View source for Engineering:Baltimore-class cruiser

{{Short description|Class of US Navy heavy cruisers}}

{|{{Infobox ship begin}}
{{Infobox ship image
| Ship image = File:USS Bremerton (CA-130) off San Francisco in 1955.JPG
| Ship caption = USS ''Bremerton'' (CA-130) in 1955
}}
{{Infobox ship class overview
| Name = ''Baltimore'' class
| Builders = * Bethlehem Steel Corporation, Fore River Shipyard (8)
* [[Company:New York Shipbuilding Corporation|New York Shipbuilding Corporation]] (4)
* [[Company:Philadelphia Naval Shipyard|Philadelphia Naval Shipyard]] (2)
| Operators = {{navy|United States}}
| Class before = {{USS|Wichita|CA-45|6}}
| Class after = {{sclass|Oregon City|cruiser|4}}
| Subclasses = * {{sclass|Boston|cruiser|4}}
* {{sclass|Albany|cruiser|4}}
| Cost = US$40&nbsp;million per ship<ref>"American Cruiser of World War 2 - A pictorial encyclopedia by Steve Ewing</ref>
| Built range = 1941–1945
| In service range = 
| In commission range = 1943–1971
| Total ships building = 
| Total ships planned = 14
| Total ships completed = 14
| Total ships active = 
| Total ships laid up = 
| Total ships lost = 
| Total ships retired = 14
| Total ships scrapped = 14
}}
{{Infobox ship characteristics
| Hide header = 
| Header caption = 
| Ship type = [[Engineering:Heavy cruiser|Heavy cruiser]]
| Ship displacement = * {{convert|13600|LT|t|abbr=on|lk=in|sigfig=5}} standard
* {{convert|17000|LT|t|abbr=on|sigfig=5}} full load
| Ship length = * {{convert|664|ft|abbr=on}} [[Engineering:Waterline|wl]]
* {{convert|673|ft|5|in|m|abbr=on}} [[Engineering:Length overall|oa]]
| Ship beam = {{convert|70|ft|10|in|abbr=on}}
| Ship height = {{convert|112|ft|10|in|abbr=on}} (mast)
| Ship draft = {{convert|26|ft|10|in|abbr=on}}
| Ship propulsion = 4 screws; 4 [[Engineering:Steam turbine|steam turbine]]sets
| Ship power = * 4 × Babcock & Wilcox boilers
* {{cvt|120000|shp|lk=in}}
| Ship speed = {{convert|33|kn}}
| Ship range = 
| Ship complement = 61 officers and 1,085 sailors
| Ship sensors = * Mk34 GFCS
* 2 × Mk37 GFCS
* '''Early''':
* SK-2 air-search radar
* SP radar fighter-direction radar
* '''Later''':
* AN/SPS-6 air-search radar
* AN/SPS-8A height-finding radar
* AN/SPS-10 surface-search radar
* AN/SPS-12 air-search radar
* AN/SPS-37 [[Engineering:Early-warning radar|early-warning radar]] (''Saint Paul'')
* AN/SPS-43 air-search radar (''Helena'')
* AN/URN-3 [[Engineering:Tactical air navigation system|TACAN]] 
* Mark 56 [[Engineering:Fire-control system|fire-control system]]
| Ship EW = 
| Ship armament = * 3 × triple 8-inch/55-caliber guns
* 6 × twin 5-inch/38-caliber guns
* 12 × quad Bofors 40 mm guns
* 24 × single [[Engineering:Oerlikon 20 mm cannon|Oerlikon 20 mm cannon]]s
| Ship armor = * Belt armor: {{convert|4|-|6|in|0|abbr=on}}
* [[Engineering:Deck (ship)|Deck]]: {{convert|2.5|in|abbr=on}}
* [[Engineering:Gun turret|Turrets]]: {{convert|1.5|-|8|in|0|abbr=on}}
* [[Engineering:Barbette|Barbette]]s: {{convert|6.3|in|0|abbr=on}}
* [[Engineering:Conning tower|Conning tower]]: {{convert|6.5|in|0|abbr=on}}
* [[Engineering:Bulkhead (partition)|Bulkhead]]s: {{convert|6|in|0|abbr=on}}
| Ship notes = 
| Ship boats = 2 × lifeboats
| Ship aircraft facilities = * 2 × aircraft catapults
* Helipad (later conversion)
}}
|}

