Baltimore class cruiser
Encyclopedia
The Baltimore class cruiser was a type of heavy cruiser
in the United States Navy
from the last years of the Second World War. Fast and heavily armed, ships like the Baltimore cruisers were mainly used by the Navy in World War II to protect the fast aircraft carrier
s in carrier battle groups. With their strong anti-aircraft armament, Baltimores could contribute especially in air defenses of these battle groups. Additionally, their 8-inch main guns and smaller medium guns were regularly used to bombard land targets in support of amphibious landings
. After the war, the ships were, for the most part, moved to the reserve fleet
but then reactivated for the Korean War
. By 1971, all ships based on the original design were decommissioned. However, four Baltimore class cruisers were refitted and converted into some of the first guided missile cruisers in the world, becoming and cruisers. The last of these was decommissioned in 1980. No example of the Baltimore class still exists.
, which had completely banned the construction of heavy cruisers, became obsolete. The Baltimore class was based partly on the USS Wichita
, a heavy cruiser from 1937, which represented the transition from inter-war to Second-World-War designs. It was also based partly on the , a light cruiser
that was then being built. In profile the Baltimores looked very much like the Cleveland-class light cruisers, the obvious difference being that the larger Baltimores carried nine 8 inches (203.2 mm) guns in three triple turrets, compared to the 12 6 inches (152.4 mm) guns in four triple turrets of the Clevelands.
The construction of the first four ships of the Baltimore class was launched on July 1, 1940 and four more were ordered before the year was out. A second order, which consisted of 16 more ships, was approved on August 7, 1942. The completion of the ships was delayed, because the Navy gave priority to the construction of the lighter Cleveland-class ships, as more of the lighter ships could be completed more quickly for deployment in carrier groups. With the construction of the first eight Baltimore class ships moving slowly, the US Navy used the time to review the initial plans and improve them. The new, modified design was itself delayed, so that construction had begun on a further seven ships--for a total of 15--using the original design before the revisions were completed. The final nine ships ordered were converted to the second, modified design. Between 1943 and 1946, 14 ships of the Baltimore class entered service. Construction of the fifteenth ship, which would have been the Norfolk, was stopped at the end of the war after eight months of work had already been done, and the half-completed hull was scrapped.
The largest contractor for the construction of the Baltimore class ships was Bethlehem Steel
, which produced eight ships at the Fore River Shipyard
in Quincy, Massachusetts
. New York Shipbuilding
in Camden, New Jersey
built four and the Philadelphia Naval Shipyard
in Philadelphia completed one in addition to working on the final, uncompleted ship. The ships were named after cities in the United States, the only exception being the , which was named in honor of the (sunk at the battle of Savo Island
) which had been named after Canberra
, the Australia
n capital. The classification "CA" originally stood for "armored cruiser" but was later used for heavy cruisers.
on September 2, 1945, though only seven took part in the battles of the Pacific Theater
and one in the European Theater. The other ships were still completing their testing in the final days of the war. By 1947, nine of the Baltimores had been decommissioned and placed in the reserve fleet, while five (Helena, Toledo, Macon, Columbus, and St Paul) remained in service. However, at the start of the 1950s, six were reactivated (Macon had been decommissioned for four short months: June-October 1950), making ten available for deployment in the Korean War
. Six of these were used for escort missions and coastal bombardment in Korea, while the other four reinforced fleets in other areas of the globe. The remaining four remained out of service: the Fall River was never reactivated, the Boston and Canberra were refitted as Boston-class guided missile cruisers (CGs)
, and the Chicago was reactivated after being converted to an Albany-class CG
.
After the Korean War, beginning in 1954 with Quincy, some Baltimores were decommissioned for good. By 1969, five ships were still in commission; four (Boston, Canberra, Chicago, Columbus) as CGs, and only one unmodified ship, the Saint Paul, which remained active to serve in the Vietnam War
, providing gunfire support. St Paul was the longest serving (26 years) member of the class, and was finally decommissioned in 1971. Boston and Canberra retired in 1970, Columbus in 1975, and finally Chicago in 1980. All fourteen of the original Baltimores were sold for scrap after being decommissioned, with Chicago being the final one broken up in 1991.
on October 13, 1944, which killed 23 men in the engine room and left the ship immobilized. The ship was hit amidships and both boiler
rooms were flooded with 3,000 tons of seawater. She was towed away by sister Boston, and as a result both ships missed the crucial Battle of Leyte Gulf
. A year later, repairs were completed at the Boston Naval Shipyard and Canberra was assigned to the Atlantic Fleet
. In June, 1945, the Pittsburgh had her entire bow ripped off in a typhoon, but there were no casualties. The ship struggled through 70 knots (137.2 km/h) winds to Guam
, where provisional repairs were made before sailing to the Puget Sound Naval Shipyard
for a full reconstruction. Pittsburgh's detached bow stayed afloat, and was later towed into Guam and scrapped.
During the Korean War, a fire in a forward turret
on April 12, 1952 killed 30 men on the St Paul. Then, in 1953, the same ship was hit by a coastal battery, though without injury to the crew. The Helena in 1951 and the Los Angeles in 1953 were also struck by coastal batteries without injuries during the war.
