Besides the armoured battery Fort IJmuiden also had two 15 cm gun in a revolving turret. These guns were designed to fire at ships that would pass through the North Sea Canal on their way to the sluices. The rate of fire was one round per gun per minute, but at those days the steam-powered ships were slow too. Unfortunately like all the other turrets in the Dutch coast forts it was removed by the Germans during WW II to make ammunition of the metal (The iron of armoured turrets was not suited to make guns out of it). Nowadays only the empty shaft remains. A drawing of the turret is shown on this site.