Professional BoatBuilder - April-May 2018

APRIL/MAY 2018 35

many smaller pieces of wood that

caused no problems. If I ever hit a log

square with the strut of the canard and

the foil going under it, [the assembly]

would shear o at the pins that attach

it to the steel plate on the stem. And it’s

similar with the main foil a .”

All told, that is a lot of technology,

but even on this short outing in the

waters of Vashon Island Talaria proved

how it works and why foiling is fun. In

our next issue we’ll look at the latest

crop of powered hydrofoils, some

pretty conventional, others more futur-

istic. A few are already on the water,

while most are still in various stages

of development. But all of them prove

that given the right design and build,

almost any boat can rise to the occasion.

About the Author: Dieter Loibner is an

editor-at-large of Professional Boat-

Builder.

only about the wheel and the throttle.

 e steering is precise, with a maxi-

mum bank angle in turns of about 20°,

and she tops out at 38 knots with the

throttle wide open.  at’s nearly 40%

faster than what the boat managed

before foiling. Compared to the old

mechanical  ight control, “the ride is

smoother now, and Talaria maintains

constant height across foiling-speed

range,” Larsen said.

Takeo speed is approximately 18

knots, and she’s fully foilborne at 3,000

rpm. According to Larsen’s math, the

engine uses approximately 4 hp (3

kW) to run the hydraulic pump for the

actuators. But what if...the engine

dies? “ e so ware monitors rpm, and

if it falls below 1,500, it sets the boat

down in controlled fashion to avoid

hurting people on board,” he said.  e

prospect of collisions with UFOs

(unknown  oating objects) does not

faze him. “In 25 years of foiling, I hit

Some Sources

Full Wiki: http://www.thefullwiki

.org/Hydrofoil.

Vellinga, Ray. Hydrofoils: Design,

Build, Fly, Peacock Hill Publishing,

2009.

Mantle, Peter J. High Speed Marine

Cra : One Hundred Knots at Sea,

Cambridge University Press, 2015.

“Controlling the ride height of

hydrofoiling boats in Ranse CFD”:

http://www.oossanen.nl/beheer/

wp-content/uploads/2015/02/029-

Bergsma-et-al-v2.pdf.

Popular Science, March 1959: 100-

knot Liner to Fly on Sea Wings.

Popular Science, July 1961: Sea-

going Hydrofoils Do 60 Knots,

Inter national Hydrofoil Society.

Foiling172-ADFinal.indd 35 2/21/18 7:39 PM