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JimC December 5th 06 04:14 PM

Google proves MacGregor 26 is flimsy
 


Martin Baxter wrote:

JimC wrote:


And you did take math, and geometry in high school? Consider a typical
crew of two people (assume total weight of 350 lbs) and a skipper of 230
lbs. (about my weight). Assuming that the skipper is sitting on the
captain's chair, about 1.5 ft forward of the center of the motor, and
about 16 feet aft of the center of mass. Assuming that the two crew
members are sitting two and three feet forward of the captain,
respectively, their total mass will be the equivalent of 350 pounds
positioned about 14.5 feet from the center of mass about which the boat
has a tendency to pitch. The motor, at about 220 pounds is about 17.5
feet from the center of mass. Squaring the distances, the relative
values of the rotational momentum of the skipper and crew are more than
twice that of the motor, despite the fact that they are closer to the
center of mass. Once again, Jeff, your theories are simply wrong. (If
you wish, I'll provide the calculations and "foot pounds" or whatever,
in greater detail.)



Jim:

I thought I'd run your numbers through my calculator, just for fun:

(14.5ft)^2*350lbs=7.36E4ft^2-lbs , that's 73,600 for the exponent
challenged.

(17.5ft)^2*220lbs=6.74E4ft^2-lbs , 67,400 ....

Maybe you think that 73,600 is more than TWICE 67,400, but I beg to
differ. To a physicist, they're essentially the same thing.

Point to Jeff.

Cheers
Marty



Aren't you forgetting the force moment to be attributed to the Skipper,
which would be added to that of the two-man crew? In this case, (230
lbs)*(16ft)^2 . My figure was 58,880, which if added to 73,600 is
132,480. - Not quite twice 67400, but close, and certainly substantially
more than 67400. Obviously, the figures would change if the crew went
forward, or if additional guests were in the cockpit, etc.

My point was that what was considered a major, overriding factor (the
momentum entailed in having a "huge" OB hanging off the stern) is
actually substantially less a factor than others such as the mass of a
typical crew and skipper. It's a matter of perspective.

Jim

Jim

Jeff December 5th 06 04:33 PM

Google proves MacGregor 26 is flimsy
 
JimC wrote:

Looks like you erased all my additional remarks POSTED IN THAT
DISCUSSION stating that the warnings should NOT be ignored. ... Why
would you do a pitiful, sneaky thing like that Jeff?? You talk about
layers' ethics. - What about your own???


Sorry Jim. No mulligans. No do-overs. If I had snipped things from
the same post you could accuse me of taking it out of context.
However, once I had called you on this and showed your hypocrisy, you
can't take it back. You could have admitted that you made a mistake,
but you preferred to defend it to the death, hanging your credibility
on people believing that when you likened the warnings on a Mac to
warnings to wear a seatbelt on the exercise machine you didn't mean it
was just lawyer talk.

So every time you try to defend, all you're doing is claiming that you
have the right to say "ignore what lawyers say, except this time."

OK, I'll repost the original in its entirety. I had said:

"The Mac is clearly unsafe without its water ballast. The
admonishments include: no more than 4 people. Keep crew aft, low and
centered. The kids can't even stay in the forward bunk! They
actually tell you not to use the forward bunks when underway! They
say it is unsafe in seas higher than one foot! So much for coming in
from offshore. You can't stand on the deck because someone might grab
the mast to hold on! What? They're afraid someone might pull the
boat over trying to hold on??? No, this is not typical of a 26 foot
sailboat, nor is it typical of a 26 foot powerboat."

You replied:

"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.
Actually, the new 26M has 300 pounds of additional permanent ballast,
in addition to the water ballast, for providing added stability when
motoring without the water ballast. (The previous model, the 26X,
didn't have this feature, yet I haven't heard of hundreds of Mac 26X
owners being lost at sea because they didn't stay below deck when
motoring the boat without the ballast. In essence, when under power
without the water ballast, the boat is a small, lightweight power
boat, and you have to take reasonable precautions to keep the com low.
(On the other hand, if you can provide statistics regarding hundreds
of Mac sailors being lost at sea because they didn't stay in the cabin
when motoring without the water ballast, I would like to see those
statistics.)

"Of course, if I were sailing or motoring with several guests, or with
children (our grandkids), I would certainly make sure that they didn't
head out to the foredeck when the boat was motoring without the water
ballast. Also, if I was going to go offshore, I would want to make
sure that the water ballast was filled. Ultimately, however, this is
a "lawyer thing." Remember, the boat is manufactured in California."


Its very clear that you're saying that the long list of rather sever
warnings about running without ballast is just, and I'm using your
words here, a "lawyer thing."

My point was never that the warning can be ignored, I was saying that
they should be taken seriously and serve as an indication that the
high speeds sometimes talked about cannot really be achieved in all
conditions. You didn't see where the discussion was going and so
chose to counter with this "lawyer thing" comment. Unfortunately, in
that moment, you lost all credibility.

