Added 6th July
Air and Artillery Delivered Wire Obstacle Cutting Munition.
Even guerrilla forces may fight from fixed positions when there is a need. Such positions may be surrounded by booby traps, sensors and barbed wire.
Barbed wire can cause problems for modern fighting vehicles, fouling their running gear. While vehicle mounted devices to cut wire can be built, and have been used in the past there are other considerations with respect to using vehicles against such obstacles. Often the enemy will construct his fighting positions on slopes that are too steep for vehicles to move up and may be too high for some vehicle weapons to elevate to engage. Even if the terrain does allow the use of vehicles it may be mined. The enemy will probably have organised his positions so they are mutually supporting. Any vehicle approaching a position will find its flanks and rear coming under fire from supporting positions. The enemy may even have constructed hidden spider holes in the area, allowing RPG armed fighters to attack unexpectedly.
It is tempting to assume that we can destroy fixed positions with artillery or airstrikes but in practice this may not be possible. A fixed position is likely to contain at least one bomb shelter in which defenders can weather out any bombardment. Some positions may have tunnel systems by which the defenders can vacate the position and return to it once the bombardment has lifted. Even when a position is assumed to have been neutralized by airstrike or artillery the infantry often end up getting sent in to make sure.
In some situations the only way to make sure a position is neutralized is by infantry assault. Since large scale overt attacks tend to be costly the preferred method is a short range stealthy infiltration, with troops crawling as close to the objective as possible before assaulting.
Wire, booby traps and sensors are obviously going to hinder any assault attempt so it is likely the intended target and other positions will be subjected to preparatory artillery and airstrikes. Such bombardments can destroy sensors, mines and booby traps and also break up the ground to provide cover for infiltrating infantry. It would also be useful if such bombardments could help cut a path through the wire for the infantry.
One current system that can be used to do this is the Line Charge. This usually takes the form of a rocket towing a hose or string of explosive charges. The rocket is fired so the line passes over a minefield or obstacle and the charge detonated to create a path. While a proven system Line Charges are normally deployed from Engineering vehicles and only have a range of a few hundred metres. Launch vehicles are obviously vulnerable to anti-tank measures. It would be useful if we can reproduce the effects of a Line Charge using and Artillery or Air Delivered system.
Simplest way I can see to do this is to have a bomb-shaped casing with an opening in the tail. Coiled inside the bomb is explosive cord, one end attached to a drogue chute and the other to the bomb body. Several hundred metres from the target the drogue is ejected from the tail. Since the drogue now moves slower than the casing the cord it pulled out straight. (Trivia -at least one ground launched line charge uses a drogue on the end of the line to straighten it).
The line drapes over the target position, and seconds after the head and tail have reached the ground the cord is detonated, cutting a path through the wire and any booby traps. Each position would be hit by several such LineCutter bombs, and nearby positions would get the same treatment to keep the enemy guessing where an assault is intended. Since the line charge also has anti-personnel effects these decoy attacks also help thin the enemy.
Could a line charge delivered in this way stand the stress of the drogue pulling it taut? It may be necessary to include a length of steel cable slightly shorter than the line charge to take the stress.
How to use the LineCutter bomb against positions on steep hillsides? The Air Force can probably work out the correct approach angles to do this and it may be just a case on impacting the head above the position and allowing the weight of the tail to drape the line over it.
Ideally the lines should cut paths in a direction the assault unit can easily approach from. This suggests positions should be bombed from the front or rear, while close air support is usually flown parallel to the enemy's position to reduce the chances of fratricide. While I can think of designs that may produced the desired effect if delivered from the side, I can also see an increased chance of those devices missing the position entirely. This problem may be one more of organisation. LineCutters are should be delivered before the infantry are within assault range and attempts to mend wire damage dealt with by mortar and sniper fire. Ideally there should be time for damage caused by LineCutters to be observed and the results used to modify the assault plan and rehersals.
The basic principle of the line cutter bomb can be easily adapted to a ground launched rocket. The weapon would not need to be particularly accurate and a range of just a few Kilometres should be sufficient. A simple design that can be fired from its shipping container should be possible.