Doug,

Wouldn't torsion be a twisting load?

The KIWI boom failed at the end when it was use for other than Outhaul
tension. Poor engineering to be sure but getting off the subject. It is
in response to the comment of "Stone Age Engineering"

Ole Thom

"John Cairns" wrote in message
m...
| Slow down, Mooron. I was merely verifying what Doug mentioned, I assuming
| that's what he was referring to, the ability of a rigid vang to support
the
| weight of an individual standing on the boom.

No John.. I believe Doug's premise is that a properly engineered vang can
equal the capacity of a topping lift... that I dispute.

I wasn't necessarily referring
| to you when I talked about "improvements in sailing technology" Of course
| the boom end is supported better by a topping lift on the end than it is
by
| a rigid vang mounted a quarter of a way along it's length.

Excellent ... then we are in agreement


But a rigid still
| offers enough support to hoist someone out of the water with the end of
the
| boom, or lift an auxiliary out of the engine compartment.

Allow me to put to you 2 separate scenarios... a rigid vang on a 20 footer
and a rigid vang on a 50 footer. Now... on the 20 footer it's obvious the
weight of a man on the end of the boom would tax the rigid vang.... but not
the topping lift. The weight of a man on the end of a boom on the 50 foot
boat would not tax the vang.... nuff said.


Not that I never
| question the merits of "technology improvements", I like to think I try to
| keep a fair amount of skepticism when I see words like"new and improved",
| but I don't reflexively assume that improvements aren't just that. In any
| event, I wouldn't think that capacity is an issue when debating the merits
| rigid boom vangs.

Not unless you decide to compare mechanical capacities between the vang and
the topping lift


One last point, if you retrofit a rigid vang to you boat
| you still have a topping lift to use for things like hoisting someone to
the
| masthead, or hoisting an auxiliary out of your engine compartment, etc.
BTW,
| I'm not rushing out to buy a rigid vang for my boat, it's fairly low on my
| list of future boat improvements.

Yes.... I concur ... but the discussion was regarding the capacity of the
vang compared to the topping lift. Both have their functions... and for
hoisting the topping lift has the advantage by a large margin.

CM

Capt. Mooron wrote:
No John.. I believe Doug's premise is that a properly engineered vang can
equal the capacity of a topping lift... that I dispute.

And you're wrong.

Allow me to put to you 2 separate scenarios... a rigid vang on a 20 footer
and a rigid vang on a 50 footer. Now... on the 20 footer it's obvious the
weight of a man on the end of the boom would tax the rigid vang....

Not necessarily. It depends entirely on how the rig is built.

You assume that the rig, particularly the boom, and the vang must be
weak. It ain't so.

I suspect that you cannot envision a box section boom, or a custom
section boom. Have you ever seen a boat where the boom was not the same
extruded section as the mast? They exist.

Furthermore, I suspect you have little to no experience with fractional
rigs. A tapered spar is not built to take huge compression loads at the
mast head. OTOH they can easily be built to take a heck of a torsion
load at the gooseneck... some have solid struts supporting the mast just
at or just below the gooseneck.

Your statements about rigid vangs are like the yokel who was shown a
picture of a giraffe and said "there cain't be no such anny-mal."

DSK

"DSK" wrote in message
...
| Capt. Mooron wrote:
| No John.. I believe Doug's premise is that a properly engineered vang
can
| equal the capacity of a topping lift... that I dispute.
|
| And you're wrong.

No I'm not!

|
| Allow me to put to you 2 separate scenarios... a rigid vang on a 20
footer
| and a rigid vang on a 50 footer. Now... on the 20 footer it's obvious
the
| weight of a man on the end of the boom would tax the rigid vang....
|
| Not necessarily. It depends entirely on how the rig is built.

Oh here we go.... the sidewind of the engineer in dire straits.... let's
bring "specialty" manufacturing alloys and specific design criteria into the
equation! It's a smoke screen and I'm not falling for it.



| You assume that the rig, particularly the boom, and the vang must be
| weak. It ain't so.

That's totally incorrect... I never stated such a thing nor utilized any
such reasoning in my argument.

|
| I suspect that you cannot envision a box section boom, or a custom
| section boom. Have you ever seen a boat where the boom was not the same
| extruded section as the mast? They exist.

