The FGM-172 SRAW (Short Range Assault Weapon), also known as the Predator SRAW (this label is only applied to the A model) and called the SRAW Mk 40 Mod 0 prior to 2006, was a lightweight, short range anti-tank missile launcher produced by Lockheed Martin. It was designed to complement the longer-ranged FGM-148 Javelin launcher and replace the AT4, but Congress cancelled further procurement in October 2003 with 750 launchers produced, questioning the similarity between the Marine Corps SRAW and Army Bunker Defeat Munition programs.
Design Details[]
The FGM-172A is a fire-and-forget missile that uses an inertial reference autopilot system called predicted line of sight (PLOS) wherein the gunner tracks the target for at least two and no more than twelve seconds, with the launcher using this data to estimate the speed and heading of the target and plot a flight trajectory to intercept it. Once the missile is launched, it uses this pre-programmed trajectory only, having no sensors linked to its flight control systems.
The system's day tracker is a simple 2.5× optic with an 8° field of view: for night operations, the grip/cover for the daysight can be removed to expose a length of Picatinny rail, allowing the mounting of an AN/PVS-17C night-vision sight.
The warhead is an overfly top-attack (OTA) type that uses a combination of laser and magnetic sensors in the missile's nose (similar to BGM-71F TOW-2B) to detect the target (the lasers locating the front and rear of the tank and the magnetic sensor the body), and detonates when directly above, firing an explosively formed penetrator down into the weak armor of the turret roof. Because of this detonation method, an FGM-172A will attack the first suitable target it encounters along its flightpath: this means that the gunner must be careful not to fire it over a previously-destroyed target, as the system has no means of differentiating a wreck from an active vehicle.
The FGM-172B converts the system for anti-structure use, with a dual-mode fuze with an automatic delay-impact mode if it strikes a soft target. The guidance system is reworked to use a direct-fire flight profile. This modification was made due to the US Marine Corps identifying a critical lack of fire-from-enclosure capable launchers for combat in Iraq: the modification to the FGM-172A was proposed by Lockheed Martin, with the entire R&D process only taking six months.
Ammunition[]
The SRAW uses 139mm guided missiles.
Variants[]
The FGM-172A uses a downward-firing top attack warhead activated by a dual sensor fuse. This variant is used as an anti-armor weapon. It can be identified by three bands on the launcher body: black near the muzzle (anti-armor), yellow at the midsection (high explosive) and brown at the rear (low explosive). FGM-172B lacks the black band as it is not an anti-tank weapon.
The FGM-172B features a blast-fragmentation warhead designed for effectiveness against personnel and structures. This variant is also known as the FGM-172B SRAW MPV ("multi-purpose variant"). All remaining SRAWs (700 launchers) were converted to the B standard in 2005.
The Kestrel was a SRAW variant designed for the British NLAW tests, apparently using some kind of dual-mode guidance with an optional direct-fire mode. The result of this testing was the adoption of the MBT LAW, and Kestrel's development did not proceed further.