The component tower was a modular base defense structure that GDI utilized during the Second Tiberium War and the Firestorm Crisis. The tower itself was just a plug into which a defensive weapon could be installed. This allowed a GDI commander to place a number of empty towers and install the actual defenses later on. The three defense options were:
- Vulcan cannon: dual 20mm Vulcan cannons effective against light vehicles and infantry, but lacked range and the penetrating power needed to damage tanks.
- RPG launcher: fired explosive projectiles effective against most vehicles as well as infantry.
- SAM battery: fired anti-aircraft missiles at hostile aircraft.
Component towers themselves could be deployed as part of a wall, opening up new defensive options. Any upgrade placed upon a damaged component tower would also have a side effect of fully repairing the tower (possibly due to coding limitations). In addition, selling a component tower that is connected to a wall damaged all walls attached to the sold structure.
Component towers were decommissioned following the Firestorm Crisis in favor of combat-ready structures like in the First Tiberium War.