Sorry Jim. No mulligans. No do-overs.

snip all further discussion on lawyers - its just too embarrassing
for Jim






And it does, though the mass aft largely comes from the 250 pound
engine hanging off the transom.


Not really. The mass aft largely comes from the crew/guests/skipper,
not the motor (unless the boat is being sailed solo). The motor is
slightly farther aft, but not much. (The captains seat is about a
foot forward of the motor.)



What a crock of ****. Do you actually read the stuff you write? Since
the moment of inertia is proportional to the square of the distance
from the center of mass, the mass of the engine is actually equivalent
to a mass 4 time larger but half the distance to the center of mass.


And you did take math, and geometry in high school? Consider a typical
crew of two people (assume total weight of 350 lbs) and a skipper of 230
lbs. (about my weight).


The weight used as the "standard" is 160 pounds. Obviously, if you
put overweight people aft in the cockpit, you can force the numbers to
look however you want.


Assuming that the skipper is sitting on the
captain's chair, about 1.5 ft forward of the center of the motor, and
about 16 feet aft of the center of mass.


Where do you get "16 feet aft"? The boat is only 26 feet long, and
the center of mass has to be at the center of buoyancy, so the bow
overhang doesn't count much and as you keep claiming the forward bit
at the waterline contributes little. And given the relatively flat
profile, you have to figure a relatively even distribution. This
means boat can only be considered about 22-23 feet long, and the
center of mass is roughly 11 to 12 feet at most from the stern.
Figuring the skipper at 10 feet and 160 lbs, that's 16K ft^2 lbs.
Repeating placing the 220 lb engine 1.5 feet aft of that gives over
29K, or almost double the moment. Placing a crew 3 feet forward of
that only has a moment of 7.8K, so you could add two crew and still
have less moment than the engine. And if the crew stay well forward,
up again the bulkhead, the moment becomes rather small.

Assuming that the two crew
members are sitting two and three feet forward of the captain,
respectively, their total mass will be the equivalent of 350 pounds
positioned about 14.5 feet from the center of mass about which the boat
has a tendency to pitch. The motor, at about 220 pounds is about 17.5
feet from the center of mass. Squaring the distances, the relative
values of the rotational momentum of the skipper and crew are more than
twice that of the motor, despite the fact that they are closer to the
center of mass. Once again, Jeff, your theories are simply wrong. (If
you wish, I'll provide the calculations and "foot pounds" or whatever,
in greater detail.)


Yes Jim, you can fudge the numbers by claiming that the center of mass
of forward of the mast. But everyone knows that's not the case. The
bottom line is that the engine makes a major contribution to the
moment, claiming that its small compared to the skipper and crew is bogus.


In
other words, the engine on the stern contributes roughly the same to
the moment as crew that would equal the safe limit of the boat.


Nope. Not if you do the math.


No, when I do the math I get the right answer. Its when you do the
math that there's a problem.



No - here you're wrong. The diagram clearly shows the largest
cross-section by far at the first station, which is halfway between
the mast and the bow.


Nope. You're ignoring the permanent ballast and also the fact that the
large section extends rearwardly aft of the mast.


I'm not ignoring it, the permanent ballast isn't the water ballast.
This entire discussion has been about the water ballast, and where its
located. Did you miss that or have you been lying about this all along?

The first and second "station" are substantially the same.


You're ****ting me, right? I mean you have looked at the diagram?

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


Actually, the first, second, and third station are essentially the same.
- The black area in the third section represents the permanent ballast,
which is heavier than water.


So now you're admitting that you knew all along that the "black area"
was not the water ballast but persisted in your lie until you could no
longer deny it.

The issue here is where the 1150 pounds of water is put, not where the
300 lbs. of permanent ballast is. Obviously, for this purpose the
permanent can be ignored.

We're not talking about the 300 pounds of permanent ballast. We're
talking about the amount that is forward. You've got 1150 pounds to
distribute. The diagram clearly shows the largest cross section of
the tank at the first station, halfway to the bow. You're claiming
there's very little aft. That would seem to imply 300 or so pounds in
the far forward area. You can babble all you want, but it doesn't
change that fact.

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


Once again, Jeff, the ballast in the first, second, and third sectional
views are essentially the same. With the exception that the permanent
ballast has a higher density, and higher mass per unit of volume.


But the water ballast isn't the same as the permanent ballast. If
there's less water ballast in the center of the boat, there must be
more up near there bow. Its as simple as that.

By lying over and over again, as you now admit, you're showing that
you had absolutely no interest in an honest discussion.




Moreover, the ballast tank is tapered at its forward and rear end
portions, further reducing the mass of ballast spaced furthest from
the central or largest portion, thereby lessening the moment of
inertia of the ballast when the boat pitches upon a wave, etc.