In June 1968, the Boston, along with its escort, the Australia
n destroyer
, were victims of friendly fire
when planes of the US Air Force mistook them for enemy targets and fired on them with AIM-7 Sparrow
missiles. Only Hobart was seriously damaged; although the Boston was hit, the warhead of the missile failed to detonate.
By the latter half of the 1940s, the navy was planning warships equipped with missiles. In 1946 the battleship
and in 1948 the seaplane tender
USS Norton Sound were converted to test this idea. Both were equipped, among other weapons, with RIM-2 Terrier
missiles, which were also used after 1952 on the first series of operational missile cruisers. Two Baltimore-class cruisers were refitted in this first series, the and the . These were the first operational guided missile cruisers in the world. They were designated the and returned to service in 1955 and 1956 respectively, reclassified as CAG-1 and CAG-2--"G" for "guided missile" and maintaining the "A" because they retained their heavy guns.
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In the following years six ships of the Cleveland class were equipped with guided missiles and in 1957 the first ship designed from the start to be a missile cruiser was completed (the ). Ships also continued to be converted, so starting in 1958, two Baltimore-class cruisers, the and the , along with an , the , were converted to the new . These were launched in 1962 and 1964, respectively. Two more ships were planned to be refitted as Albanys, the Baltimore-class and another Oregon City-class cruiser, the but these conversions were cancelled on financial considerations. As opposed to the Boston-class refit, the Albany-class refit required a total reconstruction. Both entire weapons systems and the superstructure were removed and replaced with new ones; the cost of one refit was $175 million. Because no high-caliber weapons were used, the Albany class ships received the designation CG.
Baltimore-class cruisers were 673 in 7 in (205.31 m) long and 70 in 10 in (21.59 m) wide. Since the hull was not altered in either the Albany or the Boston class, these numbers were the same for those ships as well, but the alterations differentiated them in all other categories.
Fully loaded, original Baltimores displaced 17031 long ton of water. Their draft was 23 in 11 in (7.29 m). At the bow, the top level of the hull lay 33 feet (10.1 m) above the water; at the stern, 25 feet (7.6 m). The funnel
s were 86 feet (26.2 m) high, and the highest point on the masts was at 112 feet (34.1 m). The superstructure
occupied about a third of the ship's length and was divided into two deckhouses. The gap between these housed the two thin funnels. Two masts, one a bit forward and the other a bit aft of the funnels, accommodated the positioning electronics.
The vertical belt armor
was 6 inches (152.4 mm) thick and the horizontal deck armor was up to 3 inches (76.2 mm) thick. The turrets were also heavily armored, between 3 and 6 in thick, while the command tower had the thickest armor, at 8 inches (203.2 mm).
The Boston class had a draft about 20 inches (half a meter) deeper in the water, and displaced about 500 long ton more water than their former sister ships. Because the Bostons were only partially refitted, the forward third of the ship remained virtually untouched. The first serious change was the combination of what were two funnels on the Balitmores to just one, thicker funnel, which still stood in the gap between the two deckhouses. Because the missiles required more guiding electronic systems, the forward mast was replaced with a four-legged lattice mast
with an enlarged platform. The most conspicuous change was of course the addition of the missile-launching apparatus and its magazine of missiles, which took up the entire back half of the ship and replaced the guns which had been there.
The three Albanys were completely rebuilt from the deck level up, to the point that they bear very little resemblance to their former sister ships. The deckhouse now took up nearly two thirds of the ship's length and was two decks high for almost the entire length. Above that lay the box-shaped bridge which was one of the most recognizable markers of the class. The two masts and funnels were combined into the so-called "macks
--a portmanteau word combining "mast" and "stack" (smokestack)--where the electronics platforms were attached to the tops of the funnels rather than attached to masts rising all the way from the deck. The highest points on the forward mack was more than 130 feet (39.6 m) above the water line. Such heights could only be achieved with the use of aluminum alloys, which were used to a great extent in the construction of the superstructures. Despite, this the fully loaded displacement of the Albanys grew to more than 17500 long ton.
. Each ship had four shafts, each with a propeller
. The shafts were turned by four steam turbine
s, the steam produced by four boiler
s, which at full speed reached pressures of up to 615 pound per square inches (4,240,275.7 Pa). The Baltimores each had two engine rooms and two funnels, though this was changed in the Bostons, which only had one funnel for all four turbines, as noted above. The high speed was around 33 knots (64.7 km/h) and the performance of the engine was around 120000 HP.
The original Baltimores could carry up to 2250 long ton of fuel, putting the maximum range at a cruising speed of 15 knots (29.4 km/h) at about 10000 nautical miles (18,520 km). The increased displacement of the modified Boston and Albany classes meant their range was reduced to about 9000 and 7000 miles (11,265.4 km) respectively, despite increases in fuel capacity to 2600 and 2500 tons.
of 8 in (203mm), and were 55 calibers long (440in/17.32m). Two of these were located forward and one aft. The range of these guns was 17.3 miles (27.8 km). The secondary weapons were six twin-turreted 5 in (127mm) guns, 38 calibers (190 in/7.48m) long. Two turrets were located on each side of the superstructure and two behind the main batteries. These guns could be used against aircraft, ships, and for coastal bombardment. Their range for surface targets was 10 miles (16.1 km) and they could reach airplanes at altitudes of up to 6 miles (9.7 km). In addition, the ships had very strong purely anti-aircraft defenses: 12 quadruple mounts of Bofors 40 mm (or 11 quadruple mounts and 2 twin mounts on ships with only one rear airplane-crane) as well as between 20-28 20mm machine guns, depending on when a given ship was commissioned. The small-caliber weapons were soon removed. The 20mm anti-aircraft guns were removed without replacement shortly after the war because they had been ineffective against Japanese planes. The 40mm Bofors were replaced with 3"/50 caliber guns over the course of the 1950s.
