View source for Bailey bridge

{{short description|Type of portable truss bridge}}
{{About|portable prefabricated bridges|specific bridges named "Bailey"|Bailey Bridge (disambiguation){{!}}Bailey Bridge}}
{{ infobox bridge type
| image            = PontBailey.jpg
| image_title      = Bailey bridge over the [[Meurthe River]], France
| sibling_names    = [[Callender-Hamilton bridge]]
| span_range       = Short
| descendent_names = [[Mabey Logistic Support Bridge]], [[Medium Girder Bridge]], Extra-Wide Bailey Bridge, Acrow 700XS, Mabey Universal, Mabey Compact 100 and 200.
| carries          = Pedestrians, Road vehicles, Rail Vehicles
| material         = [[Timber]], [[steel]]
| movable          = No
| design           = Low
| falsework        = None
}}

A '''Bailey bridge''' is a type of portable, [[Prefabrication|pre-fabricated]], [[Truss Bridge|truss bridge]]. It was developed in 1940–1941 by the [[British Empire in World War II|British]] for military use during the [[World War II|Second World War]] and saw extensive use by British, Canadian and American [[Military engineering|military engineering units]]. A Bailey bridge has the advantages of requiring no special tools or heavy equipment to assemble. The wood and steel bridge elements were small and light enough to be carried in trucks and lifted into place by hand, without the use of a crane. These bridges were strong enough to carry tanks. Bailey bridges continue to be used extensively in civil engineering construction projects and to provide temporary crossings for pedestrian and vehicle traffic.

== History ==
[[File:Christchurch, Stanpit Marsh - geograph.org.uk - 1705320.jpg|thumb|upright=1.3|Prototype Bailey bridge at [[Stanpit|Stanpit Marsh]] in [[Dorset]]]]
[[File:Bailey Bridge.tif|thumb|upright=1.3|Bailey bridge undergoing trials in [[Christchurch, Dorset]]]]

[[Donald Bailey (civil engineer)|Donald Bailey]] was a [[civil servant]] in the [[United Kingdom|British]] [[War Office]] who tinkered with model bridges as a hobby.<ref name=":0">{{cite news| url=https://www.latimes.com/archives/la-xpm-1985-05-07-mn-11177-story.html| title=Sir Donald Bailey, WW II Engineer, Dies| agency=Times Wire Services| date=1985-05-07| newspaper=[[Los Angeles Times]]| access-date=2018-09-19| language=en-US| issn=0458-3035| quote="He sketched the original design for the Bailey Bridge on the back of an envelope as he was being driven to a meeting of Royal Engineers to debate the failure of existing portable bridges"}}</ref> He had proposed an early prototype for a Bailey bridge before the war in 1936,{{Sfn|Harpur|1991|p=3}} but the idea was not acted upon.{{Sfn|Joshi|2008|p=29}} Bailey drew an original proposal for the bridge on the back of an envelope in 1940.<ref name=":0" />{{Sfn|Harpur|1991|p=4}} On 14 February 1941, the [[Ministry of Supply]] requested that Bailey have a full-scale prototype completed by 1 May.{{Sfn|Harpur|1991|p=31}} Work on the bridge was completed with particular support from [[Ralph Freeman (1880–1950)|Ralph Freeman]].{{Sfn|Harpur|1991|p=37}} The design was tested at the Experimental Bridging Establishment (EBE), in [[Christchurch, Dorset]],{{Sfn|Joshi|2008|p=29}}<ref name=":1" /> with several parts from [[Braithwaite & Co.]],{{Sfn|Harpur|1991|p=38–41}} beginning in December 1940 and ending in 1941.{{Sfn|Joshi|2008|p=29}}<ref name=":1">{{cite web| url=https://www.bbc.co.uk/history/ww2peopleswar/stories/42/a2697942.shtml| title=WW2 People's War – The Sappers Story| website=BBC| access-date=2018-09-19}}</ref> The first prototype was tested in 1941.{{Sfn|Joshi|2008|p=30}} For early tests, the bridge was laid across a field, about {{Convert|2|ft|m}} above the ground, and several [[Mark V tank]]s were filled with [[pig iron]] and stacked upon each other.{{Sfn|Harpur|1991|p=38-41}}

