Transport (Civ3)/Civilopedia

The troop transport ship, which in peacetime serves as a cargo or passenger vessel, is the principle means 
used by modern powers to move large quantities of military equipment and personnel over long distances. 
Because transports lack offensive weaponry, they require armed vessels as escorts during times of war. A 
properly escorted transport can move large military forces to a new area quickly to act as reinforcements 
or as an attacking force.