Four ships, the , , , and , were also each equipped with three nuclear cruise missiles of the SSM-N-8 Regulus
type between 1956 and 1958. Ultimately, though, the deployment of such missiles on surface ships remained an experiment, which was only undertaken until the 1960s. The successor UGM-27 Polaris
was carried only by nuclear submarine
s.
or later with the SPS-12 (from the Radio Corporation of America combined with a SPS-8 as a height-finder. With these systems the detection range for bombers was increased to 145 miles (233.4 km). The ships in active service longer received further upgrades in their final years: the SPS-6 was replaced with the SPS-37 (also from Westinghouse) and the SPS-12 was replaced with the SPS-10 from Raytheon
. With this equipment planes could be detected at over 250 miles (402.3 km) away.
The Baltimore-class was equipped from the start with electronic fire control systems to determine the fire-parameters by which targets over the horizon
could be hit. The main guns were controlled by a Mark 34 fire control system connected to an MK 8 radar. The AA guns were guided by Mk 37 systems with Mk-4 radar. Later, the fire control radars were replaced along with the main radar systems. The fire control systems remained the same except that the new 3 in guns were fitted upgraded to Mk 56 with Mk 35 radars.
s on the side edges of the aft deck. Between the catapults was a sliding hatchway which was the roof of an onboard hangar. Directly under the hatch was an aircraft elevator. The hangar had room to accommodate up to four aircraft at one time, one to port forward of the elevator, one to port abeam the elevator, one starboard abeam, and one on the elevator itself. The first four ships of the class had two cranes each, while the later models had only one.
At full speed, Vought OS2U Kingfisher could be launched from these catapults and later Curtiss SC-1 Seahawk as well. These planes were used for reconnaissance, anti-submarine
, and rescue missions. The planes were seaplane
s, and after their missions would land in the water near the cruiser and be lifted back up into the ship by the crane or cranes in the rear and reset upon their catapults. In the 1950s, the catapults and the accompanying capacity to launch airplanes were removed, though the cranes were left and the hangars used to house helicopters or the workings of the Regulus missile system.
The , in 1948, had a slightly elevated helipad
installed instead of the catapults. Because of the helipad, the available firing angles for the main guns were sharply narrowed and the experiment was therefore quickly abandoned and not attempted on any other ships of the class. The ships of the Albany-class did have an area on the deck for helicopters to land, but no platform.
The plans for the -light aircraft carrier
were adapted from the drafts of the Baltimore hull design, and, for example the layout of the engines was transferred as well. The hulls of these ships were, however, significantly widened. The Saipan-class ships were completed in 1947 and 1948, but by the mid 1950s, they proved too small for the planes of the jet age
and were converted for use as communication and command ship
s.
and his staff.
At launch, during and shortly after the war, the crews consisted of around 60 officers and about 1000 rank and file crewmen. When an admiral's staff was aboard during wartime, this number could swell to 80 officers and 1500 crewmen. On the Bostons, the standard crew, even in peacetime and without an admiral's staff, was 80 officers and around 1650 crewmen. Because the Albany-class was equipped almost exclusively for guided-missiles, it required less crew than the Bostons, and was roughly comparable numerically to the basic Baltimore.
Compared to today's crew sizes, these numbers seem high. The modern is manned by about 400, a sign of the advances of automation and computerization on warships through the Navy's Smart Ship program.
Quarters for the crew lay mostly below deck as the superstructure was the site of the Combat Information Center
(CIC) and possibly the Admiral's headquarters.
Heavy cruiser
The heavy cruiser was a type of cruiser, a naval warship designed for long range, high speed and an armament of naval guns roughly 203mm calibre . The heavy cruiser can be seen as a lineage of ship design from 1915 until 1945, although the term 'heavy cruiser' only came into formal use in 1930...
in 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...
from the last years of the Second World War. Fast and heavily armed, ships like the Baltimore cruisers were mainly used by the Navy in World War II to protect the fast aircraft carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...
s in carrier battle groups. With their strong anti-aircraft armament, Baltimores could contribute especially in air defenses of these battle groups. Additionally, their 8-inch main guns and smaller medium guns were regularly used to bombard land targets in support of amphibious landings
Amphibious warfare
Amphibious warfare is the use of naval firepower, logistics and strategy to project military power ashore. In previous eras it stood as the primary method of delivering troops to non-contiguous enemy-held terrain...
. After the war, the ships were, for the most part, moved to the reserve fleet
Reserve fleet
A reserve fleet is a collection of naval vessels of all types that are fully equipped for service but are not currently needed, and thus partially or fully decommissioned. A reserve fleet is informally said to be "in mothballs" or "mothballed"; an equivalent expression in unofficial modern U.S....
but then reactivated for the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
. By 1971, all ships based on the original design were decommissioned. However, four Baltimore class cruisers were refitted and converted into some of the first guided missile cruisers in the world, becoming and cruisers. The last of these was decommissioned in 1980. No example of the Baltimore class still exists.
