Jeff wrote:
JimC wrote:

And the other issue is that the water ballast extends all the way
from stem to stern. This can't be helping the pitching moment at all.


Nope. Cross-sections #4 and #5 clearly show that the ballast tank has
narrowed toward the stern such that there is an insignificant volume
(and mass) toward the stern. Instead, by far the greatest volume (and
mass) is in the area near the mast. Thus, the water ballast tank, with
greatest mass located near the center of the boat, would help rather
than augment any pitching moment.





Wrong again. it extends about 2/3rds, and the front and rear
portions of the tank taper to sharp end portions and are therefore
of little mass and no real consequence re the distribution of mass.

Not according to the published diagram:
http://www.macgregor26.com/drawings/drawings.htm

Its pretty clear from this that the ballast extends all the way
forward, and that in fact a substantial amount is forward of the
mast. You should really spend some time learning about your boat, Jim.


I never questioned whether there was a substantial amount forward of the
mast. Nevertheless, since the hull, and the tank, narrows toward the
bow, and since the lever arm extending from the mast to the bow is
relatively short, water ballast at the bow would have little effect on
the distribution of mass.

Jeff, did you happen to take courses in geometry and logic in high
school or junior high? The reason I ask is that you obviously know
nothing about either subject.


Actually, I majored in Naval Architecture for two years before switching
to Physics. Then I worked for NASA for 6 years. Any more questions?


Yes, several. - If you majored in physics and Naval Architecture, why do
you seem to know so little about them. And, what did you do for NASA. -
Surely you weren't designing any boats for them, I hope. (Incidentally,
I worked for NASA for 11 years, and was recently asked to do more work
for them.)


- The fact that the water ballast tank in the Mac extends toward the
bow, forward of the mast, is not determinative of whether it extends
about 2/3rd the length of the boat.


It starts at the bow, and it ends at the stern. The diagram clearly
shows the water ballast running the entire length of the boat. If
anything, it looks that the tanks is deepest in the forward area. The
cross-section at the forward station under the hatch appears to be by
far the largest, indicting that a large portion of the water ballast is
forward.

Here's the diagram again:
http://www.macgregor26.com/drawings/drawings.htm
please tell us if there's any other way to interpret this?


The issue, of course, is whether the mass is substantially centered
or whether substantial mass exists at the bow and stern, which might
affect the distribution of mass throughout the length of the boat. Since
that's the substantive issue, why don't we concentrate on that one.

And with a 250 pound engine hanging of the stern, that's a lot of mass
in the extremities.


Nope. The hull is built to handle the weight of the motor. As well as
the weight of several adults in the cockpit.


(Remember that my statement was in response to Scotty's ridiculous
remark that the water ballast extends "all the way from stem to
stern." - Why didn't you criticize Scotty for making such a stupid
remark?)


Because I made it. And is what is your problem with it? Are you
claiming that the diagram on the Mac site is faulty, that the tank does
not run the entire length? Or are you arguing on the meaning of "stem
to stern"?

As stated, the drawings clearly show that the ballast tank has narrowed
toward the stern such that there is an insignificant volume of ballast
water (and mass) toward the stern. Instead, by far the greatest volume
(and mass) is in the area near the mast. Thus, the water ballast tank,
with greatest mass located near the center of the boat, would help
rather than augment any pitching moment.


Also, the ballast tank is tapered at the front and back such that the
volume (and mass) of water held at the front and rear portions is
substantially less then that held toward amidships.


Clearly, there seems to be little ballast in the stern, but with the
heavy engine, plus the possibility of a full cockpit, its probably not
possible. However, the largest cross-section of the tank is shown at
the station halfway between the keel and the bow at the waterline.

While the bow obviously "tapers in" (yes indeed, they did make the bow
at the pointy end) which means the ballast must be reduced in the
forward few feet, but so is the buoyancy.

Additionally, the heavier, permanent ballast is positioned amidships,
below the mast.


Just where ballast should be. Good for them.


Jeff, I've sailed many boats. The Mac 26M doesn't pitch excessively
and doesn't pitch more than most others. (Have you sailed the 26M? - No?)


I'd love to, but most of the Mac owners hardly ever go out. I have
sailed by them a number of times and they do seem to bob around more
than heavier boats.


