Summary and key points: Modern aircraft carriers like the USS Gerald R. Fordare marvels of human engineering that, despite their enormous size, are designed for stability and efficiency.
Why aircraft carriers do not capsize in strong storms: These vessels remain stable because their center of buoyancy is higher than their center of gravity, allowing them to right themselves if they tip over. The carrier’s hull design, which tapers at the waterline to reduce drag but is wide and flat below, improves stability.
Amazing warships: The island superstructure on the starboard side of the flight deck is strategically placed to maintain balance and optimize flight operations, demonstrating the complex design that makes these ships so impressive.
Why aircraft carriers are among the most stable ships in the Navy
Few things demonstrate the wonder of human engineering like a modern aircraft carrier. The USS Gerald R. Ford, the US Navy’s newest supercarrier, is over 1,000 feet long and 250 feet above the water and is a perfect example of the engineering skill that goes into these ships.
To the casual observer, these ships would hardly be able to float, let alone withstand rough seas. The razor-sharp hull construction suggests inherent instability, while a massive superstructure on one side of the flight deck could capsize the ship at any time. But these ships are the result of centuries of shipbuilding and remain some of the most stable seaworthy platforms anywhere.
Aircraft carriers and buoyancy
Beams do not capsize because their center of buoyancy is higher than their center of gravity. Buoyancy comes from the fact that beams are less dense than water. While many of the individual components that make up a beam, such as the steel deck plates, are much denser and would sink on their own, when combined they create the many voids inside a ship that allow it to float.
Girders are designed so that all of the buoyancy force is concentrated at a point higher than their center of gravity, or the concentration of their weight. When a girder starts to tip, its center of gravity must rise further and further out of the water, requiring more and more force to maintain this. This principle means that the further the vessel tips, it actually tries harder to right itself. Despite any odd shapes or angles, girders adhere to this principle and it makes them inherently stable.
Attentive observers may notice that girders appear to have a narrow edge that cuts into the water. However, once the ship is pulled into dry dock, the truth is revealed. This taper only extends to the waterline. It is designed to reduce drag on the water’s surface. Below the surface, girders have a wide, flat bottom, a very stable platform.
Shifted superstructure and angled deck
One of the most striking features of aircraft carriers is the island superstructure. This large, blocky structure on the starboard side of the flight deck is used to control the ship and direct flight deck operations. It was introduced as early as 1917, when the difficulties of landing and taking off around a large building directly in the middle of the flight deck were apparent. By moving the deck structure to one side, designers were able to free up an entire flight deck for aircraft. Simply widening the flight deck a little on the opposite side adds enough mass to offset the mostly hollow structure and keep the ship balanced.
It is noteworthy that on almost all aircraft carriers the superstructure is located on the starboard side of the ship. This is mainly because aircraft propellers usually rotate to the left when viewed from the cockpit, causing yaw or pull in that direction.
If the pilot loses control or cannot overcome this yaw, the aircraft will be pulled away from the superstructure.
Aircraft carriers are marvels of engineering and design. At first glance, they seem like impossible ships. A closer look reveals the advances that have made modern aircraft carriers possible, and it becomes clear that they are actually some of the most stable ships in any navies.
About the author: Defense expert Maya Carlin
Maya Carlin is an analyst at the Center for Security Policy and a former Anna Sobol Levy Fellow at IDC Herzliya in Israel. She has been featured in numerous publications, including The National Interest, Jerusalem Post, and Times of Israel. You can follow her on Twitter: @MayaCarlin.
Image credit: Creative Commons.
