A number of forts and batteries had been built in the vicinity during the preceding forty years, initially in response to a perceived threat from France and subsequently upgraded to deter German naval attacks on the military and commercial installations along the Thames and Medway.

[1] The battery consisted of four gun emplacements on a lozenge-shaped earthen mound with a rectangular hollow at its centre and a gently sloping glacis to the front, taking advantage of the terrain to provide maximum concealment.

Range finder positions were constructed on the ends of the ramparts [1][2] Grain Wing Battery was initially armed with two 11-inch rifled muzzle loaders for use against large warships, plus two 4.7-inch quick-firing guns intended to be used against smaller and faster adversaries such as torpedo boats and destroyers.

It remained in use for infantry defence purposes through the First World War and buildings were constructed in the interior to provide temporary housing for the soldiers.

[5] The battery's earthworks still survive in good condition, though now somewhat overgrown, and traces of the emplacements and range finder positions can still be seen in the form of depressions in the ground and short lengths of concrete.