A Bailey bridge is a type of portable, pre-fabricated bridge made from steel. It was designed during World War II by the British engineer Sir Donald Bailey. These bridges are known for their ease of assembly and disassembly, making them ideal for military and emergency use. Bailey bridges can be quickly constructed using standard components, allowing for rapid deployment in various terrains. They are often used in situations where temporary access is needed, such as disaster relief efforts or military operations, and can support heavy loads, making them versatile for different applications.