Military mining, undermining or tunnel warfare is a siege method based on mining techniques which has been used since antiquity against a walled city, fortress, castle or other strongly held and fortified military position. A counter mine is a mine dug to allow defenders to attack miners, or destroy a mine threatening their fortifications.
The Aetolians [...] offered a gallant resistance to the assault of the siege artillery and [the Romans], therefore, in despair had recourse to mines and underground tunnels. Having safely secured the central one of their three works, and carefully concealed the shaft with wattle screens, they erected in front of it a covered walk or stoa about two hundred feet long, parallel with the wall; and beginning digging from that, they carried it on unceasingly day and night, working in relays. For a considerable number of days the besieged did not discover them carrying the earth away through the shaft; but when the heap of earth thus brought out became too high to be concealed from those inside the city, the commanders of the besieged garrison set to work vigorously digging a trench inside, parallel to the wall and to the stoa which faced the towers. When the trench was made to the required depth, they next placed in a row along the side of the trench nearest the wall a number of brazen vessels made very thin; and, as they walked along the bottom of the trench past these, they listened for the noise of the digging outside. Having marked the spot indicated by any of these brazen vessels, which were extraordinarily sensitive and vibrated to the sound outside, they began digging from within, at right angles to the trench, another underground tunnel leading under the wall, so calculated as to exactly hit the enemy's tunnel. This was soon accomplished, for the Romans had not only brought their mine up to the wall, but had under-pinned a considerable length of it on either side of their mine; and thus the two parties found themselves face to face.
Another extraordinary usage of siege-mining in the ancient Greece, where during Philip V of Macedon's siege of the little town of Prinassos, according to Polybius, "the ground around the town were extremely rocky and hard, making any siege-mining virtually impossible. However, Philip ordered his soldiers during the cover of night collect earth from elsewhere and throw it all down at the fake tunnel's entrance, making it look like the Macedonians were almost finished completing the tunnels. Eventually, when Philip V announced that large parts of the town-walls were undermined, the citizens surrendered without delay."
Mining was a siege method used in ancient China from at least the Warring States (481–221 BC) period forward. When enemies attempted to dig tunnels under walls for mining or entry into the city, the defenders used large bellows (the type the Chinese commonly used in heating up the blast furnace for smelting cast iron) to pump smoke into the tunnels in order to suffocate the intruders.
In warfare during the Middle Ages, a "mine" was a tunnel dug to bring down castles and other fortifications. Attackers used this technique when the fortification was not built on solid rock, developing it as a response to stone-built castles that could not be burned like earlier-style wooden forts. A tunnel would be excavated under the outer defenses either to provide access into the fortification or to collapse the walls. These tunnels would normally be supported by temporary wooden props as the digging progressed. Once the excavation was complete, the attackers would collapse the wall or tower being undermined by filling the excavation with combustible material that, when lit, would burn away the props leaving the structure above unsupported and thus liable to collapse. Later, explosives like gunpowder were used for even greater effect.
A tactic related to mining is sapping the wall, where engineers would dig at the base of a wall with crowbars and picks. Peter of les Vaux-de-Cernay recounts how at the battle of Carcassonne, during the Albigensian Crusade, "after the top of the wall had been somewhat weakened by bombardment from petraries, our engineers succeeded with great difficulty in bringing a four-wheeled wagon, covered in oxhides, close to the wall, from which they set to work to sap the wall"
As in the siege of Carcassonne, defenders worked to prevent sapping by dumping anything they had down on attackers who tried to dig under the wall. Successful sapping usually ended the battle, since the defenders would no longer be able to defend their position and would surrender, or the attackers could enter the fortification and engage the defenders in close combat.
Several methods resisted or countered undermining. Often the siting of a castle could make mining difficult. The walls of a castle could be constructed either on solid rock or on sandy or water-logged land, making it difficult to dig mines. A very deep ditch or moat could be constructed in front of the walls, as was done at Pembroke Castle, or even artificial lakes, as was done at Kenilworth Castle. This makes it more difficult to dig a mine, and even if a breach is made, the ditch or moat makes exploiting the breach difficult.
Defenders could also dig counter mines. From these they could then dig into the attackers' tunnels and sortie into them to either kill the miners or to set fire to the pit-props to collapse the attackers' tunnel. Alternatively they could under-mine the attackers' tunnels and create a camouflet to collapse the attackers' tunnels. Finally if the walls were breached, they could either place obstacles in the breach, for example a cheval de frise to hinder a forlorn hope, or construct a coupure. The great concentric ringed fortresses, like Beaumaris Castle on Anglesey, were designed so that the inner walls were ready-built coupures: if an attacker succeeded in breaching the outer walls, he would enter a killing field between the lower outer walls and the higher inner walls.
