The military minds of the late eighteenth century drew their fortification strategy from a handful of recognized fortification hand books. The above diagram outlining the components of a redoubt is from Lewis Lochee's Elements of Field Fortifications, written in 1783, just two years after the fighting for Yorktown.
The fortification field manuals in use during the American Revolution offered commanders a diverse set of options for building defenses to fit their tactical needs. The American, British, and French commanders probably used John Mueller's 1746 Elements of Fortification. The manual was a conglomeration and adaptation of several of the great defensive strategists of the day. Below is a glossary of the components of a typical redoubt, or you can read about the components in Lewis Lochee's Elements of Field Fortifications, written in 1783.
Abatis: A means of defense surrounding a redoubt, made of large tree branches facing the enemy, with the branches sharpened and the trunk partially buried in the ground. The branches were sometimes interwoven to make removal difficult.
Banquette: A step behind the parapet made high enough so Soldiers standing on it could fire over the parapet. A slope or step was built for the Soldiers to reach the banquette.
Berm: Level earth between the parapet and the ditch, to keep the parapet from sliding into the ditch.
Cheveaux de Frize: Pieces of wood ten to twelve feet long with thin, wooden, pointed pins along the length of all four sides.
Ditch: Six to seven and a half foot crevasse immediately before the parapet.
Embrasures: Openings in the parapet for cannons to fire through.
Entrance: Positioned in the rear of the redoubt, and built wide enough for the artillery.
Fascines: Bundles of tree branches tied with yarn, from six to eighteen feet long and a foot or wider in girth. Used as a support structure in parapet construction. Assaulting troops used fascines to fill in the ditch and create a bridge to the parapet.
Fraises: Logs, with pointed ends, placed at an angle near the base of the parapet and extended out over the berm and ditch.
Gabions: Basket-shaped devises made from intertwined branches and twigs, standing two or three feet high and several feet around.
Glacis: A slightly rising slope of earth just before the ditch.
Gun Platform: Wooden platforms upon which cannon sit.
Gun Ramp: Also known as apareilles, earth and wood ramp built to allow large cannons to be moved into and out of positions.
Merlon: The wall of the parapet between embrasures.
Palisades: Pointed vertical logs driven into the bottom of the ditch.
Parapet: The mound of earth which formed the perimeter of a redoubt. It was the primary protection for Soldiers within the redoubt.
Sacs a Terre: Burlap or cloth sacks filled with earth much like today's sandbags, used to build parapets and other defenses.
Scarp: The side of the ditch leading up to the parapet.
Sods: Earth bricks with grass on one side, placed on the parapet to prevent erosion.
Trous-de-loup: Pits shaped like an upside-down cone, six feet around the top and six feet deep, sometimes with a pointed stake in the center. These pits were usually placed in front of the ditch to trap advancing infantry and cavalry.