Mr Smith's Amazing Sailboats

The Sailloons
(Section 5 of 6)

The Sailloon Concept
Somewhat in parallel to the work already described, Bernard Smith also worked on a new concept, one that took a quite different approach to achieving high sailing speeds.   By reviewing the previous sections, it will be apparent that Bernard was developing craft that had a large sail area fitted to a craft of minimal weight and hence minimal wetted-surface area.  The rationale for this comes from the engineering needs for high speed sailing performance, which encourages large sail-area/wetted-area ratios. 

In an idealized world, the ratios between the airfoils and hydrofoils would be 800:1, that of air and water.  Bernard's design made use of aerostatic lift, from buoyant gas-filled envelopes, in order for the craft to approach this 800:1 ratio.  The generic design was dubbed the Sailloon - a fusion of the words "sail" and "balloon".

The image above shows a large-scale Sailloon design that comes close to the ideal of what could be achieved with this approach.  (A 100-ton craft would need a 300ft tall envelope.) One great advantage of the Sailloon concept is that the airfoil / hydrofoil ratios would stay the same, as they aren't greatly affected by wind speeds, so the craft's efficiency at converting wind-speed into boat-speed should remain at a high value.  Due to the apparent mass of this craft, it couldn't tack like a sailboat; rather it would operate in the same manner as a proa.  All steering would be done through  the two foils.    One drawback is that, as with a normal ballasted monohull, it would heel in a crosswind, a 25kt crosswind producing a 30° list. 

In 1969, the same year in which the RC Aerohydrofoil was tested, Bernard made a 9-ft  working model of the Sailloon.  The craft looked very similar to the RC Aerohydrofoil, with the exception of the multi-celled, transparent   gas-filled wing used as the sail.  At such a small scale however, the envelope did little to affect the craft's displacement.  The craft did perform as anticipated, but the envelope's cost and gas leakages discouraged further work in this direction.    

The Flipping Sailloon
This design overcomes the listing behavior inherent in the Sailloon.  As the title suggests, it's a combination of the Fliptacker and Sailloon concepts.  It is the only one of Bernard's designs in which hydrofoils are laid out, not to lift a boat out of the water, but to keep it in there! 

The picture above will readily indicate how the craft works.  Imagine the Flipping Sailloon motionless at anchor.  The airfoil and hydrofoils are equally efficient and are arranged to directly oppose each other. The lift of the inflated sail will, as in the original Sailloon concept, be just enough to keep the hydrofoils immersed in the water.   With everything correctly adjusted, when underway, the lift vectors of the sail and the foils would oppose each other exactly, allowing the sail/foil ratios to stay the same, with no adverse affects coming from the wind. With the Fliptacker layout, no heeling would occur. Such a machine would be fast and stable -the sail and foil vectors combine to create nothing but thrust!! 

Not all is perfect however.  It may be a difficult machine to control, ensuring the trim on the sail and the foils is just right and that the static lift of the sail won't prove to be too effective on a hot day!  For all that, flipping the rig over on this imaginary machine may be easier than with the real-life fliptackers thanks to being able to shift gas and ballast about on the craft.