Arrowslit - Design

Design

In its simplest form, an arrowslit was a thin vertical opening; however, the different weapons used by defenders sometimes dictated the form of arrowslits. For example, openings for longbowmen were usually tall and high to allow the user to shoot standing up and make use of the 6 ft (1.8 m) bow, while those for crossbowmen were usually lower down as it was easier for the user to shoot whilst kneeling to support the weight of the weapon. It was common for arrowslits to widen to a triangle at the bottom, called a fishtail, to allow defenders a clearer view of the base of the wall. Immediately behind the slit there was a recess called an embrasure; this allowed a defender to get close to the slit without being too cramped. The width of the slit dictated the field of fire, but the field of vision could be enhanced by the addition of horizontal openings; they allowed defenders to view the target before it entered range.

Usually, the horizontal slits were level, which created a cross shape, but less common was to have the slits off-set (called displaced traverse slots) as demonstrated in the remains of White Castle in Wales. This has been characterised as an advance in design as it provided attackers with a smaller target; however, it has also been suggested that it was to allow the defenders of White Castle to keep attackers in their sights for longer because of the steep moat surrounding the castle.

When an embrasure linked to more than one arrowslit (in the case of Dover Castle, defenders from three embrasures can shoot through the same arrowslit) it is called a "multiple arrowslit". Some arrowslits, such as those at Corfe Castle, had lockers nearby to store spare arrows and bolts; these were usually located on the right hand side of the slit for ease of access and to allow a rapid rate of fire.