The '''''Baltimore''-class heavy cruisers''' were a large class of [[Engineering:Heavy cruiser|heavy cruiser]]s in the United States Navy commissioned during and shortly after [[Social:World War II|World War II]].<ref group=note>The ''Baltimore'' class were the largest cruisers of World War II by tonnage.</ref> Fourteen ''Baltimore''s were completed, more than any other class of heavy cruiser (the British {{sclass2|County|cruiser|4}} had 15 vessels planned, but only 13 completed), along with three ships of the {{sclass|Oregon City|cruiser|5}} sub-class. The ''Baltimore''s also were the first cruisers in the US Navy to be designed without the limitations of the London Naval Treaty.

Fast and heavily armed, the ''Baltimore'' cruisers were mainly used in World War II to protect the fast [[Engineering:Aircraft carrier|aircraft carrier]]s in battle groups from air attack. Additionally, their {{convert|8|in|mm|0|adj=on}} main guns and secondary {{convert|5|in|mm|0|adj=on}} guns were regularly used to bombard land targets in support of [[Social:Amphibious warfare|amphibious landings]].  After the war, only six ''Baltimore''s (''St. Paul'', ''Macon'', ''Toledo'', ''Columbus'', ''Bremerton'', and ''Helena'') and two ''Oregon City''-class ships (''Albany'' and ''Rochester'') remained in service, while the rest were moved to the [[Engineering:Reserve fleet|reserve fleet]]. However, all ships except ''Boston'', ''Canberra'', ''Chicago'', and ''Fall River'' were reactivated for the Korean War.

Except for ''St. Paul'', all the ships retaining all-gun configurations had very short (18 years or less) service lives, and by 1971 were decommissioned, and started showing up in the scrap-sale lists. However, four ''Baltimore''-class cruisers were refitted and converted into some of the first guided missile cruisers in the world, becoming two of the three {{sclass|Albany|cruiser|0}} and two {{sclass|Boston|cruiser|0}} cruisers.  The last of these was decommissioned in 1980, with the ''Chicago'' lasting until 1991 in reserve.  No example of the ''Baltimore'' class still exists.

==History==

===Planning and construction===
[[File:USS Bremerton (CA-130) drydocked.jpg|thumb|left|USS ''Bremerton'' in drydock]]
Immediately after the outbreak of World War II in September 1939, the US Navy initiated studies regarding a new class of heavy cruiser that led to construction of the ''Baltimore'' class.  With the start of the war, the limitations instituted by the Second London Naval Treaty, which had completely banned the construction of heavy cruisers, became obsolete.  The ''Baltimore'' class was based partly on {{USS|Wichita|CA-45|6}}, a heavy cruiser from 1937, which represented the transition from inter-war to World War II designs. It was also based partly on the {{sclass|Cleveland|cruiser|4}}, a [[Engineering:Light cruiser|light cruiser]] that was then being built. In profile, the ''Baltimore''s looked very much like the ''Cleveland''-class light cruisers, the obvious difference being that the larger ''Baltimore''s carried nine {{convert|8|in|mm|0|adj=on}} guns in three triple turrets, compared to the twelve {{convert|6|in|mm|0|adj=on}} guns in four triple turrets of the ''Cleveland''s.

The construction of the first four ships of the ''Baltimore'' class began 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. Despite the heavy losses in cruisers during the first 14 months of the Pacific War, 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 six ships—for a total of 14—using the original design before the revisions were completed.  The final three ships ordered were converted to the second design, known as the ''Oregon City'' class. Between 1943 and 1947, 17 ships of the ''Baltimore'' and ''Oregon City'' classes entered service. Construction of the eighteenth ship ({{USS|Northampton|CLC-1|2}}) was suspended, to eventually be completed as a flagship/command ship in 1950. Five more were laid down but cancelled and scrapped before launch, and one was never started before being cancelled.

