An Iowa-class battleship—arguably the pinnacle of battleship design—was designed with extraordinary firepower and operational longevity in mind. Each ship in this class, including the USS Iowa, USS New Jersey, USS Missouri, and USS Wisconsin, could carry a staggering number of shells to feed its powerful main and secondary armament.
Main Battery Ammunition
The Iowa-class battleships were armed with nine 16-inch (406 mm) Mark 7 naval guns, housed in three triple turrets. Each turret could hold 300 to 350 shells, resulting in a total capacity of 900 to 1,050 rounds for all three turrets combined. These shells, weighing between 1,900 and 2,700 pounds each depending on the type (high-explosive or armor-piercing), were stored in armored magazines deep within the ship for protection against enemy fire.
Secondary and Anti-Aircraft Ammunition
In addition to the main guns, Iowa-class battleships were equipped with:
20 dual-purpose 5-inch/38 caliber guns: These guns were effective against both surface targets and aircraft. Each gun could fire rounds weighing around 55 pounds. The total number of 5-inch shells carried was approximately 4,800 rounds.
Bofors 40 mm and Oerlikon 20 mm anti-aircraft guns: The battleships carried tens of thousands of rounds for these smaller-caliber weapons, vital for defending against aerial attacks.
Did the Iowa-Class Fire All at Once or in Rapid Succession?
The 16-inch guns on an Iowa-class battleship were not typically fired all at once, although they were capable of doing so if necessary. Instead, the guns fired in carefully controlled salvos for several reasons:
1. Accuracy
Firing all nine guns at once created a massive shockwave that could impact the accuracy of the subsequent rounds. To counter this, the guns were fired in staggered salvos (often two or three at a time) to allow for better observation of the shell splashes and corrections to targeting.
2. Turret Mechanics
Each of the three turrets was capable of independent operation, and the loading and firing sequence for the guns took time. The guns were loaded, aimed, and fired in a coordinated but staggered manner to maintain a steady rate of fire, roughly one round per gun every 30 seconds.
3. Structural Integrity
Firing all nine 16-inch guns simultaneously caused significant strain on the ship's structure, as the combined recoil could physically push the ship sideways in the water. This maneuver, known as "shuffling," was dramatic but not ideal for prolonged combat situations.
Comparisons to Smaller Ships
Smaller ships, such as destroyers and cruisers, typically fired their guns in rapid succession because their smaller-caliber weapons had faster reload times and did not produce the same level of recoil. By contrast, the massive shells of an Iowa-class battleship required careful handling and coordination, emphasizing precision over raw speed.