Quick Dips

Third World Tap

A gravity tap designed by a group of Lincoln University students for use in Third World countries has won a $500 merit prize in the annual BHP-New Zealand Steel Universities Design Competition, run jointly with the Institute of Professional Engineers.

The competition aims to attract bright ideas from engineering and technology students, and sets the maximum material costs of each entry at $100. Judging criteria include originality, innovative use of steel products and functional suitability.

Inspiration for the gravity tap came to BE student Rob Wayne, one of the four members of the group, when he was doing voluntary work installing water supplies in Ethiopian villages.

A British model, similar to the group's design, had been used in some gravity-fed water supply systems but proved inappropriate because of the unavailability of parts and the cost. The materials for the Lincoln students' tap cost $13.27.

"The British ones which I saw were mainly broken. They were made by a company aiming to make sales overseas, but once they broke down they were useless because parts to fix them were impossible to get," says Wayne.

"In Ethiopia screw-on household taps are used extensively and these were also very prone to breaking down. I thought a tap like the British one would be excellent if it worked and could be made out of parts available in developing countries.

"It was also important that the tap had automatic closing, which is essential in systems where water conservation is required."

This is to prevent abuse of the system by powerful villagers. Wayne had observed that a channel would often be dug from tap stands to the fields of nearby farmers and the tap would be left running to irrigate the crops, at the expense of drinking water for the rest of the villagers.

The automatic shut-off valve discourages this, as does the streamlined shape of the apparatus, which makes it more difficult to fix open. An outer sleeve on the tap directs any leakage to the storage vessel and provides a barrier to contact with dirty hands.

All designs submitted in the competition remain the property of BHP New Zealand Steel. The Lincoln group prepared the tap with the intention of making the design and product readily available to people in developing countries at cost, and asked that it be withdrawn from the competition if the company wished to use the design in any other way.

They suggested that the idea might present an opportunity for the steel company to assist in donating resources to developing countries.