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Old 07-11-2007, 13:25   #61
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Yes, race a 46 foot racing monohull against a 32 foot cruising catamaran. And prove what? Mind you, how embarrassing if the cat won? That would be something like the Gunboat video wouldn't it?
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Old 07-11-2007, 13:27   #62
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OK, A J46 has about what for hull speed? About 9 knots? That might be generous.

In anything over 15 knots true, I can do better than that upwind at about 35 degrees apparent angle. But he'll probably point higher than me and it might be a race to the windward mark. Off the wind he's toast. He won't surf on a reach and I'll be going 12 - 14 knts in 15 - 20 true. Downwind I'll make 1/2+ the true wind speed without surfing. Surfing is faster still.

Now, all that said. I don't race my boat. I don't really care very much any more about racing - I got it out of my system. But I do prefer not to spill my beer........

Dave
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Old 07-11-2007, 13:34   #63
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pirate HAahah

I must be sh!@T faced off the purple coolaid.
A fast multihull is faster than a fast mono.

My 33' cat is a little more on the speedy side than most cruisers, but it'll blow the pants off a beneteau 33'. Thats right. No contest.
Unless were talking about some kind of beneteau that can hold 15 kts on a close reach for extended periods of time? Didn't think so.
50' monos start getting close. And they are faster upwind. (I can only do about 10 pinching).
It's kinda a stupid debate because I think that it is well proven that multis are faster than monohulls.

Except for a few monohulls like ORANGE 2 and Playstation... Oh wait. Those are multihulls!

BTW

A j-boat is a racer. A Catana is a cruiser.(and still probably faster with a light load) I'll take your j-46 and raise you a volvo extreme 40.
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Old 07-11-2007, 13:36   #64
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Originally Posted by 44'cruisingcat View Post
Yes, race a 46 foot racing monohull against a 32 foot cruising catamaran. And prove what? Mind you, how embarrassing if the cat won? That would be something like the Gunboat video wouldn't it?

??

Dave has a Catana 471. What are you talking about.
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Old 07-11-2007, 13:38   #65
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2Hulls

OK, first move, change to these; VARA System

Second, change the hull bottoms to the shape shown in drawing: Sailing Magazine : Perry on Design

Third, turn sharp in your modified Catana 471.

Pericles
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Old 07-11-2007, 13:39   #66
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I must be sh!@T faced off the purple coolaid.
A fast multihull is faster than a fast mono. A slow multihull is faster than a slow mono. A fast monohull is faster than a slow cat. Then there are grey areas in-between.

My 33' cat is a little more on the speedy side than most cruisers, but it'll blow the pants off a beneteau 33'. Thats right. No contest.
Unless were talking about some kind of beneteau that can hold 15 kts on a close reach for extended periods of time? Didn't think so.
50' monos start getting close. And they are faster upwind. (I can only do about 10 pinching).
It's kinda a stupid debate because I think that it is well proven that multis are faster than monohulls.

Except for a few monohulls like ORANGE 2 and Playstation... Oh wait. Those are multihulls!

BTW

A j-boat is a racer. A Catana is a cruiser. I'll take your j-46 and raise you a volvo extreme 40.
If you think a J46 is a racer you must be really into the purple coolaid.

So do you race? Can you provide race results? How many start per year do you compete in?

Figures don't lie but ....
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Old 07-11-2007, 13:43   #67
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OK, A J46 has about what for hull speed? About 9 knots? That might be generous.

In anything over 15 knots true, I can do better than that upwind at about 35 degrees apparent angle. But he'll probably point higher than me and it might be a race to the windward mark. Off the wind he's toast. He won't surf on a reach and I'll be going 12 - 14 knts in 15 - 20 true. Downwind I'll make 1/2+ the true wind speed without surfing. Surfing is faster still.

Now, all that said. I don't race my boat. I don't really care very much any more about racing - I got it out of my system. But I do prefer not to spill my beer........

Dave
Well then Dave, it's time to race. Prove what you say and join the PHRF Fleet. Let's see some real life race results. I posted race results here. All you guys do is make qualitative claims about speed.

Man up and go race! Catana versus J Boat and you may be surprised about a j Boat getting around the course.
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Old 07-11-2007, 13:48   #68
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If you think a J46 is a racer you must be really into the purple coolaid.

