What is the most common size of cargo containers used by the Marine Corps?

The most common size of cargo containers used by the Marine Corps is indeed 8 feet wide, 8 feet high, and 20 feet long. This standard dimensions are typically referred to as a "20-foot container" and are widely used due to their compatibility with various shipping methods, including maritime transport and ground logistics. They are designed to fit on ships, trucks, and trains, which makes them versatile for military operations where efficient movement and logistics are crucial.

The design and standardization of this size facilitate ease of stacking and storage, maximizing space usage whether in a shipping yard or during deployment. Additionally, the 20-foot container is commonly used in both military and civilian contexts, ensuring that the Marine Corps can readily acquire and deploy these containers as needed without bespoke solutions that could complicate logistics.

In contrast, the other dimensions listed are not standard for cargo containers widely used by the Marine Corps or in international shipping. The 10-foot, 6-foot, and 12-foot dimensions are not typically employed, making them less practical and efficient for the logistical operations that the Marine Corps engages in. Thus, the 20-foot standard size container is the optimal choice for fulfilling their cargo-handling needs.