M113/ADATS

     Notes: This mounting of the ADATS missile was used by Canada, and evaluated by the US and Greece. It was designed as a mobile air defense/antitank system that can keep up with advancing infantry and with more effectiveness than the Chaparral and M901 ITV systems. The system was to be fielded with Canadian and US Army units, but the US Army withdrew from the program and cancelled its order in 1989, citing difficulties with the guidance system and an evaluation program that was “excessively lenient.”  The Canadians eventually fielded 36 ADATS vehicles, many of them developmental or prototype systems, and withdrew them from service in 2012 with no replacement air defense system. The ADATS M113 system is still listed by Rheinmetall Canada as available for sale, but there are currently no production lines set up for manufacture.

     The system consists of eight ADATS tubes in a turret on top of the M113 chassis, and is equipped with radar, FLIR, and fire-control devices, primarily a coded beam laser designator. The electro-optical system is based on that of the AH-64 Apache attack helicopter, with a FLIR for night use and a near-IR TV camera for day use. There are two lasers mounted on the M113 ADATS, a CO2 laser for missile guidance and a Neodinium YaG laser rangefinder. The radar is a frequency-hopping design and is used for target acquisition and identification, and can track 20 targets at once; the radar cannot be used against ground targets, but the targeting computer may be used by the electro-optical system against ground targets. The radar is capable of networking with other friendly radars. The turret itself is a complete module and is not manned.

     The M113 ADATS is amphibious with a minimum of preparation (the trim vane must be lowered to its swimming configuration, which takes no more than 15 seconds) – but the M113 must already have rubber track skirts installed.  These bolt onto the sides of the M113 over the top part of the tracks; when the M113 enters the water, an air bubble forms over the top of the tracks to give the M113 the extra buoyancy needed for it to float.  Propulsion is by the movement of its tracks.  (These rubber skirts are easily torn up in normal field operations, and they are usually left in the motor pool.)  The M113 has a bilge pump that pumps water out of the engine compartment and from under the floor of the M113.  The M113 used a flat torsion bar suspension. The driver’s position is in the left front of the hull; his hatch is above him, to the front and left of the commander’s cupola.  The driver has vision blocks that cover everything except the rear and part of the right-side arcs, and the front one can be easily removed and replaced with a passive IR periscope.  The seat for the driver can be raised and lowered so that the driver may drive with his head outside the hatch or buttoned up.  The controls consist of a gearshift, a gas pedal, and a pair of tillers to steer and brake the vehicle using differential steering. 

     The engine is the turbocharged 6V53T, which develops 212 horsepower and has an improved cooling system.  The M113 ADATS also had neutral (pivot) steering capability, with the pivot steering handles being located at the front of the driver’s compartment above and in front of the tillers; however, most M113s have them disconnected as it was found that the M113 easily throws tracks under pivot steering, even when simply turning in place.

     The M113 also had a smoke grenade launcher kit; this consists of a pair of four-tube launchers mounted on either side of the front of the hull, above the fenders.  Originally designed specifically for white or dark smoke vehicular grenades, these launchers were later modified to permit the use of colored smoke or IR screening smoke as well.  The grenades are electrically fired, with a control box on the top of the wall of the engine compartment in front of the commander’s position.

     The increased weight of the M113 ADATS made swimming perilous; the tech manuals say that an M113A2 has a freeboard of 14 inches when fully loaded, but in practice, the freeboard is typically 10 inches or less, and it is quite possible for M113s to sink in even moderately choppy water.  For this reason, normal practice is to leave all top hatches of a swimming M113 open so that the occupants can quickly escape if the M113 sinks. In the late 1980s, the amphibious requirement for the entire M113 series was dropped, and the M113 ADATS was to swim only in emergencies.  Many units have not been even mounting the trim vanes on their M113-series vehicles since the late 1980s.

     The ADATS missile system had a few sales as a palletized container system with the missile turret on top and a connection to the Skyguard air defense system.  The ADATS missile system was offered as two variants mounted on an M2 Bradley IFV (see Best SP Antiaircraft that Never Were).  It was also mounted on a LAV-25/LAV II chassis, which the Canadians studied for some time to replace their M113 ADATS systems, with little result.