Take a look at these pictures :










In the second picture the section looks more quashed then it is in real life. This probably dependent on my screen resolution. Also I did use a very cheap (mobile phone) digital camera.

When you hold the Superwing section in your hand it feels alot thinner and more pointy in the front.

Sadly I don't have a cut off piece of a teardrop shape mast. But the following spec will give you an idea.

Both the Tiger and AHPC superwing mast are about 150 mm "long"; the superwing is 63 mm at its thickest point across the crossection while the Tiger section is just over 90 mm (= 43 % thicker). This makes quite a difference. So for a given longitudal length the wing mast is significantly thinner. The superwing ration length/thickness = 150/63 = 2.38 while the tiger = 1.67 In some way you can compare this ratio to the aspect ratio of the sails.

In addition to this difference The shape of the crossection is different. The teardrop shape masts has a front halve that closely resembles a circle. The rear part is faired into a curved triangle part leading up to the sail groove.

A wingmast has a front part that is elliptical in shape and this part is nearly 2/3rd of the whole section. The far rear end to faired towards the sail groove.

In he drawings I had difficulty to get it right but with wingmasts the point of maximum thickness is further back then with the teardrop shaped masts. I have held cut-offs of both sections in my hand and then the differences in shape and size is quite dramatic. The teardrop sections look and feel alot more bulky and crude in comparison.

In order to give the mast its minimal required stiffness in the sideways plane, ribs are added to the inside of the mast. These serve two functions, -1- the increase the sideways resistance to bending (which would be significantly less than the teardrop shape mast without the ribs). -2- to support the thin walls and prevent the mast failing under buckling.
a direct result is that the ratio between bending in the two planes can be fully engineered, and the mast section as a whole can have a smaller wallthickness leading to a significant weight reduction on the mast. A fully fitted Aluminium superwing mast weights between 3 to 4 kg (7 to 9 lbs) less then an aluminium Hobie FX-one mast of equal length.

Well known boats that use wingmast sections are : A-cats, Taipan 5.7, Taipan and Blade F16's, Capricorn F18 and the Ventilo or Bim F18HT's. The use of a true wingmast is said to be part of the succes of these designs and their rigs.

The two sections do seem to require a different approach to tuning. The wingmasts are often more flexible in the sideways plane and as such the mast rotation control together with the leech tension set on the mainsail are important. The elliptical shape of the crossection leads to these boat sailing with less mast rotation then a normal teardrop shape masts. The improved aerodynamic behaviour of the wingmast section allows a crew to forget about the proper transition from mast to sail. Sometimes the mast is strongly underrotated with respect to the draft of the mainsail and still the creation of seperation zones on the lee side of the sail (and close the mast) are very limited. It looks really funny but such a trim can actually be quite fast in strong winds. With such an underrotated mast the top section of the mast pumps with each gust, taking the head of the sail with it thus inducing temporary twist. This depowers the rig in the top like nobodies business while maintaining alot of drive low in the sail. When you are looking for power again, just let the rotation out a little more and the top powers up fully.

Sailing with the Superwing mast section is very lively. It feels like the mast section is talking to you. It responds to each trim and tuning adjustment in a clear and predictable way. You also quickly feel the range of depowering and powering-up, and this is quite a large range.

The first sailing with this mast in a heavy blow with strong gusts is something to experience. The top is bending away quite significantly during the gusts when the rotation is set to allow this. If the rotation is not set for it then the tops stayes where it is, you can tweak the bending off wind velocity like that. However the mast section itself is very resistance to abuse. Under a fully powered up spinnaker you initially fear for the mast but soon you learn that the mast can handle huge amounts of bending and abuse. Having said this I'm sure that there is a point where the mast had enough and folds; but I haven't it yet.

I truly think this superwing mast section is a joy to sail and I do my stints on Tigers and sort each year.

Does this answer your question ?

Wouter