Communicating with your sailmaker
Great sails and service begin and end with good communication. Here's a guide to working together with your North representative to get the results you're after. BY TIM CORBEN
In many ways, communicating with your sailmaker about your sails is similar to telling your garage about a problem with your car. Most sailors know when a sail isn't performing to expectations, but they're not often sure what the problem is or how to describe it. In order to communicate more effectively with your sailmaker, let's review the basics of how a sailmakers describe the shape of a sail.
Talking the talk. Sail shape is generally described in terms of depth (draft), and the position of the depth along the width {chord). For those of you with Fast Stripes on your sail, this is relatively easy to measure.
1. Using a photographic print of the sail, draw a line between the point where the Fast Stripe meets the luff and leech. This is the chord line.
2. Find the deepest point of the sail (maximum depth) and draw another line from this point that intersects the first line at 90°.
3. Measure the length of the chord, then the maximum depth. By dividing the chord length by the depth we come up with a percentage to describe the depth of the sail.
4. Finally, measure the distance back from the luff at which the depth line intersects the chord line. This is the position of maximum depth (X).
This should then be repeated for each fast stripe. If you do not have Fast Stripes, they can be easily fitted or you can use the horizontal seams within your sail as a guide. A sail might then be described as having a depth of 16% at 38% from the luff.
The best camera position for sail shape evaluation is in the mid foot of each sail, with the camera turned so that the fast stripe or seam is running sideways across the widest dimension of the frame. Day to day cameras are not usually waterproof, so we recommend that you use one of the new disposable "instant" cameras with a 28-50mm lens (a wider angle lens than 28mm will cause the shape of the sail to be distorted). Some manufacturers offer panoramic disposables that have an extra wide format. These are especially good for sail shape photos because you can capture the entire sail in one picture.
Digital dialog. At North, we have developed a computer program that not only simplifies the task of measuring chord and depth from photographs, but also measures the sail shape in a much more detailed and accurate form. This allows us to actually compare your sail in its current form to its original design "mold. " The program is named SAILSCAN.
Above
is a snapshot analyzed in the traditional method by drawing on the photo
and measuring camber, chord and draft position.
North's new SAILSCAN system (right)
digitizes the image, analyzes the sail's draft profile, then compares it
to the original computer design file.
Incorrect input: "Our leech is too tight " --- Correct input: We can't point in light air. "
We start by digitally scanning your sail photo and then loading it into a computer. Once the scan is on screen we plot each stripe with a minimum of six points which are automatically faired by the program. The result is a visual and numeric description of not only the maximum depth and its position for each stripe, but also the curvature in the front and back of the sail, plus the relative twist of each stripe compared to the first stripe. Because the program converts the shape to its original numeric design format, we can compare the actual flying shape to the original design shape of the sail.
Try it, you'll like it. How can you use SailScan? For racers, we recommend that you contact your sales rep at least six weeks prior to a major regatta with some current pictures of Your sails. After taking a look at the "numbers" and comparing them to the "ideal" we can advise you whether any tweaking is required.
One of the most common problems that we see is that as a sail ages, the draft moves aft. Many times, a bit more halyard tension or moving a lead is all that's needed. If you take photos at regular intervals you'll be able to track the sail's changing shape. This is very helpful in planning recuts or changing your settings.
When owners have "the slows," its often not only sails that are the culprit. It could be your rig, a slimy hull or your trimming habits. When describing a problem to your sailmaker, try and identify the problem, not the reason. Incorrect input: "Our leech is too tight. " Correct input: " We can't point in light air. " Take notes on your performance in different conditions and points of sail. The more information you provide, the better.
A good relationship with your sailmaker, like any other relationship, requires good communication. At North, we worked hard to improve dialog with our customers. Better dialog means better results. Better results make everybody happy. Tim Corben is a sail designer at North Sails U.K
North's
SAILSCAN program provides a visual and numeric description of 1)
maximum depth and its position for each stripe, 2) curvature in the front
and back of the sail and 3) relative twist for each stripe.
The
program converts the shape to its original numeric design format, so it
can compare the actual flying shape to the original design shape of the
sail.
A new slant on a valuable service
An innovative new program is being pioneered at North Sails East in Milford, CT that will allow loft sales staff to interact with more customers to help them get more out of their sails. It's called the Shape Up Program, and it uses modern technology to enhance the traditional science of sail evaluation. The program operates on two levels:
Level 1 is a complete onboard inventory analysis by a North representative which culminates in:
a. photo documentation
b. North digital SAILSCAN analysis of each sail
c. A sail inventory wind range analysis
d. If necessary, a recut evaluation on present sails
For the Level 2 program, the client is mailed an "instant" camera with detailed instructions for taking photographs of individual sails. The client then returns the camera to the North loft for digital SAILSCAN analysis, inventory analysis and recut evaluation similar Level 1.
Cost for the Level 1 program is $250. Level 2 costs $65, including camera and film processing.