View source for 240 mm howitzer M1

{{short description|1940s United States 240 mm field howitzer}}
{{Use American English|date=October 2024}}
{{Use dmy dates|date=October 2024}}
{{Infobox weapon
| is_artillery = yes
| name = 240 mm Howitzer M1
| image = 240mm howitzer.jpg
| image_size = 300
| caption = Front view of a 240 mm howitzer firing into German held territory. [[Mignano]] area, Italy. 30 January 1944
| origin = United States
| type = [[Howitzer]]

<!-- Service history -->
| service = 1943–1959 (United States)<br/>1958 – present (Taiwan)
| used_by = United States<br/>United Kingdom<br/>Philippines<br/>Taiwan
| wars = [[World War II]]<br/>[[Korean War]]<br/>[[Second Taiwan Strait Crisis]]

<!-- Production history -->
| design_date = 1940–1943
| production_date = November 1942–1945
| number = 315 manufactured by 1945

<!-- General specifications -->
| weight = {{convert|64,700|lb|kg|abbr=on}} (in action)
| length =
| part_length = {{convert|27|ft|6|in|m|abbr=on}} L/35
| width = {{convert|9|ft|2|in|m|abbr=on}}
| crew = 14

<!-- Ranged weapon specifications -->
| cartridge = {{convert|360|lb|kg|abbr=on}} separate loading, [[Shell (projectile)#Separate loading bagged charge|bagged charge]]
| caliber = {{convert|240|mm|in|abbr=on}}
| action =
| rate = 1 round per minute (maximum)<br >30 rounds per hour (sustained)
| velocity = 2,300 ft/s (701 m/s)
| range =
| max_range = 14.3 mi (23.1 km)
| feed =
| sights =

<!-- Artillery specifications -->
| breech = [[Interrupted screw]]
| recoil = [[Hydraulic recoil mechanism|Hydro-pneumatic]]
| carriage = [[Gun carriage#Modern gun carriages|Split trail]] with 2 transport wagons
| elevation = +15° to +65°
| traverse = 22.5° right and left.
}}

The '''240&nbsp;mm howitzer M1''', popularly nicknamed the "Black Dragon",<ref name="tpatch">[http://www.kwanah.com/36division/tpatch/v1n4/4408061f.htm {{"'}}Black Dragon' Italian Success"] {{Webarchive|url=https://web.archive.org/web/20120205104933/http://www.kwanah.com/36division/tpatch/v1n4/4408061f.htm |date=2012-02-05 }}, ''T-Patch 36th Infantry Division News, Army times.'', Retrieved on 2007-05-25.</ref> was a towed [[howitzer]] used by the [[United States Army]]. The 240&nbsp;mm M1 was designed to replace the World War I era [[240 mm howitzer M1918]], which was based on a 1911 French design and was outdated by World War II.

The project to replace the M1918 began in 1941.<ref>''The Illustrated Encyclopedia of  20th Century Weapons and Warfare'', Vol 7, page 779, editor Bernard Fitzsimons, Purnell & Sons Ltd 1967/1969</ref> The 240&nbsp;mm howitzer was the most powerful weapon deployed by [[United States Army Field Artillery Corps|US field artillery]] units during [[World War II]], able to fire a {{convert|360|lb|abbr=on}} [[high explosive]] [[Shell (projectile)|projectile]] {{convert|25,225|yd}}.<ref name="zaloga2">Zaloga, Delf – ''US Field Artillery of World War II'', p 34.</ref> It was the largest field piece used by the US Army during the war except for naval ordnance adapted into [[railway gun]]s.<ref name="G1">[http://www.globalsecurity.org/military/systems/ground/m1-240.htm "M1 240 mm Howitzer"], ''Globalsecurity.org'', Retrieved on 2007-05-25.</ref> The weapon addressed the requirement for super-heavy [[field artillery]] capable of attacking heavily reinforced targets, like those likely to be found along Germany's [[Siegfried Line]].

