Skipper wrote:
On Tue, 31 Aug 2004 21:46:31 GMT, Dan Best wrote:

This weekend in Olympia, Washington State, is the Harbor Days
festival. During Harbor Days are the well-known tug boat races. As a
sailor, I understand bow waves, hull speeds, and displacement hulls.
It is a pretty good bet that the 70' tug will beat the 35' tug. I
think the longer tug could win with the engine just above an idle.

But it is really amazing to watch the bow wave dynamics in action.
A 30 foot tug with 600 horsepower can build a HUGE bow wave and still
not pass its hull speed. The waves generated in this race are far
greater than the waves from cargo ships that are 10 times as long and
1,000 times larger.


Boring to watch, after a very short while.

The spectacle of this thread, that is.

Just because a bulldozer is pushing a large pile of dirt does not
mean that it has failed to exceed hull speed.

Hull speed is only a theoretically derived number. It is a gauge of
relative numerical relationships; it is not something like the speed
of light, or even the speed of sound. It's kind of like saying hands
have 5 fingers, and figuring their average length. It is not a
limit, except perhaps to fuel efficiency calculations.

Does bring to mind the Hobie style catamaran planing concept,
though. It's kind of like squeezing a watermelon seed in snotty fingers.

We need to remember there are several different factors affecting
drag and dynamic forces at work in various hull types and speed
regimes. Fuel consumption in a sailboat is possible to imply, but
impossible to measure.

I prefer to ponder the "Stove pipe submarine" and it's wake, for a
starting point. It will lead us towards some interesting insights.

Submarines are theoretically detectable from orbit by wake analysis,
amid the chaos of wave noise. Well, it's not noise, folks, its only
chaotic because we cannot measure the causative forces in sufficient
detail, and that is all. If you examine bible message analysis, it
soon becomes obvious that you can find any message, in any language,
even looking for french in a chinese translation. It all depends on
generating the right key, and mowing enough grass, as we say in the
processor hall air conditioning department.

Anyway, if a submarine was constructed like a pipe with a narrowed
internal passage containing it's propellor, would it produce a wake,
especially with a hubless fan drive?

When you push against the water with a paddle, what is (are) the
forces contributing to the thrust reaction developed? An amount of
energy equivalent to the mass*velocity/ friction and delta vee of
the vessel must be left behind in the water. It's mechanism of
transformation must simply be rationalized.

See, at the front of the sp sub, there must be a declivity in the
water as large as the hill of water that would be left behind, and
turbulent water left behind in the wake, whether organized into
visible waves, as in a "normal" wake, or not, must non the less be
transformable into friction heating of the water. It is a question
of looking at the turbulence through the right filters, like
catching a boomer by it's straight lines on the surface / filter
amidst the chop. This is an example of energy being expressed purely
as information analysis, or a set of data passed through an
analytical filter, heating it. Time is the governing constant [?]
and computational capacity limits the keys. The sump pump in the
pare bit buffer must be cooled, or its conductors overheat.

The wake formation of the sp sub would seem to double it's "hull
speed" by removing the bulge in the middle of the vessel as it
pushes through the water, or in the case of the sp sub, as it sucks
itself along. Could that principle be applied to a surface piercing
vessel on plane, like a sea-doo?

Fuel for sailboats is free as the wind. Petroleum is fuel for
engine boats.

Whatever happened to the lye and aluminum refillable battery? could
it be said to be in a sense hypergolic, and using water as a catalyst?

Terry K

Rod and reel?