GATOR mine system

The GATOR mine system is a US system of air-dropped anti-tank and anti-personnel mines, that was developed in the 1980s to be compatible with existing cluster dispensers. It is used with two dispenser systems - the Navy 500 lb CBU-78/B and the Air Force 1,000 lb CBU-89/B. Additionally the mines are used with the land and helicopter based Volcano mine system.

In use the bombs are dropped at speeds between 200 and 700 knots, and at altitudes of between 100 and 1,200 meters. A fuse in the FMU-140B controls the opening of the dispenser at one of 10 predetermined altitudes between 90 m and 900 m using a doppler ranging radar or alternatively a 1.2 second time fuse. Mine arming begins when the dispenser opens with the activation of the mines Vanadium pentoxide batteries. The circular mines have a rectangular plastic "aeroballistic" adaptor. Once the mines reach the ground they arm in between 1.2 and 10 seconds.

The mines self-destruct after a preset period of 4 hours, 15 hours or 15 days. Any that do not will be rendered disabled after 40 days when the batteries expire. The self-destruct time is set just prior to aircraft takeoff using a simple selector switch on the dispenser. It should be noted that during the Gulf War the dud rate for this system is not insignificant, in one of seven Kuwati battlefield sectors there were 205 BLU-91 and 841 BLU-92 duds. Given that 89,235 BLU-91 and 27,535 BLU-93 mines were used during the Gulf War - this represents a dud rate of somewhere between 0.5 to 2% for the BLU-91 and to 6 to 21% for the BLU-92 [http://www.gao.gov/new.items/d021003.pdf] . Additionally CMS mine field clearing personnel reported dud GATOR mines detonating with no apparent triggering event, and speculated that the extreme heat of the Kuwait desert may have triggered detonation.

The GATOR system provides a means to emplace minefields on the ground rapidly using high-speed tactical aircraft. A typical GATOR minefield is 650 m long and 200 m wide and contains 432 anti-tank mines and 132 anti-personnel mines. The minefields are used for area denial, diversion of moving ground forces, or to immobilize targets to supplement other direct attack weapons. In the 1991 Gulf War the US Air Force employed 1,105 CBU-89s — one of the reported tasks being to hamper the movements of Iraqi Scud missile launchers.

Airforce CBU-89/B

The Airforce CBU-89/B is a 1,000-pound cluster munition containing 72 antitank and 22 antipersonnel mines, consists of an SUU-64 Tactical Munitions Dispenser with an optional FZU-39 proximity sensor. The TMD is the same general configuration used for the CBU-87/B Combined Effects Munition. This commonality allows for high-rate, low-cost production of the dispenser.

When the CBU-89 is used in conjunction with the Wind Corrected Munitions Dispenser guidance tail kit, it is designated as CBU-104. [ [http://www.designation-systems.net/dusrm/app5/wcmd.html Lockheed Martin WCMD (Wind Corrected Munitions Dispenser)] ]

Navy CBU-78/B

The Navy CBU-78/B is a 500-pound cluster munition containing 45 antitank and 15 antipersonnel mines. It uses the same dispenser as the Mk7 Rockeye.

BLU-91/B anti-tank mine

The BLU-91 /B AT mine is the heart of the GATOR system. A low flat cylinder with a rectangular aeroballistic shell. A magnetic sensor in the mine detects targets, when it detects a suitable target and the target reaches the most vulnerable approach point it detonates the mine. The mine is also triggered if the mine is moved, or if the battery reaches a certain low voltage point.

Once the fuse is triggered, a small clearing charge is fired that clears any debris that may be on top of the mine. A second larger charge is triggered 30 ms later, creating an Explosively Formed Penetrator using the Misznay-Schardin effect capable of penetrating 70 mm of armour. The charge is capable of penetrating the belly of most armoured vehicles.

The mine weighs 1.95 kilograms and is 127 millimeters in diameter, with 0.58 kilograms of an RDX/Estane explosive mix. It is found in Iraq and Kuwait

BLU-92/B anti-personnel mine

After the mine reaches the ground, and the arming delay has passed - a squib is fired launching 8 tripwires from the mine. Tension on any of the wires triggers the mine electronically. The mine has an effective fragmentation radius of about 20 meters - in addition it has an anti-handling "ball and can" switch.

The mine is approximately 127 millimeters in diameter and weighs 1.68 kilograms. The mines main charge consists of 0.42 kilograms of Composition B-4. It is found in Iraq and Kuwait.

References

*
*