Pensacola-class cruiser

	USS Pensacola (CA-24)
Class overview
Name	Pensacola-class cruiser
Builders	New York Navy Yard, NY (1); New York Ship, NJ (1);
Operators	United States Navy
Succeeded by	Northampton class
Built	1926-1930
In commission	1929–1947
Planned	2
Completed	2
Retired	2
General characteristics
Type	Heavy cruiser
Displacement	9,100 long tons (9,246 t) (standard); 11,512 long tons (11,697 t) (full);
Length	570 ft (170 m) wl; 585 ft 6 in (178.46 m) oa;
Beam	65.0 ft (19.8 m)
Draft	19.5 ft (5.9 m)
Installed power	8 boilers; 107,000 hp (80,000 kW);
Propulsion	Steam turbines; 4 Screws;
Speed	32.5 kn (60.2 km/h; 37.4 mph)
Complement	1,200
Armament	10 × 8-inch (203 mm)/55 caliber guns (2×2, 2×3); 8 × single 5-inch (127 mm)/25 caliber guns; 2 × 3-pounder (47 mm (1.9 in)) saluting guns; 4 × quad 1.1-inch (28 mm)/75 caliber guns (as built); 24 × 40 mm (1.6 in) Bofors guns (6x4) (1943); 28 × 20 mm (0.8 in) Oerlikon cannons (1943); 6 × 21 inches (533 mm) torpedo tubes (removed before 1941);
Armor	Belt: 2.5–4-inch (64–102 mm) ; Decks: 1–1.75-inch (25–44 mm) ; Turrets: 0.75–2.5-inch (19–64 mm) ; Barbettes: 0.75-inch ; Conning tower: 1.25-inch (32 mm);
Aircraft carried	2
Aviation facilities	2 × catapults; no hangars;

The Pensacola class was a class of United States Navy heavy cruiser, the first "treaty cruisers" designed under the limitations set by the Washington Naval Treaty, which limited cruisers to a maximum of 10,000 long tons (10,160 t) displacement and a maximum main battery caliber of 8-inch (203 mm).

Development

Background

Innitial efforts to design what would become the Pensacola-class began in 1918 with the launch of the British Hawkins-class cruisers. The US Navy believed the Hawkins-class outclassed all American cruisers that were currently in service: an issue as Great Brittain was considered a potential rival. Japan was also identified as a potential threat, and any war in the Pacific would have required uniquely designed ships that could cope with extreme range. To counter both potential adversaries, the new American cruisers needed to exceed the capabilities of the Hawkins-class while possessing the range necessary to operate across the Pacific.^[2]^: 232

Washington Naval Treaty

In 1922, the United States and other naval powers signed the Washington Naval Treaty, intended to prevent a naval arms race and foster a sense of disarmament.^[3] The treaty limited future cruisers to displace less than 10,000 tons and armed with weapons with a caliber no greater than 8 inches (200 mm). The Pennsacola-class was the first American design built to treaty specifications, which allowed American naval architects to experiment with the requirments.^[4]

Description

In an effort to remain within treaty limits, while still mounting a very heavy main battery of ten 8-inch (203 mm) guns, the hull was of welded construction, and the armor belt was thin (varying from 2.5 to 4 inches (64 to 102 mm) in thickness). This was inadequate to protect her vitals from enemy 8-inch shells and was no thicker than the armor on 6-inch (152 mm) gun cruisers. In fact, Pensacola and Salt Lake City were classified as light cruisers due to their minimal armor, until re-designated in July 1931 as heavy cruisers in accordance with the provisions of the London Naval Treaty to designate all cruisers with guns larger than 6.1-inch as heavy cruisers.^[5]

Their main armament consisted of ten 8-inch guns, in two twin turrets on the main deck, and two triple turrets two decks above, making it one of the two US Navy ship classes (besides the Nevada-class battleships) to have different-sized turrets for main armament. All the guns in each turret were mounted in a single slide, and were unable to elevate independently of one another. Also, unlike the very few other ships with different-sized main battery turrets (Nevada-class battleships and King George V-class battleships) the Pensacolas had the larger turrets superfiring over the smaller turrets, whereas the others had the larger turrets on "bottom".^[6] Placing heavier turrets above lighter ones allows for finer lines for a given length, however causing topheaviness and reducing stability.

Unfortunately, because of the rather unusual main battery layout and their heavy tripod fore-masts, they were top-heavy and prone to excessive rolling. This combined with low freeboard forward made them inferior seaboats compared to later designs. Rework in the shipyards modified the hull and superstructure in the 1930s to eliminate the rolling.^[7]

The Navy built only two ships in this class before switching to the Northampton-class design. Many of the deficiencies of the Pensacolas were corrected by reducing the main battery to three triple turrets (two forward, one aft) and adding another upper deck forward of amidships.