The prototype of this was used to span Mother Siller's Channel, which cuts through the nearby [[Stanpit Marsh]]es, an area of marshland at the [[confluence]] of the [[River Avon (Hampshire)|River Avon]] and the [[River Stour, Dorset|River Stour]]. It remains there ({{nbsp}}{{coord|50.7252806|-1.762155|type:landmark|format=dms}}) as a functioning bridge.<ref>{{cite web| url=http://www.hengistbury-head.co.uk/stanpit.htm|title=Stanpit Marsh and Nature Reserve| website=Hengistbury Head| archive-url=https://web.archive.org/web/20160325122537/http://hengistbury-head.co.uk/hengistbury-head-stanpit.php| archive-date=March 25, 2016| access-date=2011-09-27}}</ref> Full production began in July 1941. Thousands of workers and over 650 firms, including [[Littlewoods]], were engaged in making the bridge, with production eventually rising to 25,000 bridge panels a month.{{Sfn|Harpur|1991|p=|pp=48–50}} The first Bailey bridges were in military service by December 1941,{{Sfn|Joshi|2008|p=30}} Bridges in the other formats were built, temporarily, to cross the Avon and Stour in the meadows nearby. After successful development and testing, the bridge was taken into service by the [[Corps of Royal Engineers]] and first used in North Africa in 1942.<ref name="Caney">{{cite book| url=https://archive.org/details/stevencaneysulti00cane| url-access=registration| title=Steven Caney's Ultimate Building Book| last=Caney| first=Steven| publisher=Running Press|year=2006| isbn=978-0-7624-0409-4| page=[https://archive.org/details/stevencaneysulti00cane/page/188 188]|access-date=2011-09-11}}</ref>

The original design violated a [[patent]] on the [[Callender-Hamilton bridge]]. The designer of that bridge, [[A. M. Hamilton]], successfully applied to the [[Royal Commission on Awards to Inventors]]. The Bailey Bridge was more easily constructed, but less portable than the Hamilton bridge.<ref>{{cite news| title=Bridge Claim By General 'Used As Basis For Bailey Design'| date=26 July 1955| newspaper=[[The Times]]| page=4| location=London}}</ref><ref>{{cite book| url=https://books.google.com/books?id=HGUI4ZYVnIUC&pg=PA22| title=Nature's Oracle: The Life and Work of W.D.Hamilton|last1=Segerstrale| first1=Ullica| last2=Segerstråle| first2=Ullica Christina Olofsdotter| date=2013-02-28| publisher=OUP| location=Oxford| isbn=978-0-1986-0727-4| language=en}}</ref> Hamilton was awarded £4,000 in 1936 by the War Office for the use of his early bridges and the Royal Commission on Awards to Inventors awarded him £10,000 in 1954 for the use, mainly in Asia, of his later bridges. [[Lieutenant General]] [[Sir]] [[Giffard Le Quesne Martel]] was awarded £500 for infringement on the design of his [[box girder bridge]], the Martel bridge.{{Sfn|Harpur|1991|p=113}} Bailey was later [[knight]]ed for his invention, and awarded £12,000.{{Sfn|Harpur|1991|p=108}}<ref>{{London Gazette| issue=37407| date=1 January 1946| page=2| supp=y}}</ref>

=== Use in the Second World War ===
[[file:The British Army in Italy, 1944 TR2612.jpg|thumb|upright=1.4|Allied military traffic crosses a Bailey bridge, spanning a damaged section of a masonry [[arch bridge]]. At the same time, local workers are rebuilding the original bridge. Italy 1944]]

The first operational Bailey bridge during the [[World War II|Second World War]] was built by 237 Field Company R.E. over [[Medjerda River]] near [[Medjez el Bab]] in [[Tunisia]] on the night of 26 November 1942.{{Sfn|Harpur|1991|p=69}} The first Bailey bridge built under fire was constructed at [[Leonforte]] by members of the 3rd Field Company, Royal Canadian Engineers.<ref>{{cite web |title=Bailey Bridge Primer |url=https://cmea-agmc.ca/sites/default/files/bailey_bridge_primer_v2_0.pdf |website=Canadian Military Engineers}}</ref> The Americans soon adopted the Bailey bridge technique, calling it the ''Portable Panel Bridge''. In early 1942, the [[United States Army Corps of Engineers]] initially awarded contracts to the Detroit Steel Products Company, the American Elevator Company and the Commercial Shearing and Stamping Company, and later several others.{{Sfn|Harpur|1991|p=87}}