Nice words, but wrong. Anyone can clearly see that you're wrong, so
why do you can insisting otherwise? Much of the mass of the tank is
in the forward 20% of the boat. Because the tank is on the
centerline, there is little tapering forward until you get very
close to the bow.


Wrong again, Jeff. You are apparently considering only the taper
occurring across the width of the tank. - There is also a substantial
taper in the vertical direction, when the tank is viewed from the side.
As previously discussed, the ballast tank is (already) tapering
upwardly at Section No. 1, and it continues to taper up sharply from
that point forwardly, as can be seen most clearly in the longitudinal
sectional view. I know it's a little hard for you to understand, Jeff,
but give it another try.


Sorry, the math works against you on this. To the extent that the bow
narrows, the center of flotation has to move aft. This means that the
lever arm of the ballast just aft of the bow is increased. Sorry Jim,
its pretty clear that you can go halfway from station one to the stem
without greatly reducing the size of the tank. Anyway you look at it,
there has to be hundreds of pounds of water up there.

You've insisted it isn't aft, you've now admitted that much of the
center is taken by the permanent ballast, now you can't claim there's
none forward!


Look again, Jeff. The tank is tapered in both the vertical and
horizontal directions or axes. The bottom of the tank curves upwardly
sharply as it approaches the bow.



The largest cross section is already way forward.


Nope. You're clearly wrong.


You've already admitted above I'm right!



QED. End of story.
The best that you can claim is that there isn't much in the last few
inches.


Last five or six feet.


Station one is 5 feet aft of the stem and it has the largest
cross-section of the water tank! How can you claim that the largest
part of the tank doesn't contain much ballast??? Oh, I forgot, you're
a lawyer and we can ignore what lawyers say.



why? It doesn't change anything. You tried to claim:

"the Macs have a number of advantages over most boats mentioned on
this ng. They include a double liner in the hull such that if the lower
hull is penetrated, water from the resulting opening normally does not
enter the cabin, due to the fact that it is maintained within the
ballast tank by the upper wall of the ballast tank."

You were quite happy to leave the reader with the impression that this
is a double hull, which has a very specific meaning in marine
terminology. This is 6 months after I, and others, had already called
you on this, so if this does not make you a blatant liar, I don't know
what does.


Actually, my statement was quite accurate. The ballast does provide
protection if the lower hull is penetrated. It doesn't provide
protection if the sides or chines of the boat are penetrated, and I
never said that it did.


In other words, you were able to leave the reader with a false
impression, but that didn't bother you because you had deniability.

BTW, what the area is, it doesn't include the majority of the outside
waterline, since the ballast runs down the center. Every case I've
ever seen of a major hull breech has been on the side where there is
no protection.


In that case, you still wouldn't be out of luck on the Mac as you would
be in your own boat, Jeff, since the flotation provided in the Mac would
keep you afloat. In contrast, if you were on your own boat, the keel
would quickly pull the boat to the bottom.


My boat has flotation and no keel. I have four collision bulkheads
with flotation chambers plus several other chambers. In addition, the
geometry of my boat means that I could sustain serious damage without
flooding more than one section.

But I never claimed to have a "double liner."

And, of course, you'd have a lot of trouble showing that sinking is a
major safety risk. The overwhelming cause of drowning is falling
overboard or capsizing.

This is clearly not true for a boat that is planing.


Maybe, maybe not. - The Macs don't plane high out of the water like a
high-speed power boat. - They are, after all, a sailboat.



All of the picture show the bow lifted well out of the water:

http://www.macgregor26.com/powering_...g/powering.htm

If you hit something submerged, it could clearly hit anywhere, so the
"double liner" is only protecting a small portion.


I didn't personally make it up. And I never said that the entire boat
has a double hull.



You were quite happy to word it in such a way as to leave that
impression, while still maintaining denyability.


Nope. That, again, was your own invention. And once more, you
conveniently ignore my previous remarks discussing the limitations of
the "double-hull" effect.

Shame, shame shame, Jeff. You censor out anything you think might
introduce a better understanding of my original discussion, and quote an
excerpt from my original note ONLY, ignoring my subsequent discussion of
the entire matter. Jeff, you apparently have no scruples whatsoever if
you think you can pretend to have found a "gotcha."


Actually, when you made the "double liner" comment that was your
initial response to someone asking for recommendations. This poster
clearly would not have read any of your previous comments, and yet you
made the "double liner" claim without any caveat.

You really like to maintain deniability and then coming back "holier
than thou." You're a real piece of work, Jim!


So? I ignored your comments after it was pointed out that you initial
comments were bogus. Your backpedaling is not a fun target. However,
6 months later you came back again with our "double liner" comment.


Because there is a double hull, over the lowermost, central portions of
the hull.


But you already know its not a "double hull" unless it covers the
entire hull. There's no such thing as "half a double hull."



First of all, that was 6 months after we had a lengthy discussion on
the topic, so you're lying when you say that was the original note.

