Iowa-class battleship

The Iowa-class battleships were a group of six fast warships ordered by the United States Navy. These ships were designed in 1939 and 1940 to serve as a "fast wing" for the Navy. This means they were meant to move quickly alongside aircraft carriers. Their main goal was to intercept fast Japanese capital ships in the Pacific.

They were built to be powerful enough to fight big enemy ships while remaining fast enough to protect supply lines. These four completed vessels were the very last battleships ever commissioned by the U.S. Navy.

Designing these ships was a complex engineering challenge. The Navy had to follow the Second London Naval Treaty. This treaty included an "escalator clause," which allowed for larger ships if certain conditions were met. Because of this, the standard displacement, or the total weight of the ship, was allowed to increase to 45,000 tons. Designers also had to ensure the ships could fit through the Panama Canal. This meant the width, or beam, could not be too large.

Engineers had to balance heavy armor, massive guns, and high speed within these strict limits.

To achieve high speeds, the ships required a massive power plant. The Navy wanted the ships to reach speeds of over 30 knots. This is about 35 miles per hour. To reach such speeds, the ships needed more freeboard, which is the height of the ship's side above the water. This extra height added significant weight to the structure. To keep the weight under the 45,000-ton limit, designers had to make several difficult choices. They increased the draft, which is how deep the ship sits in the water. A deeper draft allowed for a narrower beam. This helped reduce wave-making resistance, making it easier for the ship to move quickly.

One of the biggest hurdles involved the ship's main armament. The ships were designed to carry 16-inch guns. Early plans suggested using the 16-inch/50 caliber Mark 2 guns. However, these guns were extremely heavy and required large barbettes, which are the armored cylinders that hold the guns. A conflict arose between the Bureau of Construction and Repair and the Bureau of Ordnance. The two groups were working on different plans that did not fit together. The construction group used smaller barbettes, but the ordnance group was building much larger gun turrets.

This mistake could have ruined the entire design.

To save the project, engineers had to design a new weapon. They created the 16-inch/50 caliber Mark 7 naval gun. This new gun was both lighter and smaller in its outside diameter. Because it was smaller, it could fit into the smaller barbettes required by the ship's design. This single change saved nearly 1,000 tons of weight. This allowed the final design to stay at a standard displacement of 45,000 tons. It also allowed for a full load displacement of about 58,000 tons. This careful balancing act made the Iowa class possible.

These ships saw extensive service through many different conflicts. The four completed ships were the USS Iowa, USS New Jersey, USS Missouri, and USS Wisconsin. They fought in World War II, the Korean War, and the Vietnam War.

In the 1980s, the U.S. Congress ordered them to be reactivated and modernized. During this time, they were armed with missiles as part of the 600-ship Navy initiative. They even participated in Operation Desert Storm in 1991. During that conflict, the Missouri and Wisconsin fired missiles and guns at targets in Iraq.

Eventually, the cost of maintaining such massive ships led to their retirement. They were decommissioned during the post-Cold War drawdown in the early 1990s. There was a long debate in Congress about whether they should stay in the Navy. Some argued that the ships were needed for shore bombardment during amphibious operations. However, all four ships were eventually removed from the Naval Vessel Register.

Today, all four ships serve as museum ships. They are owned by non-profit maritime museums across the United States, where they act as historical monuments.