Fort Drum, known as the "concrete battleship", is a heavily fortified island fortress located at the entrance to Manila Bay directly opposite Corregidor Island.
After the Americans gained control of the Philippines from the Spanish, Fort Drum was planned as a mine control station. However, due to the imperfect defences in the area, the plan was revised: it was it was decided to level the island and then build a concrete structure on it, equipped with two 12-inch guns. Later, the War Department decided to replace the 12-inch guns with 14-inch guns, and to install two casemates with 6-inch guns. In addition, it was planned to enclose the fortress with concrete walls 7.6 to 11 metres thick.
Construction began in April 1909 and lasted 5 years, during which time Frale Island was virtually levelled to sea level, and thick layers of arroyo were thick layers of steel-reinforced concrete were laid on its surface, which then became a massive ship-like structure. By 1916, 14- and 6-inch guns were installed. Searchlights, anti-aircraft batteries and a fire control section were also installed. Inside were living quarters for 320 officers and men, power generators, a command post and ammunition storage.
Just before the outbreak of hostilities in the Pacific in December 1941, Fort Drum was manned by soldiers. On January 2, 1942, they repelled an air raid by Japanese bombers. In mid-January a new 3-inch gun was installed. During February, March and April, the fort survived several artillery bombardments and air raids, and sank several landing barges intended to attack Corredigor Island and other fortified islands. However, in May 1942 Fort Drum was surrendered to the Japanese, followed by Korredigor Island.
It was not until 1945 that the fort was stormed by the Americans as part of the operation to to liberate Manila. After heavy fighting in the air and at sea, American soldiers gained access to the fort's roof and were able to lock the Japanese garrison inside. Immediately it was decided not to try to break into the fort, but to use the method already previously tried on Caballo Island at Fort Hughes. There, soldiers pumped a mixture of oil and petrol into the mortar trenches and, from a distance, set fire to it with tracer bullets. At Fort Drum, a similar mixture was poured inside through the roof vents, and instead of bullets, a remote-controlled tube. The Japanese soldiers trapped inside were destroyed, and the fire lasted for several days for several days.
After all the forts in the Manila Bay area were recaptured American-Philippine forces, the Japanese began their retreat. The ruins of Fort Drum, with its inoperative gun turrets and 14-inch guns, are still visible today on the surface of the waters of Manila Bay.
