Obstacles to troop movement represent either natural, human habitat originated, constructed, concealed obstacles, or obstructive impediments to movement of military troops and their vehicles, or to their visibility. By impeding

strategic Strategy (from Greek στρατηγία ''stratēgia'', "art of troop leader; office of general, command, generalship") is a general plan to achieve one or more long-term or overall goals under conditions of uncertainty. In the sense of the "art ...

operational An operational definition specifies concrete, replicable procedures designed to represent a construct. In the words of American psychologist S.S. Stevens (1935), "An operation is the performance which we execute in order to make known a concept." F ...

or tactical manoeuvre, the obstacle represents an added barrier between opposing combat forces, and therefore prevent achievement of objectives and goals specified in the operational planning schedule. The constructed obstacles are used as an aid to defending a position or area as part of the general defensive plan of the commander. The obstacles that originate from the human habitat can be converted by troops into constructed obstacles by either performing additional construction, or executing demolitions to obstruct movement over the transport network, to create a

choke point In military strategy, a choke point (or chokepoint) is a geographical feature on land such as a valley, defile or bridge, or maritime passage through a critical waterway such as a strait, which an armed force is forced to pass through in ord ...

, or to deny traversing of an area to the enemy. The natural obstacles can be used defensively by securing a more difficult to breach defensive position by for example securing a flank on terrain that is deemed impossible to traverse, thus denying the enemy an ability to close into combat range of direct fire weapons.

Role of obstacles

Obstacles are used in combat operations to create

s, deny mobility corridors and avenue of approach to positions, to enhance field of fire for direct fire weapons, or to protect key tactical terrain features to the enemy.

Types of obstacles

Natural obstacles

Natural obstacles are represented by those terrain features that for which few troops and their vehicles have capability to traverse. They include water obstacles, or areas of poor drainage such as lakes, rivers, swamps and marshes. The former two can be crossed by

amphibious vehicles An amphibious vehicle (or simply amphibian), is a vehicle that is a means of transport viable on land as well as on or under water. Amphibious vehicles include amphibious bicycles, ATVs, cars, buses, trucks, railway vehicles, combat vehicles a ...

capable of swimming, or vehicles capable of

deep wading Deep wading or deep fording is a technique used by some heavy semi-amphibious vehicles to traverse water that is several metres deep - the vehicle drives on the riverbed/lakebed/seabed and uses screens or a pipe (a snorkel) that reaches above the ...

after preparation, or by constructing a water crossing, and thus creating an easily targeted choke point. Soil and rock can also represent mobility obstacles if the soil is too soft and unable to support the weight of the military vehicles, or the terrain is fractured by cliffs, or large boulders that make organised movement impossible. While soft soil is relative to vehicle ground pressure, there is little that can be done to negotiate very rocky terrain or cliffs except by using specially trained

light infantry Light infantry refers to certain types of lightly equipped infantry throughout history. They have a more mobile or fluid function than other types of infantry, such as heavy infantry or line infantry. Historically, light infantry often fought ...

troops. Vegetation such as

jungle A jungle is land covered with dense forest and tangled vegetation, usually in tropical climates. Application of the term has varied greatly during the past recent century. Etymology The word ''jungle'' originates from the Sanskrit word ''jaṅ ...

s or dense

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

s can also represent obstacles to movement, in some cases even to light infantry troops. Some natural obstacles can be a result of climatic or soil activity such as deep snow that by covering all terrain makes safe traversing difficult and slow, or

landslide Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated grade (slope), slope failures, mudflows, and debris flows. Landslides occur in a variety of ...

s that may create an obstruction suddenly despite previously clear

route reconnaissance Reconnaissance is the of the operational environment in reconnaissance operations of routes for military use, including methods of reconnoitering and classifying them for other troops. In a k during ll the primary purpose of conducting route reco ...

report.

