The airport also serves private aircraft and freight/cargo flights. The merchant marine transports cargo and passengers during peacetime. Haikou has four seaports for passenger and cargo service. The extensive road system is utilized by most internal cargo and passenger traffic. Freight forwarding firms book cargo, arrange pickup and delivery, and manage documentation. Nizhny Novgorod is an important center of Volga cargo and passenger shipping. Ilyushin focuses on the military cargo and transport sector. The fuselage has underfloor storage for cargo and baggage. The C-5C is a specially modified variant for transporting large cargo. The port handles transportation of automobiles, motorcycles and general industrial cargo. The act of hiring a ship to carry cargo is called chartering. She is capable of carrying a helicopter and has a capacity for approximately of cargo. All were converted into whaling factory ships on account of their size and cargo capacity. A drum is a cylindrical container used for shipping bulk cargo. The tank is removable using tooling that interfaces with the cargo loading system.