Inventor pedals new marine-propulsion concept

16:00, Feb 24 2010
Ken Kingsbury
HYDROFOIL-DRIVEN: Ken Kingsbury, right, propels his new pedal boat, the Treddlecat, with Cass Bay resident Chris Nitschke on Lyttelton Harbour.

Big ideas come naturally for boat designer Ken Kingsbury.

The inspiration behind the Ashburton's man-made Lake Hood project will return to the lake near Ashburton tomorrow to launch his latest invention.

Kingsbury's pedal-driven boat, the Treddlecat, uses swinging hydrofoils angled towards the water instead of a paddle-wheel.

It has cost $10,000 to develop.

The design meant the boat could reach speeds of more than five knots, he said.

"The foils stay in the water, moving side to side and tracking forward, taking the boat with them."


Kingsbury, now based in Rarotonga, worked on the design for more than nine years after being asked to build plastic pedal boats for a tourist operator.

"I started to think about making something better, and every time I thought I had come across something better, another idea cropped up."

The first prototype in 2004 used the same drive system as the Treddlecat, but was unsuccessful because its complicated layout made it vulnerable to damage.

Kingsbury said it took him three years to get the courage to make a revised model.

"I got used to failure and I was expecting this to be another project my wife would scold me for spending money on – but when it worked, it exceeded expectations," he said. "It was more reliable, more user-friendly and it went faster."

Kingsbury said he would be unable to make more Treddlecats because of the $10,000 cost to make the first one. "You learn in life that the people who put the effort into inventing have never got any money left to do anything with it ... I've got to find a manufacturer and investor to mass produce."

However, he was confident the idea was a winning one.

"I'm always optimistic when I invent something and after the first successful trial, my conviction has strengthened. I'm sinking the last of my retirement money into it, so it's got to work. Otherwise, I'm living under railway arches for the rest of my life."

The Press