The first soldiers to be garrisoned at Nothe Fort were No.2 Battery Royal Artillery (Tatton-Browns) a specialist gun emplacement unit trained in the handling of cannons up to 18 tons. They were responsible for installing the original cannons; these were 2 x 64 pounders, 4 x 9 inch cannons and 6 x 10 inch cannons.
The cannons were all rifled muzzle loaded (RMLs), with spiral grooves cut into the barrel. The groves engaged with lines of lugs positioned along the length of the shells. When a cannon was fired the shell would begin to spin as it travelled along the length of the barrel, this spinning motion improved the range and accuracy of the shell.
Seven of the original cannons were replaced in the 1890s by massive 12.5 inch cannons, each weighing 38 tons and capable of firing a 800 pound shell over a range of three and half miles. The shells for these cannons were fitted with a soft metal ring instead of lugs. When the cannons were fired the soft metal was forced in to the rifling and this caused the shells to spin.