[Rhodes22-list] Level on Board

[Bill Effros]

Art,

Most of us don't take our own comments seriously, much less the comments 
of anyone else.

Most of the time, the maximum speed of an R-22 is 6.25 kts.  No matter 
how big an engine you put on it, or how hard the wind is blowing, you 
can't push an R-22 through the water any faster than that.  This is the 
concept of "hull speed".

Planing boats (Sunfish, Hobie Cats, fast power boats) skitter along the 
top of the water at speeds greater than their hull speed precisely 
because they are skimming along the top, (at considerable discomfort) 
rather than pushing through the water.  (This is the concept of 
"displacement vs. non-displacement boat hull design".)

It is possible to make an R-22 plane in special circumstances, but for 
the purpose of this discussion, let's just say you can't do it most of 
the time, and that is not what we're talking about.

If you put a large engine on an R-22 and use more horsepower than you 
need to get to 6.25 kts., your boat will not go any faster, but it will 
start to create more and more wake.  You can't make the boat go faster, 
but the additional power used in trying is transferred into making waves 
in the water.

Few of us do this for weight and cost reasons.  8 hp is probably all you 
will ever need in a Rhodes, although some buy 9.9 hp engines.  This is 
the largely discredited concept of "just to be on the safe side."

Which brings us down to overpowering the boat by putting out too much 
sail, and then compensating with "rail meat".

In sail boats that are not limited by hull speed (planing boards, cats, 
trimarans, and very long mono-hulled racing boats) there is no effective 
hull speed limitation.  If you can put out more sail and keep the boat 
upright you will go faster.  In order to put out as much sail as you can 
fly, you counter-balance the energy of wind on the sail.

In Sunfish you sit on the rail, and arch your body as far out as you can 
for as long as you can.  In cats you get a trapeze and hang your entire 
body windward.  Large racing boats have developed many methods to 
counter-balance sails, from putting large numbers of crew members on the 
windward side of the boat, to water ballast, to bulb keels, to winged 
keels, to canted keels, etc.

You can easily overpower an R-22 with a 175 Genny.  You can move people 
around on the boat to compensate for the fact you are overpowered.  This 
can provide a far more thrilling ride, (and many sailors get a kick out 
of seeing if they can make non-sailors pee in their pants) but does not 
yield any additional boat speed.

The Rhodes-22 was designed to sail fastest upright.  None of the wind's 
energy is supposed to be wasted "heeling".  The hull is designed so that 
the maximum amount of energy in the sails can be transferred into 
forward motion of the boat, up to the boat's theoretical "hull speed" of 
roughly 6.25 kts., when the boat is maintained as upright as possible.

Stan then designed the boat with infinitely, and easily changed sail 
sizes, so the boat could be kept upright, without adding lots of people 
or complicated paraphernalia, simply by reducing the amount of sail 
aloft.  You can generally add at least 1/2 kt. to boat speed by sailing 
upright rather than heeled.  It doesn't "feel" faster.  There is less 
strain on the rigging and the crew.  But you will get wherever you are 
going sooner, and your instruments will immediately confirm that your 
boat speed has increased.

Balance your boat when it is at rest, and then learn to keep it balanced 
when you are sailing under differing conditions by reducing or enlarging 
sail area, and your boat will go faster than it will if you compensate 
for overpowering the sails.

Bill Effros





Arthur H. Czerwonky wrote:

