Raceboard Design 2

Raceboard Design 2 The “Skiffboard” – Conceptual Design

Last year I wrote an article on LBWS regarding Raceboard design. It outlined some design principles that I believe could improve Raceboard performance. Since writing that article, I’ve fleshed out a conceptual design and attempted to gain industry support to bring a new Raceboard concept to market. I’d like to share with LBWS my preliminary conceptual design and the feedback I’ve received from industry.

DESIGN
The overarching design objective is to the build a faster Raceboard: a ‘round-the-buoys’ sailboard conforming to the Raceboard class rules for use in 0 to 25+ knots. It would be used in a wide variety of conditions, typical of sailboat racing venues such as Sydney Harbour, and would need to be able to handle moderate-sized waves, and areas of light wind. It is an all-conditions racing board.
The overall design concept borrows heavily from the 18foot skiff designs (the pre-cursor of the Olympic Class 49er) of the early 1990s, hence the name “Skiffboard”. It has a long, sharp bow with a vertical stem and a wide, flat planning area at the stern. The design merges the bow of a displacement hull (such as the Starboard Serenity or Div 2) with the stern of a planning hull (such as a modern wide-ish slalom board).
>It would be 3.8m long, the maximum permitted length for the Raceboard class, and of a width equivalent to modern Raceboards. The diagram below shows a rough sketch of the concept:

This design as pictured above is preliminary and conceptual – it obviously requires significant refinement. However, I believe that this design concept (if refined) would provide superior all-round performance to any raceboard currently available. This superior performance would be driven by the reduction1 of the “hump” in the drag-speed curve¹, as discussed in my previous article on raceboard design.

POTENTIAL PERFORMANCE

In light winds, I believe that its performance would be significantly better than existing Raceboards because of its lower form drag (due to the fine bow) – its performance should be closer to a pure displacement hull than a modern Raceboard. In moderate winds, I believe that the wave-piercing abilities of its bow would continue its out- performance of existing Raceboards – in addition, it should outperform displacement hulls because it would plane earlier.

In strong winds, I believe that its performance would be comparable to the current crop of Raceboards. It would outperform displacement hulls in strong winds because it could plane on its tail like a slalom board.

However, handling may be challenging in stronger winds. I believe it may have a propensity to nose-dive while sailing downwind in chop. This can occur with high performance designs such as skiffs and catamarans. However, I believe that handling techniques may be developed to compensate and its potential all-wind performance would be worth this compromise.

Areas where this board maybe more difficult to handle is in manoeuvring/turning (particularly tacking and bearing away). The long displacement-profile bow may be difficult to ‘push’ laterally through the water. However, I don’t believe this would be any more difficult than the Div 2 boards of the 1980s and, again, handling techniques could be developed to adjust.

DESIGN CONTEXT

All of the above comments about performance are hypotheses, but based on first- principles hydrodynamics and from my experience in developing, racing and observing Moths, 18 foot skiffs and other high performance sailboats. This design concept is unproven² – it needs further refinement, particularly regarding the alignment of the shape to the key ‘numbers’ (rig & hull forces, weights, volumes, mast and centreboard locations etc), and then development / testing of prototypes.

I am not aware of any other truly comparable boards at the moment, although some designs have touched on this concept. This design concept varies significantly from a Div 2 board (displacement hull) because of the wide, flat planning area at the stern. It also varies significantly from the hybrid boards that were designed as potential Olympic boards because of its 3.8m length.

INDUSTRY