Women and girls in rural areas shoulder the burden of carrying water over long distances in buckets on their heads. This is not only exhausting and uncomfortable, but can also cause long-term neck and spinal injuries.
|Hipporollers in use in Africa|
The Hippo Water Roller was invented in South Africa to offer one solution to this problem by providing a simple water-carrying vehicle that rolls easily along the ground with a full load of water and does not need to be carried.
The Hippo Water Roller is a barrel-shaped drum made from robust, UV-stabilised low-density polyethylene and is designed to cope with rough surfaces. It holds 90 litres of water and has a large opening (135mm in diameter) covered by a tough, screw-on lid for easy filling and cleaning.
Using the steel handle, the roller can be pushed or pulled over rough terrain. The overall width of the roller allows it to be pulled through standard doorways or gates.
This parameter, together with the roll radius and the rounded shoulders, eventually determined the volume of 90 litres.
The steel handle is fitted with polymer end-caps to reduce friction and wear, and prolong the life of the pivot cavities in the drum.
During development, a water-filled roller was drawn behind a vehicle along a dirt road at 20 km/h for 15km without significant wear on either the roller or its pivot cavities.
The roller is rounded at the shoulders to simplify tilting when water is poured from the full roller.
However, it is also very stable in the upright position when it rests on a flat surface. The roller has hand grips at the bottom and top to make emptying easier.
The Hippo Water Roller was an idea of two engineers, Pettie Petzer and Johan Jonker of Joburg, who were recognised for their work by the South African Bureau of Standards and its Design Institute with the award of the Cullinan Award (industrial category) in 1992 and the “Design for Development Award” in 1997.
The water roller can transport about five times more water in less time, and with far less effort, than the traditional method of carrying 20 litres of water in a bucket on your head.
The 90kg weight of the water is borne on the ground, resulting in an effective weight of just 10kg on level ground, half the weight of a 20-litre bucket of water.
Children and the elderly, as well as adults, can therefore easily manage a full roller over most types of terrain. The other benefits include reduced strain on the neck and back, increased water availability, with benefits for health and gardening, and the hygienic storage of water in the roller.
Although the Hippo Water Roller was mainly designed as a water-carrying aid, several other uses have since been identified – as a watertight container in which to store dry food in rural communities, or dropped from helicopters to provide stricken people with life-saving resources (food, medical supplies, clothing, blankets and fresh water) in flooded disaster areas or after shipwrecks.
As polyethylene is lighter than water, the drum will only partly submerge in water, even if it contains fresh water.
There are also some spin-offs of the water-carrier. the Hippo Mobile Spaza has been developed as a small, mobile vendor display unit.
Then there is the Hippo Roller wheelbarrow/stretcher, and a Hippo Roller drip irrigation system.
The Hippo Water Roller Project is now managed by Imvubu Projects in Joburg as a social responsibility programme.
To date, more than 32 000 Hippo Water Rollers have been sold and distributed in southern, central, western and eastern Africa and Madagascar, directly benefiting about 225 000 people. – Cape Argus
For more information, go to www.hipporoller.org.
Source – IOL SciTech By Mike Bruton, September 4, 2011