cockpit seat clear
of the water. When
lowered, they should
be well-protected
against splashes
by the pod shape.
While building them I
tried to keep in mind
the forces involved.
Most of this is
compressive due to
the thrust given by
the outboards, so
9mm ply sides and
some solid wood
seemed appropriate.
The fairing is less
structural, so I used
3mm ply. Transoms
Composite cutlery drawer
for mounting the
Fuel tank lockers just after releasing from mould
engines are 3
has to be made, and that requires some
thicknesses of 9mm. The whole box is
vacuum-bagged panels, which means
well-glassed to give structural integrity
Some of the design details for the pods
isolating a part of the workshop with
and the bearings are workshop-made
have been challenging. I ended up making
bubblewrap curtains and laying up inside it.
epoxy and graphite. I find making these
a full-sized cardboard template of an engine
I have bought some more melamine-faced
over an aluminium tube has been quite
in order to be sure that it would tilt into the
chipboard panels, lovely, clean and smooth.
straightforward. The
right position and the
They give such a perfect surface finish and
alloy is well-waxed
the vacuum bag pulls down onto them so
before glassing.
well that I really enjoy this part. Of course
Heat-shrink tape
it would be easier and quicker just to use
squeezes the
“
transom would be at
To get the bearing
the correct angle when
off after curing I
the leg was correctly
immersed. I also
plywood for all the interior stuff, but the extra
laminate tightly
blast the metal tube
wanted to keep the
work in making up the composite panels is
together as the heat
fuel tanks close to the
justified by the considerable weight saving. I
accelerates the set.
with the hot air gun engines and reckoned
am not going to cut corners right at the end,
To get the bearing
until I can feel the
on there being enough
even if it takes more time….
off after curing I
space within the pods
blast the metal tube heat.
Engine pods
with the hot air gun
until I can feel the
The sections I have been tackling just
heat coming through the resin and glass.
recently have been the engine pods.
Then I run cold water through the tube to
”
to fit them in front of
the engines. But it is
not ideal for the tanks
to be tilted and access would be tricky, so
they needed to be mounted separately. The
Another departure from the original plans,
cool it as quickly as possible. The greater
solution I hit upon was to construct glass
these are located under the cockpit
shrinkage of the alloy helps to break it away
boxes to be fitted to the underside of the
and based on a picture of pods on a
from the resin and a little bashing with a
cockpit floor, accessible from the cockpit
Wharram cat. In the raised position the
hammer on the end of the tube usually does
through a hinged lid. In the raised position
8HP outboards should fit neatly inside a
the rest.
the pod will fit neatly around the box, and
when lowered there is additional splash
protection for the outboard head.
Some form of positive lock is needed
for the pod’s lowered position. Ideally
this will triangulate the pod to hold it
rigidly to the boat so that drive will be
efficiently transferred. The arrangement
on my previous boat was a home-made
parallelogram constructed from 2” angle
alloy, that worked fine in forward gear, but
in reverse the engine bounced around and
was less than efficient because there was
nothing holding the frame down. It certainly
alarmed any onlookers! This time, in addition
to the block and tackle to raise and lower
the pods as before, I shall install a bar that
will slip into a couple of slots when the pod
is fully down. It will be tensioned with some
bungee to encourage it to engage. There will
be another slot at the fully raised position.
Of course this means that someone will
need to reach down to disengage the bar
with one hand, or perhaps a piece of rope
Engine pod glued, taped and wired over a simple mould can be cunningly rigged to achieve this.
»
  JANUARY 2009 : MULTIHULL REVIEW  19
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