Sapping is a term used in siege operations to describe the digging of a covered trench to approach a besieged place without danger from the enemy's fire. 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.
Union troops of the 1st New York Engineers digging a sap with a sap roller on Morris Island, 1863
The star-shaped Fort Bourtange, restored to its 1750 condition, is an example of a trace italienne fort.
A sapper, also called a combat engineer, is a combatant or soldier who performs a variety of military engineering duties, such as breaching fortifications, demolitions, bridge-building, laying or clearing minefields, preparing field defenses, and road and airfield construction and repair.
Modern sapper equipment
Soldiers of No 2 Field Company, Bombay Sappers and Miners on duty in China in 1900. The mule carries the tools required for field engineering tasks.
The fort of Ghazni which fell as a result of mining by a mixed contingent of the Bombay and Bengal Sappers during the First Afghan War on 23 July 1839.
A sapper of the Royal Engineers watches as soldiers reinforce security at FOB (Forward Operating Base) Shawqat in Afghanistan.
