Alaska-class cruiser
The Alaska class was a class of six large cruisers ordered before World War II for the United States Navy. They were officially classed as large cruisers, but others have regarded them as battlecruisers. They were all named after territories or insular areas of the United States, signifying their intermediate status between larger battleships and smaller heavy and light cruisers. Of the six planned, two were completed, the third's construction was suspended on 16 April 1947, and the last three were cancelled. and served with the U.S. Navy for the last year of World War II as bombardment ships and fast carrier escorts. They were decommissioned in 1947 after spending only 32 and 29 months in service, respectively.
The idea for a large cruiser class originated in the early 1930s when the U.S. Navy sought to counter "pocket battleships" being launched by Germany. Planning for ships that eventually evolved into the Alaska class began in the late 1930s after the deployment of Germany's s and rumors that Japan was constructing a new battlecruiser class. To serve as "cruiser-killers" capable of seeking out and destroying these post-treaty heavy cruisers, the class was given large guns of a new and expensive design, limited armor protection against 12-inch shells, and machinery capable of speeds of about.
Background
Heavy cruiser development formalized between World War I and World War II thanks to the terms of the Washington Naval Treaty and successor treaties and conferences, where the United States, Britain, Japan, France, and Italy agreed to limit heavy cruisers to 10,000 tons displacement with 8-inch main armament. Up until the Alaska class, US cruisers designed between the wars followed this pattern.The initial impetus for the Alaska design came from the deployments of Germany's so-called pocket battleships in the early 1930s. Though no actions were immediately taken, these thoughts were revived in the late 1930s when intelligence reports indicated Japan was planning or building "super cruisers" that would be much more powerful than the current US heavy cruisers. The navy responded in 1938 when the General Board asked the Bureau of Construction and Repair to conduct a "comprehensive study of all types of naval vessels for consideration for a new and expanded building program". The US President at the time, Franklin Delano Roosevelt, may have taken a lead role in the development of the class with his desire to have a counter to raiding abilities of Japanese cruisers and German pocket battleships. While these claims are difficult to verify, they have led to the speculation that their design was "politically motivated".
Design
One historian described the design process of the Alaska class as "torturous" due to the numerous changes and modifications made to the ship's layouts by numerous departments and individuals. Indeed, there were at least nine different layouts, ranging from 6,000-ton anti-aircraft cruisers to "overgrown" heavy cruisers and a 38,000-ton mini-battleship that would have been armed with twelve 12-inch and sixteen 5-inch guns. The General Board, in an attempt to keep the displacement under 25,000 tons, allowed the designs to offer only limited underwater protection, such that they were vulnerable to torpedoes and shells that fell short of the ship. The final design was a scaled-up that had the same machinery as the s. This ship combined a main armament of nine 12-inch guns with protection against 10-inch gunfire into a hull that was capable of.The Alaskas were officially funded in September 1940 along with a plethora of other ships as a part of the Two-Ocean Navy Act. Their role had been altered slightly: in addition to their surface-to-surface role, they were planned to protect carrier groups. Because of their bigger guns, greater size and increased speed, they would be more valuable in this role than heavy cruisers, and would provide insurance against reports that Japan was building super cruisers more powerful than the American heavy cruisers.
Possible conversion to aircraft carriers
Yet another drastic change was considered during the "carrier panic" in late 1941, when the US Navy realized that they needed more aircraft carriers as quickly as possible. Many hulls currently under construction were considered for conversion into carriers. At different times, they considered some or all of the light cruisers, the heavy cruisers, the Alaska class, and even one of the s; in the end, they chose the Clevelands, resulting in the conversion of nine ships under construction at the New York Shipbuilding Corporation shipyard as the light aircraft carriers comprising the.A conversion of the Alaska cruisers to carriers was "particularly attractive" because of the many similarities between the design of the s and the Alaska class, including the same machinery. However, when Alaska cruisers were compared to the Essex carriers, converted cruisers would have had a shorter flight deck, would have been lower in the water, and could travel less at. In addition, the large cruiser design did not include the extensive underwater protections found in normal carriers due to the armor weight devoted to counter shell fire. Lastly, an Alaska conversion could not satisfy the navy's goal of having new aircraft carriers quickly, as the work needed to modify the ships into carriers would entail long delays. With this in mind, all planning to convert the Alaskas was abandoned on 7 January 1942.
