Military Tactics - Defense - Reverse Slope Defense and Defilade use

A reverse slope defense is a positioning technique characterized by the location of defensive forces on a slope of a hill, ridge, or mountain that descends away from the enemy. It is one of several time tested techniques that may be used as part or all of a unit defense.^[1]

There are numerous recorded instances of this tactic being effectively used throughout military history from the Falklands War of 1982 all the way back to the Second Punic War fought between 218 and 201 B.C. It is clear that it is a time-tested and still currently well-documented by the U.S. Army's wide array of field manuals.

The reverse slope defense protects the infantryman from enemy long-range direct and indirect fires.

Defilade is also used to refer to a position on the reverse slope of a hill or within a depression in level or rolling terrain. Defiladed positions on hilltops are advantageous because "dead space" – a space that cannot be engaged with direct fire – will be created in front of the position. Ideally, this dead space should be covered by the interlocking fields of fire of other nearby positions, and/or by pre-planned indirect fire.

Artificial entrenchments can provide defilade by allowing troops to seek shelter behind a raised berm that increases the effective height of the ground, within an excavation that allows the troops to shelter below the surface of the ground or a combination of the two. The same principles apply to fighting positions for artillery and improvised fighting vehicles or technicals.

Below is showing the prevention of "skylining" with background cover to conceal the outline or silhouette of a vehicle (or in this case a tank) while in a defilade.

Uses of defilade and concealment. (Clockwise) 1.) Turret-down position, no background concealment 2.) Turret-down position, background concealment 3.) Hull-down position, no background concealment 4.) Hull-down position, background concealment

These tactics for tanks and armored vehicles can be easily extrapolated for use with improvised fighting vehicles. Being armed on top of a piloted-pickup truck (for example), while hiding in a defilade (See Figure 0-1) allows for an effective ambush position as well as cover to move to another another fighting position or concealed exit route if needed.

In a survival scenario use of the reverse slope defense may become invaluable to those avoiding detection from hostiles.  This tactic can be used when seeking refuge or looking to ambush a force of much greater strength and numbers.

  

References

1. Reverse Slope Defense: Light Infantry in Action [http://www.globalsecurity.org/military/library/report/call/call_1-88_chpt3.htm]
2. Combat  Techniques of Fire [http://www.globalsecurity.org/military/library/policy/army/fm/23-65/Ch6.htm]