American Civil War
During the Siege of Vicksburg, in 1863, Union troops led by General Ulysses S. Grant tunnelled under the Confederate trenches and detonated a mine beneath the 3rd Louisiana Redan on June 25, 1863. The subsequent assault, led by General John A. Logan, gained a foothold in the Confederate trenches where the crater was formed, but the attackers were eventually forced to withdraw.
A more famous instance occurred during the Siege of Petersburg: Union troops dug a tunnel under the Confederate lines at Elliott's Salient and packed its end with vast amounts of gunpowder. When set off, the resulting explosion killed about 300 soldiers. It might have been decisive if not for the faulty Union tactic of storming into, rather than around, the resulting crater, allowing the defenders to shoot down onto attackers unable to climb the steep crater sides. The combat was accordingly known as the Battle of the Crater. The horror of this engagement was portrayed in the Charles Frazier novel, and subsequent Anthony Minghella movie, Cold Mountain.
World War I
Mining saw a brief resurgence as a military tactic during the First World War, when army engineers attempted to break the stalemate of trench warfare by tunneling under no man's land and laying large quantities of explosives beneath the enemy's trenches. As in siege warfare, mining was possible due to the static nature of the fighting.
During the height of the underground war on the Western Front in June 1916, British tunnellers fired 101 mines or camouflets, while German tunnellers fired 126 mines or camouflets. This amounts to a total of 227 mine explosions in one month - one detonation every three hours. Large battles, like the Battle of the Somme in 1916 (see mines on the Somme) and the Battle of Vimy Ridge in 1917, were also supported by mine explosions.
Significant mining operations were also carried out by Austro-Hungarian and Italian units on the Italian Front. Their efforts in high mountain peaks such as Col di Lana, Lagazuoi and Marmolata were portrayed in fiction in Luis Trenker's Mountains on Fire film of 1931.
Another notable example of military mining was the Battle of Messines in 1917, when a series of mines was detonated beneath German lines after about two years of sapping. The near simultaneous explosion of the Messines mines with a combined amount of 450 tonnes of high explosive created 19 large craters and ranks among the largest non-nuclear explosions of all time. Approximately 10,000 German troops were killed. Not all of the mines laid by the British Army at Messines were detonated, however. Two mines were not ignited in 1917 because they had been abandoned before the battle, and four were outside the area of the offensive. On 17 July 1955, a lightning strike set off one of these four latter mines. There were no human casualties, but one cow was killed. Another of the unused mines is believed to have been found in a location beneath a farmhouse, but no attempt has been made to remove it. The last mine fired by the British in World War I was near Givenchy on 10 August 1917, after which the tunnelling companies of the Royal Engineers concentrated on constructing deep dugouts for troop accommodation.
|Belgium||West Flanders||Ypres: Hooge||area of sustained fighting between British and German tunneling units 1915-1917; see Hooge in World War I|
|Belgium||West Flanders||Ypres: Hill 60||area of sustained fighting between British and German tunneling units 1915-1917; also see Mines in the Battle of Messines (1917)|
|Belgium||West Flanders||Ypres: St Eloi||area of sustained fighting between British and German tunneling units 1915-1917; also see The Bluff and Mines in the Battle of Messines (1917)|
|Belgium||West Flanders||Heuvelland: Wytschaete||fighting between British and German tunneling units, mainly in connection with the Mines in the Battle of Messines (1917)|
|Belgium||West Flanders||Messines Ridge||area of sustained fighting between British and German tunneling units, also see Mines in the Battle of Messines (1917)|
|France||Nord||Armentières||area of sustained fighting between British and German tunneling units|
|France||Nord||Aubers Ridge||fighting between British and German tunneling units, mainly in connection with the Battle of Aubers Ridge|
|France||Pas-de-Calais||Givenchy-lès-la-Bassée||area of sustained fighting between British and German tunneling units, area where William Hackett VC was killed|
|France||Pas-de-Calais||Cuinchy||fighting between British and German tunneling units|
|France||Pas-de-Calais||Loos-en-Gohelle||area of sustained fighting between British and German tunneling units|
|France||Pas-de-Calais||Givenchy-en-Gohelle||area of sustained fighting between British and German tunneling units, also in connection with the Battle of Vimy Ridge (1917)|
