Terrain Association - Tactical Considerations

Military cross­country navigation is intellectually demanding because it is imperative that the unit, crew, or vehicle survive and successfully complete the move in order to accomplish its mission. However, the unnecessary use of a difficult route will make navigation too complicated, create more noise when proceeding over it, cause wear and tear on equipment and personnel, increase the need for and needlessly complicate recovery operations, and waste scarce time. On receipt of a tactical mission, the leader begins his troop­leading procedures and makes a tentative plan. He bases the tentative plan on a good terrain analysis. He analyzes the considerations covered in the following mnemonics-- OCOKA and METT­T.

a. OCOKA. The terrain should be analyzed for observation and fields of fire, cover and concealment, obstacles, key terrain, and avenues of approach.

(1) Observation and fields of fire. The purpose of observation is to see the enemy (or various landmarks) but not be seen by him. Anything that can be seen can be hit. Therefore, a field of hire is an area that a weapon or a group of weapons can cover effectively with fire from a given position.
(2) Cover and concealment. Cover is shelter or protection (from enemy fire) either natural or artificial. Always try to use covered routes and seek cover for each halt, no matter how brief it is planned to be. Unfortunately, two factors interfere with obtaining constant cover. One is time and the other is terrain. Concealment is protection from observation or surveillance, including concealment from enemy air observation. Before, trees provided good concealment, but with modern thermal and infrared imaging equipment, trees are not always effective. When you are moving, concealment is generally secondary; select routes and positions that will not allow a covered or concealed enemy near you.

(3) Obstacles. These are any obstructions that stop, delay, or divert movement. Obstacles can be natural (rivers, swamps, cliffs, or mountains) or they may be artificial (barbed wire entanglements, pits, concrete or metal antimechanized traps). They may be ready­made or they may be constructed in the field. Always consider any possible obstacles along your movement route and, if possible, try to keep obstacles between the enemy and yourself.

(4) Key terrain. This is any locality or area that the seizure or retention of affords a marked advantage to either combatant. Urban areas are often seen by higher headquarters as being key terrain because they can be used to control routes. On the other hand, an urban area that is destroyed may be an obstacle instead. High ground can be key because it dominates an area with good observation and fields of fire. In an open area, a draw or wadi (dry streambed located in an arid area) may provide the only cover for many kilometers, thereby becoming key. You should always attempt to locate any area near you that could be even remotely considered as key terrain.

(5) Avenues of approach. These are access routes. They may be the routes you can use to get to the enemy or the routes they can use to get to you. Basically, an identifiable route that approaches a position or location is an avenue of approach to that location. They are often terrain corridors such as valleys or wide, open areas.

b. METT­T. Tactical factors other than the military aspects of terrain must also be considered in conjunction with terrain during movement planning and execution as well. These additional considerations are mission, enemy, terrain and weather, troops, and time available.

(1) Mission. This refers to the specific task assigned to a unit or individual. It is the duty or task, together with the purpose, that clearly indicates the action to be taken and the reason for it--but not how to do it. Training exercises should stress the importance of a thorough map reconnaissance to evaluate the terrain. This allows the leader to confirm his tentative plan, basing his decision on the terrain's effect on his mission.

(a) Marches by foot or vehicle are used to move troops from one location to another. Soldiers must get to the right place, at the right time, and in good fighting condition. The normal rate for an 8­hour foot march is 4 kilometers per hour. However, the rate of march may vary, depending on the following factors:

Time allowed.
Likelihood of enemy contact.
Physical condition of soldiers.
Equipment/weight to be carried.

A motor march requires little or no walking by the soldiers, but the factors affecting the rate of march still apply.
(b) Patrol missions are used to conduct combat or reconnaissance operations. Without detailed planning and a thorough map reconnaissance, any patrol mission may not succeed. During the map reconnaissance, the mission leader determines a primary and alternate route to and from the objective(s).

