Baltimore Class Heavy Cruisers

The Baltimore Class Heavy Cruisers were the only American heavy cruisers not limited by the pre-war Naval Treaties to see service with the US Navy during the Second World War, and were developed from the last of the treaty cruisers, USS Wichita. This was itself developed from the Brooklyn class of light cruisers, which were believed to be a superior design to the standard American treaty cruisers.

The various naval treaties had limited the United States to eighteen 8in cruisers, but only sixteen treaty heavy cruisers were built. Instead the US Navy focused on light cruisers, preferring to build a larger number of Brooklyn class ships. The last of the treaty heavy cruisers, USS Wichita (CA-45), was based on the Brooklyn class, using a similar hull form and the same general layout. She was visibly different from the previous New Orleans class, in particular because her aircraft were moved from a position amidships to the new fantail. She carried the same number of 8in guns - nine in three triple turrets, but in an improved turret. She was also more heavily armoured than the previous class, with 6in of belt armour, up from 4in. This was partly achieved by getting closer to the treaty limits, and partly by the need to protect a smaller area.

Work on the Baltimore class began in September 1939. The outbreak of the Second World War meant that the treaty limits no longer applied, and so the new ships could be significantly larger than the Wichita.

The first design was similar to the Wichita, but with the beam increased by two feet to improve stability. Over time extra demands were added to the design, and the size increased. The Wichita had carried eight 5in/38 guns in single mounts. The new ships were to carry more 5in guns, all in double mounts. They were given twelve 5in in six mounts.

The main gun was the 8in/ 55, carried in three triple turrets, two forward and one aft.

They were built with far more powerful anti-aircraft defences than any of the earlier classs. CA-68 to CA-71 were given twelve quad 40mm mountings, while CA-72 and later ships had eleven quad and two twin mountings. They were also built with twenty eight 20mm Oerlikon guns.

The eventual design was much larger than Wichita. Full load weight rose from 13,015 tons to 17,303 tons, length from 608ft 4in (oa) to 673ft 5in (oa) and width from 61ft to 70ft 10in. The increase in size meant that they were both more stable and had had more potential for later modifications.

Each ship could carry four scouting aircraft, two stored on deck and two in a hanger located below the rear quarterdeck.

The Baltimore class ships had similar armour to the Wichita. The main belt was 6in thick, tapering to 4in at the base. Fore and after of the machinery it reduced to 3in. From CA-72 onwards the thicker armour was extended forward to provide cover for the radio room. End bulkheads were 5in-6in thick. The deck armour was 2.5in thick, a slight increase on Wichita. In total they carried 1,790 tons of armour, around 300 tons more than Wichita.

The machinery used high pressure steam boilers and provided 120,000shp (up from 100,000shp on Wichita and earlier cruisers). The 20% increase in power compensated for the increase in weight and added 1kt to the design speed. Significantly more electricity generating capability was installed.

Oregon City sub-class

USS Oregon City (CA-122), USS Albany (CA-123) and USS Rochester (CA-124) were all completed to the modified Oregon City design. The basic design remained the same, but the bridge was redesigned, the superstructure shortened and the two funnels replaced with a single funnel. The aircraft hanger was reduced in size and a single crane on the centre line replaced the two cranes of the original design. Originally the plan had been to complete CA-122 to CA-129, CA-137 and CA-138 to the Oregon City design, but USS Northampton (CA-125) was completed post-war as a flagship and the other ships were cancelled. 

Production Orders

The first four Baltimore class ships were ordered on 1 June 1940 (CA-68 to CA-71). They were followed by four more on 9 September 1940 (CA-72 to CA-75). All eight of these ships were completed as designed, although the last two arrived too late to see service in the Second World War. All eight were constructed by Bethlehem at Quincy.

A third batch of seventeen ships was ordered on 7 August 1942 (CA-122 to CA-138). Eight were ordered from Quincy, five from the New York Shipbuilding Corps and four from the Philadelphia Naval Yard.

Only four of the Quincy ships were completed. Three of them were built as the modified Oregon City sub-class (CA-122 to CA-124). CA-125 was completed several years after the war as a prototype fleet flagship. CA-126 and CA-127 were laid down but cancelled at the end of the war before being launched. CA-128 and CA-129 were never laid down.

The first four ships from the New York order were all completed as standard Baltimore class ships (CA-130 to CA-133). On 25 September 1943 CA-134 was re-ordered from Bethlehem as a Des Moines class cruiser, with a quick firing 8in gun.

The first two of the Philadelphia ships (CA-135 and CA-136) were laid down in July 1943, launched in August 1944 and completed as Baltimore class ships. CA-137 and CA-138 were laid down in December 1944 but were never launched and were cancelled at the end of the war.

On 14 June 1943 another four Oregon City class cruisers were ordered from Bethlehem, Quincy (CA-139 to CA-142), but they were changed to Des Moines class cruisers before work had begun. Only CA-139 would actually be completed.

Service Records

USS Baltimore (CA-68) entered service late in 1943 and took part in the invasion of Makin and remained in action in the Pacific until the Japanese surrender. She saw some post-war service before being decommissioned in 1956.

