Sandbag

Sturdy sack used in flood control and temporary military fortifications

For other uses, see Sandbag (disambiguation).

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Residents and volunteers work to fill sandbags during the Mississippi and Missouri river floods of 1993. Members of the Georgia National Guard filling sandbags in preparation for floods.

A sandbag or dirtbag is a bag or sack made of hessian (burlap), polypropylene or other sturdy materials that is filled with sand or soil and used for such purposes as flood control, military fortification in trenches and bunkers, shielding glass windows in war zones, ballast, counterweight, and in other applications requiring mobile fortification, such as adding improvised additional protection to armored vehicles or tanks.

The advantages are that the bags and sand are inexpensive. When empty, the bags are compact and lightweight for easy storage and transportation. They can be brought to a site empty and filled with local sand or soil. Disadvantages are that filling bags is labor-intensive. Without proper training, sandbag walls can be constructed improperly causing them to fail at a lower height than expected, when used in flood-control purposes. They can degrade prematurely in the sun and elements once deployed. They can also become contaminated by sewage in flood waters making them difficult to deal with after flood waters recede.[1] In a military context, improvised up-armouring of tanks or armored personnel carriers with sandbags is not effective against cannons (though it may offer protection against some small arms).

Sandbags have traditionally been filled manually using shovels. Since the 1990s, machine filling has become more common, allowing the work to be done more quickly and efficiently.

## Usage

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Troops from the Grenadier Guards constructing sandbag defenses around government buildings in Birdcage Walk, London, May 1940.

### Flood control

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Properly stacked sandbags[2] are an effective deterrent against damaging flood waters. Sandbags can be used to build levees, barricades, dikes and berms to limit erosion from flooding. Sandbags can also be used to fortify existing flood control structures and limit the effects of sand boils. Sandbag structures do not prevent water seepage and therefore should be built with the central purpose of diverting flood water around or away from buildings.

Properly filled sandbags for flood control are filled one-half to two-thirds full with clean washed sand. In an emergency, if clean sand is in limited supply, gravel or dirt can also be used with less effective end results. When filled sandbags are stacked or laid in place, the contents need to settle flat to the ground. Sandbags filled over two-thirds full will not form an adequate seal to the ground or structure. Likewise sandbags filled under one-half will generally also form an inadequate seal to the ground when placed.

The best practices for filling sandbags require a three-person team. One team member will crouch down and hold open the bag to form a collar opening. The second team member places the tip of a pointed shovel with sand into the opened sandbag. A square shovel is not recommended as the blade of the shovel will not fit into the sandbag when filling. The third team member will transport and stockpile the filled sandbags.

Properly placed sandbags will be set lengthwise and parallel to the water flow with the folded or open end of the sandbag facing upstream. All loose debris should be removed from the placement surface and the lowest areas are the first spots to be filled in with sandbags. Each bag must be set consecutively with the tightly packed bottom slightly overlapping the previously placed sandbag. Subsequent layers of bags should be offset by 1/2 the length of a sandbag to eliminate voids and improve the wall seal. Each placed bag should be tamped and flattened to improve the seal.

The two primary methods for stacking sandbags to build flood control structures are the (1) Single Stack placement, and; (2) Pyramid Placement Method.[3]

### Fortification

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The military uses sandbags for field fortifications and as a temporary measure to protect civilian structures. Because burlap and sand are inexpensive, large protective barriers can be erected cheaply. The friction created by moving soil or sand grains and tiny air gaps makes sandbags an efficient dissipator of explosive blast.[4] The most common sizes for sandbags are 14 by 26 inches (36 by 66 cm) to 17 by 32 inches (43 by 81 cm).[5][6] These dimensions, and the weight of sand a bag this size can hold, allow for the construction of an interlocking wall like brickwork.

Individual filled bags are not too heavy to lift and move into place. They may be laid in excavated defences as revetment, or as free-standing walls above ground where excavations are impractical. As plain burlap sandbags deteriorate fairly quickly, sandbag structures meant to remain in place for a long time may be painted with a portland cement slurry to reduce the effects of rot and abrasion. Cotton ducking sandbags last considerably longer than burlap and are hence preferable for long-term use. However, the vast majority of sandbags used by modern military and for flood prevention are made of circular woven polypropylene. Some of the World War I memorial trenches were rebuilt with concrete sandbags after the First World War—although criticized as looking unnatural, they have lasted well. During World War II in Great Britain, some aircraft revetments and pillboxes were made from concrete filled sandbags, again these have lasted well.

