Starting in 1910, El Fraile Island at the mouth of Manila Bay was leveled to near water level by US Army engineers. By 1914, Fort Drum was completed which added to the other three forts in the defense of Manila Bay. The fort was 350 feet long and 144 feet wide with a top deck 40 feet above low water level. The exterior walls were from 25 to 36 feet thick. Due to its shape, Fort Drum was nicknamed the "Concrete Battleship".

The armaments of Fort Drum included:

Battery Wilson --> (two 14 inch turret mounted guns with a range of 20,000 yards)
Battery Marshall --> (two 14 inch turret mounted guns with a range of 20,000 yards)

Battery Roberts --> (two 6 inch casemated guns with a range of 17,000 yards)
Battery McRae --> (two 6 inch casemated guns with a range of 17,000 yards)

Battery Hoyle --> (one 3 inch Anti-aircraft gun with a range of 10,000 vertical feet)
Battery Exeter --> (two 3 inch Anti-aircraft guns with a range of 27,000 vertical feet)

In 1942 at the time of Corregidor’s surrender to Japanese forces, the other Malina Bay forts including Fort Drum were also surrendered.

Three years later, the tide of war had changed. April 13, 1945 was the day designated for the retaking of Fort Drum by US forces. 3,000 gallons of two parts diesel oil and one part gasoline were pumped into Fort Drum. Also 600 pounds of explosives were planted at critical areas, one being above a first floor powder magazine. Numerous explosions resulted and the fires burned for days. By the time it was safe for troops to penetrate all levels of the fort, the bodies of eight Japanese had been found in the upper levels and sixty more found in a third floor boiler room.

For historical information on Fort Drum, by far the two most comprehensive web sites are located at http://www.concretebattleship.org/ and http://corregidor.org/. You will find detailed construction drawings plus pre and post war photographs etc.