Pardon Me Doug... who the hell do you think you are discussing with here..
jaxxies or horvath???
Your suspicions are as unfounded as your initial position regarding the
suitability of a vang for hoisting.
What I suspect is that you've suddenly realized the logic of my statement
are finding yourself at a loss to formulate a rational defense.


|
| Furthermore, I suspect you have little to no experience with fractional
| rigs.

That's a rather cocky and mistaken assumption on your part Doug...

A tapered spar is not built to take huge compression loads at the
| mast head. OTOH they can easily be built to take a heck of a torsion
| load at the gooseneck... some have solid struts supporting the mast just
| at or just below the gooseneck.

Oh yeah... let's hide behind the vagaries of specific engineering in an
attempt to mask the basic tenets of the discussion... that vangs were never
designed to hoist.

|
| Your statements about rigid vangs are like the yokel who was shown a
| picture of a giraffe and said "there cain't be no such anny-mal."

Now that is just desperate and totally uncalled for.... don't be an ass
with me Doug.. I don't tolerate such gibberish. If you can't present a
viable argument to back your contentions... you have already lost the
argument before you decided to discuss it. I demand the same respect I've
shown you... and if you find yourself unable to continue this debate without
reducing your counterpoints to suggestions that I'm not up to the task of
basic comprehension... then it's time for you to pack it up and run along.

Understand this.... every poster that has joined this discussion has found
in my favour regarding the suitability of the topping lift versus the vang
for hoist situations.

CM

To those that might join this forever discussion;

Go back and read the posting on this subject of Aug 17. Bart's desire
to do away with his topping lift, My reasons for keeping the topping
lift, Doug's exceptions to my reasoning.

Doug has debated the issue into a boom, solid vang design.

Ole Thom

Doug,

A tapered Spar (Mast) held in rig by a fore stay, a back stay, Upper
star'b an Port Shrouds and Inter medium shrouds/ with spreaders are sure
as hell more than capable of supporting a man. Very often, in racing
circles, you will see a man sent aloft to look for wind sitting on the
upper spreaders. This is the type of strength the topping lift can
deliver to a hoist. A boom vang cannot.

Give it up Doug, the horse is dead, beating it won't help. Bury it.

Ole Thom

Capt. Mooron wrote:
Oh here we go.... the sidewind of the engineer in dire straits.... let's
bring "specialty" manufacturing alloys and specific design criteria into the
equation! It's a smoke screen and I'm not falling for it.

It's a "smoke screen" to say that equipment should be designed & built
to do it's job??


| You assume that the rig, particularly the boom, and the vang must be
| weak. It ain't so.

That's totally incorrect... I never stated such a thing nor utilized any
such reasoning in my argument.

Well, you keep saying over and over, "It can't be as strong as a topping
lift" as though somehow calling a piece of rigging 'topping lift'
magically renders it invulnerable.


|
| I suspect that you cannot envision a box section boom, or a custom
| section boom. Have you ever seen a boat where the boom was not the same
| extruded section as the mast? They exist.

Pardon Me Doug... who the hell do you think you are discussing with here..
jaxxies or horvath???

That may have been a bit over the top. I apologize.

But you sure don't act as if you ever saw any such thing. If you have,
then why all the bogus assumptions?

I gave a simple engineering explanation of the forces & stresses, which
you agreed with, and then you started right back up with "it can't
possibly be as strong." First, the matter is not one to be settled by
debate. Second, believe what you want... I have spent more time than I
should trying to explain, maybe some day you'll actually sail a properly
rigged boat with a solid vang and see for yourself.

Understand this.... every poster that has joined this discussion has found
in my favour regarding the suitability of the topping lift versus the vang
for hoist situations.

Ok, I'm glad that makes you feel better. Does that mean you "win"?

Fresh Breezes- Doug King

"DSK" wrote in message

| It's a "smoke screen" to say that equipment should be designed & built
| to do it's job??

That's not the point at all Doug..... the vang is indeed designed to do
it's job... it just seems that you fail to concede the point that the
vang's primary "job" is not to handle bearing loads delivered to the end of
the boom.

|
| Well, you keep saying over and over, "It can't be as strong as a topping
| lift" as though somehow calling a piece of rigging 'topping lift'
| magically renders it invulnerable.

No!... I said over and over that the mechanical advantage is to the topping
lift!

| That may have been a bit over the top. I apologize.

Accepted.

|
| But you sure don't act as if you ever saw any such thing. If you have,
| then why all the bogus assumptions?

