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Flood Disaster - Sandbag Protection
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Flood Disaster - Sandbag Protection

The use of sandbags is a simple effective way to prevent water damage. The most common bags are untreated burlap sacks available at feed stores. Plastic garbage bags tend to slip over one another and are unacceptable. Commercial polypropelyne bags specially designed for such use are acceptable. Feed sacks are generally too large.

Bags should be stored empty until flood time. That means a lot have to be filled quickly. Filling bags is a two-person operation. Bags should be filled by a two person team and transported and stacked by another two to four person team. Bags should not be tied (although they have ties) but the ends folded over and under. Sand is the easiest material to fill them with, or a heavy bodies sandy soil, but any local material is acceptable. They should be filled to 1/2 to 2/3's but in any caase not to exceed 30 pounds, which is about what the average person can manhandle without causing back injury.

Commercial sandbags are generally available in two sized. The 14 X 26 inch size (50 pound) and the 18 X 27 inch (65 pound). Get the smaller size and don't fill them to capacity.

Price of the small burlap (14 X 26) runs about $280 for 500 or .56 per bag (2009 prices)
Price of the polypropelyne (14 X 26) runs about $$310 for 1000 or .31 per bag (2009 prices)

The propyelene bags come in various colors, if you are aesthetically inclined.

The next big question is "How many bags do I need?"

The general flood control formula used by the U.S. Army Corps of Engineers is:

N = ( 3 + H + 9 X H X H) / 2
N = number of sandbags required per linear foot of dyke
H = dyke height (in feet)

Ballpark, figure per 100 linear foot of minimum-standard dyke around your house:

1 Foot dyke  = 600    sandbags per 100 linear foot
2 Foot dyke  = 2,100 sandbags per 100 linear foot
3 Foot dyke  = 4,500 sandbags per 100 linear foot
4 Foot dyke  = 7,800 sandbags per 100 linear foot

The estimated number of bags for a dyke that is twice as wide as it is tall (recommended) is:

1 Foot dyke = 600    bags per 100 linear foot
2 Foot dyke = 1,700 bags per 100 linear foot
3 Foot dyke = 3,000 bags per 100 linear foot
4 Foot dyke = 5,500 bags per 100 linear foot
5 Foot dyke = 9,000 bags per 100 linear foot
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144586 tn?1284669764
When estimating the quantity of fill, a cubic yard of fill (we yobs in the United States use yards) is 3 ft by 3 ft x 3 ft or 27 cubic foot, which will fill about 100 30 pound sandbags, assuming the fill material weighs about 110 pounds per cubic foot. Each 14-inch by 24-inch bag will contain about 0.4 cubic yards if half-filled.

It is very easy to injure your back carrying sandbags, so insure you lift properly, with your legs and not your back. Every person carrying sandbags should recieve a "lift briefing". Try to take an extra half-second to emplace them, and interlock them, rather than end up with a shifting pile of nightmare, that is nearly impossible to re-construct.

Tied sandbags are used for special situations, such as when they have to be transported by truck to a destination, to fill holes, or to form barriers backed by supportive planks.

Build the dyke at least one foot higher than the expected crest level. For planning purposes figure a four foot high flood dyke will have a base of 12 feet.

That's a lot of bags, sweety-pie, as a noted cartoon character might say.

144586 tn?1284669764
It is obvious from the above figures, a sandbag "dyke" is an undertaking requiring many man hours, and the requirements for available  filling material are significant.

Sandbags may also be used against the side of a house to prevent water entry. A plastic tarp is run on the ground and up the way to extend at least one foot above the sandbags. Plywood is affixed over openings such as rectangular cellar windows, preferably with caulking.

Sandbags are also useful for constructing temporary pedestrian walkways over large flooded areas, such as parking lots. They can be placed "lily-pad" style, or lined up two abreast.

The bags should not be layed in a continious line (daming the water) but separated by breaks every ten to twenty foot or so  to allow water passage. The breaks should be easy to step across, and of course gaps save sandbags.  The height of such walkways, is, of course limited. They work well to a limit of about four sandbags in height.