Perhaps you need to have your eyes examined.

Jim

JimC wrote:


Jeff wrote:
JimC wrote:

And the other issue is that the water ballast extends all the way
from stem to stern. This can't be helping the pitching moment at
all.


Nope. Cross-sections #4 and #5 clearly show that the ballast tank has
narrowed toward the stern such that there is an insignificant volume
(and mass) toward the stern. Instead, by far the greatest volume (and
mass) is in the area near the mast. Thus, the water ballast tank, with
greatest mass located near the center of the boat, would help rather
than augment any pitching moment.

Yes, there is less ballast aft, but it is certainly not
"insignificant." You have a way twisting the truth around. You're
saying, "Yes, I lied about the ballast but it doesn't really matter."

And, as I said, with that large engine hanging off the stern there's a
huge amount of weight back there. In fact, with a 50Hp engine running
well over 200 pounds, or perhaps 8% of the displacement, that's like a
30 foot cruising boat carrying a 800 pound dinghy in davits. Now
try telling us that has no affect on the pitch moment of inertia.






Wrong again. it extends about 2/3rds, and the front and rear
portions of the tank taper to sharp end portions and are therefore
of little mass and no real consequence re the distribution of mass.

Not according to the published diagram:
http://www.macgregor26.com/drawings/drawings.htm

Its pretty clear from this that the ballast extends all the way
forward, and that in fact a substantial amount is forward of the
mast. You should really spend some time learning about your boat, Jim.


I never questioned whether there was a substantial amount forward of the
mast. Nevertheless, since the hull, and the tank, narrows toward the
bow,

Actually, it doesn't look like it narrows that quickly. In fact there
looks like there's a lot more water ballast at station 1 than anywhere
else. Since you keep denying the truth, we'll just keep posting the
diagram so that everyone can appreciate your sense of reality:

http://www.macgregor26.com/drawings/drawings.htm

and since the lever arm extending from the mast to the bow is
relatively short,

Gee, isn't the lever arm forward of the center of mass roughly half
the length? Actually, we want to use the center of buoyancy, which is
well aft, thus increasing the lever arm.

water ballast at the bow would have little effect on
the distribution of mass.

This is total nonsense. Most designers make an effort to keep the
fuel and water tanks as close as possible to the center of the boat.
My large water tank, for example is athartships at the center. Look
at any large Hatteras and many other powerboats and you'll find the
fuel tank is at the center.

You've been making a big deal about the water ballast, but now you're
claiming its not in the stern, its not in the middle (because that's
where the fixed ballast is), and the amount forward would have "little
effect." What are you Jim, some sort of lawyer?



Jeff, did you happen to take courses in geometry and logic in high
school or junior high? The reason I ask is that you obviously know
nothing about either subject.


Actually, I majored in Naval Architecture for two years before
switching to Physics. Then I worked for NASA for 6 years. Any more
questions?


Yes, several. - If you majored in physics and Naval Architecture, why do
you seem to know so little about them.

Right Jim. You sound like a total idiot saying one thing when the
drawing of your boat clearly shows you're lying.

And, what did you do for NASA. -

I was the senior programmer for the data analysis for the Einstein
X-ray Observatory. Everything from telemetry to navigation to image
processing.

Surely you weren't designing any boats for them,

No, but I did work for a year for a successful America's Cup defender.
However, my work was almost entirely in sail research. Does that
count?

I hope. (Incidentally,
I worked for NASA for 11 years, and was recently asked to do more work
for them.)

So how much engineering did you do?



- The fact that the water ballast tank in the Mac extends toward the
bow, forward of the mast, is not determinative of whether it extends
about 2/3rd the length of the boat.


It starts at the bow, and it ends at the stern. The diagram clearly
shows the water ballast running the entire length of the boat. If
anything, it looks that the tanks is deepest in the forward area. The
cross-section at the forward station under the hatch appears to be by
far the largest, indicting that a large portion of the water ballast
is forward.

Here's the diagram again:
http://www.macgregor26.com/drawings/drawings.htm
please tell us if there's any other way to interpret this?