|France||Pas-de-Calais||Vimy Ridge||Between October 1915 and April 1917 an estimated 150 French, British and German charges were fired in this 7 kilometres (4.3 mi) sector of the Western Front. British tunnellers took over progressively from the French between February and May 1916. After September 1916, when the Royal Engineers had constructed defensive galleries along most of the front line, offensive mining largely ceased although activities continued through the Battle of Vimy Ridge (1917). The British gallery network beneath Vimy Ridge grew to a length of 12 kilometres (7.5 mi). Before the Battle of Vimy Ridge, the British tunnelling companies secretly laid a series of explosive charges under German positions in an effort to destroy surface fortifications before the assault. The original plan had called for 17 mines and 9 Wombat charges to support the infantry attack, of which 13 (possibly 14) mines and 8 Wombat charges were eventually laid.|
|France||Pas-de-Calais||Arras||fighting between British and German tunneling units, mainly in connection with the Battle of Arras (1917); also see Carrière Wellington|
|France||Somme||Beaumont-Hamel: Hawthorn Ridge||fighting between British and German tunneling units, mainly in connection with the Battle of the Somme (1916); for details, see Mines on the first day of the Somme|
|France||Somme||La Boisselle||area of sustained fighting between British and German tunneling units, major sites of underground warfare were Schwabenhöhe/Lochnagar, the Y Sap mine and the L'îlot/Granathof/Glory Hole site; for details, see Mines on the first day of the Somme|
|France||Somme||Fricourt||fighting between British and German tunneling units, mainly in connection with the Battle of the Somme (1916); for details, see Mines on the first day of the Somme|
|France||Somme||Mametz||fighting between British and German tunneling units, mainly in connection with the Battle of the Somme (1916); for details, see Mines on the first day of the Somme|
|France||Somme||Dompierre||fighting between French and German tunneling units|
|France||Oise||Tracy-le-Val: Bois St Mard||fighting between French and German tunneling units|
|France||Aisne||Berry-au-Bac||fighting between French and German tunneling units|
|France||Marne||Perthes-lès-Hurlus||fighting between French and German tunneling units|
|France||Marne||Aubérive: Butte de Tahure||fighting between British and German tunneling units, mainly in connection with the Battle of the Hills (1917)|
|France||Marne||Massiges: Main de Massiges||fighting between French and German tunneling units|
|France||Meuse||Forest of Argonne: La Fille Morte||fighting between French and German tunneling units|
|France||Meuse||Forest of Argonne: Bolante||fighting between French and German tunneling units|
|France||Meuse||Vauquois: Butte de Vauquois||area of sustained fighting, also in connection with the Battle of Verdun (1916). From 1915 to 1918, French and German tunneling units fired 519 separate mines at Vauquois, and the German gallery network beneath the hill grew to a length of 17 kilometres (11 mi).|
|France||Meuse||Vaux-lès-Palameix: Bois des Chevaliers||fighting between French and German tunneling units|
|France||Meurthe-et-Moselle||Reillon||fighting between French and German tunneling units|
|France||Haut-Rhin||Bernwiller: Ammerzwiller||fighting between French and German tunneling units|
Post-World War II
Because troop movements in World War II were too fluid, and tunneling too slow, mining warfare was of little use during that conflict.
During the Syrian civil war, rebel groups like the Islamic Front have dug tunnels and used explosives to attack fixed military positions of the Syrian Armed Forces and allied militias. A notable example is the attack on the Air Force Intelligence Building in Aleppo where on 4 March 2015, rebel forces detonated a large quantity of explosives in a tunnel dug close to or under the building. The building suffered a partial collapse as a result of the explosion which was immediately followed by an armed rebel assault.
- Polybius. Histories. 21.28
- Polybius. Histories. 16.11
- Ebrey, 29.
- les Vaux-de-Cernay, 53.
- online, access date 2016-08-03
- Tweedie, N. (2004-01-12). "Farmer who is sitting on a bomb". The Daily Telegraph. Retrieved 2010-05-17.
- The Battle of Messines, 1917
- http://www.1914-1918.net/tunnelcoyre.htm accessed 24 April 2015
- The Durand Group: Vimy Ridge online, access date 2016-08-03
- Boire (1992) pp. 22–23
- Hwaida Saad and Alan Cowell (8 May 2014). "Explosion Levels Hotel Housing Government Troops in Syria". New York Times. Retrieved 9 May 2014.
- "Islamic Front kills scores in bombing of Aleppo hotel". Long War Journal. 8 May 2014. Retrieved 9 May 2014.
- Ebrey, Walthall, Palais (2006). East Asia: A Cultural, Social, and Political History. Boston: Houghton Mifflin Company.
- Ernst, O.H. (1873). A Manual Of Practical Military Engineering, Prepared For The Use Of The Cadets Of The U. S. Military Academy, And For Engineer Troops. New York: D. Van Nostrand. Retrieved 2007-11-19.
- Jones, Simon (2010). Underground Warfare 1914-1918. Pen & Sword Military. ISBN 978-1-84415-962-8.
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