Planning and construction
Immediately after the outbreak of World War II in September, 1939, the US Navy initiated studies regarding a new class of heavy cruiser, which eventually led to the construction of the Baltimore class. With the start of the war, the limitations instituted by the Second London Naval TreatySecond London Naval Treaty
The Second London Naval Disarmament Conference opened in London, the United Kingdom, on 9 December 1935. It resulted in the Second London Naval Treaty which was signed on 25 March 1936.- Description :...
, which had completely banned the construction of heavy cruisers, became obsolete. The Baltimore class was based partly on the USS Wichita
Wichita class cruiser
The Wichita class cruiser was a class of heavy cruiser used by the United States Navy. The single ship of the class was the .-Class history:What was to become the Wichita class cruiser was conceived as another...
, a heavy cruiser from 1937, which represented the transition from inter-war to Second-World-War designs. It was also based partly on the , a light cruiser
Light cruiser
A light cruiser is a type of small- or medium-sized warship. The term is a shortening of the phrase "light armored cruiser", describing a small ship that carried armor in the same way as an armored cruiser: a protective belt and deck...
that was then being built. In profile the Baltimores looked very much like the Cleveland-class light cruisers, the obvious difference being that the larger Baltimores carried nine 8 inches (203.2 mm) guns in three triple turrets, compared to the 12 6 inches (152.4 mm) guns in four triple turrets of the Clevelands.
The construction of the first four ships of the Baltimore class was launched on July 1, 1940 and four more were ordered before the year was out. A second order, which consisted of 16 more ships, was approved on August 7, 1942. The completion of the ships was delayed, because the Navy gave priority to the construction of the lighter Cleveland-class ships, as more of the lighter ships could be completed more quickly for deployment in carrier groups. With the construction of the first eight Baltimore class ships moving slowly, the US Navy used the time to review the initial plans and improve them. The new, modified design was itself delayed, so that construction had begun on a further seven ships--for a total of 15--using the original design before the revisions were completed. The final nine ships ordered were converted to the second, modified design. Between 1943 and 1946, 14 ships of the Baltimore class entered service. Construction of the fifteenth ship, which would have been the Norfolk, was stopped at the end of the war after eight months of work had already been done, and the half-completed hull was scrapped.
The largest contractor for the construction of the Baltimore class ships was Bethlehem Steel
Bethlehem Steel
The Bethlehem Steel Corporation , based in Bethlehem, Pennsylvania, was once the second-largest steel producer in the United States, after Pittsburgh, Pennsylvania-based U.S. Steel. After a decline in the U.S...
, which produced eight ships at the Fore River Shipyard
Fore River Shipyard
The Fore River Shipyard of Quincy, Massachusetts, more formally known as the Fore River Ship and Engine Building Company, was a shipyard in the United States from 1883 until 1986. Located on the Weymouth Fore River, the yard began operations in 1883 in Braintree, Massachusetts before being moved...
in Quincy, Massachusetts
Quincy, Massachusetts
Quincy is a city in Norfolk County, Massachusetts, United States. Its nicknames are "City of Presidents", "City of Legends", and "Birthplace of the American Dream". As a major part of Metropolitan Boston, Quincy is a member of Boston's Inner Core Committee for the Metropolitan Area Planning Council...
. New York Shipbuilding
New York Shipbuilding
The New York Shipbuilding Corporation was founded in 1899 and opened its first shipyard in 1900. Located in Camden, New Jersey on the east shore of the Delaware River, New York Ship built more than 500 vessels for the U.S...
in Camden, New Jersey
Camden, New Jersey
The city of Camden is the county seat of Camden County, New Jersey. It is located across the Delaware River from Philadelphia, Pennsylvania. As of the 2010 United States Census, the city had a total population of 77,344...
built four and the Philadelphia Naval Shipyard
Philadelphia Naval Shipyard
The Philadelphia Naval Business Center, formerly known as the Philadelphia Naval Shipyard and Philadelphia Navy Yard, was the first naval shipyard of the United States. The U.S. Navy reduced its activities there in the 1990s, and ended most of them on September 30, 1995...
in Philadelphia completed one in addition to working on the final, uncompleted ship. The ships were named after cities in the United States, the only exception being the , which was named in honor of the (sunk at the battle of Savo Island
Battle of Savo Island
The Battle of Savo Island, also known as the First Battle of Savo Island and, in Japanese sources, as the , was a naval battle of the Pacific Campaign of World War II, between the Imperial Japanese Navy and Allied naval forces...
) which had been named after Canberra
Canberra
Canberra is the capital city of Australia. With a population of over 345,000, it is Australia's largest inland city and the eighth-largest city overall. The city is located at the northern end of the Australian Capital Territory , south-west of Sydney, and north-east of Melbourne...
, the Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n capital. The classification "CA" originally stood for "armored cruiser" but was later used for heavy cruisers.
