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By Lew Clayman, lew_clayman@yahoo.com
EuroPig is an anagram on pirogue, and I chose the
name because it’s the silliest anagram I could make out of that word.
“Pig Roue” might have been more appropriate (look it up) but
for some reason I just like EuroPig better.
If you find a more fitting anagram, send it along.
EuroPig is a flat-bottomed calm-water one-person
craft, although with kids or other lightweight crew it might take two:
the nominal displacement of 325lbs leaves something in range of 275 lbs
over the empty hull weight. As
such, it could carry in addition to most adult crew, such cargo as
fishing gear, light camping gear, and the like.
Although I have not designed such, I think it could readily take
a canoe sailing rig, a small outboard or trolling motor, and fabric
decks. I have shown it with
a double paddle, but I’m certain that a single paddle or oars could
readily be used. The narrow
side-decks give it a bit of extra “tip” before it ships water, and
add greatly to its strength; more about them later.
At the specified displacement, it shows a buttock
angle of 2.8 degrees, and shows a D/L limited speed of
9.63kts (S/L=2.51) against a hull speed of 5.13kts, suggesting
that with a generous rig or the right motor she could plane readily –
but prepare for a wet ride, as she’ll only have about 5” of
freeboard. More sensibly, this all suggests that she’ll glide well to
a paddle stroke. Sailing,
the skipper might not want to hike out – but seriously leaning to
windward should accomplish the task; once again, expect to be damp.
The key to the design is contained in two features,
which are perhaps most easily seen in plan and elevation views.
The plumb stem and stern define the ends of a boat with a flat
bottom and laterally-flat side-decks, both with the same curve as viewed
from the side. The outside
curve of the bottom just matches the inside curve of the side-decks.
These two facts mean that, when developed and plotted on the
material to be cut, the side-decks exactly abut the bottom, making good
use of the material. When assembled, the bottom is entirely, and exactly, visible
from above. The thickness
of the side-decks therefore defines the flare of the sides.
Kept low and to a moderate flair, as here, the side decks come
from the same two sheets of butt-jointed ply as the bottom and
side-decks.
In effect, EuroPig is just one of an infinite
family of designs which observe the above constraints.
This basic idea can be stretched or shrunk or otherwise distorted
without violating the previous paragraph.
Indeed, I had it at one point as a 7’10” skiff, bottom and
decks from one sheet and sides from the other.
In many of the possible proportions, it produces a lot of boat
from the given materials, which was a major part of the contest
challenge
The stern, here, is cut from 1x lumber; however the
ply purists may prefer to shorten the whole thing a few inches and get
the stern from the ply also. Similarly,
the breasthook is of lumber, but might be made of the excess ply by the
fastidious user of all scraps. In
a sailing application, the breasthook might be holed to serve as a mast
partner. I have claimed the
scraps for paddle blades; the motivated will find lots of leftover
lumber in the given list from which to fashion foils, steps, tillers,
and what-not.
Some possible variants, which I have not explored
in detail but which I am sure can be made to work, include the
following:
- There
is no reason why a double-ended form is impossible, within the
“concept” outlined. In
this size, I found no advantage to the pointy-stern, but clearly
nothing forbids it. It
produces an open-topped kayak, which is not to my taste.
In other proportions, using more material, I see no reason
why not.
- Similarly,
a scow form using the same constraints is quite possible.
The sides will tend to be straighter in plan view, leading to
a slightly longer boat; but the bow transom and foredeck or
quarterbraces or whatever would have consumed additional materials
and, more significantly, eliminated the nice pointy front.
- The
bow and stern here are both plumb; more generally they only need to
be parallel. Picture in
your mind’s eye the same boat, with the decks and so forth moved
forward say 3 inches. The
top and bottom curves, in elevation, still match – they are
however offset from each other.
The bow now has a jaunty, wave-cutting look to it, and the
boat has acquired a counter stern.
In some resizings, this could well have advantages; for the
present pirogue, I liked plumb better for its useful interior
volume, especially aft, and for the extra inch or so of overall
length from the given materials.
Done thusly, the sides take on a bit of twist, usually
showing hollow at the bow and, depending on the width of the
side-decks aft, anything from hollowness to convexity to even a
smidgeon of tumblehome aft.
- In
an related form, the top can be significantly longer than the
bottom, but match the curve of the bottom over the length of the
bottom - obviously, the “ends” of the deck would, in elevation,
continue the curve smoothly. Less
stingy in the use of materials, this approach might produce a very
fast and seaworthy kayak, with a v-bottom interrupted only a small
flat under the cockpit. In
another proportioning, a dory might result, or even a chined
interpretation of something like Alerion.
She might look identical as a silouette on a late-afternoon
horizon, but would in fact be very different.
The “chined Alerion” is definitely not for those who
become squeamish about torturing wood!
I make no claim that this automatically produces
the best boat; merely that it produces a lot of boat from given
sheet-goods. The
relationships noted above do not guarantee very much else – the
constraints are in fact not very constraining, and there were
uncountably many designs along the way to this one which I simply hated,
but they met the “rules” above.
EuroPig is, IMHO, the best one I came up with – not in any
sense the best possible. Play
with the form, it’s simple enough, but let your eyes guide your hands.
Illustrations
click to enlarge
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