Sandbag fortifications have been used since at least the late 16th century. For example, the rebellious Mughal governor Mirza Jani Beg used improvised sandbags made out of boat sails to construct a makeshift fort at Unarpur, Sindh, in 1592.[7] Later, British loyalists used sandbag and log fortifications in the 1781 Siege of Ninety-Six during the American Revolutionary War. Nathanael Greene was familiar enough with the fortification technique to equip his troops with hooks to pull down the sandbag and log walls when they stormed the Star Redoubt in Ninety Six, South Carolina.[8]

In ancient times, temporary sandbag forts known as an antestature were made out of sandbags. They were historically hastily established by a retreating force to slow the progress of the enemy. The word comes from the Latin ante ("before"), and statūra ("a standing").[9]

## Bulk bags

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Plastic geotextile bags

Bulk bags, also known as big bags, are much larger than traditional sandbags. Moving a bag of this size typically requires a forklift truck. Bulk bags are usually made of woven or non-woven geotextiles.

Large bags of sand are often used in flood control and making temporary patches to water barriers. For example, Thailand utilized bulk bags filled with sand to erect temporary walls to protect against the 2011 Thailand floods.

## Other uses

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Sandbags being filled using a ladder on sawhorses with traffic cones as chutes or funnels, Moorhead, Minnesota, 2009.

Sandbags are also used for disposable ballast in gas balloons, and as counterweights for theatre sets. Some temporary construction signs or advertising signs are held in place and secured against being blown over with sandbags.

During World War II, sandbags were also used as extemporized "soft armor" on American tanks, with the goal of protecting the tanks from German anti-tank rounds,[10] but they were largely ineffective.

Sandbags can also be carried within vehicles to provide improved traction during inclement weather (typically stored above the drive wheels where the increased weight improves traction). If ever stuck, sand can be removed and placed directly onto the slippery surface thereby providing greatly improved traction. Sandbags are also used by off-road enthusiasts instead of sand plates or sand ladders to assist the vehicle to get traction and momentum after being stuck in soft sand. The same sandbags can be used to bridge deep holes or ditches. Apart from being very light and taking very little space (when empty), the sandbags are a much cheaper option than any of the other options (sand plates, sand ladders, multipurpose bags, etc.).

Sandbags are often used to temporarily stabilize soil from erosion, such as oceanfront structures whose foundations have been undermined by heavy waves. Sandbags are also used in earthbag construction to make inexpensive, environmentally sustainable homes. In addition, sandbags are often used when shooting a long gun, specifically a rifle or sniper rifle, from a rest, as it provides support for the weapon, allowing for less movement during shooting.[citation needed]

Sandbags of various sizes and weights can be used for exercise or resistance training.[11]

Sandbags are used for safety in film, video and theatrical production. Sandbags are often used as easily portable weight to lower the center of gravity of a Light stand or a C-Stand where heavy items are placed at the top of a high stand often having a small base. Shot bags are another type of flexible weight used for the same purpose.

## See also

[edit]

* Hesco bastion – Flood control and military fortification barrier
* HydroSack – Commercial flood control sandbag
* Metalith

## References

[edit]

1. ^ Leibenluft, Jacob (2008-06-20). "The 25-Cent Flood Protection Device". Slate.com.
2. ^ Moellman, Mark (2017). Sandbags for Flood Control - 8 Things you Need To Know
3. ^ "US Army Corps of Engineers, Northwest Division".
4. ^ War Office. Military Training Pamphlet No 30, Part V: Protective Works. 1941. p. 39 specifies 20 inches (510 mm) of sand in bags as proof against armour piercing bullets and bomb fragments.
5. ^ Kim Williamson. How Sandbags Work. Answers.com.
6. ^ Kelly Hart. Type of Earthbags to Use. EarthbagBuilding.com.
7. ^ Akhtar, Muhammad Saleem (1983). Shāhjahānī of Yūsuf Mīrak (1044/1634) Sind under the Mughuls: an introduction to, translation of and commentary on the Maẓhar-i Shāhjahānī of Yūsuf Mīrak (1044/1634). pp. 108–113\. doi:10.25911/5d74e2bda15ab. hdl:1885/11279. Retrieved 28 December 2021.
8. ^ Lanning, Michael Lee (2009). The American Revolution 100: The Battles, People, and Events of the American War for Independence, Ranked by Their Significance. Sourcebooks, Inc. p. 319\. ISBN 9781402247309.
9. ^ Rees, Abraham (1819). The cyclopædia; or, Universal dictionary of arts, sciences, and literature. London: Longman, Hurst, Rees, Orme & Brown [etc.] doi:10.5962/bhl.title.59683.
10. ^ Hunnicut, R.P. "Sherman: A History of the American Medium Tank" ISBN 0-89141-080-5
11. ^ "Add Sandbag Training to Your Workout". Muscle & Fitness. May 2011.