The 240&nbsp;mm howitzer M1 was designed together with the longer-ranged [[8-inch gun M1]], and they shared a related carriage.<ref name="zaloga2"/> While use of the 8-inch gun was limited due to excessive bore wear and poor accuracy, the howitzer saw considerable action during World War II in Europe due to its effectiveness against difficult targets such as heavy concrete fortifications. It was also used in the [[Pacific War|Pacific campaign]], notably in the [[Battle of Manila (1945)|recapture of Manila in 1945]], but few targets there were fortified heavily enough to justify its use.<ref name="p105">Schreier – ''Standard guide to U.S. World War II Tanks & Artillery'', p 105.</ref>

The US Army retained the 240&nbsp;mm howitzer after World War II, and later deployed it in the [[Korean War]]. The howitzer remained in US service until ammunition stocks were exhausted in the late 1950s.<ref name="G1" />

The 240&nbsp;mm howitzer M1 is still in service with [[Taiwan]], stationed in hardened bunkers of the frontline [[Kinmen]] and [[Matsu Islands]].

==Development==

During World War I, the United States Army received several British [[BL 9.2-inch howitzer|9.2-inch (233.7 mm) howitzers]], but was more impressed by the French [[Mortier de 280 modèle 1914 Schneider]]. 330 of the latter weapon, in a slightly modified form, were built under license by the mid-1920s as the [[M1918 240 mm howitzer]]. In 1925, it was concluded that the design was flawed, so it was decided to build a new weapon; design work, however, did not begin until 1934 and resulted in the modification of existing weapons as the M1918A1M1, but the project stalled because of limited funding. In April 1940, another design program was begun, and resulted in the 240 mm Howitzer T1. Production began in November 1942, and the piece was standardized in May 1943 as the 240 mm Howitzer M1 on Carriage M1.<ref>{{Cite book|title=U.S. Field Artillery of World War II|last=Steven J.|first=Zaloga|date=2007|publisher=Osprey Publishing|isbn=9781846030611|pages=32–33|oclc=123895340}}</ref>

==Service==

===Transport===

A pair of three-axle, six-wheeled transport wagons were developed – one for the cannon tube, and one for the carriage. These transport wagons were also used with the 8-inch gun. These were standardized as the M2 and M3. The M2 wagon carried the carriage and the M3 wagon carried the barrel and recoil system. This separate configuration required the use of the 20-ton M2 truck-mounted crane for setup. The crane also included a clam-shell bucket that was transported on a trailer and used to dig the recoil pit for the gun. It took about two hours to emplace the gun.<ref>{{Cite book|title=U.S. Field Artillery of World War II|last=Steven J. |first=Zaloga|date=2007|publisher=Osprey Publishing|isbn=9781846030611|pages=34|oclc=123895340}}</ref>

The transport wagons were initially intended to be towed by the [[Mack NO|Mack NO {{frac|7|1|2}}-ton heavy truck]], but it was found that the trucks had problems on soft ground due to their high [[ground pressure]]. The intended replacement was the tracked [[M6 tractor]], which was explicitly designed for towing the 8-inch gun and 240&nbsp;mm howitzer. This vehicle was standardized in June 1943, but did not enter production until February 1944, so the Ordnance Department improvised in the meantime. Surplus [[M3 Lee]]-based M31 and M32B1 tank recovery vehicles and [[M10 tank destroyer|M10A1 tank destroyers]] were quickly modified and tested. These proved to be satisfactory and were adopted for use as the M33, M34, and M35 Prime Movers, respectively.<ref>{{Cite book|title=U.S. Field Artillery of World War II|last=Steven J. |first=Zaloga|date=2007|publisher=Osprey Publishing|isbn=9781846030611|pages=39–40|oclc=123895340}}</ref> Likewise, the wheeled transport wagons loaded with the heavy gun components often became bogged down in soft ground, so the Ordnance Department developed the T17E1 carriage transport wagon with a pair of tracked bogies, and the T16E1 gun transport wagon with three medium tank bogies on each side. One 240 mm howitzer battalion was deployed to the Pacific in 1945 equipped with these carriages.<ref>{{Cite book|title=U.S. Field Artillery of World War II|last=Steven J.|first=Zaloga|date=2007|publisher=Osprey Publishing|isbn=9781846030611|pages=34|oclc=123895340}}</ref>