Service
Of the fourteen completed ships, twelve were launched before the Japanese capitulationSurrender of Japan
The surrender of Japan in 1945 brought hostilities of World War II to a close. By the end of July 1945, the Imperial Japanese Navy was incapable of conducting operations and an Allied invasion of Japan was imminent...
on September 2, 1945, though only seven took part in the battles of the Pacific Theater
Pacific War
The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...
and one in the European Theater. The other ships were still completing their testing in the final days of the war. By 1947, nine of the Baltimores had been decommissioned and placed in the reserve fleet, while five (Helena, Toledo, Macon, Columbus, and St Paul) remained in service. However, at the start of the 1950s, six were reactivated (Macon had been decommissioned for four short months: June-October 1950), making ten available for deployment in the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
. Six of these were used for escort missions and coastal bombardment in Korea, while the other four reinforced fleets in other areas of the globe. The remaining four remained out of service: the Fall River was never reactivated, the Boston and Canberra were refitted as Boston-class guided missile cruisers (CGs)
Boston class cruiser
The United States Navy's Boston class were the first guided missile cruisers in the world. Both ships in this experimental class were originally Baltimore class heavy cruisers that had been decommissioned after World War II, but were redesignated as guided missile heavy cruisers and entered refit...
, and the Chicago was reactivated after being converted to an Albany-class CG
Albany class cruiser
The Albany Class guided missile cruisers were converted Baltimore and Oregon City class heavy cruisers of the United States Navy. All original superstructure and weapons were removed and replaced...
.
After the Korean War, beginning in 1954 with Quincy, some Baltimores were decommissioned for good. By 1969, five ships were still in commission; four (Boston, Canberra, Chicago, Columbus) as CGs, and only one unmodified ship, the Saint Paul, which remained active to serve in the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
, providing gunfire support. St Paul was the longest serving (26 years) member of the class, and was finally decommissioned in 1971. Boston and Canberra retired in 1970, Columbus in 1975, and finally Chicago in 1980. All fourteen of the original Baltimores were sold for scrap after being decommissioned, with Chicago being the final one broken up in 1991.
Damage and Casualties
In World War II, only the Canberra was damaged through enemy fire, when she was struck with a compressed air torpedoTorpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
on October 13, 1944, which killed 23 men in the engine room and left the ship immobilized. The ship was hit amidships and both boiler
Boiler
A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.-Materials:...
rooms were flooded with 3,000 tons of seawater. She was towed away by sister Boston, and as a result both ships missed the crucial Battle of Leyte Gulf
Battle of Leyte Gulf
The Battle of Leyte Gulf, also called the "Battles for Leyte Gulf", and formerly known as the "Second Battle of the Philippine Sea", is generally considered to be the largest naval battle of World War II and, by some criteria, possibly the largest naval battle in history.It was fought in waters...
. A year later, repairs were completed at the Boston Naval Shipyard and Canberra was assigned to the Atlantic Fleet
United States Fleet Forces Command
The United States Fleet Forces Command is an Atlantic Ocean theater-level component command of the United States Navy that provides naval resources that are under the operational control of the United States Northern Command...
. In June, 1945, the Pittsburgh had her entire bow ripped off in a typhoon, but there were no casualties. The ship struggled through 70 knots (137.2 km/h) winds to Guam
Guam
Guam is an organized, unincorporated territory of the United States located in the western Pacific Ocean. It is one of five U.S. territories with an established civilian government. Guam is listed as one of 16 Non-Self-Governing Territories by the Special Committee on Decolonization of the United...
, where provisional repairs were made before sailing to the Puget Sound Naval Shipyard
Puget Sound Naval Shipyard
Puget Sound Naval Shipyard and Intermediate Maintenance Facility is a United States Navy shipyard covering 179 acres on Puget Sound at Bremerton, Washington...
for a full reconstruction. Pittsburgh's detached bow stayed afloat, and was later towed into Guam and scrapped.
During the Korean War, a fire in a forward turret
Turret
In architecture, a turret is a small tower that projects vertically from the wall of a building such as a medieval castle. Turrets were used to provide a projecting defensive position allowing covering fire to the adjacent wall in the days of military fortification...
on April 12, 1952 killed 30 men on the St Paul. Then, in 1953, the same ship was hit by a coastal battery, though without injury to the crew. The Helena in 1951 and the Los Angeles in 1953 were also struck by coastal batteries without injuries during the war.
In June 1968, the Boston, along with its escort, the Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n destroyer
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...
, were victims of friendly fire
Friendly fire
Friendly fire is inadvertent firing towards one's own or otherwise friendly forces while attempting to engage enemy forces, particularly where this results in injury or death. A death resulting from a negligent discharge is not considered friendly fire...
when planes of the US Air Force mistook them for enemy targets and fired on them with AIM-7 Sparrow
AIM-7 Sparrow
The AIM-7 Sparrow is an American, medium-range semi-active radar homing air-to-air missile operated by the United States Air Force, United States Navy and United States Marine Corps, as well as various allied air forces and navies. Sparrow and its derivatives were the West's principal beyond visual...
missiles. Only Hobart was seriously damaged; although the Boston was hit, the warhead of the missile failed to detonate.
Refittings (Albany and Boston classes)
Battleship
A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...
and in 1948 the seaplane tender
Seaplane tender
A seaplane tender is a ship that provides facilities for operating seaplanes. These ships were the first aircraft carriers and appeared just before the First World War.-History:...