Placing planks on such walkways usually results in the plank being washed away.

Water brings mud, and mud, once churned, can make roads impassable.The problem is to "fill" the hole to permit vehicle traffic.

The rule is:

Water plus dirt = mud
Mud + dirt = more mud
And...you can't do a darned thing with mud.

Thus, dry earth or clay is NEVER placed in mud to repair a hole or a rut.
All of the mud and water have to be removed, and the dry material placed in layers and tamped every few inches (compacted).

Now here comes the emergency use of sandbags. Filled and tied sandbags may be used as an emergency repair to a muddy rutted road without removing all the mud from the ruts. This not recommended.

Sandbags are also useful as headwalls for an emergency culvert. A culvert could be corrugated steel or plaxtic pipe placed under a dirt road to permit water to pass from one side of the road to the other. On each side of the culvert a headwall is required to prevent dirt from coming down and immediately clogging the pipe.
144586 tn?1284669764
Sandbags can also be used to transport water, liquids and (not recommended) fuel.

To use them in this manner you require:

(1) Clothesline
(2) Plastic garbage bags
(3) A wooden or pipe carry pole
(4) Duct tape

The sandbags themselves are porous, but strong. Place a thick garbage bag, preferably doubled, inside the sandbag. Try not to have the seam of the garbage bag below the fluid level. Cloth (burlap) bags are recommended, but any will do.

Fill the garbage bag inside the sandbag with liquid. It may be submerged in a stream. Do not fill it up. A gallon plus is recommended, although they will hold much more. Next use a length of clothesline to tie a "quick release" knot over the top 1/3 of the bag. Do not use the ties that come with the bag. Use extra lengths of clothesline to create a "four-strand" basket.

You can then attach two six-foot lengths of pipe across the handlebars of a bicycle. On each side or each length you can affix four liquid-filled sandbags. That means sixteen liquid filled sandbags per bicycle, about 20 gallons of water or fuel.

The same method may be used to transport water-filled sandbags in the back of a pick-up truck.

Water-filled sandbags can be hauled up the side of an apartment building.

Pre-filled water filled sandbags can be rested against the side of a house, or placed on a roof, and used to transport water to dump on embers that have been transported by a forest fire. In this case you can fill them to capacity. Keep two dozen of these pre-filled "extinguishers" on the roof. You have an extension ladder set up against the side.

Now there are usually plastic jugs available, so this is not a preferred method of using sandbags, but it does work.

If you use burlap sandbags they can be used to cool the liquid inside by evaporation, in a manner similar to a military lister bag. The exterior of the sandbag is soaked in water (it doesn't have to be potable). Or a "T" shirt is slipped around the sandbag and soaked in water. The "cooling bag" consists of a plastic garbage bag inside a burlap sandbag, surrounded by one or more wet "T" shirts. Keep the cloth wet and the bags in the shade.
144586 tn?1284669764
Sandbags have a place in fighting brush fires.

One of the standard means of fighting brush fires is the back-pack "Indian Pump". The problem is, water re-supply. Often there is a small sream available, but the depth is too shallow to bail. If you attempt to deepen the pool you hit rock. The answer is to construct a small dam with sandbags to permit water to pool to a depth where it can be scooped with buckets and used to refill the Indian pumps.

This also creates a pool deep enough for a hard suction to draw water for a brush fire pump.

Sandbags with plastic bag liners can also be pre-positioned several hundred meters away from a water supply for use with those with Indian Pumps. The bags, when filled with water, will spill when tipped, so they have to be carefully placed next to one another between two lengths of lumber or poles or small logs. When an Indian Pump is empty, one only needs to use the water-filled sandbags to refill the reservoir. This saves valuable time in not having to return to the water point.
144586 tn?1284669764
Sandbags are also useful to provide traction in snow and on ice.