So do you race? Can you provide race results? How many start per year do you compete in?

Figures don't lie but ....
No I don't race. I did when I was a kid. I am a cruiser (On the cruisers forum). But how about I give you a figure from my boats sistership. (Same design)

In the 1968 Transpac "Polynesian Concept" finished in 11:16:20:10. So I guess Beneteau 33s do the transpac in 11 days? hmmmm...
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Old 07-11-2007, 13:51   #69
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hello 2 hulls the texel rating for a 471 is around 129. the rating for the 472 is 136 and for the 431 it is 127.4 all measured with the factory weights and in the past Catana has been lying there head of as far as weights where concerned to the book the 471 weighted 12600 kilo or 27400 lbs and in reality 16000 comes closer. the new factory is more honest and comes closer to reality. if your catana is loaded up for long cruises I would guess that 135 is a good figure but if you have exact weight I can calculate the rating for you
Greetings Gideon/fastcat435
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Old 07-11-2007, 13:56   #70
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hello 2 hulls the texel rating for a 471 is around 129. the rating for the 472 is 136 and for the 431 it is 127.4 all measured with the factory weights and in the past Catana has been lying there head of as far as weights where concerned to the book the 471 weighted 12600 kilo or 27400 lbs and in reality 16000 comes closer. the new factory is more honest and comes closer to reality. if your catana is loaded up for long cruises I would guess that 135 is a good figure but if you have exact weight I can calculate the rating for you
Greetings Gideon/fastcat435
I don't know this (texel) rating system. Is it linear seconds per mile? Phrf is linear time on distance. If you rate 60 and race against someone with a rating of 120 you owe them a minute a mile or 10 minutes at the end of a 10 mile race.
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Old 07-11-2007, 13:56   #71
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Well Joli, I do not have a racing boat. I have no interrest is regular racing anymore. I raced small cats for 25+ years and never was beaten by a monohull - mostly because we didn't race PHRF. I don't remember even ever getting passed by a monohull day sailing.

If you believe a J46 can beat me around a course, fine. You can tell everyone I said "OK". <yawn> But how you figure a boat limited to about 9 knots hull speed (with maybe intermittantly more surfing) can beat me with no hull speed limit and demonstrated 12 - 15 knots on flat water suggests you're the one on coolaid. But hey, if you're ever on the Bay look me up and I'll buy you a beer. We'll share racing stories.

Dave
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Old 07-11-2007, 14:03   #72
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Damn, but we are fools! Joli lives in bloody land locked Ohio. He's miles from the sea. No wonder he's talking out of his rectum. Rivers in Egypt? Purple Coolaid? What's that foul brew? I thought the State drink is tomato juice! All those race results he's been posting and all those conversations with other sailors? They're figments of his imagination.:de vil:

Sure there's some lake to the north, but I'm in England and nowhere are we more that 70 miles from the sea. That's why we can all sail.

My bet is that the 2,500+ lakes and 43,000 miles of river landscapes belong to another state and are just on loan und zer are too many Germans zer.

The State motto is "With God all things are possible." but it might well as be "Gott Mit Uns"

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Old 07-11-2007, 14:04   #73
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The texel rating system was designed by Nico Boon tocompare catamarans competing in the bigggest cat race in the world and adapted for all cats and trimarans.
The system is designed around the tornado catamaran having a rating of 100
I have attached the rating formulas below
Texel rating rule for multihulls, 2007
Preface
The purpose of this rating is to enable multihulls of various classes to race together. To give all room for research and development by designers. These rating regulations are applicable at all races where various designs or classes partake together, but one racing result is desired.
Rule administration
The rule is published under authority of the CTC, the Catamaran and Trimaran Club of the Netherlands. The CTC has the right to amend the regulations if necessary. In case of doubt about any part of the text of the rules, the spirit of the rule counts, not the letter.

