In 1813, during the Napoleonic Wars, work was carried out to alter the design of the parapet.[33] The Crimean War sparked a fresh invasion scare and in 1855 the south coast of England was refortified.[34] Yarmouth Castle underwent considerable repairs that year; four naval guns and traversing rails were installed on the castle platform, and a regular county army unit was put in place to garrison the fort.[3] In 1881 a proposal was put forward to modernise the entire fortification, but this was rejected and in 1885 the garrison and the guns were withdrawn.[35]