Habitat obstacles

While human habitat had, since early construction of roads, sought to create ways of negotiating terrain faster, the human activity on the landscape can create obstacles in its own right. Artificial lakes and ponds, canals, and areas of agricultural cultivation, particularly those that are water-intensive such as rice-paddy fields create obstacles often more difficult than the natural equivalents. Mining activity creates quarries, and the building of roads, rail roads and dams also involve construction of cuts and fills. Seeded tree-line

windbreak A windbreak (shelterbelt) is a planting usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion. They are commonly planted in hedgerows around the edges ...

hedgerow A hedge or hedgerow is a line of closely spaced shrubs and sometimes trees, planted and trained to form a barrier or to mark the boundary of an area, such as between neighbouring properties. Hedges that are used to separate a road from adjoini ...

s, stone walls and plantation forests also disrupt mobility, particularly of vehicles. Lastly the urban areas in themselves represent obstacles by offering elevated firing positions and canyon-like choke points by forcing the opponent to advance through the streets.

Constructed obstacles

Constructed obstacles are those prepared by

military engineering Military engineering is loosely defined as the art, science, and practice of designing and building military works and maintaining lines of military transport and military communications. Military engineers are also responsible for logistics be ...

troops, often

combat engineer A combat engineer (also called pioneer or sapper) is a type of soldier who performs military engineering tasks in support of land forces combat operations. Combat engineers perform a variety of military engineering, tunnel and mine warfare ta ...

s, by either using materials to construct impediments to foot and vehicle-borne troops, or by using demolition methods, or excavation such as an

abatis An abatis, abattis, or abbattis is a field fortification consisting of an obstacle formed (in the modern era) of the branches of trees laid in a row, with the sharpened tops directed outwards, towards the enemy. The trees are usually interlaced ...

, to create obstacles from natural materials and terrain in specific location in accordance with the overall plan of operations. Sometimes such obstacles can be created intentionally or unintentionally through effects of artillery fire cratering. Buildings demolished due to combat or aerial bombing become very effective obstacles as rubble represents difficult to negotiate and irregular piles of building materials.

Concealed obstacles

Concealed obstacles are used with the intention of not only preventing movement of enemy troops, but also causing casualties during attempted movement. Although one of the oldest forms of obstacle use, this became far deadlier with the invention of the

mine warfare Mine warfare refers to the use of different types of explosive devices: *Land mine, a weight-triggered explosive device intended to maim or kill people or to disable or destroy vehicles *Minelaying, deployment of explosive mines at sea **Naval mine ...

, and more so with air-delivered scattered submunition minelets that can create an instant minefield.

Obstructive obstacles

Obstructive obstacles are used primarily to deny terrain visibility to the enemy, thus creating uncertainty in targeting friendly troops. Although ancient in use as tar smoke pots, modern

smoke screen A smoke screen is smoke released to mask the movement or location of military units such as infantry, tanks, aircraft, or ships. Smoke screens are commonly deployed either by a canister (such as a grenade) or generated by a vehicle (such as ...

s are temporary and are used as a tactical measure during manoeuvring, often when a unit is performing a position change.

Obstacle negotiation

Ground troops prefer to deal with physical obstacles by circumventing them as rapidly as possible, thus avoiding becoming stationary targets to the enemy direct and indirect fire weapons, and aircraft.p.296, Liddell Hart Where this is not possible, in modern warfare the most expedient measures taken against constructed or urban obstacles are to either use armoured vehicles, preferably tanks, to remove the obstacle, or to demolish them by firing

High Explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...

munitions at them. Where combat engineers are present, they can perform this using their specialist skills and tools or vehicles. In the case of natural obstacles, specialist engineering equipment is usually required to negotiate the obstacle, commonly bridging or pontoons. The solution to obstacle bridging had at the strategic level created new forms of warfare and employment of troops in the amphibious operations, and later the airborne operations. At the operational level the use of helicopters in airmobile operations offers a vertical option to negotiating obstacles, often of considerable extent such as mountain passes or extensive areas of impossible vegetation.

References

Citations

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Bibliography

* Liddell Hart, Basil Henry, ''The Tanks: The history of the Royal Tank Regiment and its predecessors, Heavy Branch, Machine-Gun Corps, Tank Corps, and Royal Tank Corps, 1914-1945,'' Cassell, London, 1959 Land warfare Military engineering