TR2007
The TR-numbers as used in the Netherlands for 2007 are available for measured as well as un-measured boats.
Rating
Basics
Ratings will be determined for all types of multihulls on measurable data, guaranteed by the class organisation, the builder, the owner, using formulas, verifiable by anyone. A Texel Rating (TR) is calculated, with the formula given at the end of the ruletext, using normal rules of rounding.
Abbreviations, formulas and calculations used :
Hulls (sheet 1)
AOC = aft overhang component
FOC = forward overhang component
LOA = length overall
RL = rated length LOA - AOC - FOC

Weight (sheet 2)

RW = rated weight WC + WS
WC = weight crew
WE = weight declared equipment
WM = weight boat without equipment
WS = weight complete boat WE + WM

Sails (sheet 1)
EG = efficiency percentage genoa (jib)
EM = efficiency percentage mainsail
MSAG = measured area jib (genoa)
MSAM = measured area mainsail
MSAS = measured area spi or screecher
RSA = rated sail area RSAM + RSAG + RSAS
RSAG = EG * MSAG * 0.01
RSAM = EM * MSAM * 0.01
RSAS = rated sail area spinnaker or screecher (RSASc)
VLM = vertical projection of luff of main : That is the distance measured alongside the mast from the highest point of a normally hoisted sail towards the lowest point reached when the downhaul is used.
VLG = vertical projection of the luff or leech of the jib/genoa. That is the distance between the horizontals on the mast taken from the highest point of the jib/genoa towards the lowest point of luff or leech whatever. It will be measured alongside the mast. In practice :
VLG = luff * 0.94
SF = length foot of the spinnaker
SMG = distance between middle of luff and leech of the
spinnaker.
SL1 = length luff of the spinnaker.
SL2 = length leech of the spinnaker

Various (sheet 2)
P = correction factor for propellers
one folding propeller 1.02
one fixed propeller 1.025
two folding propellers 1.03
two fixed propellers 1.0375
Q = correction factor for NO (dagger) board(s)
Q = 0.94 / (draft / RL) ^ 0.037
K = Variable for catamarans, 1 for all trimarans.
1 / (0.19 * RSA ^ 0.4 / RW ^ 0.36 + 0.91), for cats, if > 1

Determination of the rated length (sheet 1)
The length over-all is the horizontal distance from the most forward point of the hull to the farthest point at the stern of the hull. Lines through these points have to be measured both from vertical positions. Rudders and rudder equipment not to be included in LOA.
FOC, Forward Overhang Component
That is the difference at the bow between the most forward point and the forward end of the rated length. If the bow is vertical or hanging backward than FOC = 0

AOC, After Overhang Component
That is the difference at the stern between the most afterward point of the stern and the aft end of the rated length. If the stern is vertical or leaning forward than AOC = 0

RL, Rated Length. The rated length is the horizontal distance measured at 2 % of LOA above the waterline of the boat, without the crew on board. To calculate FOC. the freeboard VL at the stem and the angle alpha at the top of the stem have to be measured.

FOC = VL * tangent alpha - (2 % of LOA) * tangent alpha
The same must be done to determine AOC, for designs with a genuine stern overhang.
Generally AOC = 0

RL = LOA - AOC - FOC
Determination of the sailareas (sheet 2)
The real sailarea is determined by one of the usual methods.
For cabin multihulls the area of the mainsail is measured, using the Simpson rule.
Applying the methods given on sheet 2, results in the real area of mainsail, plus mast (if swivelling) and jib, MSAM and MSAG, as well as the spinnaker (screecher) area MSAS. From these data RSAM and RSAG, the effective areas, will be calculated by using an efficiency percentage. That requires the determination of the aspect ratio A. This A is the result of the calculation : Vertical height of the sail (VLM for the main and VLG for the jib/genoa) squared, divided by the area.
A = VLM * VLM / measured area

If a mast is used which is swivelling, with a section which is not a circle, then the area of the mast (defined as follows) is added to RSAM calculated from MSAM mentioned above, to give the final RSAM to use in RSA. determined.
Area mast = 0.5 * maximum circumference * (VLM 1 + VLM 2)
eff. % = 40.1 + 18.31 * A - 2.016 * A^ 2 + 0.07472 * A^ 3
RSA = real sailarea * eff. % * 0.01 + area mast (if applicable)


Determination of the spinnaker or screecher area (sheet 2)

