Phalanx CIWS

The Phalanx Close-In Weapon System is a US gun-based, last-ditch ship defense built around a 20 mm M61A1 Vulcan Gatling gun firing roughly 4,500 rounds per minute, paired with self-contained search and tracking radars in one mount. It autonomously detects, tracks, and engages closing anti-ship missiles and aircraft, the inner layer of defense-in-depth. Developed by General Dynamics, now Raytheon, it entered US Navy service in 1980. The land-based Counter-Rocket, Artillery, and Mortar (C-RAM) system adapts the same mount ashore.