A mussel loader transformed to a breech loading gun. The hall where these guns are kept, is in the front combat building and the hall was made for the artillery. So that they could take shelter in that hall with their guns and horses. It is a semi circle so that they don't have to turn the horses and the gun carriages. And it was also used the stock the gun carriages of the fort, only the guns stayed outside dismounted and well greased to protect them from the weather. The wood carriages needed to be kept as much as possible out of the open to keep them a long as possible. See what happened to those of fort Liefkenshoek.