The Bailey provided a solution to the problem of German and Italian armies destroying bridges as they retreated. By the end of the war, the [[US Fifth Army]] and [[British 8th Army]] had built over 3,000 Bailey bridges in [[Sicily]] and [[Italy]] alone, totaling over {{convert|55|mi|km}} of bridge, at an average length of {{convert|100|ft|m}}. One Bailey, built to replace the [[Sangro River]] bridge in Italy, spanned {{convert|1126|ft|m}}. Another on the [[Chindwin River]] in [[Burma]], spanned {{convert|1154|ft|m}}.<ref>{{cite book| title=Defeat Into Victory| last=Slim| first=William|publisher=Macmillan| location=London| year=1986| url=https://archive.org/details/defeatintovictor0000slim/page/366/mode/2up?q=%22bailey+bridge%22| isbn=978-0-3334-0956-5| page=366}}</ref> Such long bridges required support from either piers or [[Float (nautical)|pontoons]].<ref name="warillustrated">{{cite journal| date=January 19, 1945| title=How the Army's Amazing Bailey Bridge is Built| url=http://www.thewarillustrated.info/198/how-the-armys-amazing-bailey-bridge-is-built.asp| archive-url=https://web.archive.org/web/20080403095316/http://www.thewarillustrated.info/198/how-the-armys-amazing-bailey-bridge-is-built.asp| url-status=usurped| archive-date=April 3, 2008| journal=The War Illustrated| volume=8| issue=198| page=564| access-date=2011-09-11}}</ref>

A number of bridges were available by 1944 for [[D-Day]], when [[British Cellophane Ltd|production]] was accelerated. The US also licensed the design and started rapid construction for their own use. A Bailey Bridge constructed over the [[Rhine|River Rhine]] at [[Rees, Germany]], in 1945 by the [[Canadian Military Engineers|Royal Canadian Engineers]] was named "Blackfriars Bridge", and, at 555&nbsp;m (1814&nbsp;ft) including the ramps at each end, was then the longest Bailey bridge ever constructed.<ref name="CMEA">{{cite web| url=https://cmea-agmc.ca/heritage-moment/blackfriars-bridge-longest-bailey-bridge-world| title=Blackfriars Bridge – Longest Bailey Bridge in the World| website=Canadian Military Engineers Association| access-date=12 November 2017}}</ref> In all, over 600 firms were involved in the making of over 200 miles of bridges composing of 500,000 tons, or 700,000 panels of bridging during the war. At least 2,500 Bailey bridges were built in Italy, and another 2,000 elsewhere.{{Sfn|Joshi|2008|p=30}}{{Sfn|Harpur|1991|p=|pp=48–50}}

[[Field Marshal]] [[Bernard Montgomery]] wrote in 1947:{{Blockquote|Bailey Bridging made an immense contribution towards ending World War II. As far as my own operations were concerned, with the eighth Army in Italy and with the [[British 21st Army Group|21 Army Group]] in [[Western Front (World War II)#1944 – 1945|North West Europe]], I could never have maintained the speed and tempo of forward movement without large supplies of Bailey Bridging.<ref>{{cite web |url=http://www.mabey.com/bailey.html |archive-url=https://web.archive.org/web/20070615101506/http://www.mabey.com/bailey.html |publisher=Mabey Bridge and Shore |title=Bailey Bridge |archive-date=2007-06-15 |access-date=2011-09-11}}</ref><ref>{{cite web |url=http://www.btinternet.com/~ian.a.paterson/equipotheritems.htm |title=Other Equipment Used By The 7th Armoured Division |website=History of the British 7th Armoured Division |access-date=2025-11-14 |url-status=usurped |archive-url=https://web.archive.org/web/20100813232737/http://www.btinternet.com/~ian.a.paterson/equipotheritems.htm |archive-date=August 13, 2010}}</ref>}}