Not assumptions Doug..... just basic engineering principles. The "Topping
Lift" will always have the advantage over the "Vang" in hoisting load
capacity

|
| I gave a simple engineering explanation of the forces & stresses, which
| you agreed with, and then you started right back up with "it can't
| possibly be as strong."

No .. I stated rather plainly that the advantage was to the topping lift...
by a large margin.

First, the matter is not one to be settled by
| debate.

Yes Doug it can... I present a point, you present a counter-point.. we
collectively review the data presented and submit rebuttals based on logic.
That's discussion and debate.

Second, believe what you want... I have spent more time than I
| should trying to explain, maybe some day you'll actually sail a properly
| rigged boat with a solid vang and see for yourself.

I think you'd better give your head a shake.... you have explained
nothing... you have obfuscated and side tracked, you've attempted to bring
in a plethora of variables to substantiate your claims. You have provided
very little in the form of actual, logical counter points to my statements.
You've been reduced to brash accusations regarding my experience.... and
now you lament wasted time.... the reasoning of a failed argument.

| Ok, I'm glad that makes you feel better. Does that mean you "win"?

No Doug... what it means is that despite your attempts at introducing wild
variables... the basic logic of my statement is understood by those who have
bothered to read this far into our debate.

That alone may be the sum total of your inability to close with this.... you
refuse to entertain it as a discussion and rather approach it as a contest.
You gain nothing in a contest... you gain information via discussion.....
but only if you are willing to grant favour to logic rather than emotion.

In regards to abilities to discuss topics... my Father always insisted on
regular discussions since I was very young.... on a wide subject of
materials... the onus /responsibility for research was placed upon us ...
and insisted we be able to defend points of view we did not agree with....
if only to better understand the complexities of differing points of view
and hone our abilities to present them.

It's a skill that still stands me well.... ;-)

CM

Capt. Mooron wrote:
That's not the point at all Doug..... the vang is indeed designed to do
it's job... it just seems that you fail to concede the point that the
vang's primary "job" is not to handle bearing loads delivered to the end of
the boom.

For a solid vang, it need not make any difference.



|
| Well, you keep saying over and over, "It can't be as strong as a topping
| lift" as though somehow calling a piece of rigging 'topping lift'
| magically renders it invulnerable.

No!... I said over and over that the mechanical advantage is to the topping
lift!

And I explained over and over (and over and over) why that is not
necessarily the case.



I think you'd better give your head a shake.... you have explained
nothing... you have obfuscated and side tracked

Bull puckey. You could have the textbook in front of you and still
insist that *you're* right and the prof & book *must* be wrong. A
classic case.

In regards to abilities to discuss topics... my Father always insisted on
regular discussions since I was very young....

Did he ever use a 2x4?

Regards
Doug King

"DSK" wrote in message
...
| Capt. Mooron wrote:
| That's not the point at all Doug..... the vang is indeed designed to do
| it's job... it just seems that you fail to concede the point that the
| vang's primary "job" is not to handle bearing loads delivered to the end
of
| the boom.
|
| For a solid vang, it need not make any difference.


A statement with no qualifiers..... it need not if the weight is within the
capacity of the vang... which will always be far less than the capacity of
the topping lift.

| |
| | Well, you keep saying over and over, "It can't be as strong as a
topping
| | lift" as though somehow calling a piece of rigging 'topping lift'
| | magically renders it invulnerable.
|
| No!... I said over and over that the mechanical advantage is to the
topping
| lift!
|
| And I explained over and over (and over and over) why that is not
| necessarily the case.

another statement with no qualifier.... not necessarily the case as long as
the load is within capacity of the vang which unless you are using cooked
linguini for the topping lift... is far less then the mechanical advantage
of the topping lift.

|
|
|
| I think you'd better give your head a shake.... you have explained
| nothing... you have obfuscated and side tracked
|
| Bull puckey. You could have the textbook in front of you and still
| insist that *you're* right and the prof & book *must* be wrong. A
| classic case.

The "prof & book" side with me in this case Doug.... try again

|
| In regards to abilities to discuss topics... my Father always insisted
on
| regular discussions since I was very young....
|
| Did he ever use a 2x4?

Only when I lost ...... as you can see that won't happen here because I
actually researched the subject at hand. You should try that avenue instead
of your current tact of repetition of erroneous data... ad nausea

CM