A glacis (/ˈgleɪ. sɪs/ or /ˈglæ. si/) in military engineering is an artificial slope of earth in the front of works such as fortifications, so constructed as to keep any potential assailant under the fire of the defenders to the last possible moment. A military is an Organization authorized by its Nation to use force usually including use of Weapons in defending its Country (or by attacking Engineering is the Discipline and Profession of applying technical and scientific Knowledge and Fortifications are Military Constructions and Buildings designed for defense in Warfare Humans have constructed defensive works for On the natural ground level, troops attacking any high work have a degree of shelter from its fire when close up to it; engineers therefore raise such ground to form a glacis, which defenders can sweep with fire from the parapet. A parapet is a wall-like barrier at the edge of a Roof or structure. The glacis was originally designed to protect stone fortifications, as vertical walls could easily be smashed down by artillery fire. Artillery (from French artillerie) is a military Combat Arm which employs any apparātus machine The glacis deflected incoming cannonballs by providing a springy, sloping surface which the cannonballs bounced off, landing behind the fragile stone fortifications.

More generally, the term glacis can denote any slope, natural or artificial, which fulfils the above requirements.

The etymology of this French word suggests a slope made dangerous with ice, hence the relationship with glacier. "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period.

Armored Vehicles

The term glacis plate describes the sloped front-most section of the hull of a tank or other armored fighting vehicle. Sloped armour is armour that is neither vertical nor horizontal and is typically mounted on Tanks and other Armoured fighting vehicles (AFVs A tank is a tracked, Armoured fighting vehicle designed for Front-line combat which combines Operational mobility and tactical An armoured fighting vehicle ( AFV) is a military Vehicle, protected by armour and armed with Weapons Most AFVs are equipped for driving in rugged ^[1] In a head-on-head armored engagement, the glacis plate is the largest and most obvious target available to an enemy gunner. Anti-tank mines which employ a tilt-rod mechanism are also designed to detonate directly underneath the glacis plate. An anti-tank mine, (abbreviated to "AT mine" is a type of Land mine designed to damage or destroy vehicles including Tanks and Armoured fighting Resultantly, the glacis plate is generally the most thickly armored section of a tank, followed by the turret face and mantlet. A gun mantlet on an Armoured fighting vehicle is an armour plate or shield attached to the vehicle's main gun or machine gun protecting the opening through which

US M1A1 Abrams main battle tank, edited to identify features (glacis plate highlighted in green)

Geology

An erosional or depositional pediment, with little slope. The M1 Abrams is a main battle tank produced in the United States. Tank classification is a Taxonomy of identifying either the intended role or weight class of Tanks The classification by role was used primarily during Erosional glacis occur mostly in arid regions, and result from intense meteorization (weathering) and surface transport via laminar, episodic water flow.

See also

• Fortification
• Siege
• Sloped armour

References

1. ^ Encarta Online Dictionary, http://ca.encarta.msn.com/encnet/features/dictionary/DictionaryResults.aspx?refid=1861675459 Retrieved 1/13/08