Barrage (artillery)
The true barrage of the British XXX Corps began at 09:20, building in intensity over the next hour, 500 guns shooting at a line 500 yards deep. The barrage included smoke shells to screen the attackers forming up behind the barrage. From 10.30 the barrage was pure high explosive and began to roll forward. A 300-yard lift was made every 12 minutes, the lifts being signalled to the infantry by yellow smoke shells, and the barrage paused for ½ hour at each defensive line. 2,500 shells were fired per square kilometre per hour until the barrage stopped at 16:30.
The barrage remained in Soviet doctrine in World War II, where the creeping barrage by massed guns was the standard accompaniment to an infantry assault. The Soviet artillery had plenty of guns. Some 7,000 guns and mortars were massed for the counter-attack at the battle of Stalingrad, and huge bombardments remained standard for the rest of the war. During the Soviet advances in 1944–45, the tactic was used extensively throughout the Eastern Front such as the Vyborg–Petrozavodsk Offensive, the Battle of the Seelow Heights, and the Battle of Berlin.

Korean War and after: The barrage continued in use into the Korean War. At the Battle of Pork Chop Hill, UN forces employed on-call, pre-registered defensive fires called flash fire to defend its outposts, in which artillery laid down a box barrage in a horseshoe-shaped pattern around the outpost. It was still in use in the Vietnam War.
In the 1982 Falklands War, the assault of 42 Commando Royal Marines on Mount Harriet  was preceded by a moving concentration from supporting artillery, firing some 100 yards ahead of the advancing Marines. Later phases of the attack used a pepperpot fire, including Milan anti-tank missiles.  However, neither of these were true barrages with fire aimed at successive lines to a strict timetable.  The term Barrage as a method of fire control was not included in the 1965 ABCA artillery agreement nor its successor NATO STANAG.

General use of the word: The word barrage, imported from the French for "barrier" around 1915, means a coordinated bombardment as a static or moving barrier, as described in this article. The word has also entered general language, where it has come to mean any intense sequence of words or missiles – such as a barrage of questions. Nowadays, any form of artillery fire of more than one round may be described as a barrage in general language. Even military historians use it in a non-technical sense, referring to any intense artillery fire.

See also: Broadside
Salvo
Fusillade
Saturation fire
Time On Target
Barrage balloon

Notes: 

References: Bidwell, Shelford, Artillery Tactics 1939-45, Almark, 1976
Blackburn, George G., The Guns of Normandy, The Guns of Victory, and Where the Hell are the Guns  McClellandStewart, 1995–97.
Griffith, Paddy (1996). Battle Tactics of the Western Front: British Army's Art of Attack, 1916-18. Yale.
Hogg, Ian V (1971). Barrage: the Guns in Action. Macdonald.
Pakenham, Thomas, The Boer War, Weidenfeld & Nicolson, London, 1979, ISBN 0-297-77395-X
"Artillery in World War II—The field artillery organisation, tactics, gunnery methods and regiments of the Royal Artillery and the artilleries of British Commonwealth". Retrieved 2 January 2010. A large and detailed site on Royal Artillery methods in World War II
US Launches Barrage in Southern Baghdad Reuters, 29 April 2007. Example of misuse of term barrage. Retrieved on 24 October 2007.
Falls, Cyril (1930). Military Operations Egypt & Palestine from June 1917 to the End of the War. Official History of the Great War Based on Official Documents by Direction of the Historical Section of the Committee of Imperial Defence. Vol. 2 Part II. A. F. Becke (maps). London: HM Stationery Office. OCLC 256950972.

External links: British Artillery in WWII Fire Planning detailed account of barrage techniques on a site devoted to technicalities of British artillery. Retrieved on 19 November 2007.
Historical Artillery and Mortar Tactics an excellent summary of artillery tactics, mainly World War II, including details of the fire pattern sizes used by different guns and units making up the barrage
Artillery Terms and Tactics glossary of Vietnam era US artillery terminology
2nd New Zealand Divisional Artillery: Planning Supercharge detailed account of a barrage plan
New York Times extracts 19 July 1918 reporting Pershing's communique including references to several tactical uses of barrages by US and German forces Retrieved on 6 November 2007