The issue, of course, is whether the mass is substantially centered
or whether substantial mass exists at the bow and stern, which might
affect the distribution of mass throughout the length of the boat. Since
that's the substantive issue, why don't we concentrate on that one.

OK. The boat weighs 3700 lbs with 1150 lbs, or 31%, of that water
ballast. Now you just claimed that at sections 4 and 5 the water
ballast is "insignificant." And the diagram clearly shows that much
of the ballast tank at section 2 and 3 is actually occupied by the
fixed ballast. So in fact, a large portion of that 1150 pounds of
water is well forward. And while the boat obviously narrows at the
bow, since the ballast tank doesn't extend the entire width, there is
actually very little narrowing of the tank until you get to the last
two feet. And, since there isn't much of a bow overhang, its pretty
clear the there is a lot of mass well forward when the tank is full.




And with a 250 pound engine hanging of the stern, that's a lot of mass
in the extremities.


Nope. The hull is built to handle the weight of the motor. As well as
the weight of several adults in the cockpit.

Again, you sound like an idiot here, Jim. You should quit trying to
sound like an engineer. There was no claim that the stern was going
to fall off. The point is that boats are usually designed to minimize
mass in the extremities, and thus reduce the pitch moment of inertia.

By comparison, on my boat, which weighs triple yours, I use the
lightest possible ground tackle to save a hundred pounds or so from
the bows. There is no excess mass at all in the forward ten feet of
the boat.



As stated, the drawings clearly show that the ballast tank has narrowed
toward the stern such that there is an insignificant volume of ballast
water (and mass) toward the stern. Instead, by far the greatest volume
(and mass) is in the area near the mast.

No, the drawing clearly shows that there is even more water forward of
the mast. Have you even looked at the drawing? By claiming there's
little water ballast aft you're claiming there's even more forward of
the mast!

Thus, the water ballast tank,
with greatest mass located near the center of the boat, would help
rather than augment any pitching moment.

Sorry Jim, anyone can clearly see that you're lying. Let's have
another look at that drawing:

http://www.macgregor26.com/drawings/drawings.htm

Yup, it still shows the largest cross section of water ballast at
section 1, well forward of the the mast.

Sorry, Jim. The Republican approach of repeating the lie over and
over until someone thinks it must be true has been discredited.

Perhaps you can get someone else here to explain it to you.

Jeff wrote:
JimC wrote:

And the other issue is that the water ballast extends all the way
from stem to stern. This can't be helping the pitching moment at all.



Wrong again. it extends about 2/3rds, and the front and rear
portions of the tank taper to sharp end portions and are therefore
of little mass and no real consequence re the distribution of mass.

Not according to the published diagram:
http://www.macgregor26.com/drawings/drawings.htm

Its pretty clear from this that the ballast extends all the way
forward, and that in fact a substantial amount is forward of the
mast. You should really spend some time learning about your boat, Jim.


Jeff, did you happen to take courses in geometry and logic in high
school or junior high? The reason I ask is that you obviously know
nothing about either subject.


Actually, I majored in Naval Architecture for two years before switching
to Physics. Then I worked for NASA for 6 years. Any more questions?

Yes. If you majored in Naval Architecture and Physics, how do you
explain the fact that you know so little about them?
And, what did you do for NASA during those 6 years? - I certainly
hope you weren't designing boats for them.
(Incidentally, it happens that I worked for NASA also, for 11
years. - Does that make me 11/6 more qualified than you?)



- The fact that the water ballast tank in the Mac extends toward the
bow, forward of the mast, is not determinative of whether it extends
about 2/3rd the length of the boat.


It starts at the bow, and it ends at the stern. The diagram clearly
shows the water ballast running the entire length of the boat. If
anything, it looks that the tanks is deepest in the forward area. The
cross-section at the forward station under the hatch appears to be by
far the largest, indicting that a large portion of the water ballast is
forward.

Here's the diagram again:
http://www.macgregor26.com/drawings/drawings.htm
please tell us if there's any other way to interpret this?