===Post-war applications===

The [[Skylark launch tower]] at [[Woomera Prohibited Area|Woomera]] was built up of Bailey bridge components.<ref>{{cite book| url=https://books.google.com/books?id=bqQsjc3BwZkC&pg=PA25| title=History of British Space Science| last1=Massie| first1=Harrie| last2=Robins| first2=M. O.| date=1986-02-27| publisher=Cambridge University Press| isbn=978-0-5213-0783-3| language=en}}</ref> In the years immediately following World War II, the [[Ontario Hydro|Ontario Hydro-Electric Power Commission]] purchased huge amounts of war-surplus Bailey bridging from the Canadian War Assets Corporation. The commission used bridging in an office building.<ref>{{cite magazine| url=https://books.google.com/books?id=1tgDAAAAMBAJ&pg=PA125|title=Bailey Bridge Becomes Office Building| magazine=[[Popular Mechanics]]| page=125| date=May 1948| language=en}}</ref><ref>{{cite web |url=https://books.google.com/books?id=-U4jAQAAMAAJ |title=Electric Light and Power |date=16 February 1955 |language=en}}</ref> Over 200,000 tons of bridging were used in a hydroelectric project.{{Sfn|Harpur|1991|p=106}} The Ontario government was, several years after World War II, the largest holder of Bailey Bridging components. After World War II and especially post [[Hurricane Hazel]] in 1954, some of the bridging was used to construct replacement bridges in the Toronto area:<ref>{{cite news |url=https://www.toronto.com/news-story/6900026-stories-from-rouge-park-canadian-military-builds-baily-bridge-to-get-traffic-moving-after-hurricane-hazel/ |title=STORIES FROM ROUGE PARK: Canadian military builds Baily Bridge to get traffic moving after Hurricane Hazel |last=Noonan |first=Larry |date=2016-10-11 |newspaper=[[Toronto Star]] |access-date=2018-11-02 |language=en-CA}}</ref>

* [[16th Avenue Bailey Bridge]] c. 1945
* [[Lake Shore Boulevard Bailey Bridge]] was built in 1952 for Ontario Hydro
* [[Old Finch Avenue Bailey Bridge]], built by the [[2nd Field Engineer Regiment]], is the last still in use.<ref>{{cite news |url=https://nowtoronto.com/news/story.cfm?content=160327&archive=27,9,2007 |title=Best of Toronto: Cityscape |date=November 2007 |work=NOW Magazine |archive-url=https://web.archive.org/web/20120210071316/https://nowtoronto.com/news/story.cfm?content=160327&archive=27,9,2007 |archive-date=February 10, 2012}}</ref>

The longest Bailey bridge was put into service in October 1975. This {{convert|788|m|ft|adj=on}}, two-lane bridge crossed the [[Derwent River (Tasmania)|Derwent River]] at [[Hobart]], Australia.<ref>{{Cite book |url=https://books.google.com/books?id=BAFjduDQUfQC|title=Journals and Printed Papers of the Parliament of Tasmania|date=1977|publisher=Government Printer|language=en}}</ref> The Bailey bridge was in use until the reconstruction of the [[Tasman Bridge]] was completed on 8 October 1977.<ref>{{Cite web |url=http://www.abs.gov.au/Ausstats/abs@.nsf/0/7a88395760718555ca256c32002417ba?OpenDocument |title=Feature Article – The Tasman bridge (Feature Article) |date=2002-09-13 |website=Tasmanian Year Book, 2000 |language=en |access-date=2018-11-02}}</ref> Bailey bridges are in regular use throughout the world, particularly as a means of bridging in remote regions.<ref>{{Cite web|url=https://www.telegraphindia.com/west-bengal/twin-bailey-bridges-to-fill-the-gap/cid/1668242|title=Twin Bailey bridges to fill the gap|website=The Telegraph|location=Kolkota|language=en|access-date=2018-11-02}}</ref> In 2018, the Indian Army erected three new footbridges at [[Elphinstone Road railway station|Elphinstone Road]], a commuter railway station in [[Mumbai, India|Mumbai]], and at [[Currey Road railway station|Currey Road]] and [[Ambivli railway station|Ambivli]]. These were erected quickly, in response to [[2017 Mumbai stampede|a stampede]] some months earlier, where 23 people died.<ref>{{Cite news|url=http://www.timesnownews.com/india/article/elphinstone-road-mumbai-foot-over-bridge-indian-army-stampede-currey-road-ambiivli-piyush-goyal-devendra-fadnavis-flower-vendor/202752|title=Built by the Army, Elphinstone Road foot-overbridge inaugurated by a flower vendor|date=27 February 2018|newspaper=[[The Times of India]]}}</ref> The [[United States Army Corps of Engineers]] uses Bailey Bridges in construction projects, including an emergency replacement bridge on the [[Hana Highway]] in Hawaii.<ref>{{Cite news|url=https://www.newburyportnews.com/news/local_news/officials-focus-on-design-of-bridge-over-artichoke-reservoir/article_d75bb0ef-7cb3-54ea-9f8e-230e972dae05.html|title=Officials focus on design of bridge over Artichoke Reservoir|author=Jennifer Solis|work=The Daily News of Newburyport|access-date=2018-11-02|language=en}}</ref> Two temporary Bailey bridges have been used on the northern span of the [[Dufferin Street bridges]] in [[Toronto]] since 2014.{{Citation needed|date=January 2020}}

