Article - application of "Froude Number" analysing a boat I worked on.
http://weldsmith.co.uk/tech/marine/221231_fhs/221231_froudehs_eg.html "Hydrodynamics, Froude number and a clever vessel design"
I knew this in late March 2022, but wrote the article on New Year's
Eve when had a virus and was alone until it passed.
A non-technical friend said "This is >>>*not*<<< trivial!" and helped
me straighten-out the language to try to make the story accessible.
What they have achieved is astonishing.
These boats are about the size they need to be at about 25m length.
But has a speed up 26kt - which should be infeasible - they've
"ripped-up a rule-book".
26kt is the domain of significant-sized military vessels and hundred-of-metres long streamlined container-ships carrying high-value time-sensitive fully-manufactured cargoes at premium speed.
The boats are no panacea - they have a very limited application
(eg. their cargo capacity is minimal for their size). But for this
one application of servicing offshore wind-farms they are pretty-much
a panacea. A crucial advantage is they ride the waves by hardly
moving at all, which makes transfer over the bow to wind-turbine
towers do-able in quite fearsome seas.
Regards,
Rich Smith
On Sat, 7 Jan 2023 13:32:23 -0500
"Jim Wilkins" <muratlanne@gmail.com> wrote:
<snip> >>https://www.businessinsider.com/coffee-company-cargo-sailboats-instead-of-container-ships-sustainable-shipping-2022-8
I remember hearing of hybrid sailing cargo ships coming soon years ago.
Seems like a good idea to me but doesn't seem to gain much
traction...
On Sat, 7 Jan 2023 13:32:23 -0500
"Jim Wilkins" <muratlanne@gmail.com> wrote:
<snip> >>https://www.businessinsider.com/coffee-company-cargo-sailboats-instead-of-container-ships-sustainable-shipping-2022-8
I remember hearing of hybrid sailing cargo ships coming soon years ago.
Seems like a good idea to me but doesn't seem to gain much
traction...
...We have a car ferry not too far away in Muskegon, MI that claims it can
hit 34kn (39mph):
https://en.wikipedia.org/wiki/HSC_Lake_Express
...We have a car ferry not too far away in Muskegon, MI that claims it can
hit 34kn (39mph):
https://en.wikipedia.org/wiki/HSC_Lake_Express
"pyotr filipivich" wrote in message >news:u0ojrh5rlqjdn0046p059jrbb7sck3aeed@4ax.com...
Leon Fisk <lfiskgr@gmail.invalid> on Sat, 7 Jan 2023 15:10:52 -0400
typed in rec.crafts.metalworking the following:
On Sat, 7 Jan 2023 13:32:23 -0500
"Jim Wilkins" <muratlanne@gmail.com> wrote:
<snip> >>>https://www.businessinsider.com/coffee-company-cargo-sailboats-instead-of-container-ships-sustainable-shipping-2022-8
I remember hearing of hybrid sailing cargo ships coming soon years ago. >>Seems like a good idea to me but doesn't seem to gain much
traction...
The issue remains as it always has: schedules, and "time
sensitive" cargos. If you're moving bulk cargo, it can make sense.
But with "just in time" global supply chains, "it positively
absolutely has to be there in two months".
Like wise, as cool as it might be to take a cruise on a sailing
ship, there is the small issue of "T be back at work, I have to catch
a flight in 10 days. Arriving on the next tide doesn't cut it."
(I had a friend who took Amtrak to Disneyland, and flew back. The
train was delayed, so 'half' the first day at Disneyland was lost
because the train was late. If there is a next time, she'll fly down,
and take the train back. Amtrak is by and large about the trip, more
than getting there.)
--
pyotr filipivich
"With Age comes Wisdom. Although far too often, Age travels alone."
--------------------------
A well publicized local effort to revive wooden sailing cargo ships did not >end well. >https://www.hrmm.org/history-blog/media-monday-coaster-a-true-story-of-the-john-f-leavitt-1983
"Richard Smith" wrote in message news:lyeds66l86.fsf@void.com...
Leon Fisk <lfiskgr@gmail.invalid> writes:
...We have a car ferry not too far away in Muskegon, MI that claims it can
hit 34kn (39mph):
https://en.wikipedia.org/wiki/HSC_Lake_Express
That's also escaping the Froude hull-speed concept.
(mps2knot
(v-from-froude-number 0.4 9.81 58.40) ;; 9.574165237763552 ;; m/s
) ;; 18.610688367142973 ;; kt
It was exciting for me to work out this, but it is obvious - make a
catamaran with largely submerged hulls and you start with a new
hydrodynamic "rulle-book".
-------------------------------
These creatures know the rules: https://www.thoughtco.com/worlds-fastest-fish-2291602
I was just reading about what is the fastest animal. Apparently the
record of 242 MPH is shared by a sky diver and his pet peregrine.
A well publicized local effort to revive wooden sailing cargo ships did not >end well. >https://www.hrmm.org/history-blog/media-monday-coaster-a-true-story-of-the-john-f-leavitt-1983
Like wise, as cool as it might be to take a cruise on a sailing<snip>
ship, there is the small issue of "T be back at work, I have to catch
a flight in 10 days. Arriving on the next tide doesn't cut it."
On Sat, 07 Jan 2023 13:23:24 -0800
pyotr filipivich <phamp@mindspring.com> wrote:
<snip>
Like wise, as cool as it might be to take a cruise on a sailing<snip>
ship, there is the small issue of "T be back at work, I have to catch
a flight in 10 days. Arriving on the next tide doesn't cut it."
I quickly learned that taking very busy time constrained vacations
wasn't for me. Always planned an extra day to both start and end.
Didn't try to fit a whole bunch of must sees together...
The job hassle was knowing there would be a bunch of stuff waiting for
me when I got back. Because there was nobody else that could do them
while I was away. Which was better than having to smooth over the ones
where they did send someone who screwed up...
I never really thought that I was that good but rather that the others
didn't care or try that hard. Pay was the same either way...
--
Leon Fisk
Grand Rapids MI
... The unstated assumption is that the
hiring person can distinguish good from bad candidates for a job they can't do themselves. ...
... The unstated assumption is that the
hiring person can distinguish good from bad candidates for a job they
can't
do themselves. ...
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