The Western Front of WWI is infamous for trench warfare, the long and grueling battles fought from dug positions separated by no man’s land. But a lesser-known type of battle also raged underground as Allied and German forces dug vast networks of secret tunnels in order to plant explosive mines under the enemy’s feet.
The Battle of Messines in July 1917 witnessed what was arguably the biggest explosion of the pre-atomic era, when 19 underground mines filled with around 1 million pounds of high explosives erupted beneath the German line. , killing countless soldiers and shattering German morale even before the real fighting began.
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Messines Ridge: Critical capture for the allies
The Battle of Messines was one of dozens of clashes between German and Allied forces in the area surrounding the Belgian city of Ypres starting in 1914. The Germans quickly gained the advantage by occupying a ridge line at east of Ypres, an elevated position that offered clear views of enemy troop movements and sharp fire from German artillery bunkers.
By 1917, the Allies had ambitious plans to break the costly deadlock at Ypres. The first and most important part of this plan was to take part of the German-held ridge line near the town of Messines. After that, the Allied forces hoped to push to the North Sea coast and destroy the German submarine bases.
Two years of tunneling
Sappers and miners tunneling under Hill 60, a strategically important high point on the southern edge of the Ypres Salient which had been captured by the Germans in 1914.
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As early as 1915, long before the Battle of Messines was planned, tunneling operations were underway under the Messines ridge. Allied forces, made up of British, Canadian, Australian and New Zealand divisions, included “tunnel companies” staffed with soldiers recruited for their excavation skills.
“Most of the tunnel boring machines were very experienced coal or gold miners at digging,” says Ian McGibbon, former editor-in-chief at the New Zealand Ministry of Culture and Heritage and co-editor of The Great New Zealand War: New Zealand, the Allies and the First World War. “The the idea was to go under your opponent’s lines and detonate the mines. It was a very nerve-racking experience, especially when you got close to their lines and knew the enemy could detonate a mine near your shaft to destroy it.
In Messines, the Allies first dug shafts closer to the surface to distract from the deeper shafts that actually contained the mines. The German tunnel boring machines took the bait and detonated charges to collapse the decoy tunnels, mistakenly believing they had defused the threat from below.
In fact, British, Canadian and Australian tunnel boring companies had succeeded in digging and arming 22 separate mine shafts beneath Messines Ridge, each containing tens of thousands of pounds of ammonium, a highly explosive combination of Nitrate. ammonium and aluminum powder.
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Blow up the ridge of Messines
British sappers digging a communication trench towards the Messines ridge in a landscape showing the scars of the battle, May 7, 1917.
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The Battle of Messines began at 3:10 a.m. on July 7, 1917, when 19 of 22 Allied mines exploded below Messines Ridge. It is impossible to know how many German soldiers were instantly killed in the mushroom cloud of earth and fire that erupted 80 feet below. The commonly cited figure is 10,000 deaths from the blast alone, but McGibbon believes that number represents the total German death toll for the entire three-day battle.
A British artillery officer, Ralph Hamilton, witnessed the explosion and compared it to the infamous gruesome Battle of the Somme.
“First, there was a double shock that shook the earth here at 15,000 meters like a gigantic earthquake,” Hamilton wrote. “I was almost thrown off my feet. Then a huge wall of fire that seemed to rise halfway to the sky. The whole country was illuminated with a red light as in a photographic darkroom. At the same time, all the cannons spoke and the battle began on this part of the line. The noise even exceeds the Somme; it is formidable, magnificent, overwhelming.
The first London newspaper articles claimed that the Prime Minister himself had been awakened by the thunderous roar of mines exploding in Messines, 140 miles from 10 Downing Street. The more likely truth was that the Prime Minister and others across the Channel heard the roar of Allied heavy artillery, which followed the shattering explosion with a synchronized barrage of 2,000 guns.
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A “ creeping dam ” ravages the Germans in Messines
Belgian King Albert I greets General Plummer after the Battle of Messines, 1917.
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The mastermind behind the Battle of Messines was Field Marshal Herbert Plumer, the British officer in charge of the Second Army at Ypres. McGibbon calls Plumer “fussy” for the way he carefully planned, trained and executed the Messines artillery attack.
By 1917, Allied engineers had dramatically improved the science of sound ranging, which used an array of battlefield microphones to calculate the precise location of enemy artillery guns. Armed with this technology, Plumer spent the weeks leading up to the attack precisely bombarding German bunkers and pillboxes to pave the way for a charge through no man’s land.
But Plumer showed his true genius right after the massive explosion that started the attack. The roar of 2,000 heavy artillery guns heard in London was the first salvo of what is called a “creeping barrage”. The courageous technique, developed at the Somme but perfected at Messines, consisted in making the artillery rain directly in front of a line of infantry in charge.
“As the troops advance, a curtain of fire descends 50 yards in front of them,” said McGibbon. “It must have been a frightening experience for the Germans, seeing it coming towards them.
For the already shaken German soldiers who survived the apocalyptic explosion, the thunderous load of the creeping barrage was too much to bear. The Allies crossed no man’s land with few casualties and easily captured Messines Ridge. Over the next two days, the Germans staged a fierce counterattack that claimed thousands of Allied lives, especially among the New Zealand division stationed in Messines, but they bravely held the ridge.
The Battle of Messines is widely regarded as one of the greatest Allied victories of WWI.
