Standard specifications Sail sizes

P

pcatterall

Well-Known Member
Joined
2 Aug 2004
Messages
5,506
Location
Home East Lancashire boat Spain
Visit site
I am searching for used sails to experiment with for our proposed boomed jib and mizzen staysail.
One issue that I have is that many used sails are listed simply under their model name.
I thought there was a list 'somewhere on line' which listed sizes against models.
I've tried various terms to search under but had no success.
Can anyone help please?
 
pcatterall said:
I am searching for used sails to experiment with for our proposed boomed jib and mizzen staysail.
One issue that I have is that many used sails are listed simply under their model name.
I thought there was a list 'somewhere on line' which listed sizes against models.
I've tried various terms to search under but had no success.
Can anyone help please?
Click to expand...

There is really no such thing as "standard" sail sizes for a specific model of boat, although you will find the standardised sail dimensions in sources such as Sail Boat Data. This does not actually indicate the dimensions of the sails actually fitted. For example the foresail measurements just give the area indicated by the dimensions of the space inside the forestay, mast and distance between them, but most foresails overlap the mast so are greater than this area. Equally replacement sails are often made to different sizes from the originals.

However when buying used sails, all this is irrelevant. You have the dimensions of your boat, or if not download a measurement guide from any of the big sailmakers. Then just ask for the luff and foot measurement of the sails on offer to see if they will fit your boat. Inevitably, particularly as your boat does not follow a common pattern, the chances of finding an exact match are pretty slim. So you might need to have undersize sails, or have oversize sails cut down, but more likely when you have reviewed these options make the sensible decision to have proper sails made specifically for your boat! Sails are consumables and have a significant impact on the way the boat performs so it makes sense to bite the bullet and buy the best you can afford.
 
Tranona said:
There is really no such thing as "standard" sail sizes for a specific model of boat, although you will find the standardised sail dimensions in sources such as Sail Boat Data. This does not actually indicate the dimensions of the sails actually fitted. For example the foresail measurements just give the area indicated by the dimensions of the space inside the forestay, mast and distance between them, but most foresails overlap the mast so are greater than this area. Equally replacement sails are often made to different sizes from the originals.

However when buying used sails, all this is irrelevant. You have the dimensions of your boat, or if not download a measurement guide from any of the big sailmakers. Then just ask for the luff and foot measurement of the sails on offer to see if they will fit your boat. Inevitably, particularly as your boat does not follow a common pattern, the chances of finding an exact match are pretty slim. So you might need to have undersize sails, or have oversize sails cut down, but more likely when you have reviewed these options make the sensible decision to have proper sails made specifically for your boat! Sails are consumables and have a significant impact on the way the boat performs so it makes sense to bite the bullet and buy the best you can afford.
Click to expand...

Absolutely ! However, we hope to get some trials with any old used sail which will 'more or less fit' so we can mess about with them and decide how they will best be fitted and determine the size required prior to spending a lot of money on the final product.

Our boom jib will have a foot of only 6 feet but the luff could be up to 25 feet, so a very tall narrow sail, we could trial with a small jib which would probably not have the final height but would at least help us site the deck fittings etc. The mizzen stay sail would be around 17x17x 15 and in a light cloth, we wont find a used sail of those dimensions or cloth weight but hope to get something approximating that as a first try.
 
pcatterall said:
Absolutely ! However, we hope to get some trials with any old used sail which will 'more or less fit' so we can mess about with them and decide how they will best be fitted and determine the size required prior to spending a lot of money on the final product.
Click to expand...

IMHO a complete waste of time and money. How can you learn anything from old unsuitable sails?

That is what you pay a sail maker to do. They are not just seamstresses sewing up pieces of fabric. They have enormous experience of designing and making sails to suit individual requirements.

Pose your requirements to a proper sailmaker and ask for a proposal. Describe what you want to achieve, give the dimensions asked for in the measuring guide and pretty good chance you will get a good result.

That is exactly what I did when I had an unusual boat that performed poorly with the original sails and the replacements were a complete success. I used Rob Kemp, but there are many others who are perfectly capable of designing a sail plan to meet your requirements.
 
Tranona said:
Pose your requirements to a proper sailmaker and ask for a proposal. Describe what you want to achieve, give the dimensions asked for in the measuring guide and pretty good chance you will get a good result.
Click to expand...

+many. Ask a professional, they'll be delighted to help. (If they're not, dump them an ask another.)
 
pcatterall said:
Our boom jib will have a foot of only 6 feet but the luff could be up to 25 feet, so a very tall narrow sail, .
Click to expand...

Suggest that you might have a problem there to start with. A sail that narrow will just "tube up" or form a semi circle in section for most of its height & will give very limited drive, if any, in the top 50%. I would first be tempted to ask a sail maker if that dimension was indeed practical before proceeding
 
Assuming the mizzen staysail is a downwind/reaching tool?
That's not likely to be too critical IMHO. More sail area, provided it's not blanketed by other sails, will drive the boat. It may give you a bit of weather helm though.

That high aspect boomed jib though, sounds like something for upwind use. Inside another headsail, or instead of as the wind pipes up?
Either way, it will need proper control of the shape in terms of twist. Possibly a lot of sheet tension. This could easily be a sail that is lovely when new, but isn't 'new' for very long I suspect.

I suspect there are relatively few sailmakers with great experience of designing sails for cutter rigged ketches. most have lots of experience of cutting simple sloop rigs, what works on one AWB will be pretty similar to what works on another. There are known amounts of fullness, twist, draft position, cloth weight etc etc, that are regarded as the norm and you won't be too far wrong with. A lot of good sailmakers will just build a conventional sail close to these norms and won't be wrong. Tens of thousands of previous sails have done the evolution. Years of racing have worked out the compromises.
Maybe Norths will start from first principles and computational fluid dynamics, most just have a program that decides panel shapes given an outline shape and some camber profiles.
The inter-actions of sails in a ketch are a bit of a dark art meeting the lower expectations of cruising folk. A lot of conflicting wish-list requirements. I'm not sure how much design work anyone expects a sailmaker to do, but IMHO it won't be much for a one-off sail for a cruising boat.
Probably best to be very clear what you want and expect, and look for sailmakers who have made a lot of sails as similar as possible?
 
You must log in or register to reply here.

Share this page

Top