USSHonolulu in 1944
Class overview
Name	Brooklyn class
Builders	Brooklyn Navy Yard, NY (3) New York Ship, NJ (3) Newport News, VA (2) Philadelphia Naval Shipyard, PA (1)
Operators	United States Navy  Argentine Navy Brazilian Navy  Chilean Navy
Preceded by	Omaha class
Succeeded by	Atlanta class
Subclasses	St. Louis class
Built	1935–1938
In service	1938–1992
In commission	1937–1992
Planned	9
Completed	9
Lost	2
Retired	7
General characteristics
Type	Light cruiser
Displacement	9,767 long tons (9,924 t) (standard) 12,207 long tons (12,403 t) (full load)
Length	600 ft (180 m)wl 608 ft 4 in (185.42 m)oa
Beam	62 ft (19 m)
Draft	23 ft (7.0 m)
Installed power	8 ×Babcock & Wilcox boilers 100,000 shp (74,570 kW)
Propulsion	4 × Parsons geared turbines 4 × shafts
Speed	32.5knots (60.2 km/h; 37.4 mph)
Range	10,000 nmi (19,000 km; 12,000 mi) at 15 knots (28 km/h; 17 mph)
Boats & landing craft carried	2 ×lifeboats
Complement	868
Sensors & processing systems	Mk34 GFCS (6in main) Mk33 GFCS (5in secondary) SK-2air-search radar
Armament	5 × triple6"/47 caliber guns 8 × single5"/25 caliber guns (Brooklyn throughHonolulu) 4 × dual5"/38 caliber guns (St. Louis andHelena) 8 × singleM2 Browning machine guns
Armor	Main belt At machinery: 5 in (127 mm) on 0.625-inch (16 mm)STS plate Atmagazines: 2 in (51 mm) on 0.625-inch STS plate Deck: 2 in Barbettes: 6 in (152 mm) Gun turret Turret roofs: 2 in Turret sides: 1.25 in (31.75 mm) Turret face: 6.5 in (165 mm) Conning tower: 5 in
Aircraft carried	4 ×floatplanes
Aviation facilities	2 ×aircraft catapults

TheBrooklyn-class cruiser was aclass of ninelight cruisers built for theUnited States Navy between 1935 and 1938. Armed with five triple 6-inch (152 mm)gun turrets (three forward, two aft), they mounted more main battery guns than any other standard US cruiser. TheBrooklyn-class ships were allcommissioned between 1937 and 1939, in the time between the start of theSecond Sino-Japanese War and before theinvasion of Poland. They served extensively in both thePacific andAtlantic theaters duringWorld War II.

Helena was sunk in thePacific, and while some of the others were heavily damaged, the remaining ships of the class weredecommissioned shortly after the end of the war. Six were transferred to South American navies in 1951, where they served for many more years. One of these,ARA General Belgrano, formerlyPhoenix, was sunk during theFalklands War in 1982.^[1]

TheBrooklyn-class ships had a strong influence on US cruiser design. Nearly all subsequent US cruisers, heavy and light, were directly or indirectly based on them.^[1] Notable among these are theCleveland-class light cruiser andBaltimore-class heavy cruiser of World War II.

TheBrooklyn-class design was a further refinement of theNew Orleans-classheavy cruiser that preceded it.^[2] The desire for theBrooklyns arose from theLondon Naval Treaty of 1930, which limited the construction of heavy cruisers, i.e., ships carrying guns withcalibers between 6.1 and 8 inches (155 and 203 mm). Great Britain needed trade control cruisers and hoped that the treaty would limit nations to smaller cruisers with a 6,000-to-8,000-long-ton (6,096 to 8,128 t) range that she could afford. Agreement to the London Treaty and the proceeding with the Americanlight cruiser design can be focused toAdmiralWilliam V. Pratt, who overrode the vehement objections of theGeneral Board.^[3]

Under the treaty the US was allowed 180,000 long tons (182,888 t) for 18 heavy cruisers and 143,500 long tons (145,803 t), with no limit on the number of ships, for light cruisers.^[4] The United States needed large cruisers to deal with the extreme ranges that operations in thePacific Ocean required. Cruisers with 6-inch (150 mm) guns and 10,000 long tons (10,160 t) were therefore desired.^[5] The US Navy's experience with theOmaha class was not all that could be hoped for. Their light hull design caused a stressed hull and was very overweight.

