Preparation
The Battle of Messines was a week-long relatively small British offensive on German lines in Belgium. It is interesting mainly because of what came before and after it.
In Spring 1915, the British began mining underground, with the intention of planting charges underneath the German-held Hill 60. In April, the British had dug 100 metres underground and had placed over 3000 pounds of explosive charges beneath the Germans. When the charges were blown at 7pm on 17th April, the British took the hill with only 7 casualties, with some apparently being caused by debris falling as a result of the British explosives. Further German counter attacks over the next 2-3 weeks would result in many British casualties. Waiting for the correct conditions, the Germans eventually recaptured the hill utilising gas attacks along the British line.
In September the Engineer-in-Chief of the BEF, Brigadier George Fowke, proposed the initial plan for the Battle of Messines. After several smaller offensives in the area, he suggested that a large attack across the entire front, using the explosives technique that was attempted in the Battle of Hill 60, would be enough to push the Germans back. Mining began in several different key positions, and eventually resulted in one of the most fascinating kinds of warfare (in my opinion) that has ever occurred.
The Germans became aware of British mining, and destroyed some of the tunnels. As a result of this, the British began to build shallower tunnels and intentionally drawing the Germans into the tunnels, to distract them from the real tunnels that were being dug underneath - tunnels which would eventually be used to place mines underneath the Germans. The Germans were also digging their own underground trenches, resulting in many encounters of close underground combat. Raid missions conducted by the Germans resulted in several of the British tunnels being blown up. Casualties occurred not only as a direct result of the explosions, but due to the poisonous fumes released by the explosives in a contained area. Colonel Füßlein seemed satisfied that the German army had foiled British plans:
"A subterranean attack by mine-explosions on a large scale beneath the front line to precede an infantry assault against the Messines Ridge is no longer possible."
The Battle
Artillery barrages at the beginning of WW1 were not that accurate. The main objective of an artillery barrage at the start of the war was to demoralise the enemy. I can not source this, but I remember reading a German account of being bombarded by French artillery in 1915. The Germans laughed as the vast majority of shells landed nowhere near their trenches. A week later, when the shells still hadn't stopped falling, nobody was laughing anymore.
By 1917, the British had perfected the art of shelling Germans. The use of field survey, gun calibration, weather data and a new and highly accurate 1:10,000 scale map, gave British artillery much improved accuracy. Target-finding became systematic, with the use of new sound-ranging equipment, better organisation of flash-spotting and the communication of results through the Army Report Centre at Locre Château. Second Army counter-battery artillery bombardments increased from twelve in the week ending 19 April, to 438 in the last ten days before the Battle of Messines began. After the battle, a survey of captured land found that 90 percent of the German artillery positions had been plotted. In some cases, false trees were constructed as lookout posts to plot enemy positions.
Starting from 3.10 a.m. on 7th June 1917, the mines at Messines were fired within the space of 20 seconds. The joint explosion ranks among the largest non-nuclear explosions of all time and surpassed the mines on the first day of the Somme fired 11 months before. The sound of the blast was considered the loudest man-made noise in history. Reports suggested that the sound was heard in London and Dublin, and at Lille University's geology department, the shock wave was mistaken for an earthquake. Some eyewitnesses described the scene as "pillars of fire", although many also conceded that the scene was indescribable.
The following is an account from Sir Philip Gibbs, a British war journalist:
"Suddenly at dawn, as a signal for all of our guns to open fire, there rose out of the dark ridge of Messines and "Whitesheet" and that ill-famed Hill 60, enormous volumes of scarlet flame ... throwing up high towers of earth and smoke all lighted by the flame, spilling over into fountains of fierce colour, so that many of our soldiers waiting for the assault were thrown to the ground. The German troops were stunned, dazed and horror-stricken if they were not killed outright. Many of them lay dead in the great craters opened by the mines."
The fact that the detonations were not simultaneous enhanced their effect on the German troops. Strange acoustic effects also added to the panic – German troops on Hill 60 thought that the Kruisstraat and Spanbroekmolen mines were under Messines village, which was located well behind their front line, while some British troops thought that they were German counter-mines going off under the British support trenches. The combined explosion is considered to have killed more people than any other non-nuclear man-made explosion in history; it killed approximately 10,000 German soldiers between Ypres and Ploegsteert.
Some of the craters are still visible today. The Battle of Messines was the prelude to the Battle of Passchendaele. Of the 4 million participants, between 400,000-850,000 died.
Damn. I can't even imagine.