The first Bailey Bridge built for civilian use in India was on the Pamba river in a place called Ranni in Pathanamthitta district of the state of Kerala. It was on 1996 November 08. 

In 2017 the [[Irish Army]] built a Bailey bridge to replace a road bridge across the [[Cabry River]], in County Donegal, after the original bridge was destroyed in floods.<ref>{{cite news |url=https://www.irishtimes.com/news/environment/donegal-bridges-gaps-after-all-hands-on-deck-flood-response-1.3206768 |title=Donegal bridges gaps after 'all hands on deck' flood response |newspaper=The Irish Times |author=Murtagh, Peter |date=2 September 2017 |access-date=24 January 2020}}</ref>

In 2021 a Bailey bridge was built across the river Dijle in Rijmenam (Belgium) for the transportation of excavated soil from one side to the other of the river. The bridge allowed the trucks to cross the river without having to pass the city center.<ref>{{Cite news|url=https://www.standaard.be/cnt/dmf20210706_93518735|title=Bridge dating from Second World War placed over the river Dijle|access-date=2018-11-02|language=nl|newspaper=[[De Standaard]]}}</ref>

In March 2021, the [[Michigan Department of Transportation]] constructed a Bailey bridge on [[M-30 (Michigan highway)|M-30]] to temporarily reconnect the highway after the old structure was destroyed in the May 2020 flooding and subsequent failure of the [[Wixom Lake|Edenville Dam]]. The department will replace the temporary bridge with a permanent structure in the coming years.

Following the [[2023 Auckland Anniversary Weekend floods]] and [[Cyclone Gabrielle]] in the North Island of New Zealand, Bailey bridges were installed to reconnect communities.<ref>{{cite news|url=https://www.rnz.co.nz/news/national/485162/six-bailey-bridges-to-help-reconnect-isolated-north-island-communities|title=Six Bailey bridges to help reconnect isolated North Island communities|publisher=Radio New Zealand|date=2 March 2023}}</ref>

Following the 2023 floods in Madrid, Spain, the [[Spanish Army]] is set to build a Bailey bridge in the village of [[Aldea del Fresno]].<ref>{{Cite web |date=2023-09-06 |title=El Ejército instala en Aldea del Fresno el puente que "ayudó a ganar" la II Guerra Mundial |url=https://www.elmundo.es/madrid/2023/09/06/64f782f121efa0a22e8b4570.html |access-date=2023-09-07 |website=ELMUNDO |language=es}}</ref>

In 2024, following the catastrophic landslide in Kerala’s Wayanad district, the [[Indian Army]] built a 190 feet Bailey bridge in the village of Mundakkai.<ref>{{Cite news |last=PTI |date=2024-08-01 |title=Indian Army constructs 190-ft-long Bailey bridge at Wayanad to connect landslide affected areas |url=https://www.thehindu.com/news/national/kerala/indian-army-constructs-190-ft-long-bailey-bridge-at-wayanad-to-connect-landslide-affected-areas/article68474877.ece |access-date=2024-08-02 |work=The Hindu |language=en-IN |issn=0971-751X}}</ref>

