Steel is used in ships, trains and train cars, and parts of planes. Most of the hulls of large ships are made of steel, and steel ships carry 90% of the global cargo. Steel is essential for sea transportation in one other way: almost all the world’s approximately 17 million shipping containers are made of steel. Besides cars, steel shows up in trains in wheels, axles, bearings, and motors. In airplanes, steel is crucial for engines and landing gear.