(c) Movement to contact is conducted whenever an element is moving toward the enemy but is not in contact with the enemy. The lead element must orient its movement on the objective by conducting a map reconnaissance, determining the location of the objective on both the map and the ground, and selecting the route to be taken.

(d) Delays and withdrawals are conducted to slow the enemy down without becoming decisively engaged, or to assume another mission. To be effective, the element leader must know where he is to move and the route to be taken.

(2) Enemy. This refers to the strength, status of training, disposition (locations), doctrine, capabilities, equipment (including night vision devices), and probable courses of action which impact upon both the planning and execution of the mission, including a movement.
(3) Terrain and weather. Observation and fields of fire influence the placement of positions and crew served weapons. The leader conducts a map reconnaissance to determine key terrain, obstacles, cover and concealment, and likely avenues of approach.

(a) Key terrain is any area whose control affords a marked advantage to the force holding it. Some types of key terrain are high ground, bridges, towns, and road junctions.
(b) Obstacles are natural or man­made terrain features that stop, slow down, or divert movement. Consideration of obstacles is influenced by the unit's mission. An obstacle may be an advantage or disadvantage, depending upon the direction of attack or defense. Obstacles can be found by conducting a thorough map reconnaissance and study of recent aerial photographs.

(c) Cover and concealment must be determined for both friendly and enemy forces. Concealment is protection from observation; cover is protection from the effects of fire. Most terrain features that offer cover also provide concealment from ground observation. There are areas that provide no concealment from enemy observation. These danger areas maybe large or small open fields, roads, or streams. During the leader's map reconnaissance, he should determine any obvious danger areas and, if possible, adjust his route.

(d) Avenues of approach are routes by which a unit may reach an objective or key terrain. To be considered an AA, a route must provide enough width for the deployment of the size force for which it is being considered. AAs are also considered for the subordinate enemy force. For example, a company would determine likely AAs for an enemy platoon; a platoon would determine likely AAs for an enemy squad. Likely AAs may be either ridges, valleys, or by air. By examining the terrain, the leader can determine the likely enemy AAs based on the tactica1 situation.

(e) Weather has little impact on dismounted land navigation. Rain and snow could possibly slow down the rate of march, that is all. But during mounted land navigation, the navigator must know the effect of weather on his vehicle. (See Chapter 12 for mounted land navigation.)

(4) Troops. Consideration of your own troops is equally important. The size and type of the unit to be moved and its capabilities, physical condition, status of training, and types of equipment assigned will all affect the selection of routes, positions, fire plans, and the various decisions to be made during movement. On ideal terrain such as relatively level ground with little or no woods, a platoon can defend a front of up to 400 meters. The leader must conduct a thorough map reconnaissance and terrain analysis of the area his unit is to defend. Heavily wooded areas or very hilly areas may reduce the front a platoon can defend. The size of the unit must also be taken into consideration when planning a movement to contact. During movement, the unit must retain its ability to maneuver. A small draw or stream may reduce the unit's maneuverability but provide excellent concealment. All of these factors must be considered.

(a) Types of equipment that may be needed by the unit can be determined by a map reconnaissance. For example, if the unit must cross a large stream during its movement to the objective, ropes may be needed for safety lines.
(b) Physical capabilities of the soldiers must be considered when selecting a route. Crossing a large swampy area may present no problem to a physically fit unit, but to a unit that has not been physically conditioned, the swampy area may slow or completely stop its movement.

(5) Time available. At times, the unit may have little time to reach an objective or to move from one point to another. The leader must conduct a map reconnaissance to determine the quickest route to the objective; this is not always a straight route. From point A to point B on the map may appear to be 1,000 meters, but if the route is across a large ridge, the distance will be greater. Another route from point A to B may be 1,500 meters-but on flat terrain. In this case, the quickest route would be across the flat terrain; however, concealment and cover may be lost.

