Fort Drum on El Fraile Island, the Philippines, was one of the most unique structures in the history of modern military engineering: an island rebuilt into the form of a 350-foot long concrete battleship.
After the United States’ annexation of the Philippines, US military planners sought to secure Manila Bay by fortifying four islands in the straits between the provinces of Bataan and Cavite. From North to South, the islands of Corregidor, Caballo, El Fraile, and Carabao would become Forts Mills, Hughes, Drum, and Frank. Construction of the fortifications and placement of artillery batteries began in 1909 and was completed by the 1920s. When completed, this network of forts was heralded as the Gibraltar of the Orient.
El Fraile was essentially cut down to sea level to form a foundation for Fort Drum’s massive concrete battlements. When completed, the structure’s length overall was 350 feet with a 144 feet beam and its decks stood 40 feet above Manila Bay. Atop the fort’s 20 feet thick walls sat two rotating armored turrets, each turret mounting two 14-inch guns. Just to their aft, engineers built a fo’c’sle and a crow’s nest, giving Fort Drum the distinct profile of a man-of-war. Indeed, the fort was unofficially christened the USS Drum after civilian cruise ships and merchant shipping repeatedly mistook the fort for a ship. Six other batteries on Fort Drum mounted nine smaller-bored guns and made Fort Drum a vicious beast to tangle with.
Early air raids on the fort in December 1941 and January 1942 barely scratched her shell. From January 1942 forward, Fort Drum and her sister forts received constant attention from enemy artillery emplacements in Cavite. The fort’s massive walls and heavy armament served her garrison well until the American surrender on 7 May 1942. When handed over to Japanese forces, the concrete battleship was still in fighting shape, having lost only one battery after enduring five months of fierce attacks.
Nearly four years later, during the campaign to liberate the Philippines, American forces faced the impregnable concrete battleship. The battle for Manila raged onshore, but the Japanese-held Fort Drum impeded Allied shipping from entering Manila Bay. The other three fortified islands had been recaptured by 13 April 1945, when landing craft, modified with extended ramps, delivered two platoons of US soldiers to Fort Drum. While snipers kept enemy troops below decks, combat engineers planted demolition charges around Fort Drum. Meanwhile, other modified landing craft fed fuel and explosives into the fort’s ventilation system. After the Americans withdrew, the explosives throughout Fort Drum went off, killing the Japanese garrison and effectively opening Manila Bay for strategic supply.
Though wrecked by warfare, the elements, and gutted by scavengers, Fort Drum still stands intact at the mouth of Manila Bay. Her crow’s nest is gone, but her twin turrets and guns remain. At a distance, unknowing passengers on cruise ships still mistake her for a ship. Despite her uniqueness, the concrete battleship is a neglected and little-known landmark. It is possible to arrange visits to Fort Drum, but treacherous currents and shifting tides often make it hard to do so; several groups of tourists and historians have been stranded upon Fort Drum when their charter boats could not safely dock.