Barrage (artillery)
However, the tactic was further refined as the Battle of the Somme wore on and by September 1916 the creeping barrage became a standard tactic for infantry attacks, and soon spread to the French Army, enabling the French recapture of Fort Vaux at the Battle of Verdun in November 1916. By the later stages of the Battle of the Somme, the British had improved the accuracy of and confidence in their artillery fire and had learned the lessons of keeping infantry close to the barrage: the British Expeditionary Force (BEF) circulated an aerial observer's report commending a "most perfect wall of fire" followed up within 50 yards (46 m) by the infantry of 50th (Northumbrian) Division, enabling them to take a village with little opposition. A report said "Experience has shown that it is far better to risk a few casualties from an occasional short round from our own artillery than to suffer the many casualties which occur when the bombardment is not closely followed up". A creeping barrage was essential to the success of the Canadian Expeditionary Force in the capture of Vimy Ridge in April, 1917. The creeping barrage was used during the action of Tell 'Asur on 12 March 1918 in the Sinai and Palestine Campaign. Six months later, it was used with devastating effect during the Battle of Megiddo (1918) when 18-pdr and Royal Horse Artillery formed a creeping barrage which fired in front of the advancing infantry up to their extreme range while 4.5-inch howitzers fired beyond the barrage, while heavy artillery were employed in counter battery work. The creeping barrage moved at a rate of between 50 yards (46 m), 75 yards (69 m) and 100 yards (91 m) per minute.

At first, British creeping barrages consisted only of shrapnel shells but an equal mix of HE was soon added, in some cases later supplemented by smoke shells. The creeping barrage would advance at a rate of 100 yards every one to six minutes, depending on terrain and conditions; although six minutes was found to be too slow. By the Battle of Arras in 1917, the creeping barrage was huge and complex, with five or six lines of fire covering a depth of 2,000 yards (1,800 m) ahead of the infantry.
Back barrages were fired, in which rearmost lines of the barrage reversed direction, and machine gun barrages were introduced. False barrages attempted to deceive the enemy about Allied intentions or to force him to reveal his positions. The creeping barrage was used to great effect in the Canadian success at the Battle of Vimy Ridge where the men had been extensively trained to move forward in the 'Vimy Glide' - a 100-yard per three minute pace which kept the infantry directly behind the barrage. The opening attack of the Battle of Passchendaele was covered by a barrage of shrapnel and HE on a colossal scale, fired by over 3,000 British guns and howitzers: one 18-pounder for every 15 yards (14 m) of front, and a heavy howitzer for every 50 yards (46 m), with yet more guns in the French sector. The British barrage advanced 100 yards (91 m) every four minutes, with the infantry following as close as 50 yards (46 m) from the bursting shells. One battery's programme required 45 lifts. As each objective was reached, the barrage settled 500 yards (460 m) beyond the new position, combing back and forth to disrupt expected German counter-attacks, while some of the artillery moved forward to support the next phase of the advance.
On the Eastern Front, German Colonel Georg Bruchmüller developed a form of double creeping barrage, with the first line of the barrage consisting of gas shells. His ideas were applied on the Western Front in the German spring offensive of 1918.
The day of the lengthy large-scale preliminary barrage had largely passed by the end of World War I, at least in Western nations, with the realisation that best results were achieved by neutralising the enemy rather than attempting his physical destruction, and that short, concentrated bombardments, including creeping barrages, were more effective in neutralising the enemy than extended bombardment. Once open warfare returned after the breaking of the Hindenburg Line in September 1918 the British fired far fewer creeping barrages, using more lifts and concentrations instead.
Attacks by tanks do not need the same form of artillery support, and the single barrage along the entire front of the advance had even been abandoned by the battle of Cambrai in 1917. More sophisticated fire control enabled infantry to call down artillery fire in direct support, or targeting of identified enemy positions. Nevertheless, barrages remained in use. On 31 August 1918 the attack of the U.S. 32nd Division was preceded by a walking barrage. After first passing over the German line, the barrage returned twice more, attempting to catch the defenders returning to their firing positions from their dugouts, or to keep them underground when the real assault went in.

Use in World War II: The barrage remained in use in World War II, but was no longer the dominant artillery plan. In the absence of the huge set-piece infantry assaults of World War I, barrages were on a smaller scale. For the opening of the second Battle of El Alamein, for example, a barrage was considered by British Lieutenant-General Bernard Montgomery's planners, but rejected in favour of fierce concentrations on known or suspected targets in turn. Along a 12,000-yard (11,000 m) front, 456 guns were considered insufficient for a true creeping barrage (at Neuve Chapelle there had been one gun for every four yards of front). But creeping and rolling barrages were used in some divisional sectors and in later phases of the Alamein battle. For Operation Supercharge on 1–2 November 1942, the attack in the 2nd New Zealand Division sector was preceded by a creeping barrage of 192 guns along a 4,000-yard (3,700 m) front, firing on three lines. There was almost one 25-pounder for every 20 yards of front, plus two medium regiments thickening the barrage.

By the fighting in Tunisia, more guns were available and the defenders were more concentrated than in the Western Desert. The artillery plan for the British attack at Wadi Akarit in April 1943 involved eight barrages in three phases ahead of the advances of 50th (Northumbrian) and 51st (Highland) Infantry Divisions. They included a standing barrage to mark the start line in the dark and enable the infantry to form up in the right alignment; a barrage that wheeled left during the advance; and an on-call creeping barrage. Nevertheless, attacks rarely relied solely on a barrage for artillery support: at Wadi Akarit pre-arranged concentrations on likely targets were called down by observers in the course of the assault.
Nevertheless, it remained in use in the Italian Campaign. In the assault on the Hitler Line during the Battle of Monte Cassino on 23 May 1944, 810 guns were amassed for the attack of I Canadian Corps. Three hundred of them fired on the first line of a 3,200-yard (2,900 m) wide barrage, beginning three minutes before the infantry moved off and lifting at a rate of 100 yards in five minutes. It was due to pause for an hour at the first objective, then lift at 100 yards per three minutes to the further objectives, but the timing was disrupted by heavy resistance and defensive artillery fire. The operation was later criticised for concentrating on too narrow a front, constrained by the need for enough guns to produce a dense barrage.
In the assault crossing of the Senio during the final offensive in Italy in 1945, dummy barrages were used to confuse the enemy, either misleading them as to the line of attack or drawing them out of shelters as the barrage passed, expecting an infantry assault, only to catch them with a renewed barrage or air attacks. On Monte Sole, U.S. artillery fired probably its heaviest barrage of the war, 75,000 shells in a half-hour to clear the advance of the South Africans.
During the Battle of Normandy, a creeping barrage fired from 344 guns preceded the opening attacks of 15th (Scottish) Infantry Division in Operation Epsom on 26 June 1944.
For the opening of Operation Veritable, the push to the Rhine, the fire of 1,050 field and heavy guns was supplemented by 850 barrels of pepper-pot barrage: other weapons – mortars, machine guns, tanks, anti-tank guns, anti-aircraft guns and rockets – supplementing the field guns. 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.