Secondly, you obviously have no trouble wording that so that one might
assume the "double liner" actually covers the hull, not a small
portion of it.


You could have easily said that there is "partial protection"
but you preferred to use terminology easily confused with "double
hull" which you know has a very specific meaning in the nautical world.


Actually, I don't. - I don't have a captains license.


Actually, the point was clearly made in a post to you by someone who
everyone knows is "big ship captain" that the term "double hull" has a
very specific meaning. The point was discussed at some length. Now
you're claiming it never happened.


Excuse me???? What about that large mass called "the engine" which
is about 10% of the dry weight and hanging of the stern???


The engine is closer to 5% of the weight of the boat with water ballast
and crew. But that's only an error of about 50%, Jeff.


I specially said "dry weight." You do know what that means?

- That's rather
typical of your guestimates. Also, check out the math. - The momentum
relating to the motor is less than half that of a typical skipper and
crew, as explained above.


Not when I do the math. When You did it, you assumed an obese
helmsman, and the the center of mass forward of the mast!

Again, reality has no place in your logic, does it?


In contrast with your cherry-picking, your censoring out or ignoring my
statements dealing with these same issues with greater specificity, your
twisting of my original meanings, and your devious "interpretations" of
what I "must have intended" (never giving me the benefit of a doubt),
you are the one who has a problem, Jeff, not me.


I have never censored one word you've said. That is a boldface lie.
Every single word you've said is still out there, something that I'm
sure you regret now!

I've ignored much of what you said; that's true.

As to your intentions, I think that is quite clear. Over and over
you've things that any normal person would interpret one way, and then
you've come back and claimed you didn't mean that. Other times,
you've denied what I've said and then when cornered, claimed I said
something different (as in the "cross-section of the water ballast"
issue).


After twisting my
statements, censoring out anything you don't like, and reaching back to
discussions posted more than a year ago, you end up concluding
dogmatically that your own particular interpretation of what I actually
was trying to say is the only acceptable interpretation.


blah blah blah. You talk a lot, but you don't say much, do you? You
must get paid by the word.

How about this? Lets see how many people come to your defense.


DSK December 5th 06 05:15 PM

!!
 
JimC wrote:
Jeff, I have not wanted to get into the issue of weight distribution in
detail


With good reason

.... since you pretty well had your assed kicked all over the ng on
that one.


???
Apparently you are just as loose with the term "ass kicking"
as you are with the term "fun to sail."



... Don't forget that you initially claimed that the

ballast
extends the full length of the boat


Which is exactly what MacGregor's own diagrams of the boat
show. Are they wrong?

.... and that was a bad distribution of
mass (and would tend to increase pitching movement).


It's a bad distribution of mass largely because it would
tend to increase pitching. Not quite the same thing.

For a lawyer, you are very poor with language.

Deliberately so, I assume.

DSK


Jeff December 5th 06 06:18 PM

!!
 
Capt. JG wrote:
"Jeff" wrote in message
. ..
I don't get it. Why does the Mac "need" an engine 3 times as powerful as
all of its competition. And why is that a safety feature?


Because the "sailor" driving it is either insecure about himself or not
experienced enough to deal with the conditions, including "getting to the
sailing area" under sail. The engine should be a last resort.


Yes, this one has had me thinking some. I understand Jim's point that
the high freeboard can cause a bit of a problem. However, the small
sail area on the boat only generates a limited amount of power. I
can't find my reference (Gere's book) but I think all he could count
on from his sails in 14 kts would be around 6 HP. Even doubling the
wind only brings it up to 24 HP. Certainly others of his size, such
as Neal's banana boat, can get up to hull speed with an engine under
10 hp.

So claiming that 50 hp is required to power the boat is essentially
claiming that the boat would be unmanageable under sail. In other
words, the big engine would allow to get offshore fast, but then
you're in deep **** if it died, because the sails do not generate
enough power to get you back.

Capt. JG December 5th 06 06:27 PM

!!
 
Yes, that's my point... I like to play what-if games when sailing...like
what if the engine dies? Can I get back to something resembling a safe-haven
without the engine... is the ebb so strong that in light winds I'll have a
problem if the engine dies...

I wonder if he contemplates reaching for the engine if there's an MOB?

--
"j" ganz @@
www.sailnow.com

"Jeff" wrote in message
...
Capt. JG wrote:
"Jeff" wrote in message
. ..
I don't get it. Why does the Mac "need" an engine 3 times as powerful
as all of its competition. And why is that a safety feature?


Because the "sailor" driving it is either insecure about himself or not
experienced enough to deal with the conditions, including "getting to the
sailing area" under sail. The engine should be a last resort.


Yes, this one has had me thinking some. I understand Jim's point that the
high freeboard can cause a bit of a problem. However, the small sail area
on the boat only generates a limited amount of power. I can't find my
reference (Gere's book) but I think all he could count on from his sails
in 14 kts would be around 6 HP. Even doubling the wind only brings it up
to 24 HP. Certainly others of his size, such as Neal's banana boat, can
get up to hull speed with an engine under 10 hp.

