[Rhodes22-list] Effros' port of sail and da list

[Bill Effros]

Phyllis,

I sail out of Brooklyn and Greenwich, Ct. with yearly driving trips to Long Beach Island to sail with Jay, occasional driving trips to North Carolina to sail with Stan, and yearly plans to trailer down to Miami and sail toward Key West (which never happens).

Motor Sailing is not a scandal.  Almost every coastal cruiser who talks about "sailing" from one place to another really means "motor sailing"; most are just not honest enough to mention it--the bigger the boat, the more likely they are to be motoring thither and yon.  Some of them put up sails while they motor dead into the wind and people on your boat may ask "how are they doing that...?"

The East River is a kick, not to be missed.   I've written about it, and others have too.  You can find old postings--someone will know where they are.

And, no, the geography does not influence the politics.  Stan is a red diaper baby living in North Carolina.  What does that tell you?  That people with all different political backgrounds are moving out of their places of origin to sun belt states.  The politics of those places will change along with their populations.

This list is probably a better polling device than any of the national surveys.  It has rich people and poor people.  It is geographically diverse, but weighted toward where most electoral votes are.  It's members are likely to vote.  Ethnic minorities are poorly represented.  Recent immigrants are poorly represented.  You can get repeat samplings from known participants.  You can determine which positions and events are important enough to draw in people who never previously participated in any discussion.  It has more than 200 members -- remember the national polls are based on only 3 to 4 times as many participants.

Don't delete the political discussions, read them and learn what is really going on in this country.  It is totally fascinating, which is why I spend so much time doing it on this list.  I trust these people, and I trust what they have to say about just about everything.  I listen, I probe, I adjust my own thinking--and I think most of the other list members do, too.

Bill Effros

----- Original Message ----- 
From: P&M Beals 
To: The Rhodes 22 mail list 
Sent: Friday, September 24, 2004 11:23 AM
Subject: [Rhodes22-list] Effros' port of sail and da list


Bill, do you sail on LIS?  I just checked Rummy's updated  list and don't
see your name on there...since I have notions of one day sailing or MOTOR
SAILING (scandal) from NJ to LIS I am curious to know where on the map to
place you.. and with the current issues you raise on East River- I know my
father always told me about those currents...I would want my motor to be
well tested and strong, which so far the Yamaha 4 stroke seems to be running
smoothly, strong and start-up reliable.


it is really interesting to see if geography and home location influence the
politics of the email author...not that I have been trying to pinpoint all
of you folks.  in fact lately I have to delete a lot since it takes so much
time to wade through-