Design started in 1930, with the first four of the class ordered in 1933, and an additional three ships in 1934. Basic criteria had been that speed and range should match heavy cruisers, and when the JapaneseMogami class carrying fifteen 6-inch main guns appeared, the new US ships would match their weaponry. Various combinations of armor and power plants were tried in the efforts to stay below the Treaty 10,000 ton limit.^[6] Aviation facilities were moved to thestern of the ship from theamidships position of theNew Orleans-class cruisers.^[7][8]

From 1942, thebridge structure was lowered andradar was fitted.

The last two ships of the class,St. Louis andHelena, were slightly modified versions of the design with new higher pressure boilers and aunit system of machinery that alternated boiler and engine rooms to prevent a ship from being immobilized by a single unlucky hit; this system would be used in all subsequent US cruisers. Additionally,AA armament was improved. They were the first US cruisers to be armed with twin5-inch (127 mm)/38-caliber guns. They could be distinguished visually from the otherBrooklyns by the placement of the after deckhouse, immediately abaft the second funnel, and by the twin 5-inch mounts.

TheBrooklyn class was equipped with 156-inch/47 caliber Mark 16 naval guns, developed from the6-inch/53 caliber Mark 8 used on theOmaha-class cruiser. The decision was reached as the gun could achieve up to ten rounds per minute rate of fire. This gave the class the ability to send up to 150 rounds a minute at its intended target. This allowed the cruiser to smother an enemy ship with fire. The turret arrangement was five turrets, each mounting three guns on a single sleeve, which did not allow the guns in a turret to move independently. The 6-inch guns were of a new design, the Mark 16, which could fire a 130-pound (59-kilogram)armor-piercing shell (AP) up to 26,100 yards (23,866 m) with twice the penetrative power of the old gun. The ammunition was of thesemi-fixed type.^[9] The impact of the shell changed the General Board's view on the usefulness of light cruisers in service.^[10]

As designed, the anti-aircraft weaponry specified eight5-inch (127 mm)/25 caliber guns and eight.50 inches (12.7 mm) caliber M2 Browning machine guns. The intention to mount1.1-inch (28 mm)/75 caliber anti-aircraft guns was frustrated and the requirement was not fully met until 1943. The weapon as deployed was less than satisfactory with frequent jamming and weight being serious issues.^[11] Some of the class had 5-in/38 caliber guns installed versus the 5-in/25 guns.^[12] There were varied mixes of20-millimeter (0.79 in) Oerlikon cannons and40-millimeter (1.6 in) Bofors gun mountings actually installed during World War II, 28 40 mm (4 × 4, 6 × 2) and twenty 20 mm (10 × 2) being the most common.^[6]

TheBrooklyn class was deployed with the Mark 34 director and later the Mark 3 radar. This would be upgraded to the Mark 8 and again to the Mark 13 radar. The secondary battery was controlled by the Mark 28 and upgraded to theMark 33 fire control systems. The associated radars were the Mark 4 fire control radar and upgraded again to the Mark 12. Two anti-aircraft fire directors were fitted to each ship. A late World War II refit saw theMk 51 director installed for the Bofors guns. Night engagements were improved when in 1945, the Mark 57 and 63 directors were installed.^[13]

The vast majority of cruisers built by the United States during World War II derive from theBrooklyn design.^[1] Modifications of theBrooklyn-class hull were the predecessors to the two main lines of wartime cruisers, respectively theCleveland-class light cruiser armed with 6-inch guns andBaltimore-class heavy cruiser armed with 8-inch guns. The third line, theAtlanta-class light cruiser armed with 5-inch guns, shared the same unit system of machinery arrangement as the other two lines, but on a smaller hull with two shafts instead of four.^[14]

TheBrooklyn class would lead to theCleveland-class light cruiser (less a fifth triple 6-inch turret), which then led to theFargo-class cruiser and finally theWorcester-class cruiser. The other successor wasUSS Wichita, built on a modifiedBrooklyn-class hull, with a heavy cruiser armament featuring three rather than five triple turrets, but each turret containing larger 8-inch guns, and increased armor.Wichita was succeeded by theBaltimore class and the laterOregon City-class cruiser class, and finally the upgradedDes Moines-class cruiser. TheAtlanta class would be succeeded by theJuneau class and then almost by the cancelledCL-154 class. As theBaltimore class began building about a year after theCleveland class, laterCleveland developments and improvements were incorporated into theBaltimore-class hull.