So claiming that 50 hp is required to power the boat is essentially
claiming that the boat would be unmanageable under sail. In other words,
the big engine would allow to get offshore fast, but then you're in deep
**** if it died, because the sails do not generate enough power to get you
back.




Donal December 5th 06 10:33 PM

Scotty - Please respond
 

"JimC" wrote in message
...
Still waiting for your answer Scotty.

Jim


Hi Jim,


Have you considered the possibility that Scotty doesn't answer you because
he is a decent Christian.

I am certain that any response from him would only demonstrate that you are
an idiot.


I think that you should accept his silence with gratitude.



Regards


Donal
--




Capt. JG December 5th 06 10:47 PM

Scotty - Please respond
 
Hey Donal... where you been?

--
"j" ganz @@
www.sailnow.com

"Donal" wrote in message
...

"JimC" wrote in message
...
Still waiting for your answer Scotty.

Jim


Hi Jim,


Have you considered the possibility that Scotty doesn't answer you because
he is a decent Christian.

I am certain that any response from him would only demonstrate that you
are
an idiot.


I think that you should accept his silence with gratitude.



Regards


Donal
--






Maxprop December 6th 06 01:39 AM

Scotty - Please respond
 

"Capt. JG" wrote in message
...
Hey Donal... where you been?


England.

Max



Capt. JG December 6th 06 02:22 AM

Scotty - Please respond
 
You know that for a fact? I know he doesn't get out much, but....

--
"j" ganz @@
www.sailnow.com

"Maxprop" wrote in message
ink.net...

"Capt. JG" wrote in message
...
Hey Donal... where you been?


England.

Max




JimC December 6th 06 07:39 PM

Google proves MacGregor 26 is flimsy
 
Jeff, despite all your ranting and ravings, repeated ad nauseum, the
following is still true:


1. Your theories relating to the effects of weight DISTRIBUTION on the
boat are wrong. - The boat does not pitch excessively, and it sails
steadily with little corrective helm. - When you have sailed a 26M on
several occasions, then you can come back and tell us about all the
terrible effects weight DISTRIBUTION on the 26M were causing. -
Meanwhile, despite all your yada, yada, yadas, and all your theories,
you have never sailed the 26M and you really don't know how it handles
or sails. And meanwhile, I'll continue enjoying sailing the boat.

2. Your theories about the "double hull" not being a significant safety
factor are just that. - Theories. Neither you or I have stats on the
significance of the efficacy of the double hull section. The difference
between us is that I'm willing to acknowledge it, whereas you want to
continue ranting and raving about it. But from my experience with the
boat, the double-hull section, positioned along the lowermost portion of
the hull from bow to aft of amidships, could be effective to prevent
incursion of sea water into the cabin if the boat were planing and ran
over a piece of wood or whatever floating at or just below the surface.
- A further factor is that visibility directly forward of the boat can
be partially obscured when planing.

3. Your theories about the boat being unsafe are, as usual, not
supported by evidence or statistics. - In view of the thousands of Macs
sold and in use, if they were inherently unsafe, you should be able to
come up with hundreds of examples of crews being lost, boats sinking,
rigging coming to pieces, boat foundering and filling with water, etc.,
etc. - But all you have is an example in which the captain was drunk,
the boat severely overloaded, and in which the captain did not have any
understanding of the boat or its water ballast system. ANECDOTES, and
statements like: "everybody knows that....." don't cut it, Jeff. If the
boat is inherently dangerous, give us evidence or stats on the
percentages of Macs that have failed at sea, or on which crew or skipper
have been killed or critically injured. While its true that positive
flotation COULD be installed in conventional sailboats, it normally IS
NOT offered. And its a significant safety factor on the Mac.

4. You have consistently ignored or brushed aside the many advantages
of the Mac design. - You fail to acknowledge that the ability to carry a
larger outboard does indeed provide a number of advantages relating both
to the ability to get to desired sailing areas, the ability to maneuver
against adverse winds and weather, family recreational uses, etc. While
not denying the advantages of a diesel as far as cog, etc., the larger
engines does get the job done and does provide greater versatility and
other advantages. - Yes, a conventional sailboat doesn't need such an
engine, and may have a greater range, but that doesn't mean that the Mac
arrangement doesn't provide a number of other advantages. While the high
freeboard does entail disadvantages, it also provides a number of
advantages. - Very few small sailboats have anywhere near the room and
accommodations provided in the Mac.

6. As to costs, you and others seem to always compare the cost of
15-year old used boats to that of new Macs. If you are going to compare
costs, take the apples and apples approach. - If you you want to talk
about new boats, compare costs of both new conventional boats and new
Macs, with equivalent equipment. And then add in the costs of slip
fees, maintenance, bottom treatments, etc.