Phyllis

> From: "Bill Effros" <bill at effros.com>
> Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
> Date: Fri, 24 Sep 2004 11:10:18 -0400
> To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
> Subject: Re: [Rhodes22-list]Speed Over Ground
> 
> Michael,
> 
> You know better.
> 
> We were discussing Speed Over Ground.
> 
> If you are in the East River, which has a current that moves in both
> directions at varying speeds up to 6 kts. It is impossible to determine gas
> "mileage" no matter what you do.
> 
> As I've mentioned before, you can go down the East River at 12 kts. (SOG) in
> an R-22.  Many days you can beat the cars down the same run.  It's a thrilling
> ride in every way.  As Peter correctly noted, there can be an incredible about
> of really big traffic in a situation where everyone else has the right of way
> and no one is completely in control of their vessel.
> 
> Granted, this is an extreme example to make the point, but as you know,
> everyone on LIS (and that's a lot of people) faces it every time we move in
> our boats, and it has to be factored into all of our equations.
> 
> Lots of other people face it too--the people on dammed lakes, people on
> rivers, in fact, the Hudson River travels in both directions down here.
> 
> There is no absolute ratio between the amount of power generated by your
> engine, the amount of gas consumed, and the amount of land you can cover in
> your boat at a given speed for a given amount of time.
> 
> Bill
> 
> 
> ----- Original Message -----
> From: Michael Meltzer
> To: Peter Thorn ; The Rhodes 22 mail list
> Sent: Thursday, September 23, 2004 11:44 PM
> Subject: Re: [Rhodes22-list] Re: Pointing
> 
> 
> Come on guys, current is an non-issue in this outboard debate, the motor
> pushes the boat thought the water, it really does not mater
> to the motor or type of motor that the water is also moving, that is how much
> power the motor is producing not how it produces it.
> It like claiming you hate bill new book because the color clashes your suit or
> that you hate it because your wife hits you every
> time you read, come on.
> 
> MJM
> 
> ----- Original Message -----
> From: "Peter Thorn" <pthorn at nc.rr.com>
> To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
> Sent: Thursday, September 23, 2004 12:11 PM
> Subject: Re: [Rhodes22-list] Re: Pointing
> 
> 
>> Roger,
>> 
>> That was great!  A wonderful, science-filled explanation of  foils, stalling
>> and the technical woes that befall skippers who pinch.   Previously, my
>> knowledge about stalling sails was merely that the outside telltales stopped
>> flowing aft.  Good job.
>> 
>> I'd like to reprint your stalling missive in our sailing club's (Carolina
>> Sailing Club, Raleigh NC) newletter, with proper attribution of course.  OK
>> with you?
>> 
>> In Bill's defense, it's pretty clear to me that you haven't cruised the East
>> River lately.  Motoring back and forth across the current there would be a
>> death defying act, exposing R22 broadsides to harbor tugs with 4' bow waves,
>> full-throttled Egg Harbors and the like. <G>
>> 
>> PT
>> 
>> ----- Original Message -----
>> From: "Roger Pihlaja" <cen09402 at centurytel.net>
>> To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
>> Sent: Thursday, September 23, 2004 9:25 AM
>> Subject: Re: [Rhodes22-list] Re: Pointing
>> 
>> 
>>> Slim,
>>> 
>>> Actually, all of the foils can stall out, both in the water & in the air.
>>> An object does not have to be a certain shape to generate lift.  To prove
>>> this to yourself, stick your hand out of the car window.  If you hold your
>>> hand at an angle to the air flow, do you feel a force?  That's lift!  Is
>>> your hand shaped like an airfoil?  Even a flat plate can generate lift if
>> it
>>> is held at an angle of attack to the fluid flow.  The fluid does not have
>> to
>>> be a gas, like air, either.  It turns out liquids obey the same laws of
>>> hydrodynamics as gases.  The only differences between gases and liquids
>> show
>>> up in the defining equations as terms for density & viscosity.  Liquids
>> are
>>> usually more dense and more viscous than gases as the same temperature &
>>> pressure.  Without going into the physics, what this means is that dense
>>> liquids will produce the same amount of lift force/unit area at a lower
>>> fluid velocity than gases.  Or alternatively, at the same fluid velocity,
>>> liquids require less surface area to produce a given amount of lift force.
>>> For example, at room temperature & pressure, the density of air is about
>>> 0.076 lb/ft^3 vs. water at about 62.4 lbs/ft^3, a factor of about 800X.
>> So,
>>> the keel only needs to have about 1/800 the surface area of the sails to
>>> generate the lift forces required to resist leeway under sail.  Water is
>>> also much more viscous than air.  This has the effect of making the
>>> underwater foils much more forgiving or less prone to stalling out than
>> the
>>> sails.  This is a good thing because it makes sailing much easier.  If