The largest contractor for the construction of the ''Baltimore''-class ships was [[Company:Bethlehem Steel|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 [[Company:Philadelphia Naval Shipyard|Philadelphia Naval Shipyard]] in Philadelphia completed two. The ships were named after cities in the United States, the only exception being {{USS|Canberra|CA-70|6}}, which was named in honor of {{HMAS|Canberra|D33|6}} (sunk at the battle of Savo Island), which had been named after [[Place:Canberra|Canberra]], the {{wipe|Australia}}n capital. The classification "CA" originally stood for "armored cruiser" but was later used for heavy cruisers.

===Service===
[[File:USS Baltimore (CA-68) being reactivated at the Puget Sound Naval Shipyard, in 1951 (NH 98241).jpg|thumb|right|USS ''Baltimore'' during her reactivation]]
Of the seventeen (including the three ''Oregon City''s) completed ships, twelve were commissioned before the Japanese capitulation on September 2, 1945, though only seven took part in the battles of the Pacific Theater and one in the European Theater. By 1947, nine of the ''Baltimore''s had been decommissioned and placed in the reserve fleet, while seven (''Helena'', ''Toledo'', ''Macon'', ''Columbus'', ''Saint Paul'', ''Rochester'', and ''Albany'') 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 thirteen available for deployment in the Korean War.  Six of these were used for escort missions and coastal bombardment in Korea, while the other seven reinforced fleets in other areas of the globe.  Four ships 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 ended and due to the high cost of keeping them in service; starting in 1954 with ''Quincy'', some of the ''Baltimore''s  decommissioned for good. By 1969, six ships were still in commission; five (''Boston'', ''Canberra'', ''Chicago'', ''Columbus'', ''Albany'') as CGs, and only one unmodified ship, the ''Saint Paul'', which remained active to serve in the Vietnam War, providing gunfire support.  ''Saint Paul'' was the only member of the class to serve continuously from commissioning (serving 26 years) and was finally decommissioned in 1971. ''Boston'' and ''Canberra'' retired in 1970, ''Columbus'' (serving 29.5 years) in 1975, and finally ''Chicago'' in 1980.  Starting in 1972 all fourteen of the original ''Baltimore''s were sold for scrap after being decommissioned, with ''Chicago'' being the final one broken up in 1991.

====Damage====
[[File:USS Pittsburgh (CA-72) underway after she lost her bow in June 1945 (80-G-325746).jpg|thumb|right|{{USS|Pittsburgh|CA-72|6}} with her bow ripped off]]
In World War II, only the {{USS|Canberra|CA-70|2}} was damaged through enemy fire, when she was struck with an air-dropped [[Engineering:Torpedo|torpedo]] on October 13, 1944, which killed 23 men in the engine room and left the ship immobilized.  The ship was hit amidships and both [[Engineering:Boiler|boiler]] rooms were flooded with 3,000 tons of seawater. She was towed away by [[Engineering:Sister ship|sister ship]] {{USS|Boston|CA-69|2}}, 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, {{USS|Pittsburgh|CA-72|2}} had her entire bow ripped off in a typhoon, but there were no casualties. The ship struggled through {{convert|70|kn|adj=on}} 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 it was later towed into Guam and scrapped.

During the Korean War, a fire in a forward [[Engineering:Gun turret|gun turret]] on 12 April 1952, killed 30 men on ''St. Paul''. Then, in 1953, the same ship was hit by a coastal battery, though without injury to the crew.  ''Helena'' in 1951 and ''Los Angeles'' in 1953 were also struck by coastal batteries without injuries during the war.

In June 1968, ''Boston'', along with its escort, the {{wipe|Australia}}n [[Engineering:Destroyer|destroyer]] {{HMAS|Hobart|D 39|6}}, were victims of friendly fire when planes of the {{wipe|US Air Force}} mistook them for enemy targets and fired on them with AIM-7 Sparrow missiles. Only ''Hobart'' was seriously damaged; although ''Boston'' was hit, the warhead of the missile failed to detonate.