USS Norton Sound were converted to test this idea. Both were equipped, among other weapons, with RIM-2 Terrier
RIM-2 Terrier
The Convair RIM-2 Terrier was a two-stage medium-range naval surface-to-air missile , and was among the earliest surface-to-air missiles to equip United States Navy ships. Originally, the Terrier had a launch thrust of 23 kN , and weight of 1392 kg...
missiles, which were also used after 1952 on the first series of operational missile cruisers. Two Baltimore-class cruisers were refitted in this first series, the and the . These were the first operational guided missile cruisers in the world. They were designated the and returned to service in 1955 and 1956 respectively, reclassified as CAG-1 and CAG-2--"G" for "guided missile" and maintaining the "A" because they retained their heavy guns.
Hull
Fully loaded, original Baltimores displaced 17031 long ton of water. Their draft was 23 in 11 in (7.29 m). At the bow, the top level of the hull lay 33 feet (10.1 m) above the water; at the stern, 25 feet (7.6 m). The funnel
Chimney
A chimney is a structure for venting hot flue gases or smoke from a boiler, stove, furnace or fireplace to the outside atmosphere. Chimneys are typically vertical, or as near as possible to vertical, to ensure that the gases flow smoothly, drawing air into the combustion in what is known as the...
s were 86 feet (26.2 m) high, and the highest point on the masts was at 112 feet (34.1 m). The superstructure
Superstructure
A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships...
occupied about a third of the ship's length and was divided into two deckhouses. The gap between these housed the two thin funnels. Two masts, one a bit forward and the other a bit aft of the funnels, accommodated the positioning electronics.
The vertical belt armor
Belt armor
Belt armor is a layer of heavy metal armor plated on to or within outer hulls of warships, typically on battleships, battlecruisers and cruisers, and on aircraft carriers converted from those types of ships....
was 6 inches (152.4 mm) thick and the horizontal deck armor was up to 3 inches (76.2 mm) thick. The turrets were also heavily armored, between 3 and 6 in thick, while the command tower had the thickest armor, at 8 inches (203.2 mm).
The Boston class had a draft about 20 inches (half a meter) deeper in the water, and displaced about 500 long ton more water than their former sister ships. Because the Bostons were only partially refitted, the forward third of the ship remained virtually untouched. The first serious change was the combination of what were two funnels on the Balitmores to just one, thicker funnel, which still stood in the gap between the two deckhouses. Because the missiles required more guiding electronic systems, the forward mast was replaced with a four-legged lattice mast
Lattice mast
Lattice masts, or cage masts, are a type of observation mast common on major warships in the early 20th century. They were used most prominently on American dreadnought battleships and armored cruisers of the World War I era. Observation posts were mounted on the masts and used to direct the fire...
with an enlarged platform. The most conspicuous change was of course the addition of the missile-launching apparatus and its magazine of missiles, which took up the entire back half of the ship and replaced the guns which had been there.
The three Albanys were completely rebuilt from the deck level up, to the point that they bear very little resemblance to their former sister ships. The deckhouse now took up nearly two thirds of the ship's length and was two decks high for almost the entire length. Above that lay the box-shaped bridge which was one of the most recognizable markers of the class. The two masts and funnels were combined into the so-called "macks
Mack (ship)
In naval architecture, a Mack is a structure which combines the radar MAsts and the exhaust stACK of a surface ship, thereby saving the upper deck space used for separate funnels and the increasingly large lattice masts used to carry heavy radar aerials. The word itself is a composite of "mast" and...
--a portmanteau word combining "mast" and "stack" (smokestack)--where the electronics platforms were attached to the tops of the funnels rather than attached to masts rising all the way from the deck. The highest points on the forward mack was more than 130 feet (39.6 m) above the water line. Such heights could only be achieved with the use of aluminum alloys, which were used to a great extent in the construction of the superstructures. Despite, this the fully loaded displacement of the Albanys grew to more than 17500 long ton.
Propulsion
The Baltimore cruisers were propelled with steam powerSteamboat
A steamboat or steamship, sometimes called a steamer, is a ship in which the primary method of propulsion is steam power, typically driving propellers or paddlewheels...
. Each ship had four shafts, each with a propeller
Propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...
. The shafts were turned by four steam turbine
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....
s, the steam produced by four boiler
Boiler
A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.-Materials:...
s, which at full speed reached pressures of up to 615 pound per square inches (4,240,275.7 Pa). The Baltimores each had two engine rooms and two funnels, though this was changed in the Bostons, which only had one funnel for all four turbines, as noted above. The high speed was around 33 knots (64.7 km/h) and the performance of the engine was around 120000 HP.
The original Baltimores could carry up to 2250 long ton of fuel, putting the maximum range at a cruising speed of 15 knots (29.4 km/h) at about 10000 nautical miles (18,520 km). The increased displacement of the modified Boston and Albany classes meant their range was reduced to about 9000 and 7000 miles (11,265.4 km) respectively, despite increases in fuel capacity to 2600 and 2500 tons.