They are placed in the trunk of the vehicle, or the bed of a pick-up truck slightly forward of the rear axel.  Try not to place them behind the rear axel as this will cause the front steering wheels to rise and lose purchase.

Sandbags can be filled to various weights, but try to fill yours to no more than thirty pounds. In the case of sandbags used for automobile use, fill them with clean sand. If you like you can place a garbage bag within the sandbag, fill it with sand, trim off the ends of the garbage bag and seal it with duct tape, then tie off the ends of the sandbags. This will prevent leakage of sand into the trunk.

Eight thirty pound sandbags provides 240 pounds of weight over the rear axel, which is what you should shoot for.

The sandbags may be broken open to provide traction over ice or packed snow if you become stuck. They may also be placed under the rear wheels if you become trapped in a watery "mud rut".

They may be placed under the wheels of a recreational vehicle to level the vehicle, and more specifically to level the generator, which operates optimally when in this position.

Sandbags are also useful for bracing a ladder against the side of a building or a small ladder used for painting. They are also sometimes used to place on top of lumber on the upper floors of a building during construction to prevent debri from being blown by the wind.

Commercial theatrical sandbags are constructed of heavy cloth with sewn canvas handles on each side and are used primarily for stabilization or cameras, tripods, cables and ladders.
144586 tn?1284669764
Sandbags have another use in disasters, such as earthquakes: The stabilization of buildings, bridges and tunnels to permit safe access by emergency workers.

The sandbag is used as a conformable, easily placed form for rapid-hardening concrete. Rapid-hardening concrete (ASTMC 928-89) is certified to attain a strength of 3,000 P.S.I.l within 3 hours and 3,000 P.S.I. with 24 hours. It sets in between fifteen and forty five minutes.

Let us suppose that a steel I beam on a bridge support requires reinforcement, perhaps on a load bearing point. A sandbag filled with rapid-hardening concrete can be tied and pushed into a small narrow area, compacted, and will harden to provide bearing support. Normally it would not be practicable to produce a form.  Similarly, in a tunnel or building collapse, bags filled with rapid-hardening concrete can be placed to insure slabs of concrete do not crush rescue workers climbing underneath them.

Because these are hydraulic cements, they will harden under water, and can be used as anchors, to stabilize piers or temporary bridging, or to plug sinkholes.
144586 tn?1284669764
Sandbags are also useful in creating bypass detours after a building collapse, sinkhole or earthquake. The most common bypass is the "sidewalk bypass". The sandbags are used to provide a ramp up onto the sidewalk for vehicles at each side of the obstacle.

These bags can also be filled with rapid-hardening concrete (ASTMC 928-89).

Wooden ramps are easily washed away by rain.

Providing a sandbag ramp so that vehicles can climb the curbs expedites the flow of traffic and prevents rear axel displacement. When a vehicle climbs a curb at an angle the rear wheels tend to be displaced on the leaf springs. This is common on emergency ambulances when the drivers jump curbs at speeds. As a result, the vehicle won't "track". The rear or the vehicle moves to one side. It is akin to driving a parallogram.
The ambulance driver first notices this when the goes through a narrow space in traffdic and scrapes the adjacent vechicle.

Sandbags can also be used as expeditious flotation devices. Use the larger bag (14 in. X 26 in.) and insert empty tightly capped liter soda bottles. The cap seal may be strengthened with adhesives, such as Gorilla glue, if available. The liter bottles are taped with duct tape in a line and inserted into the sandbag, which is then tied, sewn, bound with cord or clothesline or duct-taped. Five liter soda bottles and one large sandbag provide a considerable degree of flotation. These can be carried by rescue crews in boats.

Sandbags can also be used as emergency foot covers when crossing areas contaminated by radiation or chemicals. Use double bags and tape them over the ankles.

Sandbags can also be used to create "emergency waders" to cross shallow polls of water up to 24 inches.  Use a plastic garbage bag over each leg, and a duct-taped sandbag around each foot.