6. And, it's lots of fun to sail.


Jim






Jeff wrote:
JimC wrote:


Looks like you erased all my additional remarks POSTED IN THAT
DISCUSSION stating that the warnings should NOT be ignored. ... Why
would you do a pitiful, sneaky thing like that Jeff?? You talk about
layers' ethics. - What about your own???


Sorry Jim. No mulligans. No do-overs. If I had snipped things from
the same post you could accuse me of taking it out of context. However,
once I had called you on this and showed your hypocrisy, you can't take
it back. You could have admitted that you made a mistake, but you
preferred to defend it to the death, hanging your credibility on people
believing that when you likened the warnings on a Mac to warnings to
wear a seatbelt on the exercise machine you didn't mean it was just
lawyer talk.

So every time you try to defend, all you're doing is claiming that you
have the right to say "ignore what lawyers say, except this time."

OK, I'll repost the original in its entirety. I had said:

"The Mac is clearly unsafe without its water ballast. The admonishments
include: no more than 4 people. Keep crew aft, low and centered. The
kids can't even stay in the forward bunk! They actually tell you not to
use the forward bunks when underway! They say it is unsafe in seas
higher than one foot! So much for coming in from offshore. You can't
stand on the deck because someone might grab the mast to hold on!
What? They're afraid someone might pull the boat over trying to hold
on??? No, this is not typical of a 26 foot sailboat, nor is it typical
of a 26 foot powerboat."

You replied:

"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.
Actually, the new 26M has 300 pounds of additional permanent ballast, in
addition to the water ballast, for providing added stability when
motoring without the water ballast. (The previous model, the 26X, didn't
have this feature, yet I haven't heard of hundreds of Mac 26X owners
being lost at sea because they didn't stay below deck when motoring the
boat without the ballast. In essence, when under power without the water
ballast, the boat is a small, lightweight power boat, and you have to
take reasonable precautions to keep the com low. (On the other hand, if
you can provide statistics regarding hundreds of Mac sailors being lost
at sea because they didn't stay in the cabin when motoring without the
water ballast, I would like to see those statistics.)

"Of course, if I were sailing or motoring with several guests, or with
children (our grandkids), I would certainly make sure that they didn't
head out to the foredeck when the boat was motoring without the water
ballast. Also, if I was going to go offshore, I would want to make sure
that the water ballast was filled. Ultimately, however, this is a
"lawyer thing." Remember, the boat is manufactured in California."


Its very clear that you're saying that the long list of rather sever
warnings about running without ballast is just, and I'm using your words
here, a "lawyer thing."

My point was never that the warning can be ignored, I was saying that
they should be taken seriously and serve as an indication that the high
speeds sometimes talked about cannot really be achieved in all
conditions. You didn't see where the discussion was going and so chose
to counter with this "lawyer thing" comment. Unfortunately, in that
moment, you lost all credibility.

Sorry Jim. No mulligans. No do-overs.

snip all further discussion on lawyers - its just too embarrassing for
Jim






And it does, though the mass aft largely comes from the 250 pound
engine hanging off the transom.



Not really. The mass aft largely comes from the
crew/guests/skipper, not the motor (unless the boat is being sailed
solo). The motor is slightly farther aft, but not much. (The
captains seat is about a foot forward of the motor.)



What a crock of ****. Do you actually read the stuff you write?
Since the moment of inertia is proportional to the square of the
distance from the center of mass, the mass of the engine is actually
equivalent to a mass 4 time larger but half the distance to the
center of mass.



And you did take math, and geometry in high school? Consider a
typical crew of two people (assume total weight of 350 lbs) and a
skipper of 230 lbs. (about my weight).



The weight used as the "standard" is 160 pounds. Obviously, if you put
overweight people aft in the cockpit, you can force the numbers to look
however you want.


Assuming that the skipper is sitting on the captain's chair, about 1.5
ft forward of the center of the motor, and about 16 feet aft of the
center of mass.



Where do you get "16 feet aft"? The boat is only 26 feet long, and the
center of mass has to be at the center of buoyancy, so the bow overhang
doesn't count much and as you keep claiming the forward bit at the
waterline contributes little. And given the relatively flat profile,
you have to figure a relatively even distribution. This means boat can
only be considered about 22-23 feet long, and the center of mass is
roughly 11 to 12 feet at most from the stern. Figuring the skipper at 10
feet and 160 lbs, that's 16K ft^2 lbs. Repeating placing the 220 lb
engine 1.5 feet aft of that gives over 29K, or almost double the
moment. Placing a crew 3 feet forward of that only has a moment of
7.8K, so you could add two crew and still have less moment than the
engine. And if the crew stay well forward, up again the bulkhead, the
moment becomes rather small.

