The need for two gunpowder towers was revealed in report of the year 1756. Part of the reason was said to be the risk of placing a thousand barrels of gunpowder in one place, and secondly that other sites able to host a tower of that size were unsuitable of other reasons.
A proposal showing a gunpowder tower with a vault was sent over, but the board did not approve of this. The condition was that the attic needed to have a wooden floor resting on a tier of joists, making it possible to cover with a thick layer of horsemuck as isolation against bombardment.
The gunpowder tower was also used as prison for a period of time.
Today the building functions as suitable space for galleries and expositions.