A bicycle that floats

Traveling in flood-ravaged areas is indeed a traumatic experience for any commuter. But not for Sakda Chakdechjan.

When inventing a practical vehicle during the recent floods, he didn't think of a bicycle his favorite mode of transport but a bicycle that floats.

The invention was initially for his wife, who works in the inundated Muang district of Suphan Buri.

"My wife had to go to work every day," said Sakda, a technician who works in Ratchaburi.

When the deluge started to reach his wife's house in Muang district about two months ago, Sakda had to invent a vehicle that helped them to commute and stay dry in the waist-deep water. And it had to be affordable.

He studied and found a hydrobike on a website which seemed perfect but wasn't affordable. Inspired by the high-end vehicle, 

Sakda came up with a simpler version of the water bike, replacing expensive parts with such household items as an old bicycle frame from a flea market; PVC tubes, blade and shaft from a local hardware store.

The idea was to combine a bicycle with a raft.

The invention, Survey & Rescue Water Bike, won honorary mention in two categories _ high speed and less ripple at the recent "Mobility in the Time of Flood" contest, organized by the National Science and Technology Development Agency (NSTDA).

Sakda installed the old bicycle frame on two buoys made from a 3.3-metre PVC tube, which was also stuffed with crushed foam to help buoyancy and to prevent being filled with water in the case of a leak.

With his technical skills, it took him only five days to complete. The first day compiling the materials, and the remaining four days in the hours after work until midnight assembling all the parts. Total costs for the water bike were about 3,900 baht.

It looks as if he has simply placed a bicycle frame on the tubes, but there's also a basic mechanism to it. A water bike with a chain plate from an ordinary bike would go nowhere, he explained. 

So a gear taken from a grinding stone was added to propel the water bike on the water when pedaled.

Nonlany Ungwiwatkul, a serious cyclist, tried the water bike at Lumpini Park when the contest results were announced. While further development is required, she liked the simple design and the well-balanced buoys. 

The bike is able to go at about 10km per hour; turn left and right with a considerably wide turning circle; and reverse.

On a calm water surface, Nonlany said it worked well enough. But there may be some problems when facing a strong flood current.

Sakda's family, however, has proved that the water bike is practical enough for them to get around the flooded neighborhood during the past several weeks.

An advantage of the water bike is its human-powered system that doesn't add to air pollution, said Sakda. "It also increases oxygen to the water as it's pedaled."

The PVC tubes are a bit heavy and difficult to move, admitted Sakda. He plans to improve the vehicle to make it faster and lighter, making it more practical in flood conditions.