Yes, there is another way to interpret it. - The correct way. The Mac
26M has a a drainage opening and large gate valve positioned on the
lower portion of its transom, the purpose of which is to permit the
ballast water to drain out of the tank when desired. The narrow,
elongated, cross-hatched "bulges" shown at the bottom of the hull in
cross-sections 4 and 5 are actually channels that conduct ballast water
from the ballast tank to the drainage opening when the bow is elevated.
When the gate valve on the stern is opened with the boat sitting on a
launch ramp, for example, water from the ballast tank is permitted to
drain out through the drainage valve, a process that takes about 4
minutes. - In other words, the cross-hatched portions you interpreted
as being part of the ballast tank are actually conduits that communicate
with the ballast tank for permitting the ballast water to drain out, but
they are not part of the tank itself. And, because of their small
volume, they have little effect on the distribution of mass along the
longitudinal axis of the boat.



And with a 250 pound engine hanging of the stern, that's a lot of mass
in the extremities.


Nope. The boat is designed to be balanced fore and aft with an outboard
and several persons in the cockpit.



(Remember that my statement was in response to Scotty's ridiculous
remark that the water ballast extends "all the way from stem to
stern." - Why didn't you criticize Scotty for making such a stupid
remark?)


Because I made it. And is what is your problem with it? Are you
claiming that the diagram on the Mac site is faulty, that the tank does
not run the entire length? Or are you arguing on the meaning of "stem
to stern"?

No, I'm not claiming the diagram is faulty. - I'm simply claiming that
you need to get your eyes examined. Also, that you ought to do your
homework before pontificating like that.


Also, the ballast tank is tapered at the front and back such that the
volume (and mass) of water held at the front and rear portions is
substantially less then that held toward amidships.


Clearly, there seems to be little ballast in the stern, but with the
heavy engine, plus the possibility of a full cockpit, its probably not
possible. However, the largest cross-section of the tank is shown at
the station halfway between the keel and the bow at the waterline.

While the bow obviously "tapers in" (yes indeed, they did make the bow
at the pointy end) which means the ballast must be reduced in the
forward few feet, but so is the buoyancy.

Additionally, the heavier, permanent ballast is positioned amidships,
below the mast.


Just where ballast should be. Good for them.


As noted above, the boat is designed to be balanced with an outboard and
with several persons in the cockpit. And it is.



Jeff, I've sailed many boats. The Mac 26M doesn't pitch excessively
and doesn't pitch more than most others. (Have you sailed the 26M? - No?)


I'd love to, but most of the Mac owners hardly ever go out. I have
sailed by them a number of times and they do seem to bob around more
than heavier boats.

And, when did you last have your eyes examined, Jeff?


Seems to me that this is just one more example of the fact that the
most opinionated, inflexible critics of the Mac 26m are those who have
never sailed one.


From everything you've posted Jim, there's no evidence you've ever been
on one either.

Well, have a nice evening anyway Jeff. Happy sailing.


Jim

JimC wrote:


Jeff wrote:
JimC wrote:

Jeff, did you happen to take courses in geometry and logic in high
school or junior high? The reason I ask is that you obviously know
nothing about either subject.


Actually, I majored in Naval Architecture for two years before
switching to Physics. Then I worked for NASA for 6 years. Any more
questions?

Yes. If you majored in Naval Architecture and Physics, how do you
explain the fact that you know so little about them?

You really like the ad hominem attacks, don't you? But what do you
have to gain? Everyone reading this knows I'm right and that just
makes you look like an asshole in addition to being an idiot.

And, what did you do for NASA during those 6 years? - I certainly
hope you weren't designing boats for them.

No, but I did do that for an America's Cup syndicate.

(Incidentally, it happens that I worked for NASA also, for 11
years. - Does that make me 11/6 more qualified than you?)

I actually did engineering, what did you do? Write product liability
waivers? You have trouble taking the high road here, Jim, after you
explained to us that all of the warnings that come with a Mac is just
lawyer talk that can be ignored. Unless, of course, it can be used to
save the company when children die as the boat rolls over in calm
weather. It really amazes me how you can shift positions to suit your
need. Is that what you learn in lawyer school?

It starts at the bow, and it ends at the stern. The diagram clearly
shows the water ballast running the entire length of the boat. If
anything, it looks that the tanks is deepest in the forward area. The
cross-section at the forward station under the hatch appears to be by
far the largest, indicting that a large portion of the water ballast
is forward.

