Fractional Rig - History

History

Throughout the 20th century, most sloops of less than 20 feet in length have had fractional rigs.

Many (perhaps most) sailing sloops from the first part of the 20th century were fractional rigged. The increased prevalence of fractional rigs on sloops in the early 20th century probably coincided roughly with the disappearance of the gaff rig. One possibility for its increased prevalence during this era is that, relative to a masthead rig, it allows the designer to provide the boat with more sail area without using a bowsprit or a boom that extends beyond the stern, and without demanding that the sails be of a very high aspect ratio. This was important because the sailcloth available in those days made it made it difficult to construct high-aspect sails.

As sailcloth improved in the second half of the 20th century, it became possible to construct sails of a higher aspect ratio. It therefore became more practical for sloops to be designed with the simpler masthead-rigged mast. Most production sailboats from the '60s and '70s were masthead-rigged sloops. Masthead-rigged sloops typically carry a larger spinnaker than fractional-rigged sloops, and therefore enjoy a speed advantage when racing downwind.

Fractional rigged sloops are starting to become popular again, especially for high-performance racing boats. A fractional rig allows the mast to bend more easily, which in turn allows more adjustment to the shape of the mainsail, especially when sailing upwind. Many people believe that a fractional-rigged sloop is faster upwind than a similar masthead-rigged sloop, especially as the wind strength increases. Most of the newest generation of fractional-rigged sloops fly their spinnakers from the top of the mast. These boats are said to have "masthead spinnakers", and this development gives the boat very good performance both upwind and downwind in all wind strengths.