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