Assuming that the two crew members are sitting two and three feet
forward of the captain, respectively, their total mass will be the
equivalent of 350 pounds positioned about 14.5 feet from the center of
mass about which the boat has a tendency to pitch. The motor, at
about 220 pounds is about 17.5 feet from the center of mass. Squaring
the distances, the relative values of the rotational momentum of the
skipper and crew are more than twice that of the motor, despite the
fact that they are closer to the center of mass. Once again, Jeff,
your theories are simply wrong. (If you wish, I'll provide the
calculations and "foot pounds" or whatever, in greater detail.)



Yes Jim, you can fudge the numbers by claiming that the center of mass
of forward of the mast. But everyone knows that's not the case. The
bottom line is that the engine makes a major contribution to the moment,
claiming that its small compared to the skipper and crew is bogus.


In

other words, the engine on the stern contributes roughly the same to
the moment as crew that would equal the safe limit of the boat.


Nope. Not if you do the math.



No, when I do the math I get the right answer. Its when you do the math
that there's a problem.



No - here you're wrong. The diagram clearly shows the largest
cross-section by far at the first station, which is halfway between
the mast and the bow.



Nope. You're ignoring the permanent ballast and also the fact that the
large section extends rearwardly aft of the mast.



I'm not ignoring it, the permanent ballast isn't the water ballast. This
entire discussion has been about the water ballast, and where its
located. Did you miss that or have you been lying about this all along?

The first and second "station" are substantially the same.


You're ****ting me, right? I mean you have looked at the diagram?

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



Actually, the first, second, and third station are essentially the
same. - The black area in the third section represents the permanent
ballast, which is heavier than water.



So now you're admitting that you knew all along that the "black area"
was not the water ballast but persisted in your lie until you could no
longer deny it.

The issue here is where the 1150 pounds of water is put, not where the
300 lbs. of permanent ballast is. Obviously, for this purpose the
permanent can be ignored.

We're not talking about the 300 pounds of permanent ballast. We're
talking about the amount that is forward. You've got 1150 pounds to
distribute. The diagram clearly shows the largest cross section of
the tank at the first station, halfway to the bow. You're claiming
there's very little aft. That would seem to imply 300 or so pounds
in the far forward area. You can babble all you want, but it doesn't
change that fact.

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


Once again, Jeff, the ballast in the first, second, and third
sectional views are essentially the same. With the exception that the
permanent ballast has a higher density, and higher mass per unit of
volume.



But the water ballast isn't the same as the permanent ballast. If
there's less water ballast in the center of the boat, there must be more
up near there bow. Its as simple as that.

By lying over and over again, as you now admit, you're showing that you
had absolutely no interest in an honest discussion.




Moreover, the ballast tank is tapered at its forward and rear end
portions, further reducing the mass of ballast spaced furthest
from the central or largest portion, thereby lessening the moment
of inertia of the ballast when the boat pitches upon a wave, etc.




Nice words, but wrong. Anyone can clearly see that you're wrong,
so why do you can insisting otherwise? Much of the mass of the
tank is in the forward 20% of the boat. Because the tank is on the
centerline, there is little tapering forward until you get very
close to the bow.



Wrong again, Jeff. You are apparently considering only the taper
occurring across the width of the tank. - There is also a substantial
taper in the vertical direction, when the tank is viewed from the
side. As previously discussed, the ballast tank is (already) tapering
upwardly at Section No. 1, and it continues to taper up sharply from
that point forwardly, as can be seen most clearly in the longitudinal
sectional view. I know it's a little hard for you to understand, Jeff,
but give it another try.



Sorry, the math works against you on this. To the extent that the bow
narrows, the center of flotation has to move aft. This means that the
lever arm of the ballast just aft of the bow is increased. Sorry Jim,
its pretty clear that you can go halfway from station one to the stem
without greatly reducing the size of the tank. Anyway you look at it,
there has to be hundreds of pounds of water up there.

You've insisted it isn't aft, you've now admitted that much of the
center is taken by the permanent ballast, now you can't claim there's
none forward!


Look again, Jeff. The tank is tapered in both the vertical and
horizontal directions or axes. The bottom of the tank curves upwardly
sharply as it approaches the bow.



The largest cross section is already way forward.



Nope. You're clearly wrong.



You've already admitted above I'm right!



QED. End of story.

The best that you can claim is that there isn't much in the last few
inches.



Last five or six feet.



Station one is 5 feet aft of the stem and it has the largest
cross-section of the water tank! How can you claim that the largest
part of the tank doesn't contain much ballast??? Oh, I forgot, you're a
lawyer and we can ignore what lawyers say.



why? It doesn't change anything. You tried to claim:

"the Macs have a number of advantages over most boats mentioned on
this ng. They include a double liner in the hull such that if the lower
hull is penetrated, water from the resulting opening normally does not
enter the cabin, due to the fact that it is maintained within the
ballast tank by the upper wall of the ballast tank."

You were quite happy to leave the reader with the impression that
this is a double hull, which has a very specific meaning in marine
terminology. This is 6 months after I, and others, had already
called you on this, so if this does not make you a blatant liar, I
don't know what does.


