Editing Fort Mills (section)

==Construction==
The initial construction on Fort Mills was largely complete by 1911 except three 3-inch gun batteries. The initial gun batteries were:<ref name=Ber222>Berhow 2015, pp. 222, 233-240</ref>

{| class="wikitable"
!Name
!No. of guns
!Gun type
!Carriage type
!Years active 
|-
|[[Battery Way|Way]]||4||[[12-inch coast defense mortar|{{convert|12|in|0|adj=on}} mortar]] M1890||[[barbette]] M1896||1910-1942
|-
|Geary||8||4 {{convert|12|in|0|adj=on}} mortar M1890,<ref>Battery Geary's four M1890 mortars were transferred from Battery Whitman at [[Fort Andrews]], Massachusetts.[http://www.fortwiki.com/Battery_Whitman Battery Whitman at FortWiki.com]</ref><br/>4 {{convert|12|in|0|adj=on}} mortar M1908||barbette M1896, M1908||1910-1942
|-
|Cheney||2||[[12-inch gun M1895|{{convert|12|in|0|adj=on}} gun M1895]]||[[disappearing gun|disappearing]] M1901||1910-1942
|-
|Wheeler||2||{{convert|12|in|0|adj=on}} gun M1895||disappearing M1901||1910-1942
|-
|Crockett||2||{{convert|12|in|0|adj=on}} gun M1895||disappearing M1901||1910-1942
|-
|Grubbs||2||[[10-inch gun M1895|{{convert|10|in|0|adj=on}} gun M1895]]||disappearing M1901||1910-1942
|-
|Morrison||2||[[6-inch gun M1905|{{convert|6|in|0|adj=on}} gun M1905]]||disappearing M1905||1910-1942
|-
|Ramsey||3||{{convert|6|in|0|adj=on}} gun M1905||disappearing M1905||1911-1942
|-
|James||4||[[3-inch gun M1903|{{convert|3|in|0|adj=on}} gun M1903]]||pedestal M1903||1910-1942
|-
|}

Three additional batteries of two {{convert|3|in|0|adj=on}} 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 [[minesweeper]]s from clearing paths through underwater minefields.<ref name=Lew1>Lewis, pp. 83-89</ref>

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 [[12-inch gun M1895|{{convert|12|in|0|adj=on}} M1895 gun]] each on an M1917 long-range carriage, with an elevation of 35° and 360° of traverse, with range increased from {{convert|18,400|yd|abbr=on}} on a disappearing carriage to {{convert|29,300|yd|abbr=on}}.<ref>[http://www.fortwiki.com/Battery_Hall Battery Hall, Fort Saulsbury, Delaware at FortWiki.com, with the same weapons as Batteries Smith and Hearn]</ref><ref>Berhow 2015, p. 61</ref> The disadvantage was that the guns were completely unprotected. This type of battery was also built at eight other [[Harbor Defense Command|harbor defense commands]] in [[CONUS]], Hawaii, and Panama.<ref>Berhow 2015, pp. 227-228</ref> 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.<ref>{{Cite book | last1 = Evans | first1 = David | last2 = Peattie | first2 = Mark | title = Kaigun: Strategy, Tactics and Technology in the Imperial Japanese Navy, 1887–1941 | publisher = Naval Institute Press | place = Annapolis | year = 1997 | page = 199 | isbn = 0-87021-192-7}}</ref> Ironically, had these batteries been modernized, they would have been [[casemate]]d, 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 [[M1918 240 mm howitzer|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.<ref>Berhow 2015, p. 194</ref>

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]]).<ref name=Ber222/>

===Battery names===
The name sources for the batteries at Fort Mills were:<ref>[http://corregidor.org/btty_histories/control/names_text.htm Order of Names at Corregidor.org]</ref>

{| width=80%
|-
|
{{col-begin}}
{{col-2}}
Fixed batteries:
* Hearn - BG [[Clint Calvin Hearn|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
{{col-2}}
155&nbsp;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
{{col-end}}
|}
[[File:Battery Way.jpg|thumb|right|260px|{{convert|12|in|0|adj=on}} mortars of Battery Way in 2007]]
[[File:12-in-Disappearing-Carriage-1896.jpg|thumb|right|260px|{{convert|12|in|0|adj=on}} gun on a disappearing carriage, generally similar to Batteries Cheney, Wheeler, and Crockett]]
[[File:Battery Hearn, Corregidor Island (modern view).jpg|thumb|right|260px|{{convert|12|in|0|adj=on}} M1895 gun of Battery Hearn circa 2010]]
[[File:Corregidor Landings May 1942.jpg|thumb|260 px|Japanese landings on Corregidor, 5–6 May 1942]]
[[File:Corregidor gun.jpg|thumb|right|260px|Japanese troops celebrate the capture of Corregidor and the Philippines at Battery Hearn, May 1942]]
===Minefields===
Manila Bay and Subic Bay had [[Submarine mines in United States harbor defense|Army-operated minefields]] as well as [[naval mine]]s. These minefields were designed to stop all vessels except [[submarine]]s 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, Bataan#Geography|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 [[Fort Frank|Carabao Islands]], to close off the bay approaches not covered by Army mines.<ref name=Lew1/><ref name="AFN1"/><ref name=Minemap1>{{Cite web |url=http://maritimereview.ph/2016/03/01/the-sinking-of-ss-corregidor/ |title=Map at "The Sinking of SS ''Corregidor''" at MaritimeReview.ph |access-date=2018-03-19 |archive-date=2020-02-06 |archive-url=https://web.archive.org/web/20200206065614/https://maritimereview.ph/2016/03/01/the-sinking-of-ss-corregidor/ |url-status=dead }}</ref>

On the night of 16–17 December 1941 the passenger ship [[HMS Engadine (1911)|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.<ref>Some accounts indicate the ship sank near La Monja Island, but this would mean the ship somehow got through the Corregidor-Bataan Army minefield.</ref> 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 Commonwealth Army|Philippine Army]] personnel and seven Americans were on board, along with several [[QF 2.95-inch Mountain Gun|2.95-inch mountain guns]] badly needed by the forces in the southern Philippines. Three [[PT boat]]s ([[Motor Torpedo Boat PT-32|''PT-32'']], [[Motor Torpedo Boat PT-34|''PT-34'']] and [[Motor Torpedo Boat PT-35|''PT-35'']]) picked up 282 survivors, of which seven later died.<ref name=Minemap1/><ref>{{cite book|last=Gordon|first=John|title=Fighting for MacArthur: The Navy and Marine Corps' Desperate Defense of the Philippines|year=2011|pages=73–76|publisher=Naval Institute Press|location=Annapolis, Maryland|url=https://books.google.com/books?id=XnDzMR47AXQC&q=ss+corregidor&pg=PA74|isbn=978-1-61251-062-0}}</ref><ref>[http://corregidor.proboards.com/thread/1168/loss-corregidor Discussion with quotes from several sources about the sinking of SS ''Corregidor'' at Corregidor.com]</ref><ref>[http://www.fsteiger.com/gsteipow.html Diary of CPT George Steiger, entry for 19 December 1941]</ref>

===The Malinta Tunnel===
{{Main|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 [[Seacoast defense in the United States|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.<ref>[http://corregidor.org/chs_lean_years/leanyear_02.htm Strong, Paschal N., ''The Lean Years'', p. 2 at Corregidor.org]</ref>