The formula for mainsheet loading is not as widely accepted as that for genoa sheet loads and should only be used as a rough guide for offshore boats from 30 ft to 60 ft (9 m to 18 m).
Traveler car adjuster load is generally considered to be .2 times car load.
Calculations
| English |
 |
|
| ML |
Mainsheet load in pounds |
|
| E |
Foot length of main in feet |
|
| P |
Luff Length of main in feet |
|
| V |
Wind speed in knots |
|
| X |
Distance from aft end of boom to mainsheet attachment point in feet. |
|
|
| Metric |
 |
|
| ML |
Mainsheet load in kilograms |
|
| E |
Foot length of main in meters |
|
| P |
Luff Length of main in meters |
|
| V |
Wind speed in knots |
|
| X |
Distance from aft end of boom to mainsheet attachment point in meters. |
|
|
| Formulas are for typical cruising monohulls with fixed keel and Dacron sails, sheets, and halyards. Assumes standard roach of 7.5%. For large roach sails such as “flattops” multiply calculated load by the percentage of the mainsail roach. If a sail has 25% roach, multiply the calculated load by 1.25. For all other types, please contact Harken for technical assistance in calculating loads. |