One key to success in tactical missions is the ability to move undetected to the objective. There are four steps to land navigation. Being given an objective and the requirement to move there, you must know where you are, plan the route, stay on the route, and recognize the objective.

a. Know Where You Are (Step 1). You must know where you are on the map and on the ground at all times and in every possible way. This includes knowing where you are relative to--

Your directional orientation.
The direction and distances to your objective.
Other landmarks and features.
Any impassable terrain, the enemy, and danger areas.
Both the advantages and disadvantages presented by the terrain between you and your objective.
This step is accomplished by knowing how to read a map, recognize and identify specific terrain and other features; determine and estimate direction; pace, measure, and estimate distances, and both plot and estimate a position by resection.

b. Plan the Route (Step 2). Depending upon the size of the unit and the length and type of movement to be conducted, several factors should be considered in selecting a good route or routes to be followed. These include-

Travel time.
Travel distance.
Maneuver room needed.
Load­bearing capacities of the soil.
Energy expenditure by troops.
The factors of METT­T.
Tactical aspects of terrain (OCOKA).
Ease of logistical support.
Potential for surprising the enemy.
Availability of control and coordination features.
Availability of good checkpoints and steering marks.
In other words, the route must be the result of careful map study and should address the requirements of the mission, tactical situation, and time available. But it must also provide for ease of movement and navigation.

(1) Three route­selection criteria that are important for small­unit movements are cover, concealment, and the availability of reliable checkpoint features. The latter is weighted even more heavily when selecting the route for a night operation. The degree of visibility and ease of recognition (visual impact) are the key to the proper selection of these features.
(2) The best checkpoints are linear features that cross the route. Examples include perennial streams, hard­top roads, ridges, valleys, railroads, and power transmission lines. Next, it is best to select features that represent elevation changes of at least two contour intervals such as hills, depressions, spurs, and draws. Primary reliance upon cultural features and vegetation is cautioned against because they are most likely to have changed since the map was last revised.

(3) Checkpoints located at places where changes in direction are made mark your decision points. Be especially alert to see and recognize these features during movement. During preparation and planning, it is especially important to review the route and anticipate where mistakes are most likely to be made so they can be avoided.

(4) Following a valley floor or proceeding near (not on) the crest of a ridgeline will generally offer easy movement, good navigation checkpoints, and sufficient cover and concealment. It is best to follow terrain features whenever you can -- not to fight them.

(5) A lost or a late arriving unit, or a tired unit that is tasked with an unnecessarily difficult move, will not contribute to the accomplishment of a mission. On the other hand, the unit that moves too quickly and carelessly into a destructive ambush or leaves itself open to air strikes will also have little impact. Careful planning and study are required each time a movement route is to be selected.

c. Stay on the Route (Step 3). In order to know that you are still on the correct route, you must be able to compare the evidence you encounter as you move according to the plan you developed on the map when you selected your route. This may include watching your compass reading (dead reckoning) or recognizing various checkpoints or landmarks from the map in their anticipated positions and sequences as you pass them (terrain association). Or, better still, it should be a combination of both.
d. Recognize the Objective (Step 4). The destination is rarely a highly recognizable feature such as a dominant hilltop or road junction. Such locations are seldom missed by even the most inexperienced navigators, but they are often dangerous places for soldiers to occupy. The relatively small, obscure places are most likely to be the destinations.

(1) Just how does one travel over unfamiliar terrain for moderate to great distances and know when he reaches the destination? One minor error, when many are possible, will cause the target to be missed.
(2) The answer is simple. Select a checkpoint (reasonably close to the destination) that is not so difficult to find or recognize. Then plan a short, fine­tuned last leg from the new expanded objective to the final destination. For example, you may be able to plan and execute the move as a series of sequenced movements from one checkpoint or landmark to another using both the terrain and a compass to keep you on the correct course. Finally, after arriving at the last checkpoint, you might follow a specific compass azimuth and pace off the relatively short, known distance to the final, pinpoint destination. This is called point navigation. A short movement out from a unit position to an observation post or to a coordination point may also be accomplished in the same manner.