Re: Monday answer
Lynn was correct about the Sally port. Gary was correct in this description for the Trunnion. The drawbar answer I'm unfamiliar with. For the crossbow I know of the direct draw, rope (pulley) draw, and the lever draw but not in my experience called a drawbar. It could well be called one however given the operation of a lever draw. Anyway here are my answers.
Abatis, abattis, or abbattis (a French word meaning a heap of material thrown) is a term in field fortification for an obstacle formed of the branches of trees laid in a row, trunks anchored facing the fort walls with the tops directed towards the enemy. A pre barbed wire delaying mechanism.
A scarp and a counterscarp are the inner and outer sides of a ditch used in fortifications. In permanent fortifications the scarp and counterscarp may be encased in wood planks or stone. In less permanent fortifications, the counterscarp may be lined with paling fence set at an angle so as to give no cover to the attackers to make advancing and retreating more difficult.
a trou de loup (French for "wolf hole"; plural trous de loup, also commonly referred as a tiger pit in the East) was a type of booby trap or defensive obstacle. Each trou de loup consisted of an inverted conical pit about 2 m (6 feet) deep and 1.2 to 2 m (4 to 6 ft) at the bottom a sharpened wood stake or stakes would be hammered in. In some cases, the pit was concealed by light cover of wicker and a layer of soil.
The primary fort meaning for sally port is a small controlled space with two doors. Essentially, one must enter the space and close the first door before opening the second to proceed, rather like an airlock. A place where troops sallied forth to rush forth suddenly; to burst forth. In siege warfare, a sortie, or sudden issuing of troops against the enemy from a defensive position, can be launched against the besiegers by the defenders. If the sortie is through a sally port, either to sortie or to sally can be used.
Allure-- It is the walkway along the inside of a wall. Usually along the top of a curtain wall protected on the outside by the parapet.
Hoarding-- A covered gallery built on or near the top and OUTSIDE of a curtain wall or tower to defend against attackers. A wooden gallery built out from the battlements that provided additional protection and fighting space at the wall top; replaced in later castles by a Machicolated stone Parapet.
(*Machicolation: The projection of the parapet over corbels so that slots could be provided that faced straight down to the bottom of the wall and one could fire at, or pour boiling water or oil on, attackers who had reached that point.)
Trunnion, Trinnion is the log or pin that anchored and permitted the raising or lowering of a drawbridge. In this case a hinge pin. A trunnion is also the two �ears� on the side of a cannon that permit the cannon to ride on a carriage/platform for mobility.
Talus-- A huge sloping inner wall which prevented attackers from getting so close that they could not be seen by the castle defenders. In the Orient the fortification was built with inward sloping walls that accomplished the same purpose.
Bratticing, brattice: a wooden perimeter defense. A wooden housing erected on top of walls. When erected on top of towers, sometimes also known as "war-head".
Drawbar�the large timber that was placed on the inside of a door or gate to lend additional support to that gate if under attack. Usually it was anchored on a pin and lowered on to brackets, but could also be hung on a wall and pulled across the door in time of need.
I hope these were interesting as there were relatively few responses. Let me know.