===Combat use===

The first operational use of the super-heavy 240&nbsp;mm howitzer was by the 697th and 698th Field Artillery Battalions of the [[U.S. 5th Army]] at the [[Anzio Beachhead]] in Italy in January 1944.<ref name="p105"/><ref>{{cite book|last=Stanton|first=Shelby|date=1984|title=Order of Battle, U.S. Army, World War II|location=Novato|publisher=Presidio Press|page=}}</ref> The 240 mm howitzers and the [[8-inch gun M1|8-inch (203&nbsp;mm) guns]] of Batteries A and B, 575th Field Artillery Battalion (attached to the 697th and 698th, respectively), were used for [[counter-battery fire]] missions against long-range German guns in their class.<ref name="p105"/> Their fire was accurate enough not only to knock enemy artillery out of action, but also to destroy targets as small as German [[heavy tank]]s.<ref name="p105"/> US super-heavy artillery also played a role in countering the infamous [[Anzio Annie]] railway gun and putting it out of action.<ref name="p105"/> In Italy, the 240&nbsp;mm howitzer was highly valued for its capability to destroy key bridges at long range.<ref name="p33">Zaloga, Delf – ''US Field Artillery of World War II'', p 33.</ref> [[United States Army Ordnance Corps|Army ordnance]] officers credited the "devastating fire power and incredible accuracy" of the 240&nbsp;mm howitzer in playing a decisive role in the [[Italian Campaign (World War II)|Italian Campaign]].<ref name="tpatch"/> During the [[Battle of Monte Cassino]], the weapon  was used in the final destruction of the monastery, already damaged by air attacks.<ref name="p33"/> In the Italian [[Theater (warfare)|theater]], a small number of 240&nbsp;mm howitzers also saw action with the [[British Eighth Army]].<ref name="G1"/> Despite their initial misgivings over the deployment of such a heavy and unwieldy weapon, 5th Army commanders dubbed the 240&nbsp;mm howitzer as "the most generally satisfactory weapon" in service in 1944.<ref name="p33"/> 

By November 1944, however, all 8-inch guns and 240 mm howitzers had been withdrawn from Italy and sent to the [[Western Front (World War II)|Western Front]]. The 240&nbsp;mm howitzer saw extensive service in Europe, reducing reinforced targets requiring super-heavy artillery.<ref name="p33"/> Fifteen 240 mm howitzer battalions served in the European Theater; the 265th, 266th, [[267th Field Artillery Battalion|267th]], 269th, 270th, 272nd, 277th, 278th, 538th, 539th, 551st, 552nd, 553rd, 697th, and 698th. Five served in the Pacific; the 543rd, 544th, 545th, 778th, and 779th.

During the [[Korean War]], twelve 240 mm howitzers were brought out of "[[mothballs]]" and sent to the front lines to deal with deep bunkers and fortifications built by the [[People's Liberation Army|Chinese]] that could not be effectively attacked by the smaller artillery weapons then on hand. They were utilized in two units in Korea, the 213th and 159th Field Artillery Battalions. The weapons went into action on 1 May 1953. On that day, the first round was fired by Baker battery of the 213th at a target on top of a hill called "the donut" by [[aerial observer]]s. The first round was supposed to be just a ceremonial shot; however, it struck an [[ammo dump]] directly on top of "the donut" which set off a chain reaction and blew part of the top of the hill off in a spectacular fashion.<ref>Sobiesky, Tony., [http://www.koreanwaronline.com/arms/240mm.htm "240 mm Howitzer: Kiss Of Death"], ''the KOREAN WAR'', Updated on 2014-11-22.</ref>

In the late 1950s, several M1s were transferred to the [[Republic of China]] on [[Taiwan]] and stationed in the front-line [[Kinmen]] and [[Matsu Islands]]. The guns were put on rails to enable the howitzers to deploy outside for fire missions and to retreat inside their hardened bunkers/tunnels for protection (capable of withstanding direct hits from aerial bombs) when needed.<ref>M1 240mm Howitzer [http://www.chinamil.com.cn/site1/xwpdxw/2007-07/10/content_949294.htm "Taiwan M1 240mm Howitzer"] {{Webarchive|url=https://web.archive.org/web/20110501081419/http://www.chinamil.com.cn/site1/xwpdxw/2007-07/10/content_949294.htm |date=2011-05-01 }}, Retrieved on 2010-02-20.</ref><ref>[https://www.youtube.com/watch?v=6WCwv7PEIPA&feature=player_embedded# "Kinmen M1 240mm Howitzer firing exercise"], Retrieved on 2010-03-06.</ref>

