SANDY GOODALL Sail Design Consulting

RBS / Relax Bureau Service

As a new service, sail designers can now benefit from aero and structural analysis using Peter Heppel's widely acclaimed "Relax2" software. Relax2 is a much enhanced development of the early original DOS based "Relax" software. Until now, America's Cup syndicates have been the most frequent users of this newer, more sophisticated version. Now individual sailmakers can have access to this important tool on a "pay as you play" basis. No need to purchase the software or learn how to use it. Submit your proposed sail designs for analysis.

Sail designers often find themselves wishing they had the answers to questions like these:

1) What would the loads be on the corners of this sail, under these conditions?

2) What would stress and strain maps look like, for this sail, built and trimmed this way, in these conditions?

3) How does that stress map change with changes to pressure, trim, materials etc.?

4) What materials should be used for this sail, in these conditions?

5) What panel layout should be used for this sail, with these materials, in these conditions?

6) What fiber layout, fiber type, denier, film thickness should be used to build a "string" sail for this boat, and these conditions?

7) What will the flying shape be for this sail, under these conditions / this trim?

8) How does the flying shape relate to the designed shape?

9) What shape would be best for this sail / boat / conditions?

10) How well do these two upwind sails work together, and what could be done to improve things?

11) How much lift / drag is developed by this sail or sail combination under these conditions?

12) How much sail area can this boat bear under these conditions?

13) How should that sail area best be distributed?

14) Will this sail, built this way, and used in these conditions, set well?

15) Will it wrinkle? Where?

16) Will it break? Where?

17) What patch sizes, shapes and materials should be used on this sail under these conditions?

18) What batten lengths / stiffness should be used for this main / jib?

19) How can a sail be built with the same shape as the one in this picture?

20) How will this sail look in less / more wind?

21) How will this boat balance with these sails?

22) How should this sail / these sails be trimmed in these conditions?

23) Can I have some high res. colour pictures / graphs etc. that I can show my clients?

The standard results package for the basic analysis service comprises (for each sailing point):

1) Schedule of rigging loads and corner forces.

2) Schedule of depths, camber positions, entry angles, etc.

3) Average stress and strain values.

4) A 3D model of the flying shape.

5) Up-shot (sail seen from below).

6) Leech shot (sail seen from directly aft).

7) High resolution image coloured as magnitude of upper principle stress.

8) High resolution image coloured as magnitude of upper principle strain.

9) High resolution vector plot showing the principle stress directions.

10) High resolution vector plot showing the principle strain directions.

11) Written report with comments on the sail's structural behavior.

Other more detailed levels of analysis and information are available.

For details, contact:


SANDY GOODALL Sail Design Consulting