## External links

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Wikimedia Commons has media related to Sandbags.

* A guide from Sandbags Online: Everything you ever wanted to know about sandbags, but were too afraid to ask
* California Department of Water Resources - Flood Fighting at home, How to fill and place sandbags Archived 2018-01-11 at the Wayback Machine (PDF)
* California Department of Water Resources and the California Conservation Corps - Flood fighting Methods Archived 2017-06-29 at the Wayback Machine (PDF)
* US Army Corps of Engineers Sandbagging pamphlet (PDF)
* FEMA - Flood Response manual for Community Emergency Response Teams, including sandbagging techniques (PDF)
* US OSHA recommendations for safely Filling, Moving and Placing Sandbags During Flooding Disasters

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Bags and flexible containers

Carried|

* Bayong
* Bindle
* Briefcase
* Bug-out bag
* Dillybag
* Dromedary bag
* Flight bag
* Gaji bag
* Grocery bag
* Hambiliya
* Handbag
* Haversack
* Laundry bag
* Medical bag
* Money bag
* Nuclear briefcase
* Plastic shopping bag
* Red box (government)
* Reticule
* Reusable shopping bag
* Shell purse
* Shopping bag
* String bag
* Survival bag
* Swag
* Tote bag
* Tucker bag

Worn|

* Backpack (Canoe pack, Duluth pack)
* Bandolier bag
* Bivouac sack
* Book bag
* Fanny pack
* Golf bag
* Lightweight Rucksack
* Medicine bag
* Messenger bag
* Pack basket
* Pasiking
* Randoseru
* Sabretache
* Satchel
* Sporran
* Takiding

Luggage|

* Bug-out bag
* Carpet bag
* Diaper bag
* Diplomatic bag / pouch
* Duffel bag
* Garment bag
* Gig bag
* Gladstone bag
* Hobo bag
* Holdall
* Nomadic bag
* Norfolk case
* Portmanteau
* Saddlebag
* Suitcase
* Toiletry bag
* Train case
* Travel pack
* Trunk

Postal|

* Catcher pouch
* Mail bag
* Mail pouch
* Mail sack
* Mail satchel
* Mochila
* Padded envelope
* Portmanteau

Containers|

* Antistatic bag
* Bag-in-box
* Bin bag
* Biodegradable bag
* Bota bag
* Coffee bag
* Flexible intermediate bulk container
* Boil-in-bag
* Fuel bladder
* Mashk
* Milk bag
* Packet (container)
* Paper bag
* Paper sack
* Parfleche
* Pastry bag
* Pipe bag
* Plastic bag
* Purdue Improved Crop Storage bags
* Reusable shopping bag
* Sachet
* Security bag
* Shopping bag
* Stand-up pouch
* Thermal bag
* Tobacco pouch
* Trash bag
* Wineskin
* Zipper storage bag

Purses/handbags|

* Bayong
* Birkin bag
* Coin purse
* Evening bag
* Gaji bag
* Gucci Diana
* Handbag
* It bag
* Kelly bag
* Kinchaku
* Lady Dior
* Messenger bag
* Minaudière
* Money bag
* Reticule
* Tote bag
* Wallet
* Wristlet

Other|

* Body bag
* Burn bag
* Cowboy bedroll
* Doggy bag
* Dry bag
* Electronic flight bag
* Feedbag
* Flour sack
* Gamow bag
* Gunny sack
* Poop bag
* Sandbag
* Showbag
* Sickness bag
* Sleeping bag
* Stuff sack
* Throw bag
* Zuckertüte

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Fortifications

Ancient|

* Abatis
* Acropolis
* Agger
* Broch
* Burgus
* Caltrop
* Castellum
* Castra
* Castros
* Chengqiang
* Circular rampart
* City gate
* Crannog
* Ditch
* Defensive wall
* Dun
* Faussebraye
* Gatehouse
* Gord
* Hillfort
* Landwehr
* Limes
* Nuraghe
* Oppidum
* Palisade
* Pincer gate
* Promontory fort
* Rampart
* Ringfort (Rath)
* Refuge castle
* Schwedenschanze
* Stockade
* Sudis
* Trou de loup
* Vallum
* Wagon fort (Laager)
* Vitrified fort