Ships in class

Construction data
Ship name	Hull no.	Builder	Laid down	Launched	Commissioned	Decommissioned	Fate
Pensacola	CA-24	New York Navy Yard, Brooklyn, New York City	27 Oct 1926	25 Apr 1929	6 Feb 1930	26 Aug 1946	Struck, 28 Nov 1945; Sunk as target, 10 Nov 1948
Salt Lake City	CA-25	New York Shipbuilding Corporation, Camden, New Jersey	9 Jun 1927	23 Jan 1929	11 Dec 1929	29 Aug 1947	Struck, 18 Jun 1948; Sunk as target, 25 May 1948

References

^ Silverstone, Paul H (1965). US Warships of World War II. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-773-9.
^ Whitley, M. J. (Michael J. ) (1995). Cruisers of World War Two : an international encyclopedia. London : Arms and Armour Press.{{cite book}}: CS1 maint: publisher location (link)
^ "The Washington Treaty". www.digitalhistory.uh.edu. Archived from the original on 12 January 2025. Retrieved 19 April 2025.
^ "Speed Characteristics Of The Treaty Cruisers". U.S. Naval Institute. 1 February 1953. Retrieved 19 April 2025.
^ Friedman, Norman (1984). U.S. Cruisers: An Illustrated Design History. United States Naval Institute. p. 450. ISBN 0-87021-718-6.
^ the original design for the Lexington-class battlecruiser would have shared this unique arrangement, as they called for ten 14-inch (360 mm) guns, with the triple turrets superfiring over twin turrets, and would have appeared like scaled-up Pensacolas
^ Silverstone, Paul H (1965). US Warships of World War II. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-773-9.

External links

[1] Silverstone, Paul H (1965). US Warships of World War II. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-773-9.

[:8-2] Whitley, M. J. (Michael J. ) (1995). Cruisers of World War Two : an international encyclopedia. London : Arms and Armour Press.{{cite book}}: CS1 maint: publisher location (link)

[3] "The Washington Treaty". www.digitalhistory.uh.edu. Archived from the original on 12 January 2025. Retrieved 19 April 2025.

[4] "Speed Characteristics Of The Treaty Cruisers". U.S. Naval Institute. 1 February 1953. Retrieved 19 April 2025.

[5] Friedman, Norman (1984). U.S. Cruisers: An Illustrated Design History. United States Naval Institute. p. 450. ISBN 0-87021-718-6.

[6] the original design for the Lexington-class battlecruiser would have shared this unique arrangement, as they called for ten 14-inch (360 mm) guns, with the triple turrets superfiring over twin turrets, and would have appeared like scaled-up Pensacolas

[7] Silverstone, Paul H (1965). US Warships of World War II. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-773-9.

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v t e Pensacola-class cruisers
Pensacola Salt Lake City
Followed by: Northampton class
List of cruisers of the United States Navy

v t e United States naval ship classes of World War II
Aircraft carriers	Lexington Ranger^S Yorktown Wasp^S Essex Midway^C
Light aircraft carriers	Independence Saipan^C
Escort carriers	Long Island Charger Bogue Sangamon Casablanca Commencement Bay
Battleships	Wyoming New York Nevada Pennsylvania New Mexico Tennessee Colorado North Carolina South Dakota Iowa Montana^X
Large cruisers	Alaska
Heavy cruisers	Pensacola Northampton Portland New Orleans Wichita^S Baltimore Oregon City^C Des Moines^C
Light cruisers	Omaha Brooklyn Atlanta Cleveland Fargo^C Juneau^C Worcester^C CL-154^X
Gunboats	Dubuque Sacramento^S Asheville Plymouth^S Williamsburg^S St. Augustine^S Vixen^S Erie PGM-1 PGM-9
Destroyers	Sampson Caldwell Wickes Clemson Farragut Porter Mahan Gridley Bagley Somers Benham Sims Benson Stevenson^X Gleaves Fletcher Allen M. Sumner Robert H. Smith Gearing
Destroyer escorts	Evarts Buckley Cannon Edsall Rudderow John C. Butler
Patrol frigates	Asheville Tacoma
Patrol boats	Action PT boat
Minelayers	Oglala^S Wassuc^S Monadnock^S Miantonomah^S Terror^S Keokuk^S Salem^S Weehawken^S Camanche Chimo
Minesweepers	Lapwing Raven Auk Eagle^S Hawk Admirable
Submarines	O R S Barracuda Argonaut^S Narwhal Dolphin^S Cachalot Porpoise Salmon Sargo Tambor Mackerel Gato Balao Tench
Tankers	T1 tanker T2 tanker T3 tanker
Cargo ships	Liberty Victory Haskell Andromeda Arcturus Artemis Tolland Alstede Aldebaran Adria Acubens Arctic Denebola Hyades Mizar
Auxiliary ships	Ammunition Floating drydock Repair dock Barracks Collier Combat stores Destroyer tender Depot High-speed transport Hospital Ice cream barge Net laying Motor torpedo boat tender Reefer Oiler Repair Seaplane tender Submarine tender Underway replenishment
C Completed after the war S Single ship of class X Cancelled