Here's the diagram again:
http://www.macgregor26.com/drawings/drawings.htm
please tell us if there's any other way to interpret this?

Yes, there is another way to interpret it. - The correct way. The Mac
26M has a a drainage opening and large gate valve positioned on the
lower portion of its transom, the purpose of which is to permit the
ballast water to drain out of the tank when desired. The narrow,
elongated, cross-hatched "bulges" shown at the bottom of the hull in
cross-sections 4 and 5 are actually channels that conduct ballast water
from the ballast tank to the drainage opening when the bow is elevated.
When the gate valve on the stern is opened with the boat sitting on a
launch ramp, for example, water from the ballast tank is permitted to
drain out through the drainage valve, a process that takes about 4
minutes. - In other words, the cross-hatched portions you interpreted
as being part of the ballast tank are actually conduits that communicate
with the ballast tank for permitting the ballast water to drain out, but
they are not part of the tank itself. And, because of their small
volume, they have little effect on the distribution of mass along the
longitudinal axis of the boat.

OK, you made your point, there's not much ballast aft of the mast. Of
course, my point has really been that there's a lot forward of the
mast, so you just helped prove my point.

And by the way, what happened to your claim that the entire boat was
protected by a "doubled hull" - now you're claiming it's just a small
portion. Was that just "lawyer talk" that we can ignore?

And with a 250 pound engine hanging of the stern, that's a lot of mass
in the extremities.


Nope. The boat is designed to be balanced fore and aft with an outboard
and several persons in the cockpit.

In other words, you are totally ignorant of the concept of "moment of
inertia." Perhaps you should take some time off now and review basic
physics. This is the central issue of the discussion, and now you're
confessing that you have no idea what its about. Good one, Jim.

....
Additionally, the heavier, permanent ballast is positioned amidships,
below the mast.


Just where ballast should be. Good for them.


As noted above, the boat is designed to be balanced with an outboard and
with several persons in the cockpit. And it is.


Yes, the large mass in the stern (the engine) is nicely balanced by
the large mass of the water ballast in the bow. Now explain to us the
meaning and significance of "moment of inertia."



Jeff, I've sailed many boats. The Mac 26M doesn't pitch excessively
and doesn't pitch more than most others. (Have you sailed the 26M? -
No?)


I'd love to, but most of the Mac owners hardly ever go out. I have
sailed by them a number of times and they do seem to bob around more
than heavier boats.

And, when did you last have your eyes examined, Jeff?

Funny thing, as I've grown older my vision has improved. Now I spend
most of the time without wearing the glasses I've worn since I was
ten. I guess that means I've just gotten smarter.

"Jeff" wrote

Everyone reading this knows I'm right and that just
makes you look like an asshole in addition to being an
idiot.


We knew that before, but thanks for reinforcing it.

Scotty

Scotty wrote:
"Jeff" wrote
Everyone reading this knows I'm right and that just
makes you look like an asshole in addition to being an
idiot.


We knew that before, but thanks for reinforcing it.

I nominate Scotty as an impartial mediator in this dispute.

Jeff wrote:
JimC wrote:



Jeff wrote:

JimC wrote:

Jeff, did you happen to take courses in geometry and logic in high
school or junior high? The reason I ask is that you obviously know
nothing about either subject.



Actually, I majored in Naval Architecture for two years before
switching to Physics. Then I worked for NASA for 6 years. Any more
questions?


Yes. If you majored in Naval Architecture and Physics, how do you
explain the fact that you know so little about them?


You really like the ad hominem attacks, don't you? But what do you have
to gain? Everyone reading this knows I'm right and that just makes you
look like an asshole in addition to being an idiot.

And, what did you do for NASA during those 6 years? - I certainly
hope you weren't designing boats for them.


No, but I did do that for an America's Cup syndicate.

(Incidentally, it happens that I worked for NASA also, for 11
years. - Does that make me 11/6 more qualified than you?)


I actually did engineering, what did you do? Write product liability
waivers? You have trouble taking the high road here, Jim, after you
explained to us that all of the warnings that come with a Mac is just
lawyer talk that can be ignored.

Although I did say that I thought that attorneys were involved in
wording the warnings, where did I say that the warnings can be ignored?