They can also be used in warm weather as "waders" to prevent leather shoes from becoming wet and protect the feet. You remove your shoes and socks, string them together and put them on your shoulders. Your bare feet are protected from debri and pebbles as you wade by the sandbags. When you cross the sream, remove the sandbags, dry your feet, and put your dry socks and shoes on.
144586 tn?1284669764
Sandbags, when stuffed with straw or pine boughs, can be used as emergency pillows or mattresses. It's better than sleeping on hard ground.

The larger bags can also be used to transport and store books and valuables for short periods of time. If a waterproof storage is required, put the books in a plastic garbage bag and then place them in the sandbag. In moist weather, books stored in this manner tend to become moldy.

Sandbags can also be used to segregate rations. If foodstuffs are scarce and you have a hundred families waiting for a "package" of foodstuffs including so many cans or containers, the relief supplies can be prepared in sandbags some distance away, and then each family will be issued one or more bags of goodies. This will expedite distribution of supplies and ensure equitable division. The larger bags will hold packages of cereal, as well as canned goods. Generally refugees will not have a way to carry away a dozen cans in their arms. The sandbag provides a way to carry goods.
144586 tn?1284669764
Sanbbags, especially the large 18 inch by 17 inch size, are especially useful in helicopter air supply situations. The bags can be attached to a fifty-foot length of clothesline and lowered in areas such as steep slopes or where there is a possibility of bladestrike, and the helicopter cannot land. They can also be tossed from the door of the helicopter and the items within won't scatter. Orange sandbags can be easily seen in snow.  By using bags of the same weight the pilot can easily calculate load and weight and balance. The bags are inexpensive and expendable, in contrast to lowering a dozen high-value backpacks. The sandbags can contain water, food, tools, batteries, radios,  or clothing.

Sandbags can be filled with some light supplies and two empty liter soda bottles to supply buoyancy and they will float if dropped on the water.

They are also useful as emergency garbage bags and to pack out garbage from a wilderness area.

Of course they can also be used to avoid chafing of a lifeline over the edge of a building, as well as emergency gloves for use in rapelling.

They are also good for transporting ice, which is difficult to contain and handle.
144586 tn?1284669764
Sandbags are also useful to delineate traffic lanes, parking areas, off-limits areas, and to constrain crowds by marking pedestrian walkways. Control of vehicular traffic is essential to prevent damage to roads and parking areas. To create control paths filled sandbags are lined up end to end and may be whitewashed or painted to enhance visibility.

They are also useful to create a helipad in a sandy, muddy, or dust-prone area. The filled bags are flattened and layed edge to edge to provide a substantive surface for the skids.
144586 tn?1284669764
Sandbags are also useful to transport coal. Coal has a heating value of from 8,800 to 11,000 BTU's per pound. In icy weather, when fuel is scarce and electricity is out bags of coal should be on the list of those who prepare for catastrophes.

But how to deliver the coal? If anyone has a better idea than sandbags, they should let me know.

A cubic foot of coal pieces weighs between 40 and 60 pounds.

Try to fill the sandbags with between 30-35 pounds of coal each. Sandbags with this much coal can be transported long distances by the average person..

Coal is not widely used, however it is cheap, and can be used to heat food or heat hot water for large numbers of people.

These days, in the United States, special coal delivery trucks no longer exist, and distrinuting coal by the shovelful is impracticable.

The answer is to truck in sandbags filled with coal, to distribute to individual families or a common refugee point.
144586 tn?1284669764
Surprisingly, sandbags can also be packed with snow to create snow-structures. What kind of structures? Wind-breaking walls, for one. Noise abatement walls for another. Why can't you just use snow? For one thing the snow may not be in the area where you want your wall. As an example, say you have a very noisy (even with muffling) generator set up at a refugee site. There is snow nearby, but none in the encampment area. You can fill sandbags with packed snow and construct a wall around the generator (not too close). You can even build walls, cover them with plywood and construct ice-shelters.

Snow can also be transported long distances in sandbags to bring back to an encampment to be melted for drinking water.
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