In 2025, during [[2025 Bahía Blanca floods]], [[Argentine Army]] installed two Bailey bridges to reconnect the two halves of the city.<ref>{{cite web | url=https://www.lanueva.com/nota/2025-3-12-19-24-0-el-ejercito-anuncio-que-este-jueves-quedara-inaugurado-el-puente-modular-sobre-el-canal-maldonado | title=El Ejército anunció que este jueves quedará inaugurado el puente modular sobre el Canal Maldonado }}</ref><ref>{{cite web | url=https://www.lanueva.com/nota/2025-3-16-18-16-0-habilitan-un-nuevo-puente-modular-para-atravesar-el-canal-maldonado | title=Habilitan un nuevo puente modular para atravesar el canal Maldonado }}</ref>

== Design ==
{{More citations needed section|date=November 2018}}
[[file:Bailey bridge element, Ranville 01 09.jpg|thumb|The transoms, side-panels and stringers of a Bailey bridge section at the [[Memorial Pegasus]] museum in [[Ranville]], Calvados, France, can all be clearly seen]]
[[file:The British Army in Italy 1943 NA7082.jpg|thumb|[[Royal Engineers]] construct a Bailey bridge in Italy, September 1943. Wood planks are being laid over the stringers to construct the roadbed]]

The success of the Bailey bridge was due to the simplicity of the fabrication and assembly of its modular components, combined with the ability to erect and deploy sections with a minimum of assistance from [[heavy equipment]]. Many previous designs for military bridges required [[Crane (machine)|cranes]] to lift the pre-assembled bridge and lower it into place. The Bailey parts were made of standard [[steel]] [[alloy]]s, and were simple enough that parts made at a number of different factories were interchangeable. Each individual part could be carried by a small number of men, enabling army engineers to move more easily and quickly, in preparing the way for troops and [[materiel]] advancing behind them. The modular design allowed engineers to build each bridge to be as long and as strong as needed, doubling or tripling the supportive side panels, or on the roadbed sections.<ref>{{cite web |url=http://www.mabeybridge.com/modular-bridging/history-of-the-bailey-bridge/ |title=The Story of the Bailey Bridge |work=Mabey Bridge |publisher=Mabey Bridge Ltd. |archive-url=https://web.archive.org/web/20151031050012/http://www.mabeybridge.com/modular-bridging/history-of-the-bailey-bridge/ |access-date=3 October 2015|archive-date=2015-10-31 }}</ref>

The basic bridge consists of three main parts. The bridge's strength is provided by the panels on the sides. The panels are {{convert|10|ft|m|-long|adj=mid}}, {{convert|5|ft|m|-high|adj=mid}}, cross-braced rectangles that each weigh {{convert|570|lb|kg}}, and can be lifted by four men. The panel was constructed of welded steel. The top and bottom chord of each panel had interlocking male and female lugs into which engineers could insert panel connecting pins.<ref name="thinkdefence">{{cite web |url=http://www.thinkdefence.co.uk/2012/01/uk-military-bridging-equipment-the-bailey-bridge/ |title=UK Military Bridging – Equipment (The Bailey Bridge) |work=Think Defence |date=8 January 2012 |publisher=ThinkDefence |access-date=28 March 2015}}</ref>

The floor of the bridge consists of a number of {{convert|19|ft|m|-wide|adj=mid}} [[Transom (architecture)|transoms]] that run across the bridge, with {{convert|10|ft|m|-long|adj=mid}} stringers running between them, and over the top of the transoms, forming a square.<ref name="launching">{{cite journal |date=7 October 1943 |title=Launching the Bailey Bridge |url=http://www.lonesentry.com/articles/ttt07/bailey-bridge.html |journal=Tactical and Technical Trends |issue=35 |access-date=2011-09-11}}</ref> Transoms rest on the lower chord of the panels, and clamps hold them together. Stringers are placed atop the completed structural frame, and [[wood plank]]ing (chesses) are placed atop the stringers to provide a roadbed. Ribands bolt the planking to the stringers. Later in the war, the wooden planking was covered by steel plates, which were more resistant to damage from [[tank track]]s.

