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Our proprietary LoadPath process is the culmination of decades of research, product testing, use and development.


The LoadPath sail construction is basically a two-part process. The base sail or skin is constructed using a light and “flex friendly” laminate sail material, assembled with horizontal panels and shaping seams. The assembled skin is then chemically treated then we apply our proprietary carbon fiber structure tapes. The carbon is laid in straight passes radiating out of the corners, passing continuously over all seams to the edges of the sail. This technique is also known as external lamination, a process that allows our sail makers to apply the proper amount of carbon fiber reinforcing to the various high-load areas and directions that are best for the specific design and expected uses of the sail. This method of construction also creates proportional increases of not just carbon fiber, but of the film itself, along edges and into corners. This addresses the number one reason laminate sails age-out, the films degrade long before the fibers. This layering of films is unique to LoadPath products and gives our sails outstanding durability and longevity. We will let the race results speak for the performance and speed.



Load Path Technology is a cutting edge fiber mapping membrane system incorporating a skin or base of flexible but durable laminated sail material combined with bands of load path fibers to follow computer generated load mapping of the given sail.



Load Path Technology addresses sail loading with zero crimp super strong fibers formed in unique angles to support crosscut panel layouts The bands LP fiber are applied after the membrane is shaped and seams bonded, so loads travel; smoothly from panel to panel and don't dead end at seams. With the Load Path fiber bridging each crosscut seam, seams are non load bearing and do not require heavy reinforcement to minimize seam creep.

F 31 Colored LP.jpg


Load Path sails are a durable option for Casual and Grand prix racers as well as Cruising boats of all sizes.

Calvert Sails works closely with Sail Technologies, a sail loft in St. Petersburg, Florida, that has developed an excellent Load Path product. This is offered in three different lines, Performance Load Path, Extreme Load Path and Offshore Load Path.


This construction starts out with cross cut panels using one of the newer laminates that have been designed just for cross cut sails. The sail is assembled using a laminate that is lighter than is needed for a pure cross cut sail, and then the load path yarns are laminated on top of it to provide the strength needed in different areas of the sail. The advantages of this type of sail are that it is lighter than a cross cut sail, has continuous yarns running from corner to corner and corner to edge to fully support the membrane and take care of all seam loading, and is much more cost effective than either a triradial or pure string sail. They are slightly heavier than the pure string sails because of the extra layer of Mylar that the load path yarns are laminated with, but are coming in about the same weight as a triradial sail.

We believe that over the next few years triradial sails will mostly disappear, being replaced by some type of load path sail. Cross cut sails produce beautifully shaped, smooth sails and are much more efficient to build. In a typical triradial sail 25% to 30% of the cloth is discarded because there is so much waste in cutting out all the small, differently shaped triangular panels; in a cross cut sail a little bit is lost because we have to leave enough space between the p anels and the edges for cutting, but they have about 95% efficiency.  On a load path sail for a 30' to 40' boat we are seeing prices that are about 10% to 15% below that of a triradial sail, and 30% to 40% below the pure string sails.

The "Performance" line is constructed starting with base materials of Polyester, Pentex, or Aramid than, continuous, hand laminated yards of Pentex, Spectra, Kevlar or "S" Glass are applied in a load mapping of the sail. This option achieves a very good combination of weight, performance, durability, and price.

The "Extreme" line, represents the grand prix racing approach. These sails begin with base materials of Technora Kevlar, or Spectra, then continuous yards of Carbon Fiber, Spectra, Technora, or Kevlar are laminated to follow computer generated load maps. These sails offer the best combinations of weight, performance, strength, and durability, with prices about 10% less than Carbon triradial cut sails.

A Cat Load Path sail.jpg

"Offshore" Load Path sails are designed and engineered for the offshore cruisers and racers. These sails begin with Spectra cloth with a single side of taffeta. Then continuous fibers of Carbon Fiber, Spectra and Technora are hand laminated to follow loads from the corners, reefs, and along each side.

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