversing a capsized vessel is called righting.If a capsized vessel has sufficient flotation to prevent sinking, it may recover on its own if the stability is such that it is not stable inverted...

d, the turrets would have fallen out. Each turret would have cost US$1.4 million, but this figure did not take into account the cost of the guns themselves.

The turrets would have been "three-gun", not "triple", because each barrel would have elevated and fired independently. The ships could fire any combination of their guns, including a broadside
Broadside
A broadside is the side of a ship; the battery of cannon on one side of a warship; or their simultaneous fire in naval warfare.-Age of Sail:...

 of all 12. Contrary to popular belief, the ships would not have moved sideways noticeably when a broadside was fired.

The guns would have been elevated from −5° to +45°, moving at up to 12° per second. The turrets would have rotated about 300° at about 4° per second and could even be fired back beyond the beam
Beam (nautical)
The beam of a ship is its width at the widest point. Generally speaking, the wider the beam of a ship , the more initial stability it has, at expense of reserve stability in the event of a capsize, where more energy is required to right the vessel from its inverted position...

, which is sometimes called "over the shoulder". Within each turret, a red stripe on the wall of the turret, just inches from the railing, would have marked the boundary of the gun's recoil, providing the crew of each gun turret with a visual reference for the minimum safe distance range.

Like most battleships in World War II, the Montana class would have been equipped with a fire control computer, in this case the Ford Mk 1A Ballistic Computer
Mark I Fire Control Computer
The Mark 1, and later the Mark 1A, Fire Control Computer was a component of the Mark 37 Gun Fire Control System deployed by the United States Navy during World War II and up to 1969. It was used on a variety of ships, ranging from destroyers to battleships . The Mark 37 system used tachymetric...

, a 3150 lb (1,428.8 kg) rangekeeper
Rangekeeper
Rangekeepers were electromechanical fire control computers used primarily during the early part of the 20th century. They were sophisticated analog computers whose development reached its zenith following World War II, specifically the Computer Mk 47 in the Mk 68 Gun Fire Control system. During...

 designed to direct gunfire on land, sea, and in the air. This analog computer
Analog computer
An analog computer is a form of computer that uses the continuously-changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved...

 would have been used to direct the fire from the battleship's big guns, taking into account several factors such as the speed of the targeted ship, the time it takes for a projectile to travel, and air resistance to the shells fired at a target. At the time the Montana class was set to begin construction, the rangekeepers had gained the ability to use radar data to help target enemy ships and land-based targets. The results of this advance were telling: the rangekeeper was able to track and fire at targets at a greater range and with increased accuracy, as was demonstrated in November 1942 when the battleship engaged the Imperial Japanese Navy
Imperial Japanese Navy
The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

 battleship at a range of 18500 yd (16.9 km) at night; the Washington scored at least nine heavy caliber hits that critically damaged the Kirishima and led to her scuttling. This gave the US Navy a major advantage in World War II, as the Japanese did not develop radar or automated fire control to the level of the US Navy.
The large caliber guns were designed to fire two different 16 inches (406 mm) shells: an armor piercing round for anti-ship and anti-structure work, and a high explosive round designed for use against unarmored targets and shore bombardment.

The Mk. 8 APC (Armor-Piercing, Capped) shell weighed in at 2700 lb (1,224.7 kg), and was designed to penetrate the hardened steel armor carried by foreign battleships. At 20000 yd (18.3 km), the Mk. 8 could penetrate 20 inches (508 mm) of steel armor plate. At the same range, the Mk. 8 could penetrate 21 ft (6.4 m) of reinforced concrete. For unarmored targets and shore bombardment, the 1900 lb (861.8 kg) Mk. 13 HC (High-Capacity—referring to the large bursting charge) shell was available. The Mk. 13 shell could create a crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 50 ft (15.2 m) wide and 20 ft (6.1 m) deep upon impact and detonation, and could defoliate trees 400 yd (365.8 m) from the point of impact.

