Foresail sizes

[tim]

Hi,
What are the general ratios in size between genoa, no 1, no 2, storm jib?

My Steadfast 30 has a genoa with an 11.2 M luff, so I'm interested in what would be the approximate sizes for no1 and no 2.

Thanks,

Tim

 

[Lakesailor]

I think it depends on the rig design.
It'll make a difference if you are fractionally-rigged or masthhead.
Also the ratio between main and headsail, if you are headsail driven they'll go up in bigger increments, which depends on how far aft your mast is.
I think. Maybe a bit tired and emotional.

 

[Rick]

Luff length will remain much the same for #1 and #2, while #3 will be a bit shorter than the 2. The bigger difference is the LP or Luff Perpendicular or Projection. #1 (clew) may sheet towards back of coachroof, with #3 being somewhere near the mast. Back to LP, #11 might be 150% whereas #3 could be just 100%, yet luffs could be 11.2 and 10.5 - similar luff, huge difference in amount of sail area.

 

[William_H]

Unless you are racing in strict one class type fleet then the whole thing is a variable feast. No1 or you might call it code zero is simply the biggest you can fit into the luff and as far back as your aft fairleads. Jib sizes from there on reduce by perhaps 30% in area until you get down to a storm jib of a size that you feel is small enough for whatever you will encounter.
you might find like many people that intermediate jibs depend on what you have and what you find secondhand and from those what you feel like from experience. For innstance when racing I often seem to feel I need a jib a little smaller than no 2 but then my no 3 is too small. You might find like me that you are never quite satisfied with your jib size when actually racing. ( no don't listen to those who say get a roller furler they never work like a real correctly sized jib especially to windward in a blow).

In choosing intermediate jib shapes a taller jib that is short on the foot will theoretically give you a better aspect ratio and so is more efficient but a jib shorter on the luff brings the centre of effort lower so reducing heeling moment. Your jib sheeting points (fairleads) position will have a bearing on your choice. I have always wondered about trying a no3 jib on a boom to make it self tacking which would require a short foot and long on the luff. So we dream on........ regards olewill
PS if you are buying new jibs you may consider changing to bolt rope luff jibs and fitting a twin track foil on the forestay to acheive quick jib changes.

 

[VicS]

It won't answer your question specifically but you will find some interesting reading here:
http://www.ukhalsey.com/LearningCenter/encyclopedia/encyclopedia.asp

 

[capt_courageous]

Hi
These are from an Ed Dubois boat - I guess he knows what works for cruisers.
Luff Area Foot
No1 Genoa 34.4 277 17
No2 Genoa 33.2 224 14.8
No1 Jib 29.6 143 11.5
No2 Jib 21.6 72 10.1

Sorry- all in feet but I don't do metric. Your luff is 36.7 I reckon. As I understand it a Genoa is a jib which overlaps the main. As the others have said it is not an exact science but like aircraft if it don't look right it usually ain't right. The No2 jib looks tiny but if it is that windy I stay in the pub. My table columns seem squashed up but hope you can decipher them.