Apocalyptic War: I Am Picking up Rags in the Ruins

After the nuclear war, the earth's surface became scorched earth. I awakened the "waste recycling" system. Others were grabbing cans, while I was picking up screws. When everyone thought I was crazy, I built a fully automated defense fortress out of garbage. Until that day, when a wave of zombies besieged the city, I pressed the red button—the abandoned tanks in the entire city—and started their engines at the same time.