UNITED STATES NAVY (UNITED STATES OF AMERICA)

Ship project history: Works on the Baltimore project started in September, 1939. War in Europe cancelled all contractual limitations that allowed to return to building of cruisers with 203mm guns. Just completed Wichita was taken for a basis, an unsatisfactory stability was appeared as her unique lack. It was originally supposed to limit by increase in a hull beam at 0.6m, however it has soon been decided to go on more significant change of the project, having strengthened AA armament at the expense of placing of 127/38mm guns in twin turrets on accepted on Cleveland class light cruisers diamond-shaped scheme, and install multi-barrelled automatic guns (originally 4x4 28mm "Chicago pianos", subsequently replaced by 40/56mm Boforses). Also it was provided to lengthen a belt on a waterline.

As a result new ship was notably "grown": standard displacement has reached 13600t, and almost all gain of displacement was expended to strengthening of AA armament and providing of better seaworthiness and stability. Protection, in comparison with Wichita, practically has not changed: only deck thickness has increased to 65mm and waterline belt was hardly became longer. The immune zone under fire of 203mm guns was stretched from 77.5 to 120 cables.

Engine power has been increased by 20%, as in comparison with a prototype displacement rose sharply.

The order for building of first four ships (СА68-71) had placed in July, 1940; in September the order for next four (СА72-75) has followed. Last series from 16 ships (СА122-138) has been ordered in August, 1943.

First ship has commissioned only in the spring of 1943, and war experience was considered in her construction, therefore after commissioning ships practically were not modernised throughout war.

In 1942 the improved project, differing by reduction of funnels number to one and the improved fire sectors of an antiaircraft artillery has been created. It has been decided to finish on "1942 design" incomplete СА122-129, СА137 and СА138.

In the end of war СА134 was re-ordered as new class cruiser with automatic 203mm guns (the future De Moines class), 12/8/1945 order for building of CA126-129, CA137 and CA138 was cancelled, СА125 was completed after the war as command ship.

Ship protection: Main belt abreast machinery extended to 1.5m below and 2.86m over waterline. It was 152mm thick (76mm at lower edge) on 16mm STS plating. There were narrow belts abreast magazines. Thickness of these belts was 76mm decreasing to 51mm at lower edge. Magazines were protected by 140mm fore and 127mm aft bulkheads, machinery and magazines were separated by 152mm bulkheads. Armoured deck over main belt was 65mm. Barbettes were 178mm thick. Turrets had 203mm faces, 83-38mm sides, 38mm rears and 76mm crowns. CT was mounted from CA74.

Modernizations: 1952 - 1955, Baltimore, Boston, Canberra, Quincy: - 12 x 4 - 40/56, 24 x 1 - 20/70; + 10 x 2 - 76/50 Mk 27/33

1952 - 1955, Pittsburgh, St. Paul, Columbus, Helena: - 11 x 4 - 40/56, 2 x 2 - 40/56, 22 x 1 - 20/70; + 10 x 2 - 76/50 Mk 27/33

1952 - 1955, Oregon City, Albany, Rochester: - 11 x 4 - 40/56, 2 x 2 - 40/56, 10 x 2 - 20/70; + 10 x 2 - 76/50 Mk 27/33

1952 - 1955, Bremerton, Fall River, Macon, Toledo, Los Angeles, Chicago: - 11 x 4 - 40/56, 2 x 2 - 40/56, 14 x 2 - 20/70; + 10 x 2 - 76/50 Mk 27/33

7/1956, Helena: - 1 x 2 - 76/50; + 3 Regulus I CruM launchers (3)

3/1956-1958, Macon, Toledo, Los Angeles: - 3 x 2 - 76/50; + 3 Regulus I CruM launchers

1960-1969, Baltimore, Quincy, Pittsburgh, St. Paul, Bremerton, Fall River, Oregon City, Rochester: - (3 - 4) x 2 - 76/50

1960-1963, Helena, Macon, Toledo, Los Angeles: - 3 Regulus I CruM launchers

1955-1956, Boston and Canberra were modernized as follows:

Ship protection: Main belt abreast machinery extended to 1.5m below and 2.86m over waterline. It was 152mm thick (76mm at lower edge) on 16mm STS plating. There were narrow belts abreast magazines. Thickness of these belts was 76mm decreasing to 51mm at lower edge. Magazines were protected by 140mm fore and 127mm aft bulkheads, machinery and magazines were separated by 152mm bulkheads. Armoured deck over main belt was 65mm. Barbettes were 178mm thick. Turrets had 203mm faces, 83-38mm sides, 38mm rears and 76mm crowns.

Ship protection: Main belt abreast machinery extended to 1.5m below and 2.86m over waterline. It was 152mm thick (76mm at lower edge) on 16mm STS plating. There were narrow belts abreast magazines. Thickness of these belts was 76mm decreasing to 51mm at lower edge. Magazines were protected by 140mm fore and 127mm aft bulkheads, machinery and magazines were separated by 152mm bulkheads. Armoured deck over main belt was 65mm.