The final type of ammunition developed for the 16-inch guns were W23 "Katie" shells. These shells were born from the nuclear deterrence that had begun to shape the US armed forces at the start of the Cold War. To compete with the Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

 and the Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

, which had developed nuclear bombs and nuclear shells for use on the battlefield, the Navy began a top-secret program to develop Mk. 23 nuclear naval shells with an estimated yield of 15 to 20 kilotons. The shells entered development around 1953, and were reportedly ready by 1956; however, the cancellation of the Montana class meant that only the Iowa-class battleships, armed as they were with the same type of gun, could use the shells if the need had arisen.

Secondary battery

The secondary armament for Montana and her sisters was to be 20 5 inches (127 mm)/54 cal guns housed in 10 turrets along the island of the battleship; five on the starboard side and five on the port. These guns, designed specifically for the Montanas, were to be the replacement for the 5 inches (127 mm)/38 cal secondary gun batteries then in widespread use with the US Navy.

The 5 inches (127 mm)/54 cal gun turrets were similar to the 5 inches (127 mm)/38 cal gun mounts in that they were equally adept in an anti-aircraft role and for damaging smaller ships, but differed in that they weighed more, fired heavier rounds of ammunition, and resulted in faster crew fatigue than the 5 inches (127 mm)/38 cal guns. The ammunition storage for the 5 inches (127 mm)/54 cal gun was 500 rounds per turret, and the guns could fire at targets nearly 26000 yd (23.8 km) away at a 45° angle. At an 85° angle, the guns could hit an aerial target at over 50000 ft (15,240 m).

The cancellation of the Montana-class battleships in 1943 pushed back the combat debut of the 5 inches (127 mm)/54 cal guns to 1945, when they were used aboard the US Navy's s. The guns proved adequate for the carrier's air defense, but were gradually phased out of use by the carrier fleet because of their weight. (Rather than having the carrier defend itself by gunnery this would be assigned to other surrounding ships within a carrier battle group
Carrier battle group
A carrier battle group consists of an aircraft carrier and its escorts, together composing the group. The first naval task forces built around carriers appeared just prior to and during World War II. The Imperial Japanese Navy was the first to assemble a large number of carriers into a single...

.)

Anti-aircraft batteries

For the first time since the construction of the Iowa-class, the US Navy was not building a fast battleship class solely for the purpose of escorting Pacific-based aircraft carriers, and thus the Montana-class would not be designed principally for escorting the fast carrier task force
Fast Carrier Task Force
The Fast Carrier Task Force was the main striking force of the United States Navy in the Pacific Ocean theatre of World War II.The Fast Carrier Task Force was known under two designations. The Navy made use of two sets of upper command structures for planning the upcoming operations...

s; nonetheless they would have been equipped with a wide array of anti-aircraft guns to protect themselves and other ships (principally the US aircraft carriers) from Japanese fighters and dive bombers.

Oerlikon 20 mm anti-aircraft guns

The Oerlikon
Oerlikon Contraves
Rheinmetall Air Defence AG is a division of German armament manufacturer Rheinmetall, created when the company's Oerlikon Contraves unit was renamed on 1 January 2009 and integrated with Rheinmetall's other air-defence products...

 20 mm anti-aircraft cannon
Oerlikon 20 mm cannon
The Oerlikon 20 mm cannon is a series of autocannons, based on an original design by Reinhold Becker of Germany, very early in World War I, and widely produced by Oerlikon Contraves and others...

 was one of the most heavily produced anti-aircraft guns of World War II; the US alone manufactured a total of 124,735 of these guns. When activated in 1941, these guns replaced the .50 in (12.7 mm)/90 cal M2 Browning MG on a one-for-one basis. The Oerlikon 20 mm AA gun remained the primary anti-aircraft weapon of the United States Navy until the introduction of the 40 mm Bofors AA gun in 1943.

These guns are air-cooled and use a gas blow-back recoil system. Unlike other automatic guns employed during World War II, the barrel of the 20 mm Oerlikon gun does not recoil; the breechblock
Breechblock
A breechblock is the part of the firearm action that closes the breech of a weapon at the moment of firing....

 is never locked against the breech and is actually moving forward when the gun fires. This weapon lacks a counter-recoil brake, as the force of the counter-recoil is checked by recoil from the firing of the next round of ammunition.