Armament
The main armament of the Baltimore class consisted of three turrets, each with three barrels, a caliberCaliber
In guns including firearms, caliber or calibre is the approximate internal diameter of the barrel in relation to the diameter of the projectile used in it....
of 8 in (203mm), and were 55 calibers long (440in/17.32m). Two of these were located forward and one aft. The range of these guns was 17.3 miles (27.8 km). The secondary weapons were six twin-turreted 5 in (127mm) guns, 38 calibers (190 in/7.48m) long. Two turrets were located on each side of the superstructure and two behind the main batteries. These guns could be used against aircraft, ships, and for coastal bombardment. Their range for surface targets was 10 miles (16.1 km) and they could reach airplanes at altitudes of up to 6 miles (9.7 km). In addition, the ships had very strong purely anti-aircraft defenses: 12 quadruple mounts of Bofors 40 mm (or 11 quadruple mounts and 2 twin mounts on ships with only one rear airplane-crane) as well as between 20-28 20mm machine guns, depending on when a given ship was commissioned. The small-caliber weapons were soon removed. The 20mm anti-aircraft guns were removed without replacement shortly after the war because they had been ineffective against Japanese planes. The 40mm Bofors were replaced with 3"/50 caliber guns over the course of the 1950s.
Four ships, the , , , and , were also each equipped with three nuclear cruise missiles of the SSM-N-8 Regulus
SSM-N-8 Regulus
The SSM-N-8A Regulus was a ship and submarine launched, nuclear armed cruise missile deployed by the United States Navy from 1955 to 1964.-Design and development:...
type between 1956 and 1958. Ultimately, though, the deployment of such missiles on surface ships remained an experiment, which was only undertaken until the 1960s. The successor UGM-27 Polaris
UGM-27 Polaris
The Polaris missile was a two-stage solid-fuel nuclear-armed submarine-launched ballistic missile built during the Cold War by Lockheed Corporation of California for the United States Navy....
was carried only by nuclear submarine
Nuclear submarine
A nuclear submarine is a submarine powered by a nuclear reactor . The performance advantages of nuclear submarines over "conventional" submarines are considerable: nuclear propulsion, being completely independent of air, frees the submarine from the need to surface frequently, as is necessary for...
s.
Electronics
Initially, the Balitmores were equipped with SG radar systems for surface targets and SK systems for airborne targets. The range of these systems for surface targets, depending on the size of the target was between 15 and 22 nmi (27.8 and 40.7 km). The SK could detect bombers at medium altitudes from 100 nautical miles (185.2 km). The radar systems were replaced in the Korean war with the more effective SPS-6 (built by Westinghouse ElectricWestinghouse Electric (1886)
Westinghouse Electric was an American manufacturing company. It was founded in 1886 as Westinghouse Electric Company and later renamed Westinghouse Electric Corporation by George Westinghouse. The company purchased CBS in 1995 and became CBS Corporation in 1997...
or later with the SPS-12 (from the Radio Corporation of America combined with a SPS-8 as a height-finder. With these systems the detection range for bombers was increased to 145 miles (233.4 km). The ships in active service longer received further upgrades in their final years: the SPS-6 was replaced with the SPS-37 (also from Westinghouse) and the SPS-12 was replaced with the SPS-10 from Raytheon
Raytheon
Raytheon Company is a major American defense contractor and industrial corporation with core manufacturing concentrations in weapons and military and commercial electronics. It was previously involved in corporate and special-mission aircraft until early 2007...
. With this equipment planes could be detected at over 250 miles (402.3 km) away.
The Baltimore-class was equipped from the start with electronic fire control systems to determine the fire-parameters by which targets over the horizon
Horizon
The horizon is the apparent line that separates earth from sky, the line that divides all visible directions into two categories: those that intersect the Earth's surface, and those that do not. At many locations, the true horizon is obscured by trees, buildings, mountains, etc., and the resulting...
could be hit. The main guns were controlled by a Mark 34 fire control system connected to an MK 8 radar. The AA guns were guided by Mk 37 systems with Mk-4 radar. Later, the fire control radars were replaced along with the main radar systems. The fire control systems remained the same except that the new 3 in guns were fitted upgraded to Mk 56 with Mk 35 radars.
Aircraft
The onboard flight systems of the Baltimore-class cruisers during World War II consisted of two aircraft catapultAircraft catapult
An aircraft catapult is a device used to launch aircraft from ships—in particular aircraft carriers—as a form of assisted take off. It consists of a track built into the flight deck, below which is a large piston or shuttle that is attached through the track to the nose gear of the aircraft, or in...
s on the side edges of the aft deck. Between the catapults was a sliding hatchway which was the roof of an onboard hangar. Directly under the hatch was an aircraft elevator. The hangar had room to accommodate up to four aircraft at one time, one to port forward of the elevator, one to port abeam the elevator, one starboard abeam, and one on the elevator itself. The first four ships of the class had two cranes each, while the later models had only one.
At full speed, Vought OS2U Kingfisher could be launched from these catapults and later Curtiss SC-1 Seahawk as well. These planes were used for reconnaissance, anti-submarine
Anti-submarine warfare
Anti-submarine warfare is a branch of naval warfare that uses surface warships, aircraft, or other submarines to find, track and deter, damage or destroy enemy submarines....
, and rescue missions. The planes were seaplane
Seaplane
A seaplane is a fixed-wing aircraft capable of taking off and landing on water. Seaplanes that can also take off and land on airfields are a subclass called amphibian aircraft...
s, and after their missions would land in the water near the cruiser and be lifted back up into the ship by the crane or cranes in the rear and reset upon their catapults. In the 1950s, the catapults and the accompanying capacity to launch airplanes were removed, though the cranes were left and the hangars used to house helicopters or the workings of the Regulus missile system.