>> your
>>> underwater foils stalled out as easily as your sails; then, every time the
>>> boat lifted in a wave or every time you moved the rudder blade, these
>> foils
>>> would stall out & quit generating lift.  However, at a sufficiently high
>>> angle of attack, even your underwater foils will stall out & quit
>> generating
>>> lift.  This happens most frequently with the rudder blade.  If we define
>> the
>>> angle between the tiller & the centerline of the boat as the angle of
>> attack
>>> of the rudder blade; then, the rudder blade is starting to stall out at an
>>> angle of about 30 degrees & completely stalled out at an angle of about 45
>>> degrees.  At angles greater than about 45 degrees, the rudder blade
>> behaves
>>> more like a water brake or drag device than an underwater foil.  So,
>> unless
>>> you are trying to slow down the boat, putting the tiller over more than
>>> about 45 degrees off the centerline is counterproductive as far as
>> steering
>>> goes.
>>> 
>>> People cite the analogy of airflow moving faster over the curved surface
>> of
>>> the top of a wing vs., the straight bottom surface as causing a pressure
>>> difference between the top & bottom surfaces & that's what causes lift.
>> In
>>> the middle 1700's, a Swiss mathematician & scientist named Daniel
>> Bernoulli
>>> did a mass & energy balance on all the forms of energy contained within a
>>> moving fluid.  These days, mass & energy balances are fundamental to
>>> engineering calculations.  But, in Bernoulli's time, this was a completely
>>> new & creative approach!  Bernoulli found that, if you keep a running
>> tally
>>> on all the forms of energy in the fluid as it flows from place to place;
>>> then, total energy is conserved.  The energy can change form - i.e.
>> kinetic
>>> energy can be traded off for pressure &/or potential energy & vice versa;
>>> but, the total amount of energy remains constant.  Bernoulli expressed
>> this
>>> idea in the form of an equation that now bears his name.  Bernoulli's
>>> equation is one of the 1st things students learn in any class on fluid
>> flow
>>> or hydrodynamics.  Naval architects, aeronautical engineers, & chemical
>>> engineers have it tattooed on the inside of their eyelids so they see it
>> in
>>> their sleep!  Macroscopically, one of the things Bernoulli's equation
>>> predicts & experimental measurements have verified is that there is a high
>>> pressure region on the windward side of a sail, a low pressure region on
>> the
>>> leeward side of a sail, & greater air velocity on the leeward side vs. the
>>> windward side - hence the common analogy cited above.  The difference
>>> between these two air pressures, multiplied by the surface area of the
>>> sailcloth over which the pressure difference is acting, is a force, which
>> we
>>> call "lift".  Although Bernoulli's equation is correct, it doesn't provide
>>> much insight into what's actually going on, physically.  Physically,
>> what's
>>> actually happening is Newton's Laws of Motion are at work, as always.  The
>>> air flowing over the sail is being forced to change direction by the shape
>>> of the sail.  Since the air has mass & Newton's Laws state that it doesn't
>>> "want" to change direction, forcing the airflow to change direction
>> requires
>>> that work must be done.  The only source of energy available to do this
>> work
>>> is the kinetic energy of the moving air itself, so that's where it must
>> come
>>> from.  Macroscopically, we observe this work as an increase in the air
>>> pressure on the windward side & a decrease in pressure on the leeward side
>>> of the sail.  The speed of the windward side & leeward side airflows
>> adjust
>>> themselves in response to these new pressures.
>>> 
>>> So, what the heck is stalling out?  Well, back to Newton's Laws again.
>>> Remember the fluid flow does not want to change direction.  Forcing the
>>> fluid to change direction too abruptly will cause the more or less orderly
>>> flow of molecules to break down into a more chaotic pattern.  The fluid
>>> molecules sort of get in each other's way when they are forced to change
>>> direction too abruptly & go bouncing off in random directions.  This
>> process
>>> turns the kinetic energy of the fluid flow into random molecular
>> vibrations
>>> or heat.  We call this process "turbulence".  Bernoulli's equation doesn't
>>> "care" what form of energy we convert the fluid's kinetic energy into,
>> heat
>>> is just as good as pressure.  So, at the onset of turbulence or stalling,
>>> the pressure difference across the sail goes away in favor of a slight
>>> temperature increase in the airflow.  Again, this has been verified
>>> experimentally.  Around the turn of the 20th century, a British physicist
>>> named Osborne Reynolds came up with the concept of a dimensionless
>> parameter
>>> which could be used to predict the onset of turbulence under any set of
>>> fluid conditions.  This dimensionless parameter is now called the