===Missile conversions===
{{main|Engineering:Boston-class cruiser|Engineering:Albany-class cruiser}}

By the latter half of the 1940s, the navy was planning warships equipped with missiles. In 1946 the [[Engineering:Battleship|battleship]] {{USS|Mississippi|BB-41|6}} and in 1948 the seaplane tender {{USS|Norton Sound|AVM-1|6}} were converted to test this idea.  Both were equipped with, among other weapons, [[Engineering:RIM-2 Terrier|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, {{USS|Boston|CA-69|2}} and {{USS|Canberra|CA-70|2}}.  These were the first operational guided missile cruisers in the world. They were designated the ''Boston'' class 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.

In the following years, six light cruisers 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 ({{USS|Long Beach|CGN-9|2}}).  Ships also continued to be converted, so starting in 1958, two ''Baltimore''-class cruisers, {{USS|Chicago|CA-136|2}} and {{USS|Columbus|CA-74|2}}, along with an {{sclass|Oregon City|cruiser|1}}, (considered a sub-class of the ''Baltimore'' class) {{USS|Albany|CA-123|2}}, were converted to the new ''Albany'' class.  These were recommissioned in 1962 and 1964, respectively.  Two more ships were planned to be refitted as ''Albany''s, the ''Baltimore'' class {{USS|Bremerton|CA-130|2}} and the ''Oregon City'' class  {{USS|Rochester|CA-124|2}}, but these conversions were cancelled because of cost.  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&nbsp;million.  Because no high-caliber guns were retained, the ''Albany'' class ships received the designation ''CG'' rather than ''CAG''.

In addition to the operational conversions, four ''Baltimore''-class ships, {{USS|Helena|CA-75|2}}, {{USS|Los Angeles|CA-135|2}}, {{USS|Macon|CA-132|2}}, and {{USS|Toledo|CA-133|2}}, received modifications to operate the SSM-N-8 Regulus [[Engineering:Cruise missile|cruise missile]] between 1956 and 1958 on an experimental basis. Regulus was a nuclear-armed weapon that was primarily used by the US Navy in the nuclear deterrent role. Although associated primarily with submarines, the four ''Baltimore''-class cruisers fitted to operate the missile undertook operational taskings with it to the Western Pacific during the experimental period.

<gallery mode="nolines">
File:USS Toledo (CA-133) launching Regulus missile c1956.jpg|USS ''Toledo'' launches a Regulus cruise missile
File:USS Boston (CAG-1) underway at sea, circa in early 1957.jpg|USS ''Boston'', the first of two ''Boston''-class conversions
File:USS Chicago (CG-11) underway in the Coral Sea, in October 1979.jpg|USS ''Chicago'' after reconstruction as an ''Albany''-class cruiser 
</gallery>

==Engineering and equipment==

===Hull===
[[File:USS Los Angeles (CA-135) underway on 27 April 1959 (NH 97388).jpg|thumb|right|Side-view of ''Los Angeles'']]
[[File:USS Columbus (CG-12) underway off San Diego on 19 February 1965 (NH 82722-KN).jpg|thumb|right|Side-view of ''Columbus'', refitted as an ''Albany''-class cruiser]]
''Baltimore''-class cruisers were {{convert|673|ft|7|in|m}} long and {{convert|70|ft|10|in|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 ''Baltimore''s displaced {{convert|17031|long ton|t|lk=in}} of water.  Their draft was {{convert|23|ft|11|in|m}}.  At the bow, the top level of the hull lay {{convert|33|ft|m}} above the water; at the stern, {{convert|25|ft|m}}{{Citation needed|date=January 2018}}.  The funnels were {{convert|86|ft|m}} high, and the highest point on the masts was at {{convert|112|ft|m}}.  The [[Earth:Superstructure|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 {{convert|6|in|mm|sigfig=3}} thick and the horizontal deck armor was up to {{convert|3|in|mm|sigfig=3}} thick.  The turrets were also heavily armored, between {{convert|1.5|-|8|in|abbr=on}} thick, while the conning tower had up to {{convert|6.5|in|mm|sigfig=3}}.

