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Fortifications

There exist only a handful of events where this section will come in useful, but it is listed here since it will be encountered in your travels.

At most events, a log, RR tie, tree branch, barrel, or dirt embankment counts as both cover and concealment, this is far from reality. An 8mm bullet from a MG42 will go through most small to medium sized trees. Not to mention empty metal barrels, dirt, logs, and RR ties (which are disintegrated by a hail of gunfire). 

However, at an event like Rockford, where digging is approved. Fortifications and emplacements may be dug by the unit. Considering the fact that we *should* have a M1919 by then (in addition to Ken's two), a couple rocket launchers, and possibly a mortar, digging emplacements for display will be highly encouraged.



Click on images for larger view! 




Refer to FM 5-15 "Field Fortifications" These excepts taken from the 1944 edition. 

"There  are two  general classes of  field  fortifications.
(1)  Hasty  fortifications. Those initially constructed when in contact with the enemy or when contact is imminent. They consist generally of light clearing of fields of fire, foxholes for personnel, open weapon emplacements, hasty  antitank and antipersonnel mine fields, barbed-wire  entanglements, strengthening of natural obstacles, observation  posts, and camouflage.

(2)  Deliberate fortifications. Those constructed out of  contact with the enemy, or developed  gradually from hasty fortifications. They include  deliberate entrenchments, antitank and antipersonnel mine fields, antitank obstacles, covered weapon emplacements, barbed-wire entanglements, troop shelters which are proof against artillery fire and weather, extensive signal communication systems, gasproof inclosures of command posts and aid stations, and elaborate camouflage....


Regardless of the type of terrain and the tactical situation, terrain always can be evaluated in terms of the following five factors: observation, fields of fire, concealment and cover, obstacles, and communications.


Observation of the ground on which a fight is taking place is essential in order to bring effective fire to bear upon the enemy. Observation also aids in increasing the effectiveness of fire direct on an enemy stopped by obstacles. 

Fields of fire are essential to the defense. An ideal field of fire for infantry is an open stretch of ground in which the enemy can be see and which he has no protection from fire as far as the limits of effective range of the infantry weapons.

Concealment from view, both from the air and ground, will usually protect military personnel and installations only as long as the enemy is unaware of their location. Unconcealed installations and troops invite destruction. Cover includes protection from fire, either that provided by the terrain, or that provided by other natural or artificial means.

Obstacles are obstructions to the movement of military forces. Some of the common natural obstacles of military value are mountains, rivers, streams, bodies of water, marshes, gullies, steep inclines, and heavily wooded terrain.

Mountains parallel to the direction of advance of a force limit or prohibit lateral movement and protect the flanks; perpendicular to the advance, they are obstacles to the attacker and an aid to the defender.

Rivers are similar to mountains in their effect on forces moving parallel and perpendicular to them.Rivers flowing parallel to the advance may be used as routes of supply. 

Marshes frequently provide more delay to an advance than bodies of water, because generally it is more difficult to build causeways than bridges. Mechanized vehicles can be restricted in movement by dense woods, marshes, steep inclines, gullies, stumps, large rocks, and bodies of water.

Communications consist of roads, railroads, waterways, airways, and their facilities. They are important to both offense and defense for moving troops and supplies. In most situations, especially in operations of large bodies of troops, the means of communication are of vital importance.

Camouflage:
Concealment is of prime importance in locating defensive works. Before any excavation is started, all turf, sod, leaves, or forest humus is removed carefully from both the area to be excavated and that on which spoil is to be piled. This material is set aside and replaced over the spoil when the work is completed. To prevent discover of the work during excavation, camouflage nets are suspended from stakes or trees before excavation is started. The workers confine their activities to the area beneath the camouflage net. The net is suspended high above the ground to permit excavation without snagging equipment or entrenching tools on it. After the excavation has been completed and the spoil covered with sod or other natural camouflage material, the net is lowered close to the ground so that it is inconspicuous from ground observation. Nets are kept in position when the weapon is not being fired. Arrangements are made to withdraw or lift the net during action. 

