Defending a River against the Enemy
Defending a river against the enemy — that is, contesting the crossing in the absence of actual fortresses — can only be achieved by entrenching all the pickets and other strong posts distributed along the bank, ensuring that the river is swept by horizontal fire; patrols use small craft to cross to the opposite bank and gather intelligence on enemy movements. If there are islands in the middle of the river, they are occupied and entrenched; fords are rendered impassable, as are bridges — unless measures have been taken to cover and preserve them for our own use — and all such works are protected by redoubts to prevent the enemy from restoring the crossing. Particularly where the river curves toward the enemy, the chord of that arc must be entrenched so that, should the enemy actually cross there, they cannot fan out. Some advocate a curved line of entrenchments bowing inward — forming an arc directly opposite to that of the river.
When attempting to cross a river while an enemy army is positioned nearby, one must entrench immediately after the first troops have crossed so that they can withstand a superior enemy attack. To secure immediate anchor points for the flanks, it is advisable to cross where the river forms a bend curving away from the enemy; this positioning also allows for more effective fire against any enemy force rushing to attack the troops that have already crossed, as the riverbanks are invariably higher on the outer side of the bend. Entrenchments must be constructed as rapidly as possible, and their specific shape is of secondary importance; sandbags allow for the quickest construction. Some also recommend a curved line for the entrenchments, roughly following the bend of the river, as a suitable configuration. See Crossing a River.
Bibliography
- Grant, Charles Stewart: Scenarios for Wargames, p. 46–49, 55–57
Source: Rumpf, H. F.: Allgemeine Real-Encyclopädie der gesammten Kriegskunst (Berl. 1827)