Battery, were subsequently added to further strengthen the defences. The Royal Commission recommended that de Gomme's red brick fortification and the two later batteries, which were incapable of withstanding modern guns, should be replaced by an armoured artillery fort on the same site. Its arc of fire would overlap that of Grain Fort and Grain Tower (and later Grain Wing Battery and Dummy Battery) on the other side of the Medway on the Isle of Grain. Construction and layout Construction began in February 1861 and continued until the last of its shielding was installed in June 1872, by which time about half of the guns were already in place. The new fort took the form of a semi-circular structure, one of only two built in the 1860s fortification programme (the other being Picklecombe Fort in Cornwall). It had two gun floors, each with 17 granite-faced casemates, in which 36 heavy guns were mounted behind 2,000 tons of iron shields. Another two gun turrets were planned for the roof but were not built. The magazines were located below ground in the basement of the fort. The bulk of the structure was built of brick, with concrete additions. The walls and piers are thick. The semi-circular row of casemates is closed off to the rear by a row of defensible buildings constructed from ashlar blocks of Kentish ragstone, with loopholes and gun ports in the flanks to facilitate close defence of the fort. A parade ground occupied the middle of the fort. Operational history Garrison Point Fort was initially armed with 9-inch and 10-inch rifled muzzle loader (RML) guns. By 1880 its armament had been expanded to include 9-inch, 10-inch, 11-inch and 12.5-inch RMLs. A Brennan torpedo station, used to launch wire-guided torpedoes, was added to the fort's structure in 1884 and remained in use until around 1906. The RMLs were obsolete by the end of the 19th century and had been removed by 1896, when the casemates were all converted to barracks and stores. In 1909 two 6-inch Mk. VII breech-loading (BL) guns were mounted on the fort's roof and four 12-pounder quick-firing guns were installed in a lower tier of the casemates. A coastal artillery searchlight and concrete magazine were constructed to the east of the fort during the First World War, along with a machine-gun pillbox that no longer survives. Garrison Point Fort remained in service through the Second