New Tavern Fort had a coastal battery dating from 1780 and was intended to work in conjunction with the batteries at Tilbury Fort. The 1859 Royal Commission proposed a boom defence and mines between these two forts. Along the river bank, some four miles to the West, lay Shoremead Fort.
By 1805 this battery mounted seventeen smooth bore guns, two 32-pr, fourteen 24-pdr and a single 9-pdr. Over the succeeding years there was some changes to the armament in the fort, and by 1859 the Fort mounted ten 68-pdr SB guns. By 1865 slight amendments were made and New Tavern Fort mounted eleven smooth bore pieces, eight 68-pdr , two 10-inch and one 8-inch shell guns.
By about 1868 it would appear that work had started on the Royal Commission New Tavern Fort, but construction appears to have been intermittent. Work started about the same time at Tilbury Fort with similar guns and layouts.
By 1871 the fort appears to have been armed with nine 9-iinch RMLs and one 12-inch RML. The seven RMLs facing the river, B and F Batteries, all had iron shields, but only one of these survives. These shields were 15-inch thick, with two layers of iron separated by 5-inch of packing, early spaced armour. The other emplacements have been built over with the later 6-inch Battery. Three RMLs on the flank (A) battery was three unarmoured embrasures with thick traverses which had serving rooms with hoist down to the magazines. These three emplacements survive. The Magazine level for all these guns still survive and can be visited.
By 1900 the decision was made to upgrade the coastal battery to two 6-inch guns.