How It Works

Inside the Phalanx


The Phalanx is a close-in weapon system (CIWS) – a largely defensive piece of kit designed to shoot down incoming anti-ship missiles. The Phalanx is arguably the most cutting-edge CIWS currently around, sporting a powerful 20-millimetre (0.8-inch) M61 Vulcan autocannon, advanced dual-antenna Ku-Band radar array and huge 1,550-round munitions drum.

The Phalanx is mounted to a variety of vessels in the US Navy, where it is tasked with defending every class of surface combat ship. This defence comes courtesy of thousands of armour-piercing tungsten and depleted uranium rounds, which are projected from the autocannon at 1,100 metres (3,610 feet) per second. For perspective, that’s the equivalent of travelling the length of Manchester United’s football pitch about ten times in a second!

The rounds’ trajectories are dictated by a built-in fire control system. This central computer can instantly calculate the probability of the Phalanx taking a target out, as well as what fire rate and pattern is needed. The control system is fed data from the two antennas of the Ku-Band radar, with a wide aperture search antenna picking up incoming threats, and a gun-laying antenna taking care of the fine, narrow aperture object targeting.

In addition to providing defence against incoming missiles and shells, the Phalanx can also operate against more traditional targets – such as small surface vessels – thanks to the inclusion of a forward-looking infrared (FLIR) sensor. This tech detects infrared radiation – ie heat signatures – and helps the Phalanx deal out massive damage to enemy ships.