Capt. Mooron wrote:
Although I agree with this... my argument was regarding the actual load
capacity between the vang and the topping lift. My point is the topping lift
is able to handle much greater loads than the vang ever could.

Well, if they're both engineered appropriately, why?


.... the topping lift has the mechanical advantage
over the vang.

If you mean "the topping lift is directly opposite the weight, while the
solid vang has to support a multiple of the weight" then I agree. But
that ignores the fact that modern materials and engineering are well
equal to the task. OTOH if you're limited to Stone Age technology, then
solid vangs are not going to work too well, no.

Fresh Breezes... Doug King

"DSK" wrote in message
| Capt. Mooron wrote:
| Although I agree with this... my argument was regarding the actual load
| capacity between the vang and the topping lift. My point is the topping
lift
| is able to handle much greater loads than the vang ever could.
|
| Well, if they're both engineered appropriately, why?

Because Doug... all things being equal and even when the maximum engineering
and materials are utilized... with the current location of the vang on a
boom
" .... the topping lift has the mechanical advantage over the vang."
Always will...

| If you mean "the topping lift is directly opposite the weight, while the
| solid vang has to support a multiple of the weight" then I agree. But
| that ignores the fact that modern materials and engineering are well
| equal to the task. OTOH if you're limited to Stone Age technology, then
| solid vangs are not going to work too well, no.

Don't try and worm your way out now Doug! ;-)
No new fangled materials or honeycombed booms will ever change the fact that
the load point at the end of the boom will be subject to mechanical
advantage. Since placing the of the vang to that point is not an acceptable
option... it will retain it's loss of mechanical advantage no matter what
materials are utilized. [caveat-all structures being equally engineered]

Stick that in your Field Book.... I may not be an Engineer... but I'm a
Technician ... and usually train you guys till you get out of diapers and
into a Ring! :-P

You don't scare me Man!

CM

Because you've seen someone step up onto the boom to do some work, as did
the skipper during the Trans-Erie, he had to re-run a jiffy reefing line
through a reef clew grommet. You some of the folks here are taking up the
arguments of the lately departed Captain Neal, who never met an improvement
in sailing technology that he didn't like.
John Cairns

"DSK" wrote in message
. ..
Last but not least, booms supported by solid vangs will (if properly
engineered) hold up weights at least as heavy as a medium size adult.
Ask me how I know this for a fact!

Fresh Breezes- Doug King

Good Grief John.... how can you miss the point of this whole discussion so
adeptly.

Nobody is arguing the merits of the technology... what is being debated is
the advantage in capacity between a topping lift and a vang.

....and by the way... since when do you undertake the option of never
questioning "improvements in sailing technology"?

CM



"John Cairns" wrote in message
m...
| Because you've seen someone step up onto the boom to do some work, as did
| the skipper during the Trans-Erie, he had to re-run a jiffy reefing line
| through a reef clew grommet. You some of the folks here are taking up the
| arguments of the lately departed Captain Neal, who never met an
improvement
| in sailing technology that he didn't like.
| John Cairns
|
| "DSK" wrote in message
| . ..
| Last but not least, booms supported by solid vangs will (if properly
| engineered) hold up weights at least as heavy as a medium size adult.
| Ask me how I know this for a fact!
|
| Fresh Breezes- Doug King
|
|
|

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. 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. 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. 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. 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.
John Cairns


"Capt. Mooron" wrote in message
...
Good Grief John.... how can you miss the point of this whole discussion so
adeptly.

Nobody is arguing the merits of the technology... what is being debated
is
the advantage in capacity between a topping lift and a vang.

...and by the way... since when do you undertake the option of never
questioning "improvements in sailing technology"?

CM



"John Cairns" wrote in message
m...
| Because you've seen someone step up onto the boom to do some work, as
did
| the skipper during the Trans-Erie, he had to re-run a jiffy reefing line
| through a reef clew grommet. You some of the folks here are taking up
the
| arguments of the lately departed Captain Neal, who never met an
improvement
| in sailing technology that he didn't like.
| John Cairns
|
| "DSK" wrote in message
| . ..
| Last but not least, booms supported by solid vangs will (if properly
| engineered) hold up weights at least as heavy as a medium size adult.
| Ask me how I know this for a fact!
|
| Fresh Breezes- Doug King
|
|
|

John,

The improvements in boom technology as demonstrated by the Kiwi's Boom
in the last AC Races wasn't accepted by you and Doug as being better?

This long, long discussion was originally about doing away with the
topping lift because the use of the Rigid Vang could do everything as
well, with the exception of a spare back stay. The Hoisting ability of
the Solid vang was questioned.

The hoisting ability of the boom with the solid vang presents a
completely different engineering limit than the topping lift. SHEAR!
Shear creates a serious weakness when hoisting with the boom with end
support. Especially with new booms to make the lighter. The improved
booms of today are not meant for end loading with shear pressure.
This was demonstrated very well on that POS that the KIWI used to
defend the AC.

Ole Thom

John,

I forgot to meantion that Bart's statement about the Rigid Vang would
let him get rid of the topping lift.

Ole Thom

Thom Stewart wrote:
... The improved
booms of today are not meant for end loading with shear pressure.

Shear or torsion?

This was demonstrated very well on that POS that the KIWI used to
defend the AC.

I was unaware that the Kiwis boom broke when they were trying to hoist a
heavy weight on the end of the boom. I thought it broke under normal
sailing loads... by definition, poor engineering.

I grant you that poor engineering exists. I dispute that the existence
of poor engineering proves that good engineering does not exist.

DSK

Thom Stewart wrote:
Can you say "GIN POLE?"

Thom, put down the bottle and back away slowy...

... That is what the boom becomes with a topping
lift Hoist.

Ah, now I see your point. Yes.

So?

DSK

Get rid of having to use one to keep the boom up, sure, but actually
removing the topping lift would be silly. All sorts of uses for the topping
lift, emergency backstay, extra main halyard, safety line for bosun's chair
work. I vaguely recall someone mentioning a rigger talking about removing
the topping lift, can't imagine a competent rigger suggesting this.
John Cairns
"Thom Stewart" wrote in message
...
John,

I forgot to meantion that Bart's statement about the Rigid Vang would
let him get rid of the topping lift.

Ole Thom