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. In 1943, the revolutionary Mark 14 gunsight
Sight (device)
A sight is a device used to assist aligning or aim weapons, surveying instruments, or other items by eye. Sights can be a simple set or system of markers that have to be aligned together as well as aligned with the target...

 was introduced, which made these guns even more effective. The 20 mm guns, however, were found to be ineffective against the Japanese kamikaze
Kamikaze
The were suicide attacks by military aviators from the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, designed to destroy as many warships as possible....

 attacks used during the latter half of World War II. They were subsequently phased out in favor of the heavier 40 mm Bofors AA guns.

Bofors 40 mm anti-aircraft guns

Arguably the best light anti-aircraft weapon of World War II, the Bofors 40 mm anti-aircraft gun was used on almost every major warship in the US and UK fleet from about 1943 to 1945. Although a descendant of German, Dutch, and Swedish designs, the Bofors mounts used by the US Navy during World War II had been heavily "Americanized" to bring the guns up to the standards placed on them by the Navy. This resulted in a guns system set to British standards (now known as the Standard System
United States customary units
United States customary units are a system of measurements commonly used in the United States. Many U.S. units are virtually identical to their imperial counterparts, but the U.S. customary system developed from English units used in the British Empire before the system of imperial units was...

) with interchangeable ammunition, which simplified the logistics situation for World War II. When coupled with hydraulic couple drives to reduce salt contamination and the Mark 51 director for improved accuracy, the Bofors 40 mm gun became a fearsome adversary, accounting for roughly half of all Japanese aircraft shot down between 1 October 1944 and 1 February 1945.

Armor

Aside from its firepower, a battleship's defining feature is its armor. The exact design and placement of the armor, inextricably linked with the ship's stability and performance, is a complex science honed over decades.

A battleship is usually armored to withstand an attack from guns the size of its own, but the armor scheme of the preceding was only proof against 14 inches (356 mm) shells, while the South Dakota
South Dakota class battleship (1939)
The South Dakota-class was a group of four fast battleships built by the United States Navy. They were the second class of battleships to be named after the 40th State; the first class was designed in the 1920s and canceled under the terms of the Washington Naval Treaty. The class comprised four...

 and Iowa
Iowa class battleship
The Iowa-class battleships were a class of fast battleships ordered by the United States Navy in 1939 and 1940 to escort the Fast Carrier Task Forces which would operate in the Pacific Theater of World War II. Six were ordered during the course of World War II, but only four were completed in...

 classes were designed only to resist their original complement of Mark V 2240 lb (1,016 kg) shells, not the new "super-heavy" 2700 lb (1,224.7 kg) APC (Armor Piercing, Capped) Mark7 VIII shells they actually used. The Montanas were the only US battleships designed to resist the Mark VIII.

Until the authorization of the Montana class all US battleships were built within the size limits
Panamax
Panamax and New Panamax are popular terms for the size limits for ships traveling through the Panama Canal. Formally, the limits and requirements are published by the Panama Canal Authority titled "Vessel Requirements"...

 for the Panama Canal
Panama Canal
The Panama Canal is a ship canal in Panama that joins the Atlantic Ocean and the Pacific Ocean and is a key conduit for international maritime trade. Built from 1904 to 1914, the canal has seen annual traffic rise from about 1,000 ships early on to 14,702 vessels measuring a total of 309.6...

. The main reason for this was logistical
Military logistics
Military logistics is the discipline of planning and carrying out the movement and maintenance of military forces. In its most comprehensive sense, it is those aspects or military operations that deal with:...

: the largest US shipyards were located on the East Coast of the United States
East Coast of the United States
The East Coast of the United States, also known as the Eastern Seaboard, refers to the easternmost coastal states in the United States, which touch the Atlantic Ocean and stretch up to Canada. The term includes the U.S...

, while the United States had territorial interests in both oceans. Requiring the battleships to fit within the Panama Canal took days off the transition time from the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 to the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 by allowing ships to move through the canal instead of sailing around South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

. By the time of the Two Ocean Navy bill, the Navy realized that ship designs could no longer be limited by the Panama Canal and thus approved the Montana class knowing that the ships would be unable to clear the locks. This shift in policy meant that the Montana class would have been the only World War II–era US battleships to be adequately armored against guns of the same power as their own.