Each unit constructed in this fashion creates a single {{convert|10|ft|m|-long|adj=mid}} section of bridge, with a {{convert|12|ft|m|-wide|adj=mid}} roadbed. After one section is complete it is typically pushed forward over rollers on the bridgehead, and another section built behind it. The two are then connected together with pins pounded into holes in the corners of the panels.

For added strength up to three panels (and transoms) can be bolted on either side of the bridge. Another solution is to stack the panels vertically. With three panels across and two high, the Bailey Bridge can support tanks over a {{convert|200|ft|m|[[Span (architecture)|span]]|adj=mid}}. Footways can be installed on the outside of the side-panels. The side-panels form an effective barrier between foot and vehicle traffic, allowing pedestrians to safely use the bridge.<ref name="warillustrated" />

A useful feature of the Bailey bridge is its ability to be launched from one side of a gap, without a need for any equipment or personnel on the far bank.<ref name="launching" /> In this system the front-most portion of the bridge is angled up with short "launch-links" to form a "launching nose" and most of the bridge is left without the roadbed and ribands. The bridge is placed on rollers and simply pushed across the gap, using manpower or a truck or tracked vehicle, at which point the roller is removed (with the help of jacks) and the ribands and roadbed installed, along with any additional panels and transoms that might be needed.

During WWII, Bailey bridge parts were made by companies with little experience of this kind of engineering. Although the parts were simple, they had to be precisely manufactured to fit correctly, so they were assembled into a test jig at each factory to verify this. To do this efficiently, newly manufactured parts would be continuously added to the test bridge, while at the same time the far end of the test bridge was continuously dismantled and the parts dispatched to the end-users.<ref name="warillustrated" />

== See also ==

* {{anl|AM 50}}
* {{anl|Armoured vehicle-launched bridge}}
* {{anl|Mabey Logistic Support Bridge}}
* {{anl|Medium Girder Bridge}}
* {{anl|Military engineer}}
* [[PLA Navy landing barges]]
* {{anl|Pontoon bridge}}

== References ==

{{refs}}

== Bibliography ==

* {{Cite book|url=https://books.google.com/books?id=I4_fAAAAMAAJ|title=A Bridge to Victory: The Untold Story of the Bailey Bridge|last=Harpur|first=Brian|date=1991-01-01|publisher=H.M. Stationery Office|isbn=9780117726505|language=en}}
* {{Cite book|url=https://babel.hathitrust.org/cgi/pt?id=uva.x004788980;view=1up;seq=2|title=Bailey bridge|series=Technical manual; TM 5-277 |publisher=Department of the Army|year=1972|location=Washington, D.C.}}
* {{Cite magazine|last=Sanders|first=Gold V.|year=1944|title=Push-Over Bridges Built Like Magic from Interlocking Parts|url=https://books.google.com/books?id=PyEDAAAAMBAJ&pg=PA94|magazine=Popular Science|pages=94{{en dash}}98}}
* {{Cite book|url=https://www.drdo.gov.in/sites/default/files/monographs-documents/19-military-bridging.pdf |archive-url=https://web.archive.org/web/20211025104428/https://www.drdo.gov.in/sites/default/files/monographs-documents/19-military-bridging.pdf |archive-date=2021-10-25 |url-status=live|title=Military Bridging|last=Joshi|first=MR|publisher=Defence Research & Development Organisation|year=2008}}

== External links ==
{{commons}}

* [http://www.nzta.govt.nz/network/maintaining/management/bailey-bridge.html Bailey Bridges in New Zealand]
* [http://www.globalsecurity.org/military/library/policy/army/fm/5-277/fm5-277.pdf US Army Field Manual FM5-277] Dated 9 May 1986.
* [https://www.youtube.com/watch?v=-8HSHOzbgzE Mabey Bridge Compact 200™ - Modular Bridge Construction] Animated build of a modern Mabey Compact 200 Bridge (similar to the original Bailey Bridge)
[[Category:Truss bridges by type]]
[[Category:Bridges by structural type]]
[[Category:Military bridging equipment]]
[[Category:English inventions]]