RIM-116 Rolling Airframe Missile

The RIM-116 Rolling Airframe Missile (RAM) is a small, lightweight, infrared homing surface-to-air missile in use by the United States Navy, German Navy, Hellenic Navy, Egyptian Navy and South Korean Navy. It is intended primarily as a point-defense weapon against anti-ship cruise missiles. The missile is named because it rolls during its flight to stabilize the flightpath.

The onboard Mk 49 launcher installation weighs 5,777 kilograms (12,736 lb.s or 6.4 tons) and stores 21 missiles. The weapon cannot employ its own sensors prior to firing so it must be integrated with a ship's combat system, which directs the launcher at targets. On US ships it is integrated with the AN/SWY-2 and Ship Self Defense System combat systems.

The RIM-116 was developed by General Dynamics under a July 1976 agreement with Denmark and West Germany. (The General Dynamics missile business was later acquired by Hughes Aircraft and is today part of Raytheon.) The first 30 were built in FY85 and became operational on November 14 1992 aboard the USS Peleliu (LHA-5). The U.S. Navy hopes to purchase 1,600 RAMs and 115 launchers to equip 74 ships. The RIM-116 is currently used on several American and 25 German warships. Moreover, all new German Navy vessels will be equipped with RAM, such as the new, stealthy Braunschweig class corvettes, which will mount 2 RAM launchers per ship. The Hellenic Navy has equipped the new Super Vita-class fast attack craft and South Korea has also signed procurement contracts.


Block 0

Also known as RIM-116A in US service, the original version called Block 0 is based on the AIM-9 Sidewinder, from which it took the rocket motor, fuse and warhead. Block 0 missiles initially home in on active radiation emitted from a target (such as the Radar of an incoming antiship missile). Terminal guidance is done by infrared seeker derived from the FIM-92 Stinger MANPADS missile. In test firings Block 0 missiles achieved hit rates of over 95%.

Block 1

Block 1 (RIM-116B) is an enhanced version of the RAM missile that adds infrared-only guidance which enables it to intercept missiles that are not emitting any radar signals. Block 0's passive radar homing capabilities are retained.


In 1998 a memorandum of understanding was signed by Germany and the United States to improve the system, so that it could also engage Helicopters, Aircraft and Surface targets. The developed HAS upgrade is a mere software modification that can be applied to all Block 1 RAM missiles.


Sea RAM has been developed as direct replacement for the much shorter ranged gun-based Phalanx system, which unlike RAM is not able to deal with multiple targets coming in simultaneously.

It combines Phalanx' hardware (radar and mount) with an 11 cell RAM launcher to produce an autonomous system, which does not need any external information to engage threats. Sea RAM thus can (like Phalanx) be fitted to all kind of ships, e.g. also on replenishment ships which usually do not have integrated combat systems and only limited sensors.

General Characteristics (Block 1)

  • Primary Function: Surface-to-Air Missile
  • Contractor: Raytheon, Diehl BGT Defence
  • Length: 2780 mm
  • Diameter: 127 mm
  • Fin span: 445 mm
  • Speed: Mach 2.0+
  • Warhead: 11.3 kg blast fragmentation
  • Launch Weight: 73.5 kg
  • Range: 7.5 km
  • Guidance System: three modes—passive radio frequency/infrared homing, infrared only, or infrared dual mode enabled (radio frequency and infrared homing)
  • Unit Cost: $444,000
  • Date Deployed: 1992


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