 |
|
27-01-2011, 16:44
|
#1
|
Guest
Join Date: Jul 2010
Posts: 843
|
Sail Area . . . Question ?
was looking at some statistics about similar boats and was wondering why my hinterhoeller 28 had so little sail erea compared to other similar boats...these are the figurs I dont understand...can anyone explain what they are and how they afect sailing??
Hinterhoeller 28...sail erea; 190.4...displacement to LWL; 340...sail erea to displacement; 8.49
Tartan 27...sail erea; 376...displacement to lwl; 336...sail erea to displacement; 15.84
Northern 25...sail erea; 305...displacement to lwl; 312...sail erea to displacement; 17.15
Triton... sail erea; 379...displacement to lwl; 359...sail erea to displacement; 16:33
Alberg30...sail erea; 410...displacement to LWL; 395...sail erea to displacement; 15.16
Challenger 7.4...sail erea; 230...displacement to lwl; 217...sail erea to displacement; 14.6
|
|
|
27-01-2011, 16:54
|
#2
|
Registered User
Join Date: Dec 2009
Posts: 2,959
|
This says your SA is 357...
|
|
|
27-01-2011, 16:55
|
#3
|
Moderator
Join Date: Feb 2010
Location: La Ciudad de la Misión Didacus de Alcalá en Alta California, Virreinato de Nueva España
Boat: Cal 20
Posts: 21,624
|
According to HINTERHOELLER 28 Sailboat details on sailboatdata.com the foretriangle on your boat is 190sf.
Total SA is 364 giving you a SA/D of 17.7 in the lightship condition.
Loaded the SA/D be less but in similar proportion to similar boats.
__________________
Num Me Vexo?
For all of your celestial navigation questions: https://navlist.net/
A house is but a boat so poorly built and so firmly run aground no one would think to try and refloat it.
|
|
|
27-01-2011, 17:14
|
#4
|
Moderator

Join Date: Aug 2009
Location: Solent, England
Boat: Moody 31
Posts: 18,717
|
I have just looked at Sailboat data for my Moody 31 and they have the numbers wrong, the sail areas are larger. However, this depends on how big a genoa previous owners have decided on when replacing.
The details are, Moody 31(plain cruising yacht)
Combined sail area 553sq ft, displacement to LWL; 238...sail area to displacement; 20.1
So what does this mean? well in winds of F3 and under we could do with flying the big cruising chute. At F4 on a beam reach we hit hull speed and should consider a reef or we go sideways too much. By F5 we really need to have the first reef in and be considering the second.
Pete
|
|
|
27-01-2011, 17:24
|
#5
|
Registered User
Join Date: Dec 2009
Posts: 2,959
|
Sail Area (SA) is not an actual area, It is P*E/2 + I*J/2 (As I understand it...)
It's the foretriangle area (like a 100% genoa) plus the main triangle area excluding any roach or foot. It's just meant to be a guideline.
|
|
|
27-01-2011, 17:45
|
#6
|
Guest
Join Date: Jul 2010
Posts: 843
|
Quote:
Originally Posted by daddle
This says your SA is 357...
|
this seems more appropriate...however I disregarded that info because that site has the displacement wrong, they say 6000lb when the boat is more in the 8000lb range.
the data I posted came from carls sail calculator.
|
|
|
27-01-2011, 18:22
|
#7
|
CF Adviser
Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
|
Quote:
Originally Posted by jobi
this seems more appropriate...however I disregarded that info because that site has the displacement wrong, they say 6000lb when the boat is more in the 8000lb range.
|
I just did a search, and numerous sources list the displacement as 6,000lbs.
Official displacements are often light, and are often specked as a boat's dry weight. In other words, nothing in the tanks, and no dirty socks in the laundry.
