Gigantic explosions of the First World War

War History Online has an article by Sarah Cooper about some big explosions:

One of the common techniques used in warfare during the First World War was mining. There were various mines planted under trenches, then detonated to send part of the trench, and anyone in it, sky high. Some of these detonations were felt as far away as Switzerland. Lochnagar Crater (photo, below, taken today) in the Picardie area of France is the most recognizable example of this method.

Mines at the Somme
The Lochnagar mine was dug by the Tunnelling Companies of the Royal Engineers and was detonated at 0728 on 1 July 1916. It was just one of eight large and eleven small charges that were placed underneath German lines for the first day of the Somme. Both Lochnagar and the nearby Y Sap mines were purposely overcharged in order to leave big craters with wide rims in the ground. After the detonation, the main attack began. The crater was occupied by Allied troops as they began to fortify the eastern lip. The advance continued until the German Fourth Company counter-attacked, and the British soldiers had to retreat into the crater.

As the day progressed and artillery was fired into Sausage Valley, the Germans used machine-gun fire to shoot any British soldier who moved. They also started systematically shelling areas nearby, and wounded and lost men sought shelter and refuge within the crater, until the German forces began to bomb that as well. The British artillery then also opened fire on the crater, leaving the men stuck inside with nowhere to hide.
The mines in the Somme were detonated as part of a failed attack on the Hawthorn Ridge Redoubt, a German fortification west of the village Beaumont-Hamel. The mine was blown up ten minutes before the start of the general attack, but was not considered to be the main cause of the German’s lack of surprise. The imminence of the expected attack was made evident by the springing of the mine and, despite surface destruction to the trenches, the lifting of the heavy artillery bombardment made it safe for the German soldiers to come out and occupy the front line defenses.
Another mine with thirty thousand pounds of explosives, was laid beneath Hawthorn Ridge for the next attack, which wasn’t until 13 November 1916.
The remains of British soldier George Nugent, of the Tyneside Scottish Northumberland Fusiliers, were found at Lochnagar Crater in October of 1998. He was later reburied with military honors in Ovillers Military Cemetary in 2000, 84 years after he died in battle, and a memorial cross now sits at the mine site where his body was found.
The site at Lochnagar Crater attracts more than two hundred thousand visitors every year and an annual memorial service is held on 1 July to commemorate the detonation of the mine, while poppy petals are scattered into the crater to honor the Allied and German dead.
The tunnelers, when creating the mines, dug up to a hundred feet below the ground, and had to work in complete silence in order to avoid arousing suspicion. They were also tasked with searching for, and stopping any German tunnelers who were doing the same job but tunneling in the opposite direction. When they were confronted with German miner’s, underground hand-to-hand combat would ensue until there was a winner.
In Belgium, near the most active minefield of World War One, there still lies an unexploded 50,000lb bomb sitting under a farm on the Messines Ridge near Ypres.
The mine is eighty feet under a barn, and was located by British researchers using wartime maps.
It was one of many that were set by British miners along the Ypres Salient towards the German trenches on the Messines Ridge. The plan was to plant 25 gigantic mines under the German lines and blow them as part of a major offensive planned for the summer of 1916, but it was postponed until 1917. Work on the mines began eighteen months before the offensive actually began and eight thousand meters of tunnel were constructed.
On 7 June 1917, nineteen of the mines were detonated within half a minute. When the explosions took place, more than a million pounds of explosives were backed into the underground chambers along seven miles dug by the miners in an attack that killed six thousand German troops. The bang was heard as far away as Downing Street in London, England, buildings within a thirty-mile radius shook, and even seismographs in Switzerland were able to register a small earthquake. General Sir Herbert Plumer’s Second Army took the ridge and the Battle of Messines was considered the most successful local operation of World War One, after all initial objectives were taken within just three hours.
However six mines were not used, and one twenty-thousand-pound mine called Peckham ended up being abandoned due to a tunnel collapse before the operation began; four on the southern edge ended up not being necessary. The sixth was planted under a ruined farm called La Petite Douve, but was discovered by German forces in a counter-mining attack on 24 August 1916, so it was never used. One of the four unused mines exploded after nearly forty years, in 1955, believed to be triggered by a lightening strike.
After the war La Petite Douve was rebuilt and later renamed. The mine sat almost forgotten for years. Farmer Roger Mahieu told The Telegraph in 2004, “It doesn’t stop me sleeping at night. It’s been there all that time, why should it decide to blow up now?”
The unused Peckham mine is also located underneath a farmhouse on the Messines ridge, still ticking….

Rico says they all pale in comparison to the atomic bomb, unless you were there...