the more successful. The term "off-route mine" refers to purpose designed and manufactured anti-tank mines. Explosively Formed Projectiles (EFPs) are one type of IED that was used in Iraq, but most "home made" IEDs are not employed in this manner. Countermeasures The most effective countermeasure deployed against mine fields is mine clearing, using either explosive methods or mechanical methods. Explosive methods, such as the Giant Viper and the SADF Plofadder 160 AT, involve laying explosives across a minefield, either by propelling the charges across the field with rockets, or by dropping them from aircraft, and then detonating the explosive, clearing a path. Mechanical methods include plowing and pressure-forced detonation. In plowing, a specially designed plow attached to the front end of a heavily armored tank is used to push aside the earth and any mines embedded in it, clearing a path as wide as the pushing tank. In pressure-forced detonation, a heavily armored tank pushes a heavy spherical or cylindrical solid metal roller ahead of it, causing mines to detonate. There are also several ways of making vehicles resistant to the effects of a mine detonation to reduce the chance of crew injury. In case of a mine's blast effect, this can be done by absorbing the blast energy, deflecting it away from the vehicle hull or increasing the distance between the crew and the points where wheels touch the ground–where any detonations are likely to centre. Another way to protect a vehicle from mines was to attach wooden planks to the sides of armored vehicles to prevent enemy soldiers from attaching magnetic mines. In the close combat on Iwo Jima, for example, some tanks were protected in this manner. A Japanese soldier running up from a concealed foxhole would not be able to stick a magnetic mine on the side of a tank encased in wood. A simple, and highly effective, technique to protect the occupants of a wheeled vehicle is to fill the tires with water. This will have the effect of absorbing and deflecting the mine's blast energy. Steel plates between the cabin and the wheels can absorb the energy and their effectiveness is enhanced if they can be angled to deflect it away from the cabin. Increasing the distance between the wheels and passenger cabin, as is done on the South African Casspir personnel carrier, is an effective technique, although there are mobility and ease of