"Roger Long" wrote in message
...

"Wilbur Hubbard" wrote

a really stupid interior design. The entire accommodation is
ill-conceived and obviously designed by a lubber. Why put the berths
way forward for the roughest ride possible?

Because the berths are infrequently used and generally in port or
while on station (moving slowly and just maintaing position). The
heads on the other hand, are used constantly.


Used almost constantly? What's the matter with the crew? Chronic
diarrhea?

Being 'on station' is perhaps the worst of all worlds. You pitch AND
roll. You don't want to even try sleeping in the bow under those
conditions. Those poor seasick blokes stumbling from bow to aft heads
will just manage to puke all over everything in between. Nope, it's a
dumb layout. They took a freaking pleasure yacht layout and tried to
incorporate it into a workboat. Like I said, ill-conceived. The
designer's incompetent.

Wilbur Hubbard

"Wilbur Hubbard" wrote in message
anews.com...

Being 'on station' is perhaps the worst of all worlds. You pitch AND roll.
You don't want to even try sleeping in the bow under those conditions.
Those poor seasick blokes stumbling from bow to aft heads will just manage
to puke all over everything in between. Nope, it's a dumb layout. They
took a freaking pleasure yacht layout and tried to incorporate it into a
workboat. Like I said, ill-conceived. The designer's incompetent.

Wilbur Hubbard


What is your home page address? I want to see that mustard yellow swamp
boat with the mauve interior again.

Being 'on station' is perhaps the worst of all worlds. You pitch AND
roll. You don't want to even try sleeping in the bow under those
conditions.

This is the fourth boat in a series, the first having more than a decade of
operation. No complaints about comfort yet, quite the opposite. Each
institution has talked to the operator of the previous boats to get ideas
and changing the berth layout has never come up.

It's the comfort on station and the qualities as a good platform for
handling heavy, delicate, and expensive stuff over the sides that keeps
oceanographic institutions coming back to me for designs. There are now
more oceanographic vessels in the under 150 foot size range of my design
operating in the Atlantic than by any other designer. I know a couple of
captains that have spent their entire careers on vessels that I designed.

These aren't your daddy's trawler yachts. The hull weight distribution is
carefully managed to detune the roll period to the critical sea states and
the hulls have a great deal of damping. The difference in comfort compared
to a boat with freeboard and deckhouses piled high to make an impression
inside at the boat shows is remarkable. I got a letter from someone at Woods
Hole who had deployed the same gear on the original 50 foot version and on
an 80 footer of four times the displacement and proportions typical of
trawler yachts. He found the smaller boat more comfortable and a better
working plantform. That had a lot to do with my designing the one for Woods
Hole.

Someday, someone will realize what a great yacht one of these boats would
make. In that case, the berths probably will go in the middle. The purpose
of these boat is to do science; not have people sleep. The most important
function goes in the most comfortable part of the boat.

--
Roger Long

I just fixed couple of broken links and you can now view the homepages for
the three previous boats he

http://home.maine.rr.com/rlma/Challenger_Class.HTM

All three home pages have arrangement plans for the boats and there are even
some videos if you look around.

--
Roger Long

....
http://home.maine.rr.com/rlma/Challenger_Class.HTM

All three home pages have arrangement plans for the boats and there are even
some videos if you look around.
....

Thanks for all that. Not every designer in the world is willing to
share lines drawings. When I bought the design for my current boat I
had to sign a NDA with the designer and return the plans on
completion! Anyway, since you've been generous with sharing your work
I'm going to be rude enough to ask some questions. Feel free to
ignore them! I'm curious about why you've chosen jets for the new
design. Is the cruise speed higher? I'm also fascinated by the bilge
keels. Are they just to help the handling?

-- Tom.

It is a jet boat because it will be operating primarily in the shallow
waters of Cheaspeak Bay and a lot of areas of interest are the thin parts.
The draft of the jet boat isn't significantly different than a prop boat
with tunnels but there is a big difference running with just a foot or two
of water under you when the first thing to strike will be spinning props
that will send you the the shipyard for haulout if they touch. The jets
will ingest a lot of oyster shells and other debris. The jet boat could
probably plow right through an oyster bar and keep right on operating
although the transducers and bottom paint would suffer.

The jets are less fuel effecient. Another way of putting this is that the
boat will burn more fuel at the same speed. We expect the cost of this fuel
to be offset by not hauling out to repair props so often and being able to
extend the working area safely into shallower waters. The jets also
contribute significantly to maneuverability since they can essentially
vector thrust in any direction.

The fins are to provide the directional stability normally contributed by
the drag of struts, props, and rudders. They also contribute to roll
damping.

--
Roger Long

"Roger Long" wrote in news:46add541$0$16582
:

The jet boat could
probably plow right through an oyster bar and keep right on operating
although the transducers and bottom paint would suffer.


That really depends a LOT on which jet pump is used. If the jet used has a
stator a few cm behind its spinning impeller, it will very soon be
destroyed by the first piece of hard flotsam that it ingests. Case in
point is any jetski jet or the Mercury SportJet pumps. The spinning
impeller is very, very close to the cast aluminum stator used to stop the
water spinning out the back and is required to produce linear thrust. If
ANYTHING gets between that stator and the prop, it eats the drivetrain,
instantly.

Not all jets are made for river bottom dragging service like those
wonderful jetboats made in Oz.....(c; You get a SportJet near the bottom,
it's going to be a very expensive cruise...very quickly.

Larry
--

On Jul 30, 2:11 am, "Roger Long" wrote:
It is a jet boat because it will be operating primarily in the shallow
waters ...
The fins are to provide the directional stability normally contributed by
the drag of struts, props, and rudders. They also contribute to roll
damping. ...

That sounds very sensible. The placement and shape of the fins is
also interesting. I was wondering if you had chosen the long, shallow
fins outboard on the chines to control the flow at the jet intakes or
increase hull lift (perhaps to make up for the absence of strakes). I
was also curious about the linkage between the jets and the engines.
On the profile it looks like you might need two CV joints because the
shaft doesn't line up. Thanks again for the education. FWIW, I
think it is a handsome design. I suspect the builders appreciate the
straight forward development of the hull, too.

-- Tom.

On 2007-07-30 08:11:00 -0400, "Roger Long" said:

It is a jet boat because it will be operating primarily in the shallow
waters of Chesapeake Bay and a lot of areas of interest are the thin
parts. The draft of the jet boat isn't significantly different than a
prop boat with tunnels but there is a big difference running with just
a foot or two of water under you when the first thing to strike will be
spinning props that will send you the the shipyard for haulout if they
touch. The jets will ingest a lot of oyster shells and other debris.
The jet boat could probably plow right through an oyster bar and keep
right on operating although the transducers and bottom paint would
suffer.

Most of the bay has a thick bottom of mostly mud, but an awful lot of
it is 6'.

Interesting set of considerations. Hope to see it operating about the Bay.

Any idea where they plan to berth it?

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's new pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI pages: http://homepage.mac.com/jerelull/BVI/

The jets
will ingest a lot of oyster shells and other debris. The jet boat could
probably plow right through an oyster bar and keep right on operating

Gee, destroying the waters they're trying to research isn't exactly sound
logic. I'd also wonder how much more damage the water flow from the jets
would cause during maneuvering a boat of that size.

Not saying this as an argument for props though. More that it's dumb to
plan to go into places that will very likely cause greater harm to the
enivonment that necessary. Take a dinghy or launch instead, not some huge
vessel.