Sapping
Sapping is a term used in siege operations to describe the digging of a covered trench (a "sap"[1]) to approach a besieged place without danger from the enemy's fire.[2] The purpose of the sap is usually to advance a besieging army's position towards an attacked fortification. It is excavated by specialised military units, whose members are often called sappers.
By using the sap, the besiegers could move closer to the walls of a fortress, without exposing the sappers to direct fire from the defending force. To protect the sappers, trenches were usually dug at an angle in zig-zag pattern (to protect against
Once the saps were close enough, siege engines or
Before the development of explosives, sapping was the undermining of an enemy's fortifications, which would collapse when the sap's supports were removed.[2] Later, explosives were placed surreptitiously in the undermining sap or mine, then detonated, as was done with 450 tons of high explosive in the First World War battle of Messines, the largest planned explosion until the 1945 Trinity atomic bomb test.
History
Pre-gunpowder
A way to force entry into a fortified structure was to dig a mine or sap under defensive walls, typically shored up by wooden props. On collapsing the tunnel, for example by burning the props, the wall would collapse.[3]
1500s
Sapping trenches, cannons and gunpowder explosives were a potent force against fortifications. However, the
Trace Italienne forts
Sapping became necessary as a response to the development and spread of trace Italienne in defensive architecture in the 1500s. The Italian style star fort bastion made siege warfare and sapping the modus operandi of military operations in the late medieval and first decades of the early modern period of warfare.
1600s
During the English Civil War, there was a siege of
American Civil War
In the American Civil War, troops advanced their sap under cover of a sap roller[7] or mantlet[8] by forming a parapet on the engaged side of the trench one gabion at a time and filling it with earth taken from the trench.
First World War
During First World War trench warfare, the combatant's sappers, who were often experienced civilian miners who had been rejected for combat duties due to age or ill-health, strived to undermine each other's positions, working silently to avoid detection. After completing a mine it was filled with explosives, sometimes hundreds of tons, and detonated, followed by an attack on the surprised survivors from the destroyed position.[9]
Russian sap
A Russian sap is a tunnel dug at a shallow depth under
See also
- Mining (military)
References
- Notes
- ^ "sap". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.) (noun)
- ^ a b "sap". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.) (verb)
- ^ "Ironclad: The siege of Rochester (1215)". BBC. 29 October 2009.
- ^ (in German) Ernst Weyden. Godesberg, das Siebengebirge, und ihre Umgebung. Bonn: T. Habicht Verlag, 1864, p. 43.
- ^ Charles Townshend (editor). The Oxford history of modern war. Oxford: Oxford University Press. 2000, p. 28.
- ^ Townshend, pp. 28-29. ("Such projections from the wall both forced the hostile cannon to fire from longer range and enabled the defenders to enfilade attackers.")
- ^ http://civilwarfortifications.com/dictionary/xgs-003.html
- ^ http://civilwarfortifications.com/dictionary/xgm-003.html
- ^ "Was the tunnellers' secret war the most barbaric of WW1?". BBC. Retrieved 22 April 2019.
- Bibliography
- Campell, E.S.N (1844). A Dictionary Of The Military Science:Containing an Explanation Of The Principal Terms Used In Mathematics, Artillery, and Fortification, And Comprising The Substance Of The Latest Regulations On Courts Martial, Pay, Pension, Allowances, Etc. A Comparative Table Of Ancient And Modern Geography; Achievements Of The British Army; With An Address to Gentlemen Entering The Army (New ed.). London: James Maynard. Retrieved 2007-11-19.
- Charles, Townshend, ed. (2000). The Oxford history of modern war (PDF). Oxford: Oxford University Press.
- Weyden, Ernst (1864). Godesberg, das Siebengebirge, und ihre Umgebung (in German). Bonn: T. Habicht Verlag.