==Self-propelled mount==

The 240 mm howitzer M1 was broken down into two loads for travel (the barrel and recoil mechanism and the carriage), each towed on a six-wheeled wagon by a [[Mack NO 7½-ton 6x6 truck]] or another heavy prime mover such as the [[M3 Lee|M33]] or [[M10 tank destroyer|M35]]. A truck-mounted crane was required to assemble and disassemble the weapon. Due to the problems with moving such a large, heavy weapon, a self-propelled version was made by mounting it on a stretched [[M26 Pershing|Heavy Tank T26E3]] chassis that featured an extra bogie wheel per side, as the [[T92 Howitzer Motor Carriage]],<ref>[http://www.wwiivehicles.com/united-states/vehicle/self-propelled-guns/t92-howitzer-motor-carriage.asp "United States' T92 Howitzer Motor Carriage"] {{Webarchive|url=https://web.archive.org/web/20170329082639/http://www.wwiivehicles.com/united-states/vehicle/self-propelled-guns/t92-howitzer-motor-carriage.asp |date=2017-03-29 }}, ''wwiivehicles.com''. Retrieved on 2010-02-28.</ref> While 115 were planned, only five were built and the war ended before they could be used and they were later scrapped.<ref>Chamberlain & Ellis ''British and American Tanks of World War II'' 1969 p161</ref>

<gallery>
File:240mmHowitzerM1FortSillRear2005.jpg | Rear view of a 240mm howitzer at the U.S. Army Field Artillery Museum, [[Ft. Sill]], [[Oklahoma]]
File:240mmHowitzerM1FortSillLeftSide2005.jpg | Side view of a 240mm howitzer at the U.S. Army Field Artillery Museum, [[Ft. Sill]], [[Oklahoma]]
</gallery>

==Footnotes==
{{Reflist}}

==See also==
* [[List of U.S. Army weapons by supply catalog designation]] SNL D-31

==References==
* [[Ian V. Hogg|Hogg, Ian V.]] (1970).  ''The Guns, 1939–45''. New York: Ballantine Books. {{ISBN|0-01-906710-0}}.
* {{cite book |last=Hogg |first=Ian V. |authorlink=Ian V. Hogg |year=1998 |title=Allied Artillery of World War Two |publisher=Greenhill Books |isbn=1-85367-478-8}}
* Schreier, Konrad F., Jr. (1994). ''Standard Guide to U.S. World War II Tanks & Artillery''. Krause Publications. {{ISBN|0-87341-297-4}}.
* Zaloga, Steven J., Brian Delf (2007). ''US Field Artillery of World War II''. New Vanguard 131. Osprey Publishing. {{ISBN|978-1-84603-061-1}}.

==External links==
{{Commons category}}
* [http://www.globalsecurity.org/military/systems/ground/m1-240.htm "M1 240 mm Howitzer"], ''Globalsecurity.org'', Retrieved on 2007-05-25.
* [http://members.tripod.com/~nigelef/gunsintro.htm British Artillery in World War II]
* [https://books.google.com/books?id=PiEDAAAAMBAJ&dq=popular+science+1945+%22Biggest+Gun+On+Wheels%22&pg=PA76 ''Biggest Guns On Wheels''] July 1945 [[Popular Science]] article

{{WWIIUSGuns}}
{{WWIIBritishCommGuns}}

{{DEFAULTSORT:240 Mm Howitzer M1}}
[[Category:World War II artillery of the United States]]
[[Category:Cold War artillery of the United States]]
[[Category:World War II field artillery]]
[[Category:240 mm artillery]]
[[Category:World War II howitzers]]
[[Category:Weapons and ammunition introduced in 1942]]