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Baltimore Class, U.S. Heavy Cruisers


Photograph of Baltimore-class heavy cruiser

Naval Historical Center #NH 91451

Schematic diagram of Baltimore class heavy cruiser

ONI 222


Specifications:


Tonnage 14,472 tons standad displacement
Dimensions 673'6" by 70'11" by 26'11"
205.26m by 21.59m by 7.32m
Maximum speed       33 knots
Complement 2039
Aircraft 2 catapults
4 seaplanes
Armament 3x3 8"/55 guns
6x2 5"/38 dual-purpose guns
11x4, 2x2 40mm Bofors AA guns
28 20mm Oerlikon AA guns
Protection 1790 tons
6" (152mm) machinery belt tapering to 3" (76mm) backed by 0.625" (16mm) STS steel
6" (152mm) machinery bulkheads
3" (76mm) magazine belts tapering to 2" (51m)
5.5" (140mm) forward magazine bulkhead
5" (127mm) aft magazine bulkhead
2.5" (65mm) armored deck
6.3" (160mm) barbettes
8"/3"/3.75"/1.5" (203mm/76mm/95mm/38mm) turret face/roof/side/rear
1"/0.75" (25mm/19mm) secondary battery turret face/sides and roof
6"/3" (152mm/76mm) conning towers sides/roof
Immune zone
12000 to 24000 yards (11000m to 22000m) against 8" shells
1000lb (454 kg) bombs to 10,000' (3000m)
Machinery
4-shaft General Electric geared turbines (120,000 shp)
4 Babcock & Wilcox boilers
Bunkerage 2243 tons fuel oil
26.8 tons aviation gasoline
Range 7900 nautical miles (12,700 km) at 15 knots
Sensors
SG surface search radar
SK air search radar
Mark 8 fire control radar
Mark 12/22 fire control radar (2 sets)

The Baltimores were completed in 1943-45. A development of the singular Wichita, work on the design began in September 1939. The ships were designed to remedy the stability problems and cramped layout of Wichita while retaining her protective scheme, and the turret arrangement was to be based on Cleveland. A powerful secondary battery of 5"/38 dual-purpose guns was also specified. The final design deviated considerably from Wichita, extending the hull by 65' (19.8m) and the beam by 9' (2.7m). Much of the increase in weight over Wichita went into strengthening the hull rather than increasing the protection. The machinery was the same high-pressure design adopted for the Clevelands, but the cruising turbines were abandoned in the later construction and removed from the first units.

They were the definitive wartime American heavy cruiser class, well-protected and well-armed, particularly in their antiaircraft battery, and with good subdivision. This was in spite of the fact that their design originated under the treaty restrictions and there was little time to take advantage of the lapse of the treaties in the rush of naval construction just before and during the war. No foreign navy's heavy cruisers came close to matching them. They were almost as capable as the German Panzerschiffe (pocket battleships). The ships were intended as the middle class of a three-class system of cruisers, with the Clevelands forming the lightweight class and the Alaskas forming the heavyweight class.

The U.S. Navy was never happy about the slow rate of fire of 8" guns relative to 6" guns, which was one reason light cruisers continued to be built in large numbers. The loading angle on the Baltimores was brought as close as practical to the likely firing angle, the elevation speed was improved to ten degrees per second, and separate hoists were provided for each gun, but the gun cycle could not be reduced in practice to below about 13 seconds.

All the ships were fitted with CICs, but there was some uncertainty where these should be located. They initially replaced the navigator's sea cabin and chart house, then were placed on the main deck, and finally were placed within the citadel on Pittsburgh and later units.

Though the ships could carry four seaplanes, the hangar only had capacity for two seaplanes.

None of the ships ever saw surface combat. They were used primarily as escorts for carrier task forces, having an antiaircraft battery second only to the fast battleships. None were lost and only Canberra suffered significant battle damage, from an aircraft torpedo.

They were quite expensive ships at $40 million apiece.


Units in the Pacific:

Baltimore arrived 1943-10
Boston arrived 1943-12-1
Canberra arrived 1944-1-20
Pittsburgh       arrived 1945-1-20
Quincy arrived 1945-3-10
Chicago arrived 1945-5-15
Saint Paul arrived 1945-5-25


Photo Gallery

Baltimore-class cruiser, port forward view

U.S. Navy

Baltimore-class cruiser, profile view

U.S. Navy

Baltimore-class cruiser, overhead view

U.S. Navy

Baltimore-class cruiser, forward view

U.S. Navy

Baltimore-class cruiser, aft view

U.S. Navy

Baltimore-class cruiser, forward close up

U.S. Navy

Baltimore-class cruiser, amidships close up

U.S. Navy

Baltimore-class cruiser, aft close up

U.S. Navy

Baltimore-class cruiser in drydock showing hull form and armor belt

U.S. Navy

Shell handing room on Baltimore-class cruiser

U.S. Navy

Baltimore-class cruiser interior with VIP

U.S. Navy

Baltimore-class cruiser endurance chart

U.S. Navy


References

DANFS

Friedman (1984)

Globalsecurity.org (accessed 2014-12-13)

Gogin (2010; accessed 2012-12-7)

Whitley (1995)

Worth (2001)



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