The ''Boston'' class had a draft about {{convert|20|in|mm}} deeper in the water and displaced about {{convert|500|long ton|t}} more water than their former sister ships.  Because the ''Boston''s 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 ''Balitmore''s 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 [[Engineering:Lattice mast|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 ''Albany''s were completely rebuilt from the deck level up; except for the hull, they bore 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 [[Engineering:Bridge (nautical)|bridge]] which was one of the most recognizable markers of the class. The two masts and funnels were combined into the so-called "[[Engineering:Mack (naval architecture)|macks]], 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 were more than {{convert|130|ft|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 ''Albany''s grew to more than {{convert|17500|long ton|t}}.

===Propulsion===
The ''Baltimore'' cruisers were propelled with [[Engineering:Steamboat|steam power]].  Each ship had four shafts, each with a [[Engineering:Propeller|propeller]].  The shafts were turned by four [[Engineering:Steam turbine|steam turbine]]s, the steam produced by four [[Engineering:Boiler|boiler]]s, which at full speed reached pressures of up to {{convert|615|psi|lk=in}}.  The ''Baltimore''s each had two engine rooms and two funnels, although this was changed in the ''Boston''s, which had only one funnel for all four boilers, as noted above. The high speed was around {{convert|33|kn|km/h}} and the performance of the engine was around {{convert|120000|HP|MW|lk=in}}.

The original ''Baltimore''s could carry up to {{convert|2250|long ton|t}} of fuel, putting the maximum range at a cruising speed of {{convert|15|kn|km/h}} at about {{convert|10000|nmi|km}}.  The increased displacement of the modified ''Boston'' and ''Albany'' classes meant their range was reduced to about 9000 and {{convert|7000|mi|km}} respectively, despite increases in fuel capacity to 2600 and 2500 tons.

===Armament===
[[File:USS Saint Paul (CA-73) provides gunfire support off South Vietnam, circa in October 1966 (80-G-K-33437).jpg|thumb|right|Salvo by both forward turrets on ''St. Paul'' during the Vietnam War]]
[[File:SSM-N-8 Regulus cruise missile on USS Toledo (CA-133) in 1958.jpg|thumb|A Regulus missile ready to launch from ''Toledo'' in 1958]]
The main armament of the ''Baltimore'' class consisted of three turrets, each with three Mark 15 8"/55 caliber guns (Mark 12 in ''Baltimore''). Two of these were located forward and one aft. They fired a 335-pound (152&nbsp;kg) shell out to a maximum range of 30,050   yards (27,480 m). The armor-piercing shell could penetrate six inches of armor plating at {{convert|20,800|yd}}. The secondary armament consisted of twelve 5"/38 caliber guns in six twin mounts. Two mounts were located on each side of the superstructure and two were behind the main batteries fore and aft. These guns could be used against aircraft and surface targets. Their maximum range for surface targets was {{convert|17,575|yd}} and they could reach aircraft at altitudes of up to {{convert|12,400|yd}}. In addition, the ships had numerous light anti-aircraft weapons: 12 quadruple mounts of Bofors 40 mm guns (or 11 quadruple mounts and 2 twin mounts on ships with only one rear aircraft crane) as well as 20–28 [[Engineering:Oerlikon 20 mm cannon|Oerlikon 20 mm cannon]]s, depending on when a given ship was commissioned. After World War II the 20 mm anti-aircraft guns were removed without replacement, due to limited effectiveness against kamikaze attacks, and because it was expected they would be completely ineffective against postwar aircraft.  The 40 mm Bofors were replaced with 3"/50 caliber guns in the 1950s.