The , in 1948, had a slightly elevated helipad
Helipad
Helipad is a common abbreviation for helicopter landing pad, a landing area for helicopters. While helicopters are able to operate on a variety of relatively flat surfaces, a fabricated helipad provides a clearly marked hard surface away from obstacles where a helicopter can safely...
installed instead of the catapults. Because of the helipad, the available firing angles for the main guns were sharply narrowed and the experiment was therefore quickly abandoned and not attempted on any other ships of the class. The ships of the Albany-class did have an area on the deck for helicopters to land, but no platform.
Later designs
The hull of the Baltimore-class was used for the development of a number of other classes. The Oregon City-class cruisers differ only slightly from Baltimores, because they were originally planned as Baltimore-class cruisers but were constructed based on modified plans. Though nine ships were planned, only three were completed. The main differences between the two classes is the reduction to a single-trunked funnel, a redesigned forward superstructure that was placed 40 feet (12.2 m) further aft, primarily to decrease top-heaviness and increase the arcs of fire for the guns. A somewhat enlarged design resulted in the . While the basic deck layout was unchanged, this class carried the first fully automated high-caliber guns on a warship, though none was constructed in time to take part in World War II.The plans for the -light aircraft carrier
Light aircraft carrier
A light aircraft carrier is an aircraft carrier that is smaller than the standard carriers of a navy. The precise definition of the type varies by country; light carriers typically have a complement of aircraft only ½ to ⅔ the size of a full-sized or "fleet" carrier.-History:In World War II, the...
were adapted from the drafts of the Baltimore hull design, and, for example the layout of the engines was transferred as well. The hulls of these ships were, however, significantly widened. The Saipan-class ships were completed in 1947 and 1948, but by the mid 1950s, they proved too small for the planes of the jet age
Jet age
The Jet Age is a period of history defined by the social change brought about by the advent of large aircraft powered by turbine engines. These aircraft are able to fly much higher, faster, and farther than older piston-powered propliners, making transcontinental and inter-continental travel...
and were converted for use as communication and command ship
Command ship
Command ships serve as the flagships of the Commander of a fleet. They provide communications, office space, and accommodations for a fleet commander and his staff, and serve to coordinate fleet activities....
s.
Crew
The size of the crew of a Baltimore-class cruiser varied by era and by tactical situation. Different sources also differ about the numbers. Naturally, the crew sizes were larger during wartime and furthermore, some cruisers--including all three of the modified Albany-class--were used as flagships and therefore housed an admiralAdmiral
Admiral is the rank, or part of the name of the ranks, of the highest naval officers. It is usually considered a full admiral and above vice admiral and below admiral of the fleet . It is usually abbreviated to "Adm" or "ADM"...
and his staff.
At launch, during and shortly after the war, the crews consisted of around 60 officers and about 1000 rank and file crewmen. When an admiral's staff was aboard during wartime, this number could swell to 80 officers and 1500 crewmen. On the Bostons, the standard crew, even in peacetime and without an admiral's staff, was 80 officers and around 1650 crewmen. Because the Albany-class was equipped almost exclusively for guided-missiles, it required less crew than the Bostons, and was roughly comparable numerically to the basic Baltimore.
Compared to today's crew sizes, these numbers seem high. The modern is manned by about 400, a sign of the advances of automation and computerization on warships through the Navy's Smart Ship program.
Quarters for the crew lay mostly below deck as the superstructure was the site of the Combat Information Center
Combat Information Center
The Operations Room is the tactical center of a warship or AWAC aircraft providing processed information for command and control of the near battle space or 'area of operations'...
(CIC) and possibly the Admiral's headquarters.
Ships in class
- USS Boston (CA-69, CAG-1)USS Boston (CA-69)USS Boston , a Baltimore-class heavy cruiser, was the sixth ship of the United States Navy to be named for the city of Boston, Massachusetts. Boston was launched 26 August 1942 by Bethlehem Steel Company's, Fore River Shipyard, Quincy, Mass.; sponsored by Mrs. Maurice J. Tobin, wife of the Mayor of...
- USS Canberra (CA-70, CAG-2)USS Canberra (CA-70)USS Canberra was a Baltimore class cruiser and later a Boston class guided missile cruiser of the United States Navy. Originally to be named USS Pittsburgh, the ship was renamed Canberra before launch, for the Royal Australian Navy's County class cruiser, , which was sunk during the Battle of Savo...
- USS Columbus (CA-74, CG-12)USS Columbus (CA-74)The third USS Columbus , a Baltimore-class heavy cruiser, was the second ship of the United States Navy named for Columbus, Ohio. She was launched 30 November 1944 by Bethlehem Steel Co., Quincy, Massachusetts; she was sponsored by Mrs. E. G...
- USS Chicago (CA-136, CG-11)USS Chicago (CA-136)USS Chicago was a Baltimore class heavy cruiser laid down on 28 July 1943 at Philadelphia, Pennsylvania, USA, by the Philadelphia Navy Yard. Launched on 20 August 1944 she was sponsored by Mrs. Edward J. Kelly, wife of the Mayor of Chicago, Illinois, and commissioned at the Philadelphia Navy Yard...