Unless, of course, it can be used to
save the company when children die as the boat rolls over in calm
weather. It really amazes me how you can shift positions to suit your
need. Is that what you learn in lawyer school?

It starts at the bow, and it ends at the stern. The diagram clearly
shows the water ballast running the entire length of the boat. If
anything, it looks that the tanks is deepest in the forward area.
The cross-section at the forward station under the hatch appears to
be by far the largest, indicting that a large portion of the water
ballast is forward.

Here's the diagram again:
http://www.macgregor26.com/drawings/drawings.htm
please tell us if there's any other way to interpret this?


Yes, there is another way to interpret it. - The correct way. The Mac
26M has a a drainage opening and large gate valve positioned on the
lower portion of its transom, the purpose of which is to permit the
ballast water to drain out of the tank when desired. The narrow,
elongated, cross-hatched "bulges" shown at the bottom of the hull in
cross-sections 4 and 5 are actually channels that conduct ballast
water from the ballast tank to the drainage opening when the bow is
elevated. When the gate valve on the stern is opened with the boat
sitting on a launch ramp, for example, water from the ballast tank is
permitted to drain out through the drainage valve, a process that
takes about 4 minutes. - In other words, the cross-hatched portions
you interpreted as being part of the ballast tank are actually
conduits that communicate with the ballast tank for permitting the
ballast water to drain out, but they are not part of the tank itself.
And, because of their small volume, they have little effect on the
distribution of mass along the longitudinal axis of the boat.

Jeff, further to my comment above, note, in Figures 4 and 5, that the
cross-hatched elements near the bottom of the hull (the ones you
interpreted as being part of the ballast tank) are of identical
configuration in both FIGS. 4 and 5, further demonstrating that they are
actually linear conduits or passageways rather than part of the
ballast tank itself.


OK, you made your point, there's not much ballast aft of the mast.

I'm not sure I follow that last statement, Jeff. - Are you now saying I
was right (after all that discussion) in describing the ballast tank as
not extending along the full length of the boat? Or that your statement,
copied below, was wrong?

"And the other issue is that the water ballast extends all the way from
stem to stern. This can't be helping the pitching moment at all."



And by the way, what happened to your claim that the entire boat was
protected by a "doubled hull" - now you're claiming it's just a small
portion. Was that just "lawyer talk" that we can ignore?

Give us a break Jeff. - Where did I say that the "entire boat" was
protected by a doubled hull? A large portion of the lower portion of
the hull is, indeed, "doubled," but the two-layer "doubled" portion
doesn't extend beyond the ballast tank. In all prior discussions of the
matter, I have certainly attempted to make that point clear.

Jeff, you criticise me for making ad hominem attacks, etc. Actually, my
friends and colleagues consider me a courteous, laid-back, amicable kind
of guy willing to listen patiently to all sides of a discussion. - I
would be happy to minimize the ad hominems and to treat you and other
Mac-Bashers with all the respect and deference you deserve, and I'll do
so just as soon as I see some of the same from you and the other
Mac-Bashers. Meanwhile, I suppose that I'll continue to give as well as
I get.

Jim

Jeff wrote:
Scotty wrote:
"Jeff" wrote
Everyone reading this knows I'm right and that just
makes you look like an asshole in addition to being an
idiot.


We knew that before, but thanks for reinforcing it.

I nominate Scotty as an impartial mediator in this dispute.


Note to self: NEVER, upon pain of death, ask another question about a
Macgregor! Such controversial subjects cause neurological damage and an
utter lack of civility.

Macgregors are the BEST sailing ships ever constructed. !!

JimC wrote:



I actually did engineering, what did you do? Write product liability
waivers? You have trouble taking the high road here, Jim, after you
explained to us that all of the warnings that come with a Mac is just
lawyer talk that can be ignored.

Although I did say that I thought that attorneys were involved in
wording the warnings, where did I say that the warnings can be ignored?


Your comment was:
"Jeff, have you had many dealings with corporate attorneys?
Or tort lawyers? If you had, you would recognize that these
warnings, if taken literally, are something like the warnings
posted in our health center warning us to be sure to
wear our seat belt when using the Nautilus weight
training equipment. Or, like the long list of warnings
you get when you purchase any electrical appliance,
audio equipment, etc. "

I really don't see how anyone can reasonably interpret this as meaning
anything other than this is just lawyer talk. So Jim, do you think
anyone is going to take your side on this one???