>Bill,
>My comments were not meant to trivialize your balance and performance evaluations, just to inject a little 'chess' humor, as Ed describes the logistics of passenger shuffling.  I am curious about the side to side balance question.  Have you found it necessary or helpful to have passengers sit outboard of the cockpit to make the boat level?  I wonder if a trapeze rig has ever been used in the R22s in racing or how helpful it would really be.
>Best to you,
>Art
>
>-----Original Message-----
>From: Bill Effros <bill at effros.com>
>Sent: Aug 13, 2005 11:34 AM
>To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
>Subject: Re: [Rhodes22-list] Level on Board
>
>Slim,
>
>True enough.  However, the point of the exercise is not to truly level 
>the boat, but to find the balance where your boat sails best.  I would 
>like my cockpit seats canted a little more to the stern.  That would 
>help the water drain better.  Also, I want the cockpit floor slightly 
>canted toward the stern for the same reason.
>
>When my little level indicates that I am fairly level, that is a very 
>good starting point for my boat.  If my "lines" matched this reading, it 
>would be a better visual indication for me.  As it is, they are just 
>decorative, and create an optical illusion that the boat is inexplicably 
>bow heavy.  If Stan is using his own bow lines to advise people to sail 
>their boats bow heavy, it may be that the boat simply sails best when it 
>is as neutrally balanced as possible, but appears to be bow heavy 
>because the lines are not in the right place.
>
>As soon as a bunch of people sit in the cockpit, the balance of the boat 
>changes.  But it changes less than you would think because of the very 
>broad aft section. 
>
>I have a comparatively light motor sitting way out on the stern (63 
>lbs.) and little weight in the lazarette.  It is hard for me to 
>unbalance the boat forward and aft, no matter what I do with people and 
>liquids in the cockpit.
>
>This may not be true if you have a heavy motor, or carry liquids in the 
>lazarette.
>
>When I sleep in the cabin the boat becomes truly bow heavy (rain falling 
>into the cockpit doesn't drain.)
>
>If anyone goes into the head while I'm sailing it throws the entire 
>balance of the boat way off.
>
>Bill Effros
>
>
>
>
>Slim wrote:
>
>  
>
>>Bill,
>>
>>This seems like a good idea to me and worth the hassle to get the boat
>>balanced.  Putting the level on the companionway port to starboard sounds
>>good, but bow to stern assumes the companionway is the "level" to target.
>>Why not the cockpit floor?  Why not the cabin top?  Placing a 4 foot level
>>across an 8 foot plank--you have an 8 foot level, and very accurate.  But
>>putting a 6" level across a 2" board--you have a 2" level which is hardly
>>accurate at all.  I would not assume the boot stripe is off by comparing it
>>to a 2" level, especially when the "levelness" of those two inches are
>>suspect.  That said, Stan, Roger and others have always maintained the boat
>>performs better up wind if it's a little bow heavy.
>>
>>Slim
>>
>>On 8/12/05 7:44 AM, "Bill Effros" <bill at effros.com> wrote:
>>
>> 
>>
>>    
>>
>>>For $3.69 I bought a 6 inch level at a job lot outlet, and brought it
>>>out to the harsh marine environment.  The data yielded so far by the
>>>instrument have been interesting.
>>>
>>>Water weighs roughly 8 lbs. per gallon.  Gas weighs roughly 6 lbs. per
>>>gallon.
>>>
>>>I carry 2 3-gallon gas tanks under the port seat -- 36 pounds when full.
>>>
>>>My fresh water tank is 15 gallons (I think) but overflows when heeling
>>>when full, so I try to keep it less than full.  Maximum Weight 120
>>>pounds on starboard side.
>>>
>>>My waste tank is ... 10 gallons?  80 pounds maximum on port side.
>>>
>>>I generally carry 2 2 1/2-gallon portable water tanks under the cockpit
>>>seats--40 lbs.
>>>
>>>I leave some water in my bilge.
>>>
>>>All of these fluids are constantly changing.
>>>
>>>So I've got roughly 250 pounds (effective maximum) down to an effective
>>>minimum of roughly 100 pounds of fluids on board most of the time.
>>>
>>>Remember that moving 100 pounds of anything from the low side to the
>>>high side has the same effect on the boat as a 200 pound person sitting
>>>on the high side.
>>>
>>>Placing the level on the companionway entrance, both port to starboard
>>>and bow to stern, I find I can easily balance the boat in both
>>>directions with me standing or sitting near the companionway.  I wish my
>>>house was as level as I can make the boat.
>>>
>>>The "lines" on the exterior of the boat are not level.  They make it
>>>appear the boat is bow heavy when it is actually level.
>>>
>>>As soon as I and the boat start moving, everything changes.  I move my
>>>level to a position in the cockpit near me to see how I am doing.
>>>
>>>I start from a roughly level boat by moving things around.  Once sailing
>>>I can keep the boat roughly level by altering the balance of the sails.
>>>
>>>I find I can gain at least 1/2 knot in boat speed by keeping the boat
>>>roughly level.  Upright the boat doesn't "feel" as fast as when it is
>>>heeled and there is a lot of pressure--but you go faster.  Moving sails
>>>in (IMF and Roller Furling) also will speed up the boat if you keep it
>>>balanced.  (I know this is counter-intuitive, but try it.  You will be
>>>surprised.  Reduce sail for better balance, go faster.)
>>>
>>>Since I start with a balanced boat, it is fairly easy to keep it
>>>balanced all the time.  I will be taking people out with me this
>>>weekend, and I will ask them to move around in the boat trying to keep
>>>it balanced.   I'm sure we'll go faster, and there will be fewer
>>>unexpected "wind shifts" if they help to keep the boat balanced.
>>>
>>>I'll let you know how it goes.
>>>
>>>Bill Effros
>>>
>>>
>>>__________________________________________________
>>>Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>>>   
>>>
>>>      
>>>
>>__________________________________________________
>>Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>>
>> 
>>
>>    
>>
>__________________________________________________
>Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>
>__________________________________________________
>Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>
>  
>