2. The Artillery’s Job
This is the second in a series of four articles on the Australian artillery in World War I. This article covers what the Australian artillery was trying to do on the Western Front and the evolving methods of doing it.
Australian artillery units fought as part of the broader British artillery force on the Western Front from 1916 to 1918. For most of this time the British Army was on the offensive and faced with the problem of how to break through, or at least into, the German defences. Both offensive and defensive artillery tactics evolved in response to each other. Because we're concentrating on the logic of innovation and response here, some things are simplified.
Three aspects of the German defences had to be considered:
1. Barbed wire. Strewn across No Man's Land, barbed wire was cheap and plentiful. It could halt infantry attacks or channel them into killing zones. It had to be cleared.
2. Enemy artillery. This could accurately pour down fire on attacking infantry, causing huge casualties and smashing an attack.
3. Enemy infantry and machine guns. Whether in the front line trenches or sited behind, enemy riflemen and (especially) defensive machine guns could fire enough bullets to stop an attack.
Therefore, for an attack to be successful, the barbed wire had to be cleared using high explosive shells, enemy artillery had to be destroyed or at least prevented from firing (in what was called counter-battery fire), and German trenches and machine gun positions needed to be bombarded to kill the enemy and prevent defensive fire.
These lanes through the barbed wire near Mont St Quentin channelled where attacking troops could go and allowed defensive machine guns to concentrate fire on them.
Clearing barbed wire
Barbed wire was cleared by high explosive shells. In 1915 and 1916, this was a difficult business: poor quality shells failed to go off, while even good shells would often explode only after they had burrowed into the mud. By mid-1917, wire clearing was much more efficient. A new type of impact fuse (the No. 106) and improved quality control in shell manufacture meant many fewer shells were needed to clear a patch of wire. This meant the guns could be switched to other tasks. Tanks were also helpful here because they could crush wire, cross trenches and also provide close fire-support to infantry. They were an alternative to artillery in opening up the battlefield.
To prevent the German artillery from smashing an infantry attack, German batteries (a group of 4-6 guns, the basic small unit of artillery) were targeted either with High Explosives (HE) (to destroy guns and kill gunners) or gas (to injure gunners and overload the casualty evacuation system). Of course, the Germans also engaged in counter-battery fire, meaning Australian gunners were constantly at risk.
Bombardment of enemy infantry
Infantry on both sides lived in trenches and deep dugouts, often lined with wood and concrete. This made them very difficult to reach for howitzers, and practically impossible for field guns like the 18 pounder - even the heaviest bombardments would only kill some of the defenders (even if being under bombardment was a very unpleasant experience). But, for an attack to succeed, it was normally enough to keep the enemy riflemen and machine gunners in their dugouts, to stop them coming out and firing at the attacking infantry. What made this difficult was that machine guns could be effective at quite long range (upwards of 2000m) and those most damaging to an attack were sited on its flanks, able to fire across the zone the infantry would have to cross (which was known as enfilade fire).
The creeping barrage timetable for the Battle of Amiens on 8 August 1918.
The Australian (and wider British) artillery, working together, could create different types of barrage:
1. Creeping barrage. The artillery guns fired on a particular line, starting in front of the enemy trenches, and then jumping forward a certain distance (e.g. 100m every three minutes). The point was to allow friendly infantry to advance immediately behind the barrage while smashing opposition close ahead. Creeping barrages had been in use since 1915 and remained effective to the end of the war, but allowed only a slow, methodical advance and required careful planning and coordination between infantry and artillery.
2. Lifting barrage. This was a variation on a creeping barrage, possible by late 1917 due to improvements in target registration (see below). The barrage started on the enemy trench line rather than before it and then 'lifted' to the next trench line. It allowed the same effect as a creeping barrage but quicker and using fewer shells.
3. Box barrage. Imagine a line of shells falling behind and on both sides of an enemy position. The aim of a box barrage was to stop anyone getting in or out. It was good for preventing reinforcements.
4. Defensive SOS. This was in response to an infantry call, often by a pre-arranged flare. It meant "enemy infantry are attacking and we need artillery support NOW." A defensive barrage fired at a pre-arranged zone in front of friendly lines. The aim was to smash attacks and kill enemy soldiers. Because enemy infantry would be in the open, this might involve a lot of shrapnel shells, often fused for airburst.
5. Hurricane barrage. Often used as the culminating point of a pre-attack bombardment, this was when most friendly guns were firing as quickly as they could onto the enemy front line. A German officer described how to recreate the sound of a friendly hurricane barrage: "Put your hands over your ears and then drum your fingers vigorously on the back of your head".[^1]
Australian infantry following close behind a creeping barrage at Polygon Wood, 20 September 1917.
[^1]: Quoted in Strong and Marble, Artillery in the Great War, p. 170.