Construction
Of the six Alaska-class cruisers that were planned, only three were laid down. The first two, and, were completed by the New York Shipbuilding Corporation. Construction of, the third, was suspended on 16 April 1947 when she was 84% complete. The last three, Philippines, Puerto Rico, and Samoa, were delayed since all available materials and slipways were allocated to higher priority ships, such as aircraft carriers, destroyers, and submarines. Construction had still not begun when steel shortages and a realization that these "cruiser-killers" had no more cruisers to hunt—as the fleets of Japanese cruisers had already been defeated by aircraft and submarines—made the ships "white elephants". As a result, construction of the last three members of the class never began, and they were officially cancelled on 24 June 1943.Service history
and served with the U.S. Navy during the last year of World War II. Similar to the fast battleships, their speed made them useful as shore bombardment ships and fast carrier escorts. Both Alaska and Guam protected when she was on her way to be repaired in Guam after being hit by two Japanese bombs. Afterward, Alaska supported the landings on Okinawa, while Guam went to San Pedro Bay to become the leader of a new task force, Cruiser Task Force 95. Guam, joined by Alaska, four light cruisers, and nine destroyers, led the task force into the East China and Yellow Seas to conduct raids upon shipping; however, they encountered only Chinese junks. By the end of the war, the two had become celebrated within the fleet as excellent carrier escorts. During the war, both ships were part of Cruiser Division 16 commanded by Rear Admiral Francis S. Low, USN.After the war, both ships served as part of Task Force 71, the designation for the U.S. Seventh Fleet's North China Naval Force. Its mission was to support the allied occupation of the Korean peninsula. This included executing various show-the-flag operations along the western coast of Korea as well as in the Gulf of Chihli. These naval demonstrations preceded Operation Campus, the amphibious landing of U.S. Army ground forces at Jinsen, Korea, on 8 September 1945. Subsequently, both ships returned to the United States in mid-December 1945, and they were decommissioned and "mothballed" in 1947. after having spent 32 months and 29 months in service.
In 1958, the Bureau of Ships prepared two feasibility studies to explore whether Alaska and Guam could be suitably converted into guided-missile cruisers. The first study involved removing all of the guns in favor of four different missile systems. At $160 million, the cost of this proposed removal was seen as prohibitive, so a second study was initiated. The study left the forward batteries unchanged, and added a reduced version of the first plan on the stern of the ship. Even though the proposals would have cost approximately half as much as the first study's plan, it was still seen as too expensive. As a result, both ships were stricken from the Naval Vessel Register on 1 June 1960. Alaska was sold for scrap on 30 June 1960, and Guam on 24 May 1961.
The still-incomplete was considered for a conversion to be the Navy's first guided-missile cruiser; this thought lasted until 26 February 1952, when a different conversion to a "large command ship" was contemplated. In anticipation of the conversion, her classification was changed to CBC-1. This would have made her a "larger sister" to, but a year and a half later she was re-designated CB-3. Hawaii was stricken from the Naval Vessel Register on 9 June 1958 and was sold for scrap in 1959.
"Large cruisers" or "battlecruisers"
The Alaska class, along with the Dutch Design 1047 battlecruiser and the Japanese Design B-65 cruiser, were specifically to counter the heavy cruisers being built by their naval rivals. All three have been described as "super cruisers", "large cruisers" or even "unrestricted cruisers", with some advocating that they even be considered as battlecruisers, however, they were never officially classified as capital ships, as that designation was reserved for true battlecruisers and battleships. Early in its development, the class used the US battlecruiser designation CC, which had been planned for the. However, the designation was changed to CB to reflect their new status, "large cruiser", and the practice of referring to them as battlecruisers was officially discouraged. The U.S. Navy then named the individual vessels after U.S. territories, rather than states or cities, to symbolize the belief that these ships were supposed to play an intermediate role between heavy cruisers and fully-fledged battleships.The Alaska class certainly resembled contemporary US battleships in appearance, including the familiar 2-A-1 main battery and massive columnar mast. Their displacement was twice that of the newest heavy cruisers, being only 5,000 tons less than the Washington Treaty's battleship standard displacement limit of 35,000 long tons . They were also longer than several treaty battleships such as the and North Carolina class.
In design and armor the Alaska class are regarded as "large cruisers" rather than battlecruisers. Their design was scaled up from, the latter being a treaty cruiser limited by the Washington, 1930 London and Second London naval treaties. Their armor scheme had sufficient gunfire protection not only against 8″ heavy cruiser shells but even the larger 11″ shells used by Germany's "pocket battleships" and. However, they lacked the underwater protection systems found on full-fledged battleships and even intermediate capital ships like the French and German classes. This left the Alaskas virtually defenseless against torpedoes, as well as vulnerable to shells falling slightly short and continuing underwater to hit the hull.
In addition, despite being much larger than the Baltimore class, the numbers of secondary and anti-aircraft batteries of the Alaskas were similar. Whereas the Alaska class carried twelve 5"/38 caliber in six twin turrets, fifty-six 40 mm, and thirty-four 20 mm guns, the Baltimore class carried the same number of 5"/38s, eight fewer 40 mm, and ten fewer 20 mm., considerably fewer than new U.S. battleships that had ten 5"/38 twin mounts while older refitted U.S. battleships had eight. The dearth of anti-aircraft weaponry for a ship of its size was attributed to the amidships aircraft catapult like older US cruisers; while other modern U.S. cruisers and battleships opted for stern-mounted aircraft catapults to free up space along the central superstructure for more secondaries and anti-aircraft guns. In common with U.S. heavy cruisers, they had aircraft hangars and a single large rudder; the single rudder combined with the hull's long length gave the Alaskas a turning radius of 800 yards which exceeded the turning circles of larger battleships and carriers in the U.S. Navy. Author Richard Worth remarked that when they were finally completed, launched, and commissioned, they had the "size of a battleship but the capabilities of a cruiser". The Alaska class was similarly expensive to build and maintain as contemporary battleships yet far less capable due to armor deficiencies, while able to put up an anti-aircraft defense comparable only to the much cheaper Baltimore cruisers.
