The Most Heavily-Armed American Ships in World War II

The Atlanta-class boasts a series of guns of varying calibers, including Mark 12s, anti-aircraft cannons, and 8 torpedo tubes. Mark 12s were dual-purpose deck guns that were widely used across the U.S. Navy and armed forces, with over 8,000 being produced between 1940 and 1945. As a light cruiser, the armaments on these vessels tended to be lower caliber compared to heavy cruisers or even battleships.

The Cleveland-class of light cruisers was the most-produced light cruiser during WWII and boasted a wide array of smaller arms. While the cannons and main guns on this warship were not as big as other cruisers or battleships, this class had more than 70 different guns. The ship had Mark 16 guns, which were typically triple turret batteries used against surface targets; twin Bofors guns, which were anti-aircraft autocannons used in intermediate range; and Oerlikon cannons, which shot smaller caliber rounds providing for close-range anti-aircraft defense.

The Brooklyn class, like many other light cruiser classes, provided close anti-aircraft support for carriers or larger ships in its convoys. This is reflected in the Brooklyn-class’s armament, which is primarily low-caliber guns intended to defend against aerial assaults in close ranges. These ships were also capable of bombardment and support with their five sets of triple turrets pushing 152 mm/.47 cal rounds.

Omaha-class light cruisers were designed and built after WWI, and their weapons systems reflected this. This class of ships was originally designed as a high-speed ocean scout and would act as an inspiration for later classes of light cruisers, including the Brooklyn class. As such, the armament for these vessels consists of lower-caliber guns more intended for anti-aircraft measures.

Only two St. Louis-class light cruisers, commissioned by the United States Navy in the late 1930s, were built – the USS St. Louis (CL-49) and USS Helena (CL-50). This class of ship was meant to improve on the Brooklyn-class with better combat survivability and anti-aircraft guns. Originally designed to serve as convoy escorts, these warships featured Mark 6 guns, which are known for their accuracy and destructive capabilities and were grouped into five triple turrets located along their decks. This, combined with a series of lower-caliber anti-aircraft guns, helped the class play a key support role.

The New Orleans-class of heavy cruiser warships were originally constructed during the 1930s, prior to the war. Their primary armament consisted of nine .55 caliber guns mounted in three triple turrets, delivering long-range firepower against enemy vessels. Additionally, the cruisers were equipped with an array of secondary armaments, which provided support against aerial assaults.

The USS Saint Paul (CA-73) did not enter WWII until late in the conflict, but it was one of the more technologically advanced ships, as reflected in its armament. The USS Saint Paul had nine 203 mm-caliber cannons and 12 more 127 mm-caliber canons, flanked by Oerlikon anti-aircraft cannons. Historically, this ship is significant because it was in Tokyo Bay to participate in the formal surrender ceremony.

The primary firepower of the Pensacola-class consisted of 10 203 mm guns mounted in four turrets, providing substantial range and striking power during engagements. The secondary armament featured 127 mm dual-purpose guns complemented by an array of anti-aircraft weaponry. The lead ship of this class, the USS Pensacola, played a key role in aerial defense and rescue during the Battle of Midway.

As its primary armament, the Portland class was equipped with a series of 8-inch/.55 caliber guns mounted in triple turrets. Additionally, the Portland-class was outfitted with an anti-aircraft defense system, consisting of eight 5-inch/.25 caliber dual-purpose guns and a range of other smaller caliber machine guns.

The Northampton-class heavy cruisers were equipped with nine 8-inch/.55 caliber rapid-fire naval guns arrayed in triple turrets, which allowed them to engage enemy vessels from a significant distance. At the same time, these warships featured anti-aircraft weaponry, which included four 5-inch/.25 caliber guns and a variety of smaller caliber machine guns, which acted as a deterrent against enemy aerial threats.

The Alaska-class was one of the most heavily-armed U.S. Navy cruisers, with 200 mm-caliber cannons, some of the biggest at the time. The USS Alaska (CB-1) played a key role in covering the carriers Yorktown, Intrepid, Independence, and Langley as they advanced towards Japan in March 1945. Over the course of the first month of this operation, the ship is credited with downing 12 Japanese aircrafts.

