SRPA 3 possessed a anti-aircraft artillery cannon that was used against the Chimeran Fleet which attacked San Francisco on May 15th, 1953. Chimera ground forces were sent to destroy the battery station; however, Nathan Hale and American soldiers stationed at SRPA 3 were able to beat back the assault. Sentinel Benjamin Warner was capable of activating the cannon and firing it into a Chimeran airship. Once the ship was hit, Chimeran fighters closed in on the gun and destroyed it.