Four ships, {{USS|Toledo|CA-133|2}}, {{USS|Macon|CA-132|2}}, {{USS|Helena|CA-75|2}}, and {{USS|Los Angeles|CA-135|2}}, 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 [[Engineering:Nuclear submarine|nuclear submarine]]s.  In the late 1950s, plans were made to fit Polaris to missile conversions of these cruisers, but the only missile cruiser conversion ever so equipped was the {{ship|Italian cruiser|Giuseppe Garibaldi|1936|6}}, (four tubes), and the missiles were never actually shipped.

===Electronics===
[[File:USS Pittsburgh (CA-72) underway on 11 October 1955 (NH 98248).jpg|thumb|left|USS ''Pittsburgh'' with the SPS-8 on the aft mast, and the SPS-6 on the forward mast]]
Initially, the ''Baltimore''s 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 {{convert|15|and|22|nmi|km}}.  The SK could detect bombers at medium altitudes from {{convert|100|nmi|km}}.  The radar systems were replaced in the Korean War with the more effective SPS-6 (built by Westinghouse Electric or later with the SPS-12 (from the Radio Corporation of America combined with an SPS-8 as a height-finder.  With these systems, the detection range for bombers was increased to {{convert|145|mi|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 [[Company:Raytheon|Raytheon]].  With this equipment, planes could be detected at over {{convert|250|mi|km}} away.

The ''Baltimore'' class was equipped from the start with electronic and electromechanical fire control systems to determine the fire parameters by which targets over the [[Horizon|horizon]] could be hit.  The main guns were controlled by a Mark 34 fire control system connected to an Mk 8 radar. The 5-inch/38 dual-purpose guns were guided by two 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-inch guns were upgraded to Mk 56 with Mk 35 radars.

===Aircraft===
[[File:OS2U Kingfishers aboard USS Quincy (CA-71), in August 1944 (80-G-K-1948).jpg|thumb|right|Two Kingfishers on their catapults on board USS ''Quincy'']]
The onboard flight systems of the ''Baltimore''-class cruisers during World War II consisted of two aircraft catapults 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, the [[Engineering:Vought OS2U Kingfisher|Vought OS2U Kingfisher]] could be launched from these catapults and later the Curtiss SC-1 Seahawk.  These planes were used for reconnaissance, anti-submarine, and rescue missions.  The planes were [[Engineering:Seaplane|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, ship's boats or the workings of the Regulus missile system.

''Macon'' 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.

===Later designs===
The hull of the ''Baltimore'' class was used for the development of several other classes.  The ''Oregon City''-class cruisers differed only slightly from ''Baltimore''s, 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 are the reduction to a single-trunked funnel; a redesigned forward superstructure that was placed {{convert|40|ft|m}} further aft, primarily to decrease top-heaviness; and an increase in the arcs of fire for the guns. 

A fourth ''Oregon City''-class cruiser, the {{USS|Northampton|CLC-1|3}}, was ultimately completed as a light command cruiser. Despite having a heavy cruiser hull, she was classed as a light cruiser because her main armament was smaller than 8 inches.

The {{sclass|Des Moines|cruiser|1}} was an entirely new heavy cruiser design that attempted to improve upon the ''Baltimore'' class.  While the basic deck and machinery layout was largely unchanged, this class carried the first fully automated high-caliber guns on a warship and had improved damage protection features. None was constructed in time to take part in World War II.

The plans for the {{Sclass|Saipan|aircraft carrier|0}} light aircraft carrier were adapted from the drafts of the ''Baltimore'' hull design, including the layout of the engines.  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 [[Engineering:Command ship|command ship]]s.

==Crew==
[[File:Crewmen in the Main Battery Plot of USS Canberra (CAG-2) off Vietnam, in March 1967 (USN 1142153).jpg|thumb|right|The crew of ''Canberra'' plotting target data]]

The size of the crew of a ''Baltimore''-class cruiser varied by era and by tactical situation.  Different sources also differ on the numbers. Naturally, the crew sizes were larger during wartime. Some cruisers—including all three of the modified ''Albany'' class—were used as flagships and therefore housed an admiral 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 ''Boston''s, 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 fewer crew than the ''Boston''s and was roughly comparable numerically to the basic ''Baltimore''.