Jeff, further to my comment above, note, in Figures 4 and 5, that the
cross-hatched elements near the bottom of the hull (the ones you
interpreted as being part of the ballast tank) are of identical
configuration in both FIGS. 4 and 5, further demonstrating that they are
actually linear conduits or passageways rather than part of the ballast
tank itself.


OK, you made your point, there's not much ballast aft of the mast.

I'm not sure I follow that last statement, Jeff. - Are you now saying I
was right (after all that discussion) in describing the ballast tank as
not extending along the full length of the boat? Or that your statement,
copied below, was wrong?

"And the other issue is that the water ballast extends all the way from
stem to stern. This can't be helping the pitching moment at all."



You really don't get it. First of all, the tank truly does extend all
the way from the stem to the stern. If all they wanted was a conduit,
they could have put in a tube with a lot less expense. You're only
claiming that the volume aft is relatively small. But that just means
the the volume forward of the mast is that much higher. This supports
my claim that there is a lot of mass in the extremities. Go back to
my comments, this is about mass in the extremities which increase the
moment of inertia.

And of course, your claim that the ballast tank is only a "conduit"
rather blows away your "double hull" assertion.



And by the way, what happened to your claim that the entire boat was
protected by a "doubled hull" - now you're claiming it's just a small
portion. Was that just "lawyer talk" that we can ignore?

Give us a break Jeff. - Where did I say that the "entire boat" was
protected by a doubled hull? A large portion of the lower portion of
the hull is, indeed, "doubled," but the two-layer "doubled" portion
doesn't extend beyond the ballast tank. In all prior discussions of the
matter, I have certainly attempted to make that point clear.

But the problem is that when the boat is at high speed it will be
planing with the bow raised up. Thus the vulnerable portion is the
aft part that you're claiming now is not double hulled. In other
words, although you have repeatedly claimed this as a significant
advantage, its value is really limited. In fact, even the Mac
marketing literature doesn't mention this; why do you think this is?
Is this something you made up, or just something a salesman told a
gullible customer?

BTW, if the hull was compromised and you brought it up on a plane, the
tank could possibly drain, leaving you in the dangerous situation of
having several hundred pounds of water surging around.




Jeff, you criticise me for making ad hominem attacks, etc. Actually, my
friends and colleagues consider me a courteous, laid-back, amicable kind
of guy willing to listen patiently to all sides of a discussion.

I'm sure you're one helluva guy. Did I ever mention that my closest
sailing buddy had, as his first boat, a Venture 22? (Its a period he
doesn't like to talk about!)

- I
would be happy to minimize the ad hominems and to treat you and other
Mac-Bashers with all the respect and deference you deserve,

I really don't know why you consider me a "mac basher," all I've tried
to do is honestly consider the attributes of the boat. In fact, my
involvement in this thread only started with a consideration of how
water ballast affects stability. You've tried to make it sound like
all proper boats (you said "most ocean-going vessels") use internal
ballast, but in fact most designers would consider it a choice of last
resort. Of course, for a trailerable boat it makes sense, but a lot
of Macs I see are kept in slips, which certainly minimizes that.

and I'll do
so just as soon as I see some of the same from you and the other
Mac-Bashers. Meanwhile, I suppose that I'll continue to give as well as
I get.

I wouldn't get too excited about how much you've "given."

"CJH" wrote in message
...
Jeff wrote:
Scotty wrote:
"Jeff" wrote
Everyone reading this knows I'm right and that just
makes you look like an asshole in addition to being an
idiot.


We knew that before, but thanks for reinforcing it.

I nominate Scotty as an impartial mediator in this dispute.


Note to self: NEVER, upon pain of death, ask another question about a
Macgregor! Such controversial subjects cause neurological damage and an
utter lack of civility.

Nah. Everyone here, including yours truly, has been brain-damaged/dead for
years. You can thank Capt. Neal and Bubbles for that. As for the utter
lack of civility, what do you expect from sockpuppets?

Max