 were replaced by 1865 with a pair of 10-inch shell guns, with a further 8-inch shell gun added, though all were still smooth-bore guns.Four early breech-loading RBL 40 pounder Armstrong guns mounted on field carriages had replaced the earlier movable guns in 1862.The focus of the Army's fortification efforts was initially on the outer forts at Coalhouse Point, Cliffe and Shornemead, and it was not until January 1868 that instructions were issued by the War Office to reconstruct Tilbury and New Tavern Forts.