Northampton Class Heavy Cruisers

The Northampton class heavy cruisers were improved versions of the earlier Pensacola Class, with reduced armament, a hanger for their aircraft, improved sub-division of the boiler rooms and a forecastle to give them superior sea keeping abilities.

USS Northampton (CA-26), early 1930s
USS Northampton (CA-26),
early 1930s

The two Pensacola class cruisers were the first American heavy cruisers constructed after the First World War. They were armed with ten 8in guns in four turrets, and carried four aircraft, all of which were stored on deck. They were limited a displacement of 10,000t by the Washington Naval Treaty of 1921 but were lightly armoured and were significantly under weight.

Work on the Northampton class began before either of the Pensacola class ships had been laid down. On 24 February 1926 the General Board asked about the possibility of reducing the number of guns carried and using the weight that was saved to add bulkheads to split up the two large boiler rooms used on the earlier design, add a forecastle to improve see keeping and improve the aircraft facilities - the Pensacola ships carried four aircraft but they had to be stored on the deck.

By April 1926 two alternative gun layouts had been studied - one with four twin turrets and one with three tipple turrets, two at the front and one at the rear of the ship. The nine gun design was found to be superior - the extra turret on the eight gun ship took up space and added weight

USS Chester (CA-27), Mare Island Navy Yard, 16 May 1945
USS Chester (CA-27), Mare Island Navy Yard, 16 May 1945
Interior of No.2 Turret, USS Louisville (CA-28)
Interior of No.2 Turret,
USS Louisville (CA-28)

The secondary armament was provided by four 5in guns in single mountings. Four more 5in guns, to be carried on the hanger roof, were approved in February 1935 but not installed until 1938-39.

Initial anti-aircraft armament was poor. Eight .5in Browning machine guns with high angle directors were installed in 1933. In 1940 the US Navy decided to install four quad 1.1in gun mountings on its cruisers in response to the threat posed by airpower in the first year of the Second World War. The Northampton class ships were given four 3in guns while they waited for the 1.1in quads. As the war progressed 20mm guns were installed wherever there was space, while the 1.1in guns were replaced with 40mm Oerlikon guns on those ships that survived for long enough. By the end of the war the surviving ships all had powerful but varied anti-aircraft batteries.

Six torpedo tubes were installed when the ships were built, but they were later removed.

The improved aircraft accommodation consisted of blast proof hangers that were installed around the after funnel. These could carry four aircraft. Another two could be stowed on the two catapults, which were mounted on towers in the amidships area. The towers compensated for the increased size of the superstructure on these ships.

The Northampton class had similar armour to their predecessors. There was 3in plate on the side, 13ft deep with 5ft below the waterline. The magazines had 3 3/4in armour on their sides. The armoured deck was 1in thick over the machinery and 2in over the magazine. The gun turrets had 2.5in of front armour, 2in on the roof and .75in to the sides and rear. A total of 1,057 tons of armour was carried. Some thought was given to increasing the armour protection when it became clear that the ships would be under-weight, but the weight was used elsewhere.

Six ships were authorised under the FY29 budget. Three of them were equipped as Divisional Flagships and three as Fleet Flagships (with extra accommodation between the forward superstructure and the catapult towers.

Most of the Northampton class ships served in the Pacific during the Second World War, and three were lost in action (USS Northampton, USS Chicago and USS Houston). The only exception was the Augusta, which served in the Mediterranean, with the British Home Fleet and took part in the Normandy landings.

Originally the US Navy had planned to build five more ships of the Northampton class as part of the 1929 programme, to be funded under Fiscal Year 29. When it became clear just how under-weight the Northamptons actually were these plans were abandoned. CA-33 and CA-35 were completed as the Portland class, while the other three became the first ships of the New Orleans class. Both carried more armour, with the biggest improvement on the New Orleans class.

Displacement (standard)


Displacement (loaded)


Top Speed



10,000nm at 15kts

Armour – belt

3in over machinery
1in deck

 - magazines

3.75in side
2in deck

 - barbettes


 - gunhouses

2.5in face
2in roof
0.75in side and rear


600ft 3in oa


Nine 8in guns (three 3-gun turrets)
Four 5in guns (four single positions)
Six 21in torpedo tubes
Four aircraft

Crew complement

617? (734-48 for USS Chicago and USS Houston)

Ships in Class


CA26 USS Northampton

Sunk 1 December 1942

CA27 USS Chester

Broken up 1959

CA28 USS Louisville

Broken up 1960

CA29 USS Chicago

Sunk 30 January 1943

CA30 USS Houston

Sunk 1 March 1942

CA31 USS Augusta

Broken up 1960

US Heavy Cruisers 1941-45: Pre War Classes, Mark Stille. Looks at the 'treaty cruisers' built in the US between the wars, limited by treaty to 10,000 tons and 8in guns. Five classes of treaty cruisers were produced and they played a major role in the fighting during the Second World War, despite the limits imposed on them by the treaty restrictions. [read full review]
cover cover cover


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How to cite this article: Rickard, J (26 February 2014), Northampton Class Heavy Cruisers ,

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