Finally, bothCleveland andBaltimore hulls were converted to light aircraft carriers. TheIndependence class of light aircraft carriers, were converted fromCleveland-class cruisers under construction,^[15] and theSaipan-class light carriers used the basic form of theBaltimore-class cruiser design.^[16]

SeveralBrooklyns were seriously damaged during World War II, although all but one of the cruisers survived.Boise was severely damaged by a shell that hit her forward turretmagazine during theBattle of Cape Esperance on 11 October 1942, suffering many casualties, but the magazine (being partially flooded as a result of shell hits in her hull) did not explode.Nashville was hit by akamikaze attack on 13 December 1944, offMindoro, which killed or wounded 310 crewmen.Honolulu was torpedoed at theBattle of Kolombangara on 12–13 July 1943, as was her near-sisterSt. Louis. After being repaired in the United States,Honolulu returned to service only to be torpedoed by a Japanese aircraft on 20 October 1944, during theinvasion of Leyte.^[17] On 11 September 1943,Savannah was hit by a GermanFritz X radio guided bomb which penetrated her #3 turret and blew out the bottom of the ship. Skillful damage control by her crew saved her from sinking. While under repair in the United States,Savannah andHonolulu were rebuilt with a bulged hull that increased their beam by nearly 8 feet (2.4 m) and their 5-inch/25 caliber guns were replaced by four twin 5-inch/38 caliber guns, although the repairs toSavannah were completed too late for her to see frontline action again.^[18]

Helena was sunk in 1943 during theBattle of Kula Gulf. The remains of the ship were discovered below the surface ofNew Georgia Sound byPaul Allen's research shipPetrel in April 2018.St. Louis was seriously damaged twice, but survived the war.

All ships of the class went into reserve in 1946-47. Six were sold toSouth American countries in the early 1950s, and served for many more years:Brooklyn andNashville to Chile,St. Louis andPhiladelphia to Brazil, andBoise andPhoenix to Argentina.Savannah andHonolulu remained in reserve until struck in 1959.ARA General Belgrano (ex-Phoenix) was torpedoed and sunk byHMS Conqueror during the Falklands War,^[19] whileO'Higgins (ex-Brooklyn) remained in service with the Chilean Navy until 1992.^[20] She sank under tow, on her way to the scrappers, in the mid-Pacific in 1992.^{[citation needed]}

• List of cruisers of the United States Navy
• List of ships of the Second World War
• List of ship classes of the Second World War

Wikimedia Commons has media related toBrooklyn class cruiser.

• Ewing, Steve (1984).American Cruisers of World War II. Missoula, Montana: Pictorial Histories Publishing Company.ISBN 0-933126-51-4.
• Fahey, James C. (1945).The Ships and Aircraft of the United States Fleet. New York: Ships and Aircraft.
• Friedman, Norman (1984).U.S. Cruisers: An Illustrated Design History. Annapolis, Maryland: U.S. Naval Institute Press.ISBN 9780870217180.
• Preston, Antony (1980).Cruisers. Englewood Cliffs, New Jersey: Prentice-Hall.ISBN 013-194902-0.
• Silverstone, Paul H. (1968).U.S. Warships of World War II. Garden City, New York: Doubleday & Company.
• Stille, Mark (2016).U.S. Navy Light Cruisers 1941–45. Bloomsbury.ISBN 978-1472811400.
• Whitley, M. J. (1995).Cruisers of World War Two: An International Encyclopedia. London: Arms and Armour Press.ISBN 1-85409-225-1.

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• World War II cruisers of the United States

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