The Fort near Spijkerboor is located in the southwest corner of the Beemster Polder. It is the most northern fort of the Defence Line of Amsterdam and also the biggest one.
Passable part of an inundation in the form of elevated terrain, a road, (railway) embankment or waterway.
Collective term for projectile weapons.
Also called bulwark. An outward-projecting pentagonal structure, suitable for delivering flanking fire.
A storage site for military equipment. The parks in the Defence Line are spread out over sectors (sector parks) and groups (group parks).
A battery that is positioned behind armour plates.
A fort with one or more armoured artillery positions.
A number of artillery pieces combined into one group.
Shielded position from which defenders can harass the enemy.
A (low) defensive structure that extends into the moat and can be used to give flanking fire.
A space that is protected against enemy fire and is outfitted with a gun port, behind which a piece of artillery is placed.
An army division whose tasks include, amongst other things, the construction of temporary and permanent defensive structures. The term ‘engineer’ is derived from the French word ‘ingenieur’.
Also called covert way. A pathway that is protected from enemy fire by an earthen wall and can be used for transporting soldiers and military equipment.
Also called stop-log sluice. A temporary dam that stops the inundation water when beams are stacked up in its recesses.
Water purification system that improves the quality of drinking water by extracting iron.
Earthen elevation surrounding a defensive structure, featuring a breastwork.
A (wooden) shed where artillery and military engineering equipment were stored.
The part of a terrain that can be fired at.
Long-range flanking fire: fire support for the secondary forts. Short-range flanking fire: fire that covers the surroundings of the defensive structure itself.
Known in Dutch as ‘Vestingwet’. The act of the 18th of April 1874 that stipulated which forts would become part of the Dutch national defence system.
The side of a defensive structure that is facing away from the enemy.
In the Defence Line forts this is a casemate giving short-range and long-range flanking fire.
Undercarriage for a cannon or other heavy firearm.
Shell that is filled with highly explosive material.
The flooding of land to keep the enemy at bay.
Also called inlet sluice. A sluice that is constructed with the aim of letting water into a certain area.
An independent system of connected defensive structures.
Artillery that gives frontal fire over large distances, directly aimed at enemy positions.
A simple (temporary) defensive structure manned by a small number of soldiers.
An underground connecting passageway that is shellproof.
Known in Dutch as ‘Kringenwet’. Act of January 1853 that stipulates restrictions with regard to the construction of buildings in the vicinity of defensive structures, the so-called forbidden zones (‘kringen’), in order to guarantee a free field of fire.
A chart that is installed next to the gun port to give the operators of the artillery insight into the distances of targets and the corresponding firing angles.
A place of last refuge for the defenders of a fort, which can be defended independently.
A turret that is lifted up to give fire and is retracted and thus made almost invisible once the firing has stopped.
Position that provides shelter to retreating troops.
Battery that is situated in close proximity to a fort and performs some of the tasks that have been assigned to that fort.
The ability of a building to withstand gunfire thanks to brickwork, concrete or a bottom layer.
A shellproof depot for storing artillery and other essential military equipment.
A fort’s courtyard.
A turnable armoured artillery position.