Compared to today's crew sizes, these numbers seem high.  The modern {{Sclass|Ticonderoga|cruiser|1}} is manned by about 400.  These differences are mostly due to the much less manpower-intensive nature of modern weapon systems.

==Ships in class==
(Note: the three ''Oregon City''-class ships are not listed here)
{| class="sortable wikitable plainrowheaders"
|+ Construction details
|-
! scope="col" | Ship name
! scope="col" | {{abbr|Hull no.|Hull number}}
! scope="col" | Builder
! scope="col" | Laid down
! scope="col" | Launched
! scope="col" | {{abbr|Comm./{{wbr}}Recomm.|Commissioned/Recommissioned}}
! scope="col" | {{abbr|Decomm.|Decommissioned}}
! scope="col" | Fate
|-
! scope="row" rowspan=2|{{USS|Baltimore|CA-68|2}}
! scope="row" rowspan=2|CA-68
|rowspan=14|Bethlehem Steel Corporation, Fore River Shipyard
|rowspan=2|26&nbsp;May 1941
|rowspan=2|28&nbsp;July 1942
|15&nbsp;April 1943
|8&nbsp;July 1946
|rowspan=2|Struck 15&nbsp;February 1971, Broken up at {{wipe|Portland, Oregon}}, 1972
|-
|28&nbsp;November 1951
|31&nbsp;May 1956
|-
! scope="row" rowspan=2|{{USS|Boston|CA-69|2}}
! scope="row" |CA-69
|rowspan=2|30&nbsp;June 1941
|rowspan=2|26&nbsp;August 1942
|30&nbsp;June 1943
|29&nbsp;October 1946
|rowspan=2|Struck 4&nbsp;January 1974; Sold for scrap 28&nbsp;March 1975
|-
! scope="row" |CAG-1
|1&nbsp;November 1955
|5&nbsp;May 1970
|-
! scope="row" rowspan=2|{{USS|Canberra|CA-70|2}}<br>({{nowrap|ex-''Pittsburgh''}})
! scope="row" |CA-70
|rowspan=2|3&nbsp;September 1941
|rowspan=2|19&nbsp;April 1943
|14&nbsp;October 1943
|7&nbsp;March 1947
|rowspan=2|Struck 31&nbsp;July 1978; Sold for scrap 31&nbsp;July 1980
|-
! scope="row" |CAG-2
|15&nbsp;June 1956
|2&nbsp;February 1970
|-
! scope="row" rowspan=2|{{USS|Quincy|CA-71|2}}<br>({{nowrap|ex-''St. Paul''}})
! scope="row" rowspan=2|CA-71
|rowspan=2|9&nbsp;October 1941
|rowspan=2|23&nbsp;June 1943
|15&nbsp;December 1943
|19&nbsp;October 1946
|rowspan=2|Struck 1&nbsp;October 1973; Broken up at Portland, Oregon, 1974
|-
|31&nbsp;January 1952
|2&nbsp;July 1954
|-
! scope="row" rowspan=2|{{USS|Pittsburgh|CA-72|2}}<br>({{nowrap|ex-''Albany''}})
! scope="row" rowspan=2|CA-72
|rowspan=2|3&nbsp;February 1943
|rowspan=2|22&nbsp;February 1944
|10&nbsp;October 1944
|7&nbsp;March 1947
|rowspan=2|Struck 1&nbsp;July 1973; Broken up at Portland, Oregon, 1974
|-
|25&nbsp;September 1951
|28&nbsp;August 1956
|-
! scope="row" |{{USS|Saint Paul|CA-73|2}}<br>({{nowrap|ex-''Rochester''}})
! scope="row" |CA-73
|3&nbsp;February 1943
|16&nbsp;September 1944
|17&nbsp;February 1945
|30&nbsp;April 1971
|Struck 31&nbsp;July 1978; Broken up at Terminal Island, California, 1980
|-
! scope="row" rowspan=2|{{USS|Columbus|CA-74|2}}
! scope="row" |CA-74
|rowspan=2|28&nbsp;June 1943