Post-classical|

* Advanced work
* Albarrana tower
* Alcazaba
* Alcázar
* Amba
* Arrowslit
* Barbican
* Bartizan
* Bastion
* Battery tower
* Battlement
* Bawn
* Bent entrance
* Bergfried
* Berm
* Boom
* Bretèche
* Bridge castle
* Bridge tower
* Burh
* Butter-churn tower
* Caer
* Castle
* Chamber gate
* Chartaque
* Chashi
* Chemin de ronde
* Chemise
* Cheval de frise
* Citadel
* Coercion castle
* Concentric castle
* Corner tower
* Counter-castle
* Curtain
* Drawbridge
* Enceinte
* Embrasure
* Flanking tower
* Fortified buildings (church, house, Dzong)
* Fujian tulou
* Ganerbenburg
* Gate tower
* Gabion
* Glacis
* Guard tower
* Gulyay-gorod
* Gusuku
* Half tower
* Hoarding
* Inner bailey
* Kasbah
* Keep
* Kremlin (Detinets)
* Ksar
* Landesburg
* Loophole
* L-plan castle
* Machicolation
* Merlon
* Moat
* Motte-and-bailey
* Murder hole
* Neck ditch
* Outer bailey
* Outwork
* Parapet
* Peel tower
* Portcullis
* Postern
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* Qalat
* Reduit
* Ribat
* Ricetto
* Ringwork
* Roundel
* Quadrangular castle
* Shell keep
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* Shiro
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* Tower castle
* Tower house
* Turret
* Viking ring fortress
* Wall tower
* Bailey (or ward)
* Watchtower
* Witch tower
* Yagura
* Yett
* Zwinger

Modern|

| Early modern|

* Abwurfdach
* Arsenal
* Barricade
* Bastion
* Blockhouse
* Breastwork
* Canal
* Caponier
* Casemate
* Cavalier
* Counterguard
* Couvreface
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* Crownwork
* Device Forts
* Entrenchment
* Flèche
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* Gunpowder magazine
* Hornwork
* Kotta mara
* Lunette
* Magazine
* Orillon
* Ostrog
* Palanka
* Place-of-arms
* Polygonal fort
* Presidio (Spanish America)
* Punji sticks
* Ravelin
* Redan
* Redoubt
* Retrenchment
* Sally port
* Sandbag
* Scarp and Counterscarp
* Sconce
* Schanze
* Sea fort
* Station
* Star fort
* Tenaille

|

19th century|

* Barbed wire
* Barbette
* Border outpost
* Bunker
* Coastal artillery
* Disappearing gun
* Fire control tower
* Gun turret
* Land mine
* Martello tower
* Outpost
* Polygonal fort
* Sangar
* Wire obstacles

20th century|

* Admiralty scaffolding
* Air raid shelter
* Anti-tank trench
* Barbed tape
* Belgian gate
* Blast shelter
* Blast wall
* Border security
* Bomb shelter
* Buoy
* Bremer wall
* Concertina wire
* Defensive fighting position
* British "hedgehog" road block
* Czech hedgehog
* Dragon's teeth
* Entry control point (ECP)
* Electric fence
* Fallout shelter
* Fire support base
* Flak tower
* Hardened aircraft shelter
* Hesco bastion
* Kabal
* Loophole
* Main line of resistance
* Missile launch facility
* Pillbox
* Revetment
* Sentry gun
* Spider hole
* Submarine pen
* Underground hangar
* Weapon storage area
* Weapons Storage and Security System

By topography|

* Cave castle
* Hill castle
* Hillfort
* Hillside castle
* Hilltop castle
* Island castle
* Lowland castle
* Marsh castle
* Moated castle
* Promontory fort
* Ridge castle
* Rocca
* Rock castle
* Spur castle
* Water castle
* Floating water castle

By role|

* Border barrier
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* Coercion castle
* Counter-castle
* Fence
* Ganerbenburg
* Hunting lodge
* Imperial castle
* Kaiserpfalz
* Landesburg
* Lustschloss
* Military base
* Obstacle
* Ordensburg
* Refuge castle
* Toll castle
* Urban castle

By design|

* Bastion fort
* Bridge castle
* Circular rampart
* Concentric castle
* L-plan castle
* Motte-and-bailey castle
* Quadrangular castle
* Ringfort
* Ringwork
* Tower castle
* Z-plan castle

Lists|

* Bastion forts
* Castles
* Cities with defensive walls
* Defense line
* Fortified estate
* Fortifications
* Forts
* Military installations
* Walls

Related word|

* Castle town
* Château
* Dungeon
* Festung
* Fortified gateway
* Gatekeeper
* Loophole
* National redoubt
* Palas
* Picket
* Schloss
* Trench
* Vedette

Other topics|

* Civil defense
* Continuity of government
* Military urbanism
* Subterranean warfare
* Siege
* Siege engine
* list
* Tunnel warfare
* Trench warfare
* Urban warfare
* Guerrilla

* See also:  Category

Authority control databases |

* NARA

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