The castle was already obsolete by the time it had been completed, as European military design had moved beyond curved bastions, embracing the angular designs seen in the later star forts. Nonetheless, it remained operational as an artillery fort for the rest of the century, with an initial garrison in 1540 of 24 men under the command of Chute, rising to 28 men and the captain after 1542. Although it had been fitted with gunloops for handguns from the very start, the castle initially relied heavily on archers for its own protection against attack from the land. It had stocks of 140 longbows and 560 sheaves of arrows in 1568, for example, probably for use by the local militia in the event of a war. Polearms were also stored there in considerable numbers, again probably for use by the militia.