Fort Mills (Corregidor, the Philippines) was the location of US Major General George F. Moore's headquarters for the Philippine Department's Harbor Defenses of Manila and Subic Bays in early World War II, and was the largest seacoast fort in the Philippines.Forts in the Philippines at American Forts NetworkHarbor Defenses of Manila and Subic Bays at the Coast Defense Study Group Most of this Coast Artillery Corps fort was built 1904–1910 by the United States Army Corps of Engineers as part of the Taft program of seacoast defense. The fort was named for Brigadier General Samuel Meyers Mills Jr., Chief of Artillery 1905–1906.Fort and battery names at Corregidor.org It was the primary location of the Battle of Corregidor in the Japanese invasion of the Philippines in 1941–42, and of the recapture of Corregidor in February 1945, both in World War II.McGovern and Berhow 2003, pp. 7-12
Overview The United States acquired the Philippines as a territory as a result of the Spanish–American War in 1898. The Taft board of 1905 recommended extensive, then-modern fortifications at the entrance to Manila Bay. The islands there had been declared military reservations on 11 April 1902. Construction soon started and the forts were substantially complete by 1915 as the Coast Defenses of Manila and Subic Bays (renamed Harbor Defenses in 1925).Berhow 2015, p. 430 All of them were on islands at the mouth of the bay, except Fort Wint on Grande Island in Subic Bay. As the only large island of these, Corregidor had more gun batteries than the others, along with barracks, other garrison buildings, and facilities for controlling two underwater minefields. Corregidor also had 13 miles of electric railway, an unusual feature in US forts.Morton, p. 473 The forts were designed for one purpose: to prevent enemy surface vessels from entering Manila Bay or Subic Bay. They were designed before airplanes became important in war, and (except for Fort Drum) were vulnerable to air and high-angle artillery attack, being protected only by camouflage. Except for the mortar batteries, the turrets of Fort Drum, and the two guns of the 1920s Batteries Smith and Hearn, the forts' guns had restricted arcs of fire of about 170°, and could only bear on targets entering the bay from the west.
Construction The initial construction on Fort Mills was largely complete by 1911 except three 3-inch gun batteries. The initial gun batteries were:Berhow 2015, pp. 222, 233-240
NameNo. of gunsGun typeCarriage typeYears active Way4 mortar M1890barbette M18961910-1942Geary84 mortar M1890,Battery Geary's four M1890 mortars were transferred from Battery Whitman at Fort Andrews, Massachusetts.Battery Whitman at FortWiki.com4 mortar M1908barbette M1896, M19081910-1942Cheney2 gun M1895disappearing M19011910-1942Wheeler2 gun M1895disappearing M19011910-1942Crockett2 gun M1895disappearing M19011910-1942Grubbs2 gun M1895disappearing M19011910-1942Morrison2 gun M1905disappearing M19051910-1942Ramsey3 gun M1905disappearing M19051911-1942James4 gun M1903pedestal M19031910-1942
Three additional batteries of two guns each followed within a few years; Battery Keyes in 1913 and Batteries Cushing and Hanna in 1919. The 3-inch "mine defense" guns were intended to prevent enemy minesweepers from clearing paths through underwater minefields.Lewis, pp. 83-89
The last new armament at Fort Mills until 1940 was significant but small in quantity: Batteries Smith and Hearn, completed in 1921. These had one M1895 gun each on an M1917 long-range carriage, with an elevation of 35° and 360° of traverse, with range increased from on a disappearing carriage to .Battery Hall, Fort Saulsbury, Delaware at FortWiki.com, with the same weapons as Batteries Smith and HearnBerhow 2015, p. 61 The disadvantage was that the guns were completely unprotected. This type of battery was also built at eight other harbor defense commands in CONUS, Hawaii, and Panama.Berhow 2015, pp. 227-228 In 1923 the Washington Naval Treaty prohibited additional fortifications in the Pacific, thus the Philippine forts received no further weapons until after 1936, when Japan withdrew from the treaty, rendering it void. Ironically, had these batteries been modernized, they would have been casemated, restricting them to a 180° field of fire, and would have been less useful against the Japanese on Bataan. One result of the Washington Naval Treaty was the diversion of twelve 240 mm howitzers on a ship bound for the Philippines to Hawaii, where they were placed on fixed mountings on Oahu. The total lack of mobile high-angle artillery was a major impediment to the defense of the Philippines.Berhow 2015, p. 194
Spare gun barrels were provided near some batteries, including Smith and Hearn, due to the inability to re-line used barrels except at specialized facilities in the continental United States (CONUS).
