Editing Caltrop (section)

==Modern uses==
[[File:Crows feet 2, Balaclava 1854.jpg|thumb|right|Crow's feet boards studded with spikes. These were laid on the ground to prevent the enemy from approaching the defences. This board was used by the Russian Army during the [[Battle of Balaclava]]. On display at Royal Engineers Museum, Kent.]]

===World War I===
During service in [[World War I]], [[Australian Light Horse]] troops collected caltrops as keepsakes. These caltrops were either made by welding two pieces of wire together to form a four-pointed star or pouring molten steel into a mould to form a solid, seven-pointed star. The purpose of these devices was to disable horses. They were exchanged with French troops for bullets. The Australian Light Horse troops referred to them as "Horse Chestnuts".{{citation needed|date=June 2014}}

===World War II===
Caltrops were used extensively and effectively during [[World War II]]. The modifications and variants produced by the [[Special Operations Executive]] (SOE) and the [[Office of Strategic Services]] (OSS) of the United States{{sfn|Lovell|1964|pp=42–43}} are still in use today within special forces and law enforcement bodies.{{who|date=January 2012}}

The Germans dropped ''crow's feet'' ({{langx|de|Krähenfüße}}).{{sfn|Civil Defence Training Pamphlet No 2|p=25}} These were made from two segments of sheet metal welded together into a tetrapod with four barbed points and then painted in camouflage colours. They came in two sizes with a side length of either {{convert|65|or|75|mm|in}}. They were dropped from aircraft in containers the same size as {{convert|500|kg|abbr=on}} bombs and were dispersed by a small explosive charge.{{sfn|Civil Defence Training Pamphlet No 2|p=25}}<ref>{{cite web
 | url        = http://www.lonesentry.com/articles/ttt08/german-spikes.html
 | title      = German Metal Spikes (Crowsfoot)
 | work       = Tactical and Technical Trends
 | date       = 5 November 1942
 | access-date = 30 April 2015
}}</ref>

===Tire deflation device===
{{See also|Spike strip}}
[[File:Caltrop.jpg|thumb|right|Caltrop used by the US [[Office of Strategic Services]]. The hollow spikes puncture self-sealing rubber tires. The hole in the center allows air to escape even if other ends of the tube are sealed by soft ground.]]
Inventors patented caltrop-like devices to deflate vehicle tires in a manner useful to law enforcement agencies or the military.<ref>
{{cite web
| url= http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=US2346713&F=0&QPN=US2346713
| title= Caltrop
| access-date=11 April 2008
| first= Walker
| last= Brooks
| date= 18 April 1944
| work= US2346713
| publisher= European Patent Office}}
</ref><ref>
{{cite web
| url = http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=US5921703&F=0
| title= Caltrop
| access-date=11 April 2008
| first= Jonathan
| last= Becker
| date= 13 July 1999
| work= US5921703
| publisher= European Patent Office|display-authors=etal}}
</ref> They are currently used by the military and police.<ref name=HistoryNet/>

===Labour disputes===
Caltrops have been used at times during [[labour strike]]s and other disputes. Such devices were used by some to destroy the tires of management and replacement workers.

Caltrops, referred to as "jack rocks" in news articles, were used during the [[Caterpillar Inc.|Caterpillar]] strike in 1995, puncturing tires on vehicles crossing the picket line in [[Peoria, Illinois]]. Because of their small size and the difficulty proving their source, both the company and the [[United Auto Workers]] blamed each other. Collateral damage included a school bus and a walking mail carrier.<ref>{{Cite news |url=http://www.nwitimes.com/uncategorized/spiky-jack-rocks-newest-weapon-in-cat-strike/article_497e117d-f0ae-5829-8ac8-0846bb8e136e.html |title=Spiky 'jack rocks' newest weapon in CAT strike |agency=Associated Press |newspaper=The New York Times|access-date=2017-01-11}}</ref> In [[Illinois]], the [[state legislature]] passed a law making the possession of such devices a [[misdemeanor]].<ref>{{ILCS|720|5|21-1.4 |title=Jackrocks violation |accessdate=21 October 2007}}{{Dead link|date=February 2024}}</ref>

=== Via drones ===
During the [[Russian invasion of Ukraine]], Ukraine has used drones to drop caltrops on key roads to disrupt wheeled vehicles carrying Russian military [[materiel]], and make them easier to target with [[loitering munition]]s.<ref>{{Cite web |last=Hambling |first=David |title=Ukraine Drops Ancient Roman Weapons From Drones To Stop Russian Trucks |url=https://www.forbes.com/sites/davidhambling/2024/04/12/ukraine-teams-ancient-and-modern-weapons-to-stop-russian-trucks/ |access-date=2024-04-13 |website=Forbes |language=en}}</ref>