- "You want to see a really big fucking gun? This is it."
- ―Overview of the BP-33 railgun (from Alien: The Roleplaying Game — Colonial Marines Operations Manual)
The BP–33 Celestial Defense Artillery Railgun was a towering anti–aircraft artillery railgun resembling an oil pump. Six BP–33s were installed at the Ouragan Testing Facility on the Union of Progressive Peoples planet KOI-571.02 as of 2184; these guns were controlled by the base's 1VAN/3 computer, and were arrayed at a distance of 250 meters from the facility. Ouragan's BP–33 railguns inflicted damage on the United States Colonial Marine Corps warship USS Tamb'Itam when it hove too close to the base during a groundside incident in 2184.