__________________
cruising is entirely about showing up--in boat shoes.
|
|
|
27-01-2011, 18:41
|
#8
|
Moderator
Join Date: Feb 2010
Location: La Ciudad de la Misión Didacus de Alcalá en Alta California, Virreinato de Nueva España
Boat: Cal 20
Posts: 21,624
|
Quote:
Originally Posted by jobi
this seems more appropriate...however I disregarded that info because that site has the displacement wrong, they say 6000lb when the boat is more in the 8000lb range.
the data I posted came from carls sail calculator.
|
You got the displacement from Carl's?
__________________
Num Me Vexo?
For all of your celestial navigation questions: https://navlist.net/
A house is but a boat so poorly built and so firmly run aground no one would think to try and refloat it.
|
|
|
27-01-2011, 18:57
|
#9
|
Registered User
Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 21,196
|
Quote:
Originally Posted by Pete7
I have just looked at Sailboat data for my Moody 31 and they have the numbers wrong, the sail areas are larger. However, this depends on how big a genoa previous owners have decided on when replacing.
(...)
|
But should not the SA/something factor calculate the 100% triangle ONLY?
Otherwise we could be comparing apples and oranges.
(?)
b.
|
|
|
27-01-2011, 19:19
|
#10
|
CF Adviser
Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
|
Quote:
Originally Posted by barnakiel
But should not the SA/something factor calculate the 100% triangle ONLY?
Otherwise we could be comparing apples and oranges.
(?)
b.
|
That's exactly what daddle's formula does. However, boat manufacturers publish their own specifications, and decisions on what to post are often being made by the marketing guys. Which is why a given manufacturer might want to post the actual sail area of a boat running a genoa. If you manipulate the numbers, a boat can seem more or less stiff than it really is.
I guess the rule is not to trust the SA/D unless you've got it from the architect, or perhaps the builder, rather than the dealer trying to sell you the boat.
__________________
cruising is entirely about showing up--in boat shoes.
|
|
|
27-01-2011, 19:39
|
#11
|
Registered User
Join Date: Dec 2006
Location: Seattle
Boat: Cal 40 (sold). Still have a Hobie 20
Posts: 2,975
|
From sail calculator:
Also all data included was entered by users
|
|
|
28-01-2011, 06:09
|
#12
|
Guest
Join Date: Jul 2010
Posts: 843
|
Quote:
Originally Posted by Bash
I just did a search, and numerous sources list the displacement as 6,000lbs.
Official displacements are often light, and are often specked as a boat's dry weight. In other words, nothing in the tanks, and no dirty socks in the laundry.
|
the boat was wieghted for transport and only the boat dry 4,43 tons...this number was engraved by the canadian governement on the bulkhead.
I think its accured
|
|
|
28-01-2011, 13:32
|
#13
|
Registered User
Join Date: Jun 2009
Posts: 146
|
I think the 357 SA is about right, the 190 is 100 percent jib. I have seen displacement @6800#. The transport Canada number may be a theoretical number. Next time it is lifted you may be able to get a real number if the lifter has built in scale. If it was me I would want it to be 6800 not 8000 something, lighter will be faster in light wind and you can reef for the big wind. Anyway he was a great designer look at his shark 24 done in 59 I think in plywood first before fiberglass. Enjoy and good luck.
|
|
|
29-01-2011, 09:56
|
#14
|
cruiser
Join Date: Nov 2008
Posts: 506
|
Daddle is correct.
But on modern boats with huge roaches it seems silly not to factor in the area of the roach so you have to make a subjective decision a some point whe to use total mainsail area and when to use E and P. They are just numbers.
|
|
|
29-01-2011, 12:05
|
#15
|
Registered User
Join Date: Jul 2005
Location: Bellingham
Boat: Outbound 44
Posts: 9,319
|
Quote:
Originally Posted by blgklr
..... I have seen displacement @6800#. The transport Canada number may be a theoretical number. Next time it is lifted you may be able to get a real number if the lifter has built in scale. If it was me I would want it to be 6800 not 8000 something, lighter will be faster in light wind and you can reef for the big wind.....
|
The tonnage spec'd in documentation certificates is not weight. It is an odd ball measure of volume. For a cruising boat you basically ignore that number.
Paul L SV Jeorgia
|
|
|
 |
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|