Handling of Spoil:
Excavated soil is much lighter in color and tone than surface soil and must be hidden carefully lest its presence disclose the fortification. Spoil may be disposed of ins several ways. 

Spoil can be used to form a parapet, if the topsoil is carefully saved and used to cover the parapet. Turf, leaves, or other litter from the nearby bushes or trees may be used to make the parapet resemble its surroundings.

It may be removed and carefully hidden under trees or bushes or in ravines. Care must be taken to avoid revealing tracks.

It may be collected and used, partly camouflaged, to form parapets for dummy positions. 

Sandbags: 
Sandbags  are  laid  as follows  (fig.  11):
1.  Fill bags uniformly about three-fourths full.
2.  Tuck in bottom corners of bag after filling.
3.  Build walls with slope 3 on 1 to 4 on 1.
4.  Place bags perpendicular to slope.
5.  Place bottom row headers.
6.  Alternate intermediate rows as headers and stretchers.
7.  Complete with a top row of headers.
8.  Place side seams and choked ends on the inside.
9.  Break joints and beat bags into place and into rectangular shape with back of shovel, or tamp with feet




Foxholes:
Foxholes are entrenchments normally dug for individual protection when contact with the enemy is imminent or in progress. They provide excellent protection against small-arms fire, artillery shell fragments, airplane fire or bombing, and the crushing action of tanks. The one- and two-man foxholes are basic types, the choice of type resting with the squad leader if not prescribed by higher authority. The two-man foxhole is used when men must work in pairs or when, for psychological reasons, battlefield comradeship is desirable.

One-Man Foxhole: (fig. 17) 

Dimensions:

The size and shape of the foxhole are affected by the following: 
It is as small as practicable, to present the minimum target to enemy fire. 
It is wide enough to accommodate the shoulders of a man sitting on the firestep. 
It is long enough to permit the use of large-size entrenching tools. 
It is at least 4 feet deep to the firestep, from which the standing occupant should be able to fire. 
A sump is dug in one end for bailing out water and for the feet of the seated occupant.

Details of construction:

In most types of soil the foxhole gives positive protection against the crushing action of tanks, provided the shoulder crouches at least 2 feet below the ground surface (fig. 18). In very sandy or soft soils it may be necessary to revet the sides to prevent caving in. The spoil is piled around the hole as a parapet, 3 feet thick and approximately 2 foot high, leaving a berm or shelf wide enough for the shoulder to rest his elbows upon while firing. If turf or topsoil is to be used to camouflage this parapet, the soldier first removes the topsoil from an area 10 feet square and sets it aside until the foxhole is completed.


Foxhole With Camouflage Cover: (fig. 19)
It may be practicable for the soldier to remove the spoil to an inconspicuous place and to improvise a camouflage cover for his foxhole. This technique is especially effective against a mechanized attack supported by foot soldiers. Riflemen remain concealed until the tanks have overrun the position; they then rise up and combat the enemy foot soldiers following the tanks.



Two-Man Foxhole: (fig. 20)
The two-man foxhole consists of essentially two adjacent one-man foxholes. Since it is longer than the one-man type, the two-man foxhole offers somewhat less protection against tanks crossing along the long axis, as well as against airplane strafing and bombing and artillery shell fragments.



Individual Prone Shelter: (fig. 21)
Prone shelters seldom are dug in forward areas. They may be authorized in rear areas when ground attack is unlikely, or when the warning service insures sufficient time to construct foxholes. The prone shelter, being shallow, does not provide protection against the crushing action of tanks and is not suitable as a firing position. The prone shelter gives considerable protection against hostile artillery and aviation and against small-arms fire.



Observation Posts: (figs. 17, 19, 20, and 23)
When observers are located in exposed positions, they should be well protected and concealed. Both the one-man foxhole and the two-man foxhole with camouflage cover are suitable for use as observation posts.

The covered observation post, although a good type, takes considerable time to build. Since the overhead cover provides splinterproof protection only, this type of observation post is valuable only when well concealed. It requires 21 cubic feet of excavation per foot of length or a total of 105 cubic feet per 5 foot section.



