Home' Afloat : AFLOAT February 2017 Contents Take monthly with water February 2017 7
Letter of the month
The Editor ’s choice for letter of the month will
receive a 28" Yachtsman’s Waterproof Bag.
Made from tough double
coated PVC fabric with
seams sewn and tape
welded the Burke bag is
This month’s prize goes to
from Cowan, NSW.
Got Something to Say?
PO BOX 709 WILLOUGHBY 2068
web forum: www.afloat.com.au
Please keep your letters short. Letters longer than 250 words are
liable to sub-editing at the Editor ’s discretion.
02 6496 1999
• 3 bedroom home, sunroom,
2 living areas, double garage.
• Gently sloping 794 sq m block -
potential for 3 unit development.
• Breathtaking uninterrupted ocean
& bay views.
• Close to shops & Snug Cove -
proposed new safe harbour & marina
• Eden is the only deep water port
halfway between Sydney & Melbourne
and east of Bass Strait - the new
Maritime Hub of the South-East.
AUCTION - EDEN
17 Hosies Road
EDEN, NSW South Coast
Saturday February 25 1pm on site
Agent: Glenn Brunette ph: 0427 260 500 e: firstname.lastname@example.org
He whose keel doesn’t fail
wins. Is it true that Perpetual
Loyal and Wild Oats have failed
to finish two of the last three
Hobart races because of
canting keel failures?
Those canting keels seem
designed to mimic in a
negative way the advantages
of a multihull. Instead of a
float providing stability out to leeward they have an immensely
heavy keel canting out to windward. And how many of these
boats have lost their keels entirely and capsized?
It is time for the yachting establishment to be honest with
themselves and admit multihulls into the major yachting races
or at least a class for them. Half a century ago I and a bunch of
ocean sailing novices sailed Bandersnatch, a small trimaran built
on the smell of an oily rag, in the Hobart race and thrashed over
95% of the fleet.
That performance put paid to their acceptance as we had
dented the egos of the public’s yachting heroes. Listen up guys,
if you want a really thrilling race, admit multis to the Hobart race
just as many other great ocean races have done.
The designer Locke Crowther, who also crewed, started a
company that has grown to become Crowther Incat which designs
and builds multimillion dollar catamaran RoRo ferries worldwide.
Incidentally, asked how he named it, the owner skipper replied;
“ You might as well try to catch a Bandersnatch.”
Bandersnatch becalmed off
Tasmania’s east coast in 1966.
RiverCat hull modification
The correspondence regarding RiverCat ferry wash and the
damage it causes has been very interesting. One of the most
extraordinary things about the wake or wash is that it has two
There is the conventional component which runs over the
surface of the water; and there is a very unconventional underwater
component which runs, at least near the shore, over the surface
of the river bed or harbour bottom. The RiverCats seem to be the
only vessels which generate this two component wash or wake.
The lower component is capable of pushing normally vertical
marine plants (which are rooted in the river bed) horizontally in
one direction, and then horizontally in the opposite direction.
It clearly contains a lot of energy which presumably is paid for
by the fuel consumption of the ferry.
I would propose a trial modification of a RiverCat’s hull by
the installation of a substantially horizontal rectangular metal
plate which extends between the bottoms of the two hulls. There
would be no internal modification, each side edge of the plate
would merely be attached to (or replace) the rubbing strip which
presumably extends along each keel. The front edge of the plate
would be adjacent the bow and the rear edge of the plate just
forward of the propellers.
The idea is that moving the plate through the water at a
constant depth would not take up too much energy but that the
plate would disrupt the second, unconventional, underwater
wake component. If this were successful there may be both a
fuel saving and a considerable reduction in sea wall damage.
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