The Indiana class is perhaps the oldest class of any warship to participate in WWII – it was one of the United States’ first true battleship classes built before the turn of the 20th century. These ships’ main weapon was the four 13-inch/.35 caliber guns mounted on the hull, flanked by a series of lower-caliber guns and torpedo tubes. The USS Oregon (BB-3) Indiana-class ship was nearly scrapped under the Washington Treaty but ultimately saved and later saw duty, primarily cargo transport, in WWII.

The first New York-class battleship was built in 1912 and some of these battleships’ weaponry lagged more current ships. Their primary armament consisted of 10 14-inch/.45 caliber guns, split into five twin-gun turrets. As secondary armament, these ships carried 21 5-inch/.51 caliber guns, which were versatile weapons for engaging both smaller vessels and aircraft.

The Nevada-class battleships’ primary weaponry consisted of 10 14-inch/.45 caliber guns. For anti-aircraft and supplementary fire, these warships were equipped with 21 5-inch/.51-caliber guns. These ships are considered some of the first “standard battleships” built in the era of WWI. One ship of the class was sunk in the Pearl Harbor bombing, and the other, though badly hit, would see action later in the war.

The New Mexico-class battleships’ primary armament consisted of 12 14-inch/.50-caliber guns, strategically arranged in four triple turrets, delivering a powerful and concentrated barrage. Complementing the main armament, these warships featured 5-inch/.51-caliber secondary guns to defend against closer surface threats and torpedo boats. These battleships were also equipped with an array of anti-aircraft guns and torpedoes to protect the fleet from both aerial and underwater attacks.

The Tennessee-class battleships were equipped with a total of 12 14-inch/.50 caliber guns as their primary armament, mounted in four triple-gun turrets. The USS Tennessee (BB-43) was the lead ship of this class of two and was present at the bombing of Pearl Harbor, suffering some damage and needing a major overhaul. However, the USS Tennessee would return with upgraded combat systems and sink the Japanese battleship Yamashiro in the Battle of Surigao Strait. The ship participated in bombardment of Okinawa and was hit by a suicide plane but remained in action for almost another month before returning for more repairs.

The Pennsylvania-class battleships’ main battery consisted of 12 14-inch/.45 caliber guns, arranged in four triple-gun turrets, with its secondary armament featuring 5-inch/.51 caliber guns, designed for quick firing against smaller vessels and airborne threats. This class was equipped with a variety of anti-aircraft weapons and over time ships were retrofitted with advanced fire control systems to increase their striking power and defensive capabilities.

The South Dakota-class battleships were developed in the late 1930s and launched just in time for the war. Considering their later development, these warships were equipped with larger guns than previous generations of battleships. This class was outfitted with nine 16-inch/.45 caliber Mark 6 guns, housed in three triple turrets. Additionally, these vessels carried an array of anti-aircraft armaments, including 127 mm/.38 caliber guns, as well as various smaller caliber weapons and machine guns.

The primary weaponry of the Colorado-class consisted of 16-inch/.45 caliber guns. Complementing the primary guns were 5-inch/.51 caliber secondary guns, which were meant for combating both smaller enemy vessels and weak points on enemy warships. This class was outfitted with an array of anti-aircraft weapons, providing some defense against close aerial threats as well as two torpedo tubes for dealing with other enemy vessels.

The North Carolina-class battleships boasted an array of armaments that solidified their position as formidable warships. Their primary armament consisted of nine Mark 6 16-inch/.45-caliber guns as well as 5-inch/.38-caliber dual-purpose guns for anti-aircraft and surface engagement capabilities. There were a series of smaller caliber guns that served in defensive roles. The USS North Carolina was the lead ship of its class and had an impressive service record over the course of the war, recording 15 battle stars. Also during the Battle of the Eastern Solomons, the ship is said to have shot down between seven and 14 Japanese aircraft.

The Iowa-class battleships’ primary armament consisted of 16-inch/.50 caliber Mark 7 guns, which were capable of accurately firing 2,700-pound armor-piercing shells across distances up to 23 miles. This class also had a variety of secondary and anti-aircraft weaponry, including a combination of 40 mm Bofors anti-aircraft guns and 20mm Oerlikon cannons.