Caliber .30 Machine Gun (light)
There are two types of emplacements for this gun: the horseshoe type and the two foxhole type.

Horseshoe Type: (fig. 25)
The gun is placed in a firing position ready for immediate action. Lying down, if exposed to fire, the crew first excavate about 1/2 foot beneath the gun and then a similar depth for themselves, thus making an open shallow pit. The spoil is piled around in a parapet. 

The emplacement is competed by digging out a horseshoe-shaped trench, about 2 feet wide, along the rear and sides of the pit, leaving a chest high shelf to the center and front to serve as a gun platform (fig 25.). The spoil is piled around the emplacement to form a parapet at least 3 feet thick and low enough to permit all-around fire. 

This emplacement furnishes protection against small arms fire and shell or bomb fragments. In firm soil, this emplacement offers protection against the crushing action of tanks. In loose soil, logs about 8 inches in diameter, placed across the front rear and sides of the emplacement and embedded flush with the top of the ground, help make the emplacement resistant to the crushing action of tanks. When tanks appear about ot overrun the position, the gunners pull the weapon to the bottom of the trench at the rear of the emplacement and then crouch down to either side. 



Two-Foxhole Type: (fig. 26)
This emplacement consists of two one-man foxholes close to the gun position. To lay it out, a short mark is scratched on the ground in the principal direction of fire. On the right of this mark a foxhole is dug for the gunner. On the left of the mark and 2 feet to the front, another foxhole is dug for the assistant gunner. The spoil is piled all around the position to form a parapet, care being taken to pile it so as to permit all-around fire of the weapon. In firm soil the two-foxhole type provides protection for the crew and weapon against the crushing action of tanks. When tanks appear about to overrun the position the gun is removed from the tripod and taken into one foxhole, the tripod into the other. The gunner and assistant gunner crouch in the holes. 



Choice of Type: 
As a firing position, the two-foxhole type is a little less flexible than the horseshoe type, but it is easier to construct and more nearly tankproof than the horseshoe type. Therefore, the two-foxhole type generally is preferred.


60-mm Mortar Emplacement: (fig. 30)
Open Type:
This consists of a rectangular pit large enough to accommodate the mortar, the gunner, and the assistant gunner. The emplacement is kept to the minimum size to afford protection against airplane fire and bombing and against artillery shells, but it allows room for firing the mortar and storing necessary ammunition. The front edge is sloped so that the aiming stake, about 10 yards to the front, is visible through teh sight and so the weapon's fire will be clear. The spoil from the excavation is piled all around the pit to form a low parapet. Foxholes for members of the mortar squad not required at teh gun are prepared not far from the emplacement. Additional ammunition is placed in nearby shelters.


Two-Foxhole Type: (fig. 31)

This shows the 60-mm mortar in action with only the base plate dug in, the crew operating from one-man foxholes. This two-foxhole type of emplacement is preferred when the mortar is in defilade. 




Rocket Launcher
There are two types of emplacement for this weapon, the pit-foxhole type and the pit type. 
Pit-Foxhole Type: (fig. 33)
This emplacement is a circular pit, 3 feet in diameter and about 3 1/2 feet deep, large enough for two men. It permits the assistant rocketeer to turn with the traversing weapon so that he is never behind it when it is fired. The emplacement is shallow enough to permit the rear end of the rocket launcher at maximum elevation to be clear of the parapet, thus insuring that the hot back-blast from the rockets is not deflected to the occupants. This emplacement is not tankproof. Therefore foxholes for the crew are dug nearby. As the antitank mission of this weapon requires that it be kept in action against hostile tanks until the last possible moment, these foxholes will boe occupied only when a tank is about to overrun the emplacement.

Pit Type: (fig. 33)
In firm soil the diameter of the circular pit can be increased to 4 feet and an additional circular pit 2 feet deep and 2 feet in diameter excavated in the center. The leaves a circular firing step 1 foot wide and about 3/12 feet below the surface. When tanks appear about to overrun the position, the rocketeer and assistant rocketeer crouch down into the lower pit. When tanks have passed, the rocket launcher quickly is returned to action.

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