Hi, folks. I ordered a jib that was Luff 34, Leach 31, and Foot 15. It looks mammoth. I did not want a genoa sail but this looks like it might be one. What is the standard size for a jib for a 27' Hunter Cherubini?
Size of Jib
- Thread starter Dana Shields
- Start date
I don't know what was "standard" in terms of percentage, but this page:
http://sailboatdata.com/viewrecord.asp?class_id=819
shows the foresail at 198.38 square feet (unless you have the tall rig).
http://sailboatdata.com/viewrecord.asp?class_id=819
shows the foresail at 198.38 square feet (unless you have the tall rig).
Dana,
Those measurements of yours calculate out to a 119% genoa (19% overlap), thereabouts, based on the published "J" dimension of 11.5 ft and a calculated LP of 13.7 ft, namely: 13.7/11.5 = 1.19. So, as you say -- the sail may be a bit large but you'll have to put it on to see if it fits or not.
Published: HUNTER 27 (1979-84) JIBSAIL
Luff 31.45*ft (9585mm)
Foot 14.74*ft (4492mm)
Leech 27.61*ft (8415mm)
Perc LP 115.02*
Length Perp 12.94*ft (3944mm)
Deck Angle 11.99*
Area 203.47*ft2 (18903mm2)
*Calculated from boat's rig dimensions.
Those measurements of yours calculate out to a 119% genoa (19% overlap), thereabouts, based on the published "J" dimension of 11.5 ft and a calculated LP of 13.7 ft, namely: 13.7/11.5 = 1.19. So, as you say -- the sail may be a bit large but you'll have to put it on to see if it fits or not.
Published: HUNTER 27 (1979-84) JIBSAIL
Luff 31.45*ft (9585mm)
Foot 14.74*ft (4492mm)
Leech 27.61*ft (8415mm)
Perc LP 115.02*
Length Perp 12.94*ft (3944mm)
Deck Angle 11.99*
Area 203.47*ft2 (18903mm2)
*Calculated from boat's rig dimensions.
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jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,846
Dana
Welcome to the forum. I see you recently joined. SFS is right. The number is for the sloop built from 1974 to 1984. If your boat is in that range then you got the quick answer.
But what ever happened to "How did he figure that out?" If you know the "HOW" then you can decide if it is "standard size" for your boat.
Here is a link that (in simple terms) how to decide if you have a "standard size" (assuming you mean a 100% fore sail).
http://www.sailboat-cruising.com/sail-dimensions.html
For a working jib that fills the fore triangle - but no more - and with a foot that's parallel to the deck, then you've got a 'proper' right-angled triangular sail, whose area is:~
Area = (luff x foot)/2, or
Area = (I x J)/2, where:~
So Measuring your boat and putting the numbers into the formula you can be the judge - Does the sail I bought equal the standard area for a foresail on my boat.
Best wishes and welcome.
"Give a man a fish you feed him for a day... teach him to fish and you feed him for his lifetime..."
Welcome to the forum. I see you recently joined. SFS is right. The number is for the sloop built from 1974 to 1984. If your boat is in that range then you got the quick answer.
But what ever happened to "How did he figure that out?" If you know the "HOW" then you can decide if it is "standard size" for your boat.
Here is a link that (in simple terms) how to decide if you have a "standard size" (assuming you mean a 100% fore sail).
http://www.sailboat-cruising.com/sail-dimensions.html
For a working jib that fills the fore triangle - but no more - and with a foot that's parallel to the deck, then you've got a 'proper' right-angled triangular sail, whose area is:~
Area = (luff x foot)/2, or
Area = (I x J)/2, where:~
- 'I' is the distance down the front of mast from the genoa halyard to the level of the main deck, and
- 'J' is the distance along the deck from the headstay pin to the front of the mast.
Best wishes and welcome.
"Give a man a fish you feed him for a day... teach him to fish and you feed him for his lifetime..."
well, now I'm starting to get a little worried about the luff (that I won't even have adequate clearance to hoist it fully). I'll hoist it tonight to see.
Welcome aboard, Dana. Click on 'Boat Info' at the top of this page. Click on your model. Click on Specs. That will give you the info you need. A 15 ft. foot headsail is indeed a genoa for your boat . Listed 100% jib foot for the 27 is 11' 3".
Ooops, I did not calculate for LP. Not as big a genoa as I had envisioned. Thanks, KG and Jssailem. And Stu.
If my calculations are correct, the sail you ordered will be 232.4 square feet, will have an LP of 13.67 ft, and would therefore be a 119% jib (actually 118.87%). Again, I have assumed the rig is not the tall version.
Note: I haven't done this calculation in about 43 years, so I could be wrong. I was thrilled that it all came back, because geometry was one of my favorite subjects in the 8th grade. Didn't hurt that the teacher wore mini-skirts (this was 1972).
PS: And clearly other people more in practice can do it faster than I can. But I got distracted, thinking about mini-skirts.
That's my story, and I'm sticking to it.
Note: I haven't done this calculation in about 43 years, so I could be wrong. I was thrilled that it all came back, because geometry was one of my favorite subjects in the 8th grade. Didn't hurt that the teacher wore mini-skirts (this was 1972).
PS: And clearly other people more in practice can do it faster than I can. But I got distracted, thinking about mini-skirts.
That's my story, and I'm sticking to it.
No offense...but the sail in your example is a mainsail. And mainsails are not sized the same way as headsails. The common and simple way to determine a headsail's size is to compare it's LP to the boat's J. Your formulas are misleading. IxJ/2 is the area of the fore triangle... LxLP/2 is a headsail's area.Dana
Welcome to the forum. I see you recently joined. SFS is right. The number is for the sloop built from 1974 to 1984. If your boat is in that range then you got the quick answer.
But what ever happened to "How did he figure that out?" If you know the "HOW" then you can decide if it is "standard size" for your boat.
Here is a link that (in simple terms) how to decide if you have a "standard size" (assuming you mean a 100% fore sail).
http://www.sailboat-cruising.com/sail-dimensions.html
So Measuring your boat and putting the numbers into the formula you can be the judge - Does the sail I bought equal the standard area for a foresail on my boat.
For a working jib that fills the fore triangle - but no more - and with a foot that's parallel to the deck, then you've got a 'proper' right-angled triangular sail, whose area is:~
Area = (luff x foot)/2, or
Area = (I x J)/2, where:~
- 'I' is the distance down the front of mast from the genoa halyard to the level of the main deck, and
- 'J' is the distance along the deck from the headstay pin to the front of the mast.
Best wishes and welcome.
"Give a man a fish you feed him for a day... teach him to fish and you feed him for his lifetime..."
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