The Long Island-class escort carrier only had one ship within its class, the USS Long Island (CVE-1). As an aircraft carrier the armament for this ship was not especially impressive. However, the 21 aircraft that this vessel was able to launch were capable of incredible damage with their individual payloads. As for the actual armament, the USS Long Island had a 5-inch/.51 caliber gun and two 2-inch/.50 caliber guns.

The Bogue-class of escort carriers was headed by the USS Bogue (CVE-9), which played a critical role in the Hunter-Killer practice of hunting and destroying submarines. Along with a complement of high-caliber weapons and anti-aircraft cannons, the USS Bogue hosted 24 aircraft that were capable of spotting and bombing submarines. Over the course of the war, the USS Bogue sank a total of 10 German submarines, two Japanese submarines, while reportedly damaging at least seven more submarines.

The Casablanca-class was the most widely produced escort carrier of WWII with a total of 50 entering the service. The primary armament was a 5-inch/.38 caliber gun, which was flanked by 40 mm Oerlikon cannons and 20 mm Bofors anti-aircraft guns that provided aerial defense in intermediate and close ranges. These escort carriers were capable of hosting 28 aircraft, commonly Grumman F4F Wildcats or Hellcats.

The Independence-class aircraft carriers were introduced in the later years of WWII . Like most aircraft carriers, they were not heavily armed but their destructive capability lay with the aircraft that they hosted. Their air wings, composed of fighter, bomber, and torpedo aircrafts, delivered powerful airborne firepower across land and sea. Additionally, these carriers were equipped with a combination of anti-aircraft guns, such as the 40 mm Bofors, which provided reliable protection against aerial threats.

The Wasp-class of aircraft carriers had only one ship within its class, the USS Wasp (CV-7). The primary guns on this aircraft carrier included eight 5-inch/.25 caliber guns, four 1.1-inch anti-aircraft guns, and a series of 24 .50 caliber machine guns. The USS Wasp was host to 80 aircraft that included fighters, bombers, and more. However, this ship would not survive the war as it was sunk in the Battle of Guadalcanal. The ship was awarded two battle stars.

The USS Ranger (CV-4) is the only aircraft carrier of its class and was host to a total of 86 aircraft. Like many other aircraft carriers, the USS Ranger relied on other ships for the big guns and as such its own armament was relatively weaker compared to cruiser or battleship classes. The primary weapons on the USS Ranger were a series of eight 5-inch/.25 caliber guns, flanked by forty .50-caliber machine guns. While this carrier was not as celebrated as other classes it still earned two battle stars over the course of the war.

The Essex-class was an iconic group of aircraft carriers that was a vital component of the United States Navy during WWII. The primary anti-aircraft weaponry consisted of 12 5-inch/.38 caliber twin guns, which were placed strategically around the ship to provide maximum coverage. Additionally, the Essex class carriers hosted a complement of 90 aircraft. The lead ship of this class, the USS Essex, played a vital role in the landings at Iwo Jima and the campaign against Okinawa.

The Yorktown-class aircraft carriers, like the other carriers on this list, relied predominantly on its fleet of aircraft as opposed to its own physical armaments. Still, these vessels were armed with dual-purpose 5-inch/.38 caliber guns, complemented by a series of 1.1-inch/.75 caliber machine guns serving in an anti-aircraft role. As the war progressed, the carriers saw upgrades to their anti-aircraft arsenal, with the addition of 20 mm Oerlikon and 40 mm Bofors anti-aircraft guns, enhancing their capabilities to defend against rapidly evolving aerial threats. The USS Enterprise (CV-6) is perhaps the most famous carrier in this class, boasting the most battle stars of any vessel in WWII.

The Lexington-class aircraft carriers were some of the largest in the U.S. Navy by crew, number of aircraft at 90, and size. These carriers were designed with four 8-inch/.55 caliber twin guns and lower caliber anti-aircraft guns. Lexington-class ships were originally designed as battlecruisers in the early 1920s but were later outfitted to be aircraft carriers. The lead ship of this class, the USS Lexington, played a key role in the Battle of Coral Sea, when its air group scored the first sinking of the battle, destroying the Japanese ship Shoho. However, the ship would not survive the war as it was sunk in May 1942.