A hovercraft built on a shoestring budget

When most engineering students are obsessed with building Formula One cars for their practical projects, a bunch boys from an engineering college in the city have built the long-forgotten hovercraft. Five students -- Pradeep R Gatti, Deepak P Mane, Rakesh N, Nandakishore T and Dhananjay N from the Mechanical department of Acharya Institute of Technology have designed a one-seater hovercraft under the guidance of Dr D Madhu, R Shadakshari, Nagaprasad K S as a part of their eighth semester practical project.

A hovercraft, also called a air cushion vehicle, is an amphibian vehicle, which can run on both land and water. These are generally used in exploring shallow and narrow waterways that cannot be reached by boat. It works with a cushion of air ejected from an annular ring beneath it without any contact with the land or water surface over which it travels.

The overall size of this craft, designed and built completely by the students, is 8.5 feet and uses a Yezdi Roadking 2-stroke, 250cc, 16 bhp engine with R.A.C.E technology. The engine has been modified to make it suitable for low speed and higher load operating conditions. The craft is designed to carry 200 kilogram and can carry a person weighing 60 kilogram. The lift that is achieved is about one feet from the ground and the hovercraft has been successfully tested. The added features include a coat of resin reinforced by glass fibres throughout the body of the craft which gives the craft added strength and also makes it water proof and fire resistant.

The students say that it took them about three weeks of round the clock work to complete this project, but about two months just to gather enough information and data.

But the going has not been obstacle-free.

Says Pradeep R Gatti, one of the team members: "We initially had a two-blade propeller, which broke as its tip went beyond the critical speed. Since there were not many propeller manufacturers in India, we had to get a new multi-blade fan imported from US, and we had to assemble it ourselves using just a manual provided." He also adds that they had to overhaul the engine since it was second hand.

While the hovercraft that the Indian Navy uses is acquired for about Rs 30 to 40 lakh, Pradeep says, there's cost them about Rs 60,000! "Of course, those hovercraft are far more equipped with GPS and other paraphernalia and can also carry much higher loads, but we believe we still can build an equally sophisticated  hovercraft for a lot lesser than what the Navy pays!"

What are hovercraft?

Often considered as the brainchild of Sir Christopher Cockerell, a British engineer, hovercraft are used throughout the world as a method of specialised transport wherever there is the need to travel over multiple types of surfaces. A well-designed hovercraft is superior to a boat because it has less drag and requires less horsepower to operate. It is 100 per cent more fuel-efficient than a boat with similar capacity or size. Rising fuel prices and shortages will make the hovercraft a desirable form of transportation in the future.

Hovercraft ride much smoother than boats because they travel over the surface of the water, not through it. It travels over water with no concern for depth or hidden obstacles.