>> "Reynold's
>>> Number" in his honor.  (NOTE: In engineering, one of the highest honors is
>>> to have a dimensionless number or fundamental defining equation named
>> after
>>> you!)  The Reynold's Number is given by:
>>> 
>>> Re = (L * V * ro) / mu
>>> 
>>> Where:
>>> Re = Reynold's Number
>>> L = Characteristic Dimension Or Length Of The Flowing System (ft)
>>> V = Fluid Velocity (ft/sec)
>>> ro = Fluid Density (lb/ft^3)
>>> mu = Fluid Viscosity (lb/ft-sec)
>>> 
>>> Note: all the physical parameters that go into this calculation must be in
>>> units that cancel each other out, hence the term "dimensionless number".
>>> For any given physical geometry, there is a certain critical Reynold's
>>> Number above which the fluid tends to become turbulent.  For example, for
>>> fluids flowing in pipes, the L parameter is usually the inside diameter of
>>> the pipe & (Re)critical = about 2100.  Note that the fluid viscosity
>> appears
>>> in the denominator of this equation.  i.e., more viscous fluids like
>> liquids
>>> tend to resist the onset of turbulence better than less viscous fluids
>> like
>>> gases.  Again, this tends to make the underwater foils more resistant to
>>> stalling out than the sails & this is a good thing!
>>> 
>>> There, that's probably more than you ever wanted to know about foils &
>>> stalling out!  hopefully, I answered your question.
>>> 
>>> Roger Pihlaja
>>> S/V Dynamic Equilibrium
>>> 
>>> ----- Original Message -----
>>> From: "Steve Alm" <salm at mn.rr.com>
>>> To: "Rhodes" <rhodes22-list at rhodes22.org>
>>> Sent: Thursday, September 23, 2004 3:26 AM
>>> Subject: [Rhodes22-list] Re: Pointing
>>> 
>>> 
>>>> Peter,
>>>> 
>>>> Hold on, thar!  "Lift" from the keel, CB and rudder?  The underwater
>>>> appendages are symmetrical with the hull and cannot provide any lift.
>>> They
>>>> only serve to prevent lee way, or to provide lateral resistance.  That
>>> part
>>>> I agree with.  Brad might have a better description, but lift happens
>> when
>>>> air (or presumably water) has to travel farther around one side than the
>>>> other, creating a difference in pressure between the two sides.  Lift is
>>>> created by the curved shape of the sail or airplane wing and will stall
>> if
>>>> not going fast enough.  The keel, CB and rudder do not have that kind of
>>>> shape.  I'm with you on the rest as far as pinching vs. pointing goes,
>> but
>>>> it's the sails that stall out, not the keel, CB or rudder.
>>>> 
>>>> Slim
>>>> 
>>>> On 9/22/04 7:58 PM, "Peter Thorn" <pthorn at nc.rr.com> wrote:
>>>> 
>>>>> Hello Ed,
>>>>> 
>>>>> If you verify that you're able to point your R22 35 degrees off the
>> true
>>>>> wind, I certainly would like to visit Lake Hartwell to see that.
>>> Perhaps
>>>>> it's the apparent wind, the combination of the boat's velocity across
>>> the
>>>>> bottom combined with the true wind direction, that's making you think
>>> you're
>>>>> pointing so close. On a reasonably fast boat like R22, the apparent
>> wind
>>>>> angle can move quite a bit forward.  In an extreme example such as
>>> iceboats
>>>>> (that travel many times the true windspeed) the wind indicator points
>>> almost
>>>>> straight forward.
>>>>> 
>>>>> Are your headsail sheets led to tracks at the foot of the cabinhouse
>>> roof?
>>>>> That, I think, would certainly improve pointing.
>>>>> 
>>>>> It's good to be aware of the difference between pointing and pinching.
>>>>> Sailing too close to the wind can cause the underwater foils to slow
>>> down
>>>>> then stall.  That's pinching.  When the keel, cb and rudder stop
>>> producing
>>>>> lift, the boat will start to produce a lot of leeway, or sideways
>> drift.
>>> It
>>>>> is very difficult to detect leeway when aboard the boat that's making
>>> all
>>>>> the leeway.  The bow points higher, so the skipper might think he's
>>> pointing
>>>>> pretty high because the sideslip is so hard to feel.  To avoid this
>>>>> condition, foot off and keep the boat moving.  After regaining speed,
>>> head
>>>>> up a little.
>>>>> 
>>>>> If you have a GPS you can verify your pointing angle by measuring your
>>>>> heading (not the direction the bow is pointing), tack to the other
>> tack,
>>>>> measure heading again and divide the angle difference by 2.  I think
>>> someone
>>>>> mentioned this not too long ago on the list.
>>>>> 
>>>>> I too have wondered about the diamond board, and would guess Phil
>> Rhodes
>>>>> original cb is pretty hard to improve on.   A while back Roger wrote a
>>> very
>>>>> scientific sounding comparison, do you recall that?
>>>>> 
>>>>> Perhaps you Lake Hartwell guys should conduct on-the-water pointing
>>> trials
>>>>> and settle the issue.
>>>>> 
>>>>> PT
>>>> 
>>>> __________________________________________________
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>>>> 
>>>> 
>>> 
>>> 
>>> __________________________________________________
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>> 
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