1890s
Between 1886 and 1892, major modifications were made to three of the bastions to accommodate new armaments, including Moncrieff disappearing guns. These modifications included cutting down the bastions and infilling them internally, and the creation of new magazines underneath. By 1892, the fort was equipped with three 6-inch (150 mm) RBLs, two 9-inch (230 mm) RMLs and 1 64 pounder.
Read more about this topic: Fort Cumberland (England), Re-armament: The 1880s