Construction of an Emergency Raft for Savage of Household Items

• In case of danger of flooding, a member of a household can put together a floating platform or raft in a very short time. This ability can be achieved through an instruction program raising general public awareness.
• All materials needed, like sticks and the reeds to weave baskets can be expected to be freely available in a rural area. However with one clear exception: the plastic sheet that is needed has to be provided for well in advance. Only new and unpunctuered black, general purpose building and agricultural PE sheets of 0,1 mm thickness will give the expected result. To ensure the availability of this essential material in case of need, it can be considered to cut it to the required size and distribute it to each household in the endangered area. What is needed are six circular pieces of plastic foil with a diameter of 1,7 m. This type of plastic sheet (black PE-sheet, 01 mm thickness) is often sold on a roll 6 meter wide. The total surface area per user is 18 m2.
• To maximize save use in a state of emergency, in which rough conditions may be expected, of the six floats that are used in each platform, two may fill up without immediate danger of sinking or capsizing. As the floats are open at the top and accessible from the platform, it is possible to remove water that has entered each float.
• A carrying capacity of 200 kg is to be attained with six floats. An estimate for the distance between the top and the water surface is 0,25 m. For this purpose the baskets should have dimensions as indicted below.

  Author: Demotech, design for self-reliance Version: Juli 27, 2008	Feedback email info@demotech.org Postal: Biesenwal 3, 6211 AD Maastricht, the Netherlands
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  1. Preparing materials

• 12 light baskets, as used for transport to a market of vegetables or fruits. Size height 0,5 m, diameter top 0,7 m, diameter bottom 0,5 m. These baskets fit into each other and may be used for other purposes as well when there is no danger of flooding.
• 6 poles, wood or bamboo, length 3 m, thickness 4 to 6 cm.
• One or more mats to cover the open space between the poles, after the poles are attached together in the shape of a star.

  Author: Demotech, design for self-reliance Version: Juli 27, 2008	Feedback email info@demotech.org Postal: Biesenwal 3, 6211 AD Maastricht, the Netherlands
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  2. Construction

  Three poles are attached to form a triangle. At each of the three crossings one float is attached. Each float is made by inserting one basket into a second one, after a circular piece of plastic sheet is carefully lined into the first basket. The purpose of the outer basket is to protect this plastic sheet lining from being punctured from outside during use.
  Two triangles with attached floats are tided together in a star-like shape. Mats are tied to the poles, while taking care that the inside of the baskets can be reached when sitting on top of the platform.

  Author: Demotech, design for self-reliance Version: Juli 27, 2008	Feedback email info@demotech.org Postal: Biesenwal 3, 6211 AD Maastricht, the Netherlands
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  3. Use

  The floating platform may be moved around or anchored at a suitable location. However it is not meant to be towed along behind a boat at some speed. For this purpose, a different type of floats has to be considered.