For boats provided with a spinnaker, RSAS = MSAS * 0.15 , if the spinnaker area and the spinnaker boom satisfy the following conditions. Spinnaker areas as given in class regulations. Otherwise us maximum allowed spinnaker areas, as given below.

one man crew two man crew
up to 16 ft < 4.87 m.14 m2 17 m2
from 16 up to 19 ft. > 4.87 m. <= 5.80 m
17 m2 21 m2
from 19 up to 22 ft. > 5.80 m. <= 6.71 m.
20 m2 25 m2

For boats with a length of more than 22 ft (6.71 m) depending on the spinnaker area, a rating number will be calculated. Spinnakers have to be measured as illustrated on the drawing.
For open cats, the maximum boom length is the distance from the footend on mastbeam or at the foot of the mast, to the end of one stem, plus 80 cm. No limits for cabin multihulls.

The following dimensions have to be measured along the sides, stretched normally.
SF = foot
SL 1 = luff
SL 2 = leech
SMG = straight line connecting the middle of luff and leech.

The area is calculated as follows :
MSAS = SF * (SL1 + SL2)/4 + (SMG - SF/2) * (SL1 + SL2)/3
SMG >= 75 % of SF. For a screecher 50 % SF < SMG < 75 % SF.
RSAS = 0.07 * MSAS
RSAS = 0.15 * MSAS (for open cats)
RSASc = 0.10 * MSAS (for a screecher)

All spinnakers have to be measured by a measurer and have to be stamped by the measurer with the following information :
* date of measuring
* spinnaker area
* name and/or nr. of the measurer
* paraph of the measurer

Determination of the weight of the crew (sheet 2)
For calculation purposes : weight each crew
LOA boat <= 4.00 m: 65 kg
LOA boat <= 4.80 m: 70 kg
LOA boat > 4.80 m: 75 kg

If the total sailarea >= 11 m2, than for crew one-man boats always take 75 kg.
For cabin multihulls the crew weight in kg. is calculated as follows:
WC = RL * 40 - 70

Centreboards
The rating for open catamarans not having an efficient centreboard is calculated by raising the not rounded ratingnumber with 3 %.
For cabin multihulls the correction factor Q for not using a centreboard or daggerboard, using RL and the draft as input, is calculated as follows:
Q = 0.94 / (draft/RL) ^ 0.037
Rating formula (sheet 1)
TR rating = 100 / (0.99 * RL^ 0.3 * RSA^ 0.4/ RW ^0.3) * K * P * Q

The rating number is rounded to an integer of two or three digits, using the normal rules for rounding. A TCF number, if preferred is calculated as follows: 100 / TR number.

Inspection during races

During the season, the CTC rating committee may inspect boats on the measurements and weights used in the formulas.
To keep the rating system as simple as possible (the KISS principle), no penalties are included yet, for instance for excess bowsprit (spinnaker boom) length, or for less than minimum headroom etc. It is easy to include extra multiplying factors if users want it.

************************************************** ************************************************** ************************
Easy calculator
On this website you find an easy calculator to test with your own boat or to experiment with a new design.
Only use the tab key to go to all cells that may need your input. Starting with the name of your boat to the last one, asking a true wind value Vt. In the example given on the file, (the catalac), the value of the heeling force
is made equal to the righting force by adapting Vt. This value for Vt is the stability limit.
Above that value, reefing is recommended, if not required.

You can find the spread sheets in the web site of the Dutch multihull club
Welkom op de site van de Catamaran en Trimaran Club Nederland from there go to texel rating English version and than go to unmeasured boats , just fill in the figures given for your own cat or tri and your rating comes out good luck
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Old 07-11-2007, 14:05   #74
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No I don't race. I did when I was a kid. I am a cruiser (On the cruisers forum). But how about I give you a figure from my boats sistership. (Same design)

In the 1968 Transpac "Polynesian Concept" finished in 11:16:20:10. So I guess Beneteau 33s do the transpac in 11 days? hmmmm...
How about you post some race results from a gold cup or a W/L that your sisitership has entered? How about you go get a rating and sign up for a few races and post the results?

Lets see some quantitative data to support the claims. Let's see race results.
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Old 07-11-2007, 14:08   #75
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Thanks Fastcat, I'll spend some time looking at that.
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