USS Boston (CA-69) arrived in the Pacific in January and served in the Pacific until the end of the war. In the 1950s she was converted into a guided missile cruiser (CAG-1) and was finally decommissioned in 1970.

USS Canberra (CA-70) was one of the few American ships to be named after foreign cities, in this case to honour HMAS Canberra, lost at the battle of Savo Island. She served in the Pacific from the spring of 1944 until she was hit by a torpedo in October 1944. She wasn't repaired until October 1945 and was decommissioned in 1947. She was later recommissioned as missile cruiser CAG-2 and served in that role from 1956-1970.

USS Quincy (CA-71) served in the Atlantic from March 1944 to July 1944, helping to support the D-Day landings. She took part in Operation Dragoon, before joining the Pacific Fleet for the last few months of the war in the Pacific. She was recommissioned in 1952, serving in the Korean War, but was decommissioned for the final time in 1954.

USS Pittsburgh (CA-72) served in the Pacific from February 1945 until she was badly damaged in a typhoon in June 1945. She was decommissioned in 1946, recommissioned from 1951-56, but didn't see combat during this second spell.

USS St Paul (CA-73) took part in the last carrier raids in the Pacific in 1945. She carried out three tours off Korea and also fought during the Vietnam War. She was decommissioned in 1971.

USS Columbus (CA-74) was completed too late for the Second World War. She remained in service until 1959 when work began on converting her to a guided mission cruiser (CG-12). She served in that role from 1962 until 1975.

USS Helena (CA-75) arrived too late for the Second World War, but saw combat during the Korean War and was paid off in 1963.

USS Oregon City (CA-122) was commissioned in 1946, decommissioned in 1947 and remained in the reserve until she was sold off in 1970.

USS Albany (CA-123) was converted into a guided missile cruiser (CG-10) and wasn't decommissioned until 1980.

USS Rochester (CA-124) served in the Korean War. She was decommissioned in 1961.

USS Northampton (CA-125) was completed in the 1950s as an experimental flagship (CLC-1/ CC-1).

USS Bremerton (CA-130) was in service for a brief period post war, before being decommissioned in 1948. She was recommissioned in 1951 and served in the Korean War. She was decommissioned for the second and final time in 1960.

USS Fall River (CA-131) had a brief service career. She was completed in the summer of 1945, but decommissioned in October 1947 and never recommissioned.

USS Macon (CA-132) entered service just before the Japanese surrender. She was decommissioned briefly in 1950, but then recommissioned and used in the Atlantic until she was decommissioned for the second time in 1961.

USS Toledo (CA-133) didn't enter service until 1946. She saw combat during the Korean War, and was decommissioned in 1960.

USS Los Angeles (CA-135) entered service just before the end of the Second World War but didn’t see combat. She was decommissioned in 1947, recommissioned in January 1951 and saw combat in Korea. She was decommissioned in 1963.

USS Chicago (CA-136) arrived just in time to take part in the final bombardments of Japan in July-August 1945. She was decommissioned in 1947, but recommissioned in 1964 as guided missile cruiser CG-11. She was decommissioned for a second time in 1980.

Displacement (standard)

14,472t

Displacement (loaded)

17,031t

Top Speed

33kts

Range

10,000nm at 15kts

Armour – belt

4-6in

 - armour deck

2.5in

 - barbettes

6.3in

 - turrets

8in face
3in roof
2-3.75in sides
1.5 rear

 - conning tower

6in
3in roof

 - underwater magazines

3in side
2.5in deck

Length

673ft 5in oa

Armaments

Nine 8in guns (three triple turrets)
Twelve 5in/38 guns (six double positions)
Forty eight 40mm guns (11x4, 2x2)
Twenty four 20mm guns
Four aircraft

Crew complement

2039

Ships in Class

Fate

CA68 USS Baltimore

Stricken 1971

CA69 USS Boston

Stricken 1973

CA70 USS Canberra (originally Pittsburgh)

Stricken 1973

CA71 USS Quincy (originally St Paul)

Stricken 1973

CA72 USS Pittsburgh (originally Albany)

Stricken 1973

CA73 USS St Paul (originally Rochester)

Sold for break up 1978

CA74 USS Columbus

Stricken 1976

CA75 USS Helena (originally Des Moines)

Stricken 1974

CA122 USS Oregon City

Stricken 1970

CA123 USS Albany

Sold for scrap 1990

CA124 USS Rochester

Stricken 1974

CA125 USS Northampton

Stricken 1977

CA126 USS Cambridge

Cancelled 1945

CA127 USS Bridgeport

Cancelled 1945

CA128 USS Kansas City

Cancelled 1945

CA129 USS Tulsa

Cancelled 1945

CA130 USS Bremerton

Stricken 1974

CA131 USS Fall River

Stricken 1971

CA132 USS Macon

Stricken 1969

CA133 USS Toledo

Stricken 1974

CA135 USS Los Angeles

Stricken 1974

CA136 USS Chicago

? extant 1980 ?

CA137 USS Norfolk

Cancelled 1945

CA138 USS Scranton

Cancelled 1945

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How to cite this article: Rickard, J (1 January 2015), Baltimore Class Heavy Cruisers , http://www.historyofwar.org/articles/weapons_baltimore_class_heavy_cruisers.html

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