Editing Baltimore-class cruiser (section)

==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'', heavily 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 [[funnel (ship)|funnel]]s were {{convert|86|ft|m}} high, and the highest point on the masts was at {{convert|112|ft|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 {{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 ''Baltimore''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 [[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 [[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 "[[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 [[steamboat|steam power]]. 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 {{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 gun]]s (Mark 12 in ''Baltimore''). Two of these were located forward and one aft. They fired a {{convert|335|lb|kg|adj=on}} shell out to a maximum range of {{convert|30,050|yd|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 gun]]s 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 Automatic Gun L/60|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 [[Oerlikon 20 mm cannon]]s, depending on when a given ship was commissioned. After World War II the 20&nbsp;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 jet aircraft. The 40&nbsp;mm Bofors were replaced with [[3"/50 caliber gun]]s 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 [[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 (1886)|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 [[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 system]]s 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 5-inch/38 dual-purpose guns were guided by two [[Mark 37 Gun Fire Control System|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 catapult]]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, the [[Vought OS2U Kingfisher]] could be launched from these catapults and later the [[SC Seahawk|Curtiss SC-1 Seahawk]]. These planes were used for reconnaissance, [[anti-submarine warfare|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, 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 of four 5 inch guns was smaller than the 8 inch guns usually found on heavy cruisers.

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, greatly improving both firepower and survivability. 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 [[command ship]]s.