Coatings & Corrosion Control
Double Tro^ TrouWe,
The U.S. was instrumental in the introduction on a
large scale of double-hulled tankers. Born out of a
desire to make tanker vessels safer by making them
more resilient in the event of a grounding or collision,
double-hull designs nonetheless have corrosion proper-
ties that legislators did not foresee. Double-hulled car-
riers quickly proved themselves far more susceptible to
internal corrosion than their single-hulled predeces-
sors. Coatings manufacturers are now working hard
towards a solution, according to one leading coatings
specialist.
"When the first generation of double-hulled
tankers were taken into service, their owners were
startled to find that their state-of-the-art ships
were rotting away almost twice as quickly as sin-
gle-hulled tankers. Pitting corrosion in the inner
tank top plating was taking place at an annual rate
of between 1 mm and 2 mm. In some instances,
pits developed as deep as 7 mm to 9 mm within
five years. That's 40 percent of the original plat-
ing thickness," says Ed Jansen of Antwerp-based
Expertise- en Ingenieursbureau Touw-Jansen, a
f
OmniTHRUSTER 3EADOUi
Mixed-Flow Impeller
PATENTED SYSTEM
' Kinetic Converter takes
input shaft energy and
produces usable hydraulic
energy by the use of a
mixed flow impeller
• Steering Vanes continu-
ously meter or proportion
a percentage of the fluid
flow to one or both sides of
the vessel
. Nozzles accelerate the
mass of water creating a
thrust force at the hull
interface
• Thrust Directors (optional)
deflect the water flow
forward or aft producing
slow speed auxiliary
propulsion
• Electronic Control System
controls the 360° thrust
vector resultant from a
fixed or variable speed
prime mover rotating
continuously in one
direction.
. There are no rotating parts
that have to be stopped or
started as thrust direction
and/or magnitude changes.
•
J'L
i .
Hl V* M m v
30555 Solon Industrial Parkway • Cleveland, OH
440 542-0200 www.omniWruster.com
Circle 243 on Reader Service Card
True
or
False..
Ballast tanks
are normally
damp.
Ballast Tank Solutions
37 Offices world-wide including:
Japan
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March, 2001 www.maritimetoday.com Circle 328 on Reader Service Card 43