|rowspan=2|30&nbsp;November 1944
|8&nbsp;June 1945
|8&nbsp;May 1959
|rowspan=2|Struck 9&nbsp;August 1976; Sold for scrap on 3&nbsp;October 1977
|-
! scope="row" |CG-12
|1&nbsp;December 1962
|31&nbsp;January 1975
|-
! scope="row" |{{USS|Helena|CA-75|2}}<br>({{nowrap|ex-''Des Moines''}})
! scope="row" |CA-75
|9&nbsp;September 1943
|28&nbsp;April 1945
|4&nbsp;September 1945
|29&nbsp;June 1963
|Struck 1&nbsp;January 1974; Broken up at Richmond, California, 1975 
|-
! scope="row" rowspan=2|{{USS|Bremerton|CA-130|2}}
! scope="row" rowspan=2|CA-130
|rowspan=6|[[Company:New York Shipbuilding Corporation|New York Shipbuilding Corporation]], Camden, New Jersey
|rowspan=2|1&nbsp;February 1943
|rowspan=2|2&nbsp;July 1944
|29&nbsp;April 1945
|9&nbsp;April 1948
|rowspan=2|Struck 1&nbsp;October 1973; Broken up at Portland, Oregon, 1974
|-
|23&nbsp;November 1951
|29&nbsp;July 1960
|-
! scope="row" |{{USS|Fall River|CA-131|2}}
! scope="row" |CA-131
|12&nbsp;April 1943
|13&nbsp;August 1944
|1&nbsp;July 1945
|31&nbsp;October 1947
|Struck 19&nbsp;February 1971; Broken up at Portland, Oregon, 1972
|-
! scope="row" rowspan=2|{{USS|Macon|CA-132|2}}
! scope="row" rowspan=2|CA-132
|rowspan=2|14&nbsp;June 1943
|rowspan=2|15&nbsp;October 1944
|26&nbsp;August 1945
|12&nbsp;April 1950
|rowspan=2|Struck 1&nbsp;November 1969; Broken up at Port Newark, New Jersey, 1973
|-
|16&nbsp;October 1950
|10&nbsp;March 1961
|-
! scope="row" |{{USS|Toledo|CA-133|2}}
! scope="row" |CA-133
|13&nbsp;September 1943
|6&nbsp;May 1945
|27&nbsp;October 1946
|21&nbsp;May 1960
|Struck 1&nbsp;January 1974; Broken up at Terminal Island, California, 1974
|-
! scope="row" rowspan=2|{{USS|Los Angeles|CA-135|2}}
! scope="row" rowspan=2|CA-135
|rowspan=4|[[Company:Philadelphia Naval Shipyard|Philadelphia Naval Shipyard]]
|rowspan=2|28&nbsp;July 1943
|rowspan=2|20&nbsp;August 1944
|22&nbsp;July 1945
|9&nbsp;April 1948
|rowspan=2|Struck 1&nbsp;January 1974; Broken up at San Pedro, California, 1975
|-
|27&nbsp;January 1951
|15&nbsp;November 1963
|-
! scope="row" rowspan=2|{{USS|Chicago|CA-136|2}}
! scope="row" style="white-space: nowrap;" |CA-136
|rowspan=2|28&nbsp;July 1943
|rowspan=2|20&nbsp;August 1944
|10&nbsp;January 1945
|6&nbsp;June 1947
|rowspan=2|Struck 31 January 1984; Sold for scrap 9&nbsp;December 1991
|-
! scope="row" |CG-11
|2&nbsp;May 1964
|1&nbsp;March 1980
|}

==See also==
*List of cruisers of the United States Navy
*List of ship classes of the Second World War

==Notes==
{{reflist|group=note}}

==References==
{{Reflist}}

== External links ==
*[http://www.microworks.net/pacific/ships/cruisers/baltimore.htm Statistics]
*[https://ca-69boston.org/ Website of a Baltimore Class Cruiser]

[[Category:Cruiser classes]]

{{Sourceattribution|Baltimore-class cruiser}}