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