Barrage (artillery)

In military usage, a barrage is massed sustained artillery fire (shelling) aimed at a series of points along a line. In addition to attacking any enemy in the kill zone, a barrage intends to suppress enemy movements and deny access across that line of barrage. The impact points along the line may be 20 to 30 yards apart, with the total line length of the barrage zone anything from a few hundred to several thousand yards long. Barrages can consist of multiple such lines, usually about 100 yards apart, with the barrage shifting from one line to the next over time, or several lines may be targeted simultaneously.

A barrage may involve a few or many artillery batteries, or even (rarely) a single gun. Typically each gun in a barrage, using indirect fire, will fire continuously at a steady rate at its assigned point for an assigned time before moving onto the next target, following the barrage's detailed timetable. Barrages typically use high-explosive shells, but may also be shrapnel, smoke, illumination, poison gas (in World War I), or potentially other chemical agents. Barrages are in contrast with concentrated artillery fire, which has a single specific target such as a known enemy position or structure, and in contrast with direct fire which targets enemies within the direct line of sight of the gun.

Barrages may be used defensively or offensively, and have a variety of patterns. Defensive ones are often static (such as a standing barrage) while offensive ones are moved in coordination with the advancing friendly troops (such as creeping, rolling, or block barrages). They may target along the front line, or further into enemy back area to isolate certain enemy positions (such as a box barrage). A series of different patterns may be employed as a battle develops, with each barrage lasting only a few minutes or many hours. Barrages are usually integral with larger operations of multiple military formations, from divisions to armies, requiring days to weeks of preparation and exact planning.

The barrage was developed by the British Army in the Second Boer War. It came to prominence in World War I, notably its use by the British Expeditionary Force and particularly from late 1915 onwards when the British realized that the suppressive effects of artillery to provide covering fire were the key to breaking into defensive positions. By late 1916 the creeping barrage was the standard means of applying artillery fire to support an infantry attack, with the infantry following the advancing barrage as closely as possible. Its employment in this way recognised the importance of artillery fire in suppressing or neutralizing, rather than destroying, the enemy. It was found that a moving barrage immediately followed by the infantry assault could be far more effective than weeks of preliminary bombardment.

Barrages remained in use in World War II and later, but only as one of a variety of artillery tactics made possible by improvements in predicted fire, target location and communications. The term barrage is widely - and technically incorrectly - used in the popular media for any artillery fire.