Despite these cruiser-like characteristics, and the U.S. Navy's insistence on their status as cruisers, the Alaska class has been frequently described as battlecruisers. The official navy magazine All Hands said "The Guam and her sister ship Alaska are the first American battle cruisers ever to be completed as such." Author Chris Knupp noted that while "other nations fulfilled the battlecruiser role by designing vessels like battleships, but stripped of armor and other features to gain speed", the United States "fulfilled the battlecruiser role by creating a larger, more powerful heavy cruiser... design already offered less armor and higher speed, but by enlarging the ship they gained the heavier firepower". The Alaskas percentage of armor tonnage, 28.4%, was slightly less than that of fast battleships; the British King George V class, the American Iowa class, and the battlecruiser/fast battleship all had armor percentages between 32 and 33%, whereas the Lexington-class battlecruiser design had a nearly identical armor percentage of 28.5%. In fact, older battlecruisers, such as , had a significantly lower percentage. Armament-wise, they had much larger guns than contemporary heavy cruisers; while the Baltimore class only carried nine 8"/55 caliber Marks 12 and 15 guns, the Alaska class carried nine 12"/50 caliber guns that were as good as, if not superior to, the old 14"/50 caliber gun used on the U.S. Navy's pre-treaty battleships.
Armament
Main battery
As built, the Alaska class had nine 12"/50 caliber Mark 8 guns mounted in three triple turrets, with two turrets forward and one aft, a configuration known as "2-A-1". The previous 12" gun manufactured for the U.S. Navy was the Mark 7 version, which had been designed for and installed in the 1912The turrets were very similar to those of the Iowa-class battleships, but differed in several ways; for example, the Alaska class had a two-stage powder hoist instead of the Iowa class's one-stage hoist. These differences made operating the guns safer and increased the rate of fire. In addition, a "projectile rammer" was added to Alaska and Guam. This machine transferred shells from storage on the ship to the rotating ring that fed the guns. However, this feature proved unsatisfactory, and it was not planned for Hawaii or any subsequent ships.
Because Alaska and Guam were the only two ships to mount these guns, only ten turrets were made during the war. They cost $1,550,000 each and were the most expensive heavy guns purchased by the U.S. Navy in World War II.
Secondary battery
The secondary battery of the Alaska class was composed of twelve dual-purpose 5"/38 caliber guns in twin mounts, with four offset on each side of the superstructure and two centerline turrets fore and aft. The 5"/38 was originally intended for use on only destroyers built in the 1930s, but by 1934 and into World War II it was being installed on almost all of the U.S.'s major warships, including aircraft carriers, battleships, and heavy and light cruisers.Anti-aircraft battery
For anti-aircraft armament, the Alaska-class ships carried 56 40 mm Bofors guns and 34 × 20 mm guns. These numbers are comparable to 48 × 40 mm and 24 × 20 mm on the smaller Baltimore-class heavy cruisers and 80 × 40 mm and 49 × 20 mm on the larger Iowa battleships.Arguably the most efficient light anti-aircraft gun of World War II, the 40 mm Bofors was used on nearly every major warship in the U.S. and UK fleets during World War II from about 1943 to 1945. Although they were a descendant of German and Swedish designs, the Bofors mounts used by the United States Navy during World War II had been heavily "Americanized" to U.S. Navy standards. This new standard resulted in a gun system set to English standards with interchangeable ammunition, simplifying 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 40 mm Bofors became a fearsome adversary, accounting for roughly half of all Japanese aircraft shot down between 1 October 1944 and 1 February 1945.
The Oerlikon 20 mm anti-aircraft gun was one of the most extensively used anti-aircraft guns of World War II; the U.S. alone manufactured a total of 124,735 of these guns. When introduced in 1941, it began to replace the 0.50" M2 Browning machine gun, which lacked sufficient range and stopping power for airborne threats, on a one-for-one basis. The Oerlikon remained the primary anti-aircraft weapon of the United States Navy until the introduction of the 40 mm Bofors in 1943.
Ships
- was commissioned on 17 June 1944. She served in the Pacific, screening aircraft carriers, providing shore bombardment at Okinawa, and going on raiding missions in the East China Sea. She was decommissioned on 17 February 1947 after less than three years of service and was scrapped in 1960.
- was commissioned on 17 September 1944. She served in the Pacific with Alaska on almost all of the same operations. Along with Alaska, she was decommissioned on 17 February 1947 and was scrapped in 1961.
- was intended as a third ship of the class, but she was never completed. Numerous plans to utilize her as a guided-missile cruiser or a large command ship in the years after the war were fruitless, and she was scrapped.
- USS Philippines, Puerto Rico, and Samoa were planned as the fourth, fifth, and sixth ships of the class, respectively. All three ships were to be built at Camden, New Jersey, but they were cancelled before construction could begin.
Footnotes