Aircraft

The Montana-class would have used aircraft for reconnaissance
Aerial reconnaissance
Aerial reconnaissance is reconnaissance that is conducted using unmanned aerial vehicles or reconnaissance aircraft. Their roles are to collect imagery intelligence, signals intelligence and measurement and signature intelligence...

 and for gunnery spotting. The type of aircraft used would have depended on when exactly the battleships would have been commissioned, but in all probability they would have used either the Kingfisher or the Seahawk. The aircraft would have been floatplane
Floatplane
A floatplane is a type of seaplane, with slender pontoons mounted under the fuselage; only the floats of a floatplane normally come into contact with water, with the fuselage remaining above water...

s launched from catapults on the ship's fantail. They would have landed on the water and taxied to the stern of the ship to be lifted by a crane back to the catapult.

Kingfisher

The Vought
Vought
Vought is the name of several related aerospace firms. These have included, in the past, Lewis and Vought Corporation, Chance Vought, Vought Sikorsky, LTV Aerospace , Vought Aircraft Companies, and the current Vought Aircraft Industries. The first incarnation of Vought was established by Chance M...

 OS2U Kingfisher
OS2U Kingfisher
The Vought OS2U Kingfisher was an American catapult-launched observation floatplane. It was a compact mid-wing monoplane, with a large central float and small stabilizing floats. Performance was modest, because of its light engine...

 was a lightly armed two-man aircraft designed in 1937. The Kingfisher's high operating ceiling made it well-suited for its primary mission: to observe the fall of shot from a battleship's guns and radio corrections back to the ship. The floatplanes used in World War II also performed search and rescue
Search and rescue
Search and rescue is the search for and provision of aid to people who are in distress or imminent danger.The general field of search and rescue includes many specialty sub-fields, mostly based upon terrain considerations...

 for naval aviators
Naval aviation
Naval aviation is the application of manned military air power by navies, including ships that embark fixed-wing aircraft or helicopters. In contrast, maritime aviation is the operation of aircraft in a maritime role under the command of non-naval forces such as the former RAF Coastal Command or a...

 who were shot down or forced to ditch in the ocean.

Seahawk

In June 1942, the US Navy Bureau of Aeronautics
Bureau of Aeronautics
The Bureau of Aeronautics was the U.S. Navy's material-support organization for Naval Aviation from 1921 to 1959. The bureau had "cognizance" for the design, procurement, and support of Naval aircraft and related systems...

 requested industry proposals for a new seaplane to replace the Kingfisher and Curtiss SO3C Seamew. The new aircraft was required to be able to use landing gear as well as floats. Curtiss submitted a design on 1 August, and received a contract for two prototypes and five service-test aircraft on 25 August. The first flight of a prototype XSC-1 took place on 16 February 1944 at the Columbus, Ohio
Columbus, Ohio
Columbus is the capital of and the largest city in the U.S. state of Ohio. The broader metropolitan area encompasses several counties and is the third largest in Ohio behind those of Cleveland and Cincinnati. Columbus is the third largest city in the American Midwest, and the fifteenth largest city...

 Curtiss plant. The first production aircraft were delivered in October 1944, and by the beginning of 1945 the single-seat Curtiss SC Seahawk floatplane began replacing the Kingfisher. Had the Montana-class been completed, they would have arrived around the time of this replacement, and would likely have been equipped with the Seahawk for use in combat operations and seaborne search and rescue.

Further reading

  • Dulin, Robert O., William H. Garzke, and Robert F. Sumrall. Battleships: United States Battleships in World War II, fourth printing with corrections and additions. Annapolis, Md: Naval Institute Press, 1976 (1985). ISBN 0-87021-099-8. Chapter 5, pp. 153–174. Devotes more space to the components of the (chosen) design, and less to the design studies, than Friedman's work.
  • Friedman, Norman. U.S. Battleships: An Illustrated Design History. Annapolis, Md: Naval Institute Press, 1985. ISBN 0-87021-715-1. Chapter 15, pp. 329–344. Includes details on all of the design studies conducted, including fast, heavily armored versions. .
  • Scarpaci, Wayne. US Battleships 1941–1963: An Illustrated Technical Reference, Second Edition. Gardnersville, Nevada: Art by Wayne, 2009. ISBN 1-4382-5744-9. pgs 105–106.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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