Pensacola-class cruiser

	USS Pensacola (CA-24)
Class overview
Name	Pensacola-class cruiser
Builders	New York Navy Yard; New York Shipbuilding Corporation;
Operators	United States Navy
Succeeded by	Northampton class
Built	1926-1930
In commission	1929–1947
Planned	2
Completed	2
Retired	2
Preserved	0
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).

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.^[2]

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".^[3] 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.^[4]

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.
^ 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.

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

[3] 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

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

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Pensacola-class cruiser

Contents

Description

Ships in class

See also

References

External links

Class overview
USS Pensacola (CA-24)
Name	Pensacola-class cruiser
Builders	New York Navy Yard New York Shipbuilding Corporation
Operators	United States Navy
Succeeded by	Northampton class
Built	1926-1930
In commission	1929–1947
Planned	2
Completed	2
Retired	2
Preserved	0
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^[1]
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