Battery names The name sources for the batteries at Fort Mills were:Order of Names at Corregidor.org
Fixed batteries: Hearn - BG Calvin Hearn, commander of HD Manila Bay in 1919 Smith - BG Frank G. Smith, Field Artillery, retired 1903 Way - 2nd. Lt. Henry Newell Way, killed in the Philippine–American War 1900 Geary - Capt. Woodbridge Geary, killed in the Philippine–American War 1899 Cheney - 1st. Lt. Ward Cheney, killed in the Philippine–American War 1900 Wheeler - Capt. David Porter Wheeler, killed in the Philippines 1904 Crockett - 2nd. Lt. Allen T. Crockett, killed in the Philippine–American War 1901 Grubbs - 1st. Lt. Haydon Young Grubbs, killed in the Philippine–American War 1899 Morrison - 1st. Lt. John Morrison, Jr., killed in the Philippine–American War 1901 Ramsay - 1st. Lt. Charles R. Ramsay, killed in the Philippine–American War 1901 James - 1st. Lt. John F. James, killed in the Philippines 1906 Keyes - 2nd. Lt. Maxwell Keyes, killed in the Philippine–American War 1899 Cushing - 1st. Lt. Alonzo Cushing, killed in the American Civil War 1863 Hanna - Capt. Guy G. B. Hanna, killed in an accident 1913
155 mm GPF batteries: Martin - unknown Hamilton (South) - Capt. Alvah H. Hamilton, killed at Fort Mills 2 January 1942 Kysor (North) - Capt. Benjamin B. Kysor, Medical Corps, mortally wounded at Fort Mills 29 December 1941 Rock Point - location on Corregidor Sunset - location on Corregidor Stockade - location on Corregidor Monja - location on Corregidor Concepcion - Barrio Concepcion on Corregidor Levagood - 1st. Lt. George E. Levagood, killed at Fort Mills April 1942
Minefields Manila Bay and Subic Bay had Army-operated minefields as well as naval mines. These minefields were designed to stop all vessels except submarines and shallow-draft surface craft. In Manila Bay, two controlled minefields were placed, one extending west from Corregidor to La Monja Island, and the other extending north from Corregidor to the Bataan Peninsula east of Mariveles Bay. Both of these were operated from Corregidor. Also, in mid-1941 US Navy minefields of contact mines were laid between Mariveles Bay and La Monja Island, and between Corregidor and Carabao Islands, to close off the bay approaches not covered by Army mines.
On the night of 16–17 December 1941 the passenger ship SS Corregidor (formerly HMS Engadine) hit a mine and sank near Corregidor Island. The ship departed Manila that night without obtaining permission from the US Navy's Inshore Patrol, which meant the minefield operators were not alerted that a friendly ship was departing the harbor. The minefield's usual state in wartime was active, which meant they would detonate on contact. This probably applied to the mines in the designated ship channel as well. When the ship was spotted, some accounts state that Colonel Paul Bunker, commander of the Seaward Defenses, ordered that the minefield remain active. Due to wartime conditions, no official investigation was ever conducted, leaving many questions open. The location at which the ship sank has not been determined, for example.Some accounts indicate the ship sank near La Monja Island, but this would mean the ship somehow got through the Corregidor-Bataan Army minefield. Accounts state that US Army officers informally told Filipino reporters that the mines were placed in safe mode immediately after the sinking. The ship was crowded with 1,200 to 1,500 persons, mostly Filipino civilians evacuating to Mindanao. 150 Philippine Army personnel and seven Americans were on board, along with several 2.95-inch mountain guns badly needed by the forces in the southern Philippines. Three PT boats (PT-32, PT-34 and PT-35) picked up 282 survivors, of which seven later died.Discussion with quotes from several sources about the sinking of SS Corregidor at Corregidor.comDiary of CPT George Steiger, entry for 19 December 1941
The Malinta Tunnel
The main part of the Malinta Tunnel complex was built on Corregidor from 1932 to 1934, with construction continuing until the Philippines were invaded in December 1941. Most US forts of this era had only small underground facilities, and this tunnel complex was the largest in the US coastal defense system. Due to the Washington Naval Treaty's prohibition on new fortifications, most of the complex was built without appropriated funds, using Filipino convict labor for unskilled tasks, and explosives slated for disposal. During the siege, the Malinta Tunnel proved important to the survival of the Philippine government, the military high command, the medical staff, and numerous civilians.Strong, Paschal N., The Lean Years, p. 2 at Corregidor.org
Japanese conquest of the Philippines
Prelude From the late 1930s through the surrender in 1942 a number of batteries for GPF gunsA French design, designated Grand Puissance Filloux for its designer. were built at Fort Mills. These were mobile field guns adopted by the Coast Artillery Corps for use in "tractor-drawn" units, such as the 92nd Coast Artillery. At least a few of these were delivered to the Philippines in 1921 with transfer of the 59th Coast Artillery to the islands.Gaines, William C., Coast Artillery Organizational History, 1917-1950, Coast Defense Journal, vol. 23, issue 2, pp. 34-35 Nine batteries with emplacements for 22 guns were built. The US Army's official history states that 19 of these weapons were on Corregidor during the final battle in 1942. Most of these batteries simply had "Panama mounts", circular concrete platforms to stabilize the gun on its mobile carriage. One battery was exceptional, Battery Monja in the southwest part of Corregidor, with two emplacements. One or both of these were casemated by being built into a rock face; this proved to be crucial to the battery remaining in action during the siege. By December 1941 there were seven antiaircraft batteries totaling 28 3-inch guns on Corregidor (including one nearby on Bataan), some manned by the 60th Coast Artillery (AA) and some manned by batteries of the harbor defense regiments.Morton, p. 474Table of Armaments & Coast Artillery Assignments at corregidor.org
On 26 July 1941 Lieutenant GeneralMajor General when recalled, promoted two days later. Douglas MacArthur was recalled to active duty and made the commander of U.S. Army Forces in the Far East (USAFFE), which included the Philippine Scouts and the Philippine Commonwealth Army. MacArthur had been an official U.S. advisor to the Philippine forces as a Philippine Field Marshal from 1935 to 1937, and had continued this function as a civilian since his retirement from the U.S. Army at the end of that period.Morton, p. 19
The siege begins