Actually, my statement was quite accurate. The ballast does provide
protection if the lower hull is penetrated. It doesn't provide
protection if the sides or chines of the boat are penetrated, and I
never said that it did.



In other words, you were able to leave the reader with a false
impression, but that didn't bother you because you had deniability.

BTW, what the area is, it doesn't include the majority of the outside
waterline, since the ballast runs down the center. Every case I've
ever seen of a major hull breech has been on the side where there is
no protection.



In that case, you still wouldn't be out of luck on the Mac as you
would be in your own boat, Jeff, since the flotation provided in the
Mac would keep you afloat. In contrast, if you were on your own boat,
the keel would quickly pull the boat to the bottom.



My boat has flotation and no keel. I have four collision bulkheads with
flotation chambers plus several other chambers. In addition, the
geometry of my boat means that I could sustain serious damage without
flooding more than one section.

But I never claimed to have a "double liner."

And, of course, you'd have a lot of trouble showing that sinking is a
major safety risk. The overwhelming cause of drowning is falling
overboard or capsizing.

This is clearly not true for a boat that is planing.


Maybe, maybe not. - The Macs don't plane high out of the water like a
high-speed power boat. - They are, after all, a sailboat.




All of the picture show the bow lifted well out of the water:

http://www.macgregor26.com/powering_...g/powering.htm

If you hit something submerged, it could clearly hit anywhere, so the
"double liner" is only protecting a small portion.


I didn't personally make it up. And I never said that the entire
boat has a double hull.



You were quite happy to word it in such a way as to leave that
impression, while still maintaining denyability.



Nope. That, again, was your own invention. And once more, you
conveniently ignore my previous remarks discussing the limitations of
the "double-hull" effect.

Shame, shame shame, Jeff. You censor out anything you think might
introduce a better understanding of my original discussion, and quote
an excerpt from my original note ONLY, ignoring my subsequent
discussion of the entire matter. Jeff, you apparently have no scruples
whatsoever if you think you can pretend to have found a "gotcha."



Actually, when you made the "double liner" comment that was your initial
response to someone asking for recommendations. This poster clearly
would not have read any of your previous comments, and yet you made the
"double liner" claim without any caveat.

You really like to maintain deniability and then coming back "holier
than thou." You're a real piece of work, Jim!


So? I ignored your comments after it was pointed out that you
initial comments were bogus. Your backpedaling is not a fun target.
However, 6 months later you came back again with our "double liner"
comment.


Because there is a double hull, over the lowermost, central portions
of the hull.



But you already know its not a "double hull" unless it covers the entire
hull. There's no such thing as "half a double hull."



First of all, that was 6 months after we had a lengthy discussion on
the topic, so you're lying when you say that was the original note.

Secondly, you obviously have no trouble wording that so that one
might assume the "double liner" actually covers the hull, not a small
portion of it.



You could have easily said that there is "partial protection"

but you preferred to use terminology easily confused with "double
hull" which you know has a very specific meaning in the nautical world.



Actually, I don't. - I don't have a captains license.



Actually, the point was clearly made in a post to you by someone who
everyone knows is "big ship captain" that the term "double hull" has a
very specific meaning. The point was discussed at some length. Now
you're claiming it never happened.


Excuse me???? What about that large mass called "the engine"
which is about 10% of the dry weight and hanging of the stern???



The engine is closer to 5% of the weight of the boat with water
ballast and crew. But that's only an error of about 50%, Jeff.



I specially said "dry weight." You do know what that means?

- That's rather typical of your guestimates. Also, check out the
math. - The momentum relating to the motor is less than half that of a
typical skipper and crew, as explained above.



Not when I do the math. When You did it, you assumed an obese helmsman,
and the the center of mass forward of the mast!

Again, reality has no place in your logic, does it?



In contrast with your cherry-picking, your censoring out or ignoring
my statements dealing with these same issues with greater specificity,
your twisting of my original meanings, and your devious
"interpretations" of what I "must have intended" (never giving me the
benefit of a doubt), you are the one who has a problem, Jeff, not me.



I have never censored one word you've said. That is a boldface lie.
Every single word you've said is still out there, something that I'm
sure you regret now!

I've ignored much of what you said; that's true.

As to your intentions, I think that is quite clear. Over and over
you've things that any normal person would interpret one way, and then
you've come back and claimed you didn't mean that. Other times, you've
denied what I've said and then when cornered, claimed I said something
different (as in the "cross-section of the water ballast" issue).


After twisting my statements, censoring out anything you don't like,
and reaching back to discussions posted more than a year ago, you end
up concluding dogmatically that your own particular interpretation of
what I actually was trying to say is the only acceptable interpretation.



blah blah blah. You talk a lot, but you don't say much, do you? You
must get paid by the word.

How about this? Lets see how many people come to your defense.



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