Machine capable of lifting 350kg weight
* Students to visit US to participate in international science fair
ISLAMABAD: Three intermediate students from the Sir Syed Science College, Rawalpindi, have developed Pakistan’s first hovercraft. A project sponsored by Intel under the ‘Intel ISEF Awards’ made Muhammad Naeem Khan, Zaki Hussain and Muhammad Qasim excel in the field of technology, as they developed a machine having the capability to lift up to 350 kilogrammes.
The students said they were now preparing to visit the United States to participate in the International Science and Engineering Fair (ISEF). They will exhibit their project at the fair later this month. The ISEF is a global science competition for students in grades between 9 and 12. This year’s programme will include a record number of 1,557 high school students from 51 countries, presenting 1,241 projects. The finalists are selected from more than 550 affiliated fairs around the world every year. Each affiliated fair can send its top two individual projects and one team project to the ISEF. Hammad Hassan speaks volumes of the young minds. An expert over the subject, Hammad defines their work as ‘a great job’. “These students have done a brilliant job. It was not an easy task, as there were a number of essential designs and construction principles they had to keep in mind,” he said.
He said the basic principle of an air cushion was that if you lift an object off the ground using air, you reduce the force needed to move it. “Because the object is no longer in contact with the ground, friction is reduced, making it easier to move. This implies that the smoother the surface, the lesser the friction. Uneven surfaces with rocks and other obstacles can significantly slow down or even stop and damage an air-cushion vehicle if the chamber containing air cushion (the plenum chamber) is made of rigid materials,” he said. He said some hovercraft used a single-engine system to provide both the air for the plenum chamber and propulsion. “The difficulty in using one engine is to provide optimal efficiency for both systems, dividing the power for propulsion as well as for the fan to produce enough air for the lift,” he said. “The next consideration for a properly-functioning hovercraft is the power-to-weight-to-strength ratio. This deals with the structural strength of the raft; to be light enough to be lifted by the air cushion created underneath, and strong enough to carry the weight of the engine, its passengers or payload,” Hammad said. He said constructing an air-cushion vehicle-hull based more on aviation rather than marine constructions makes sense for the simple reason that aviation hulls were a combination of strength and lightness as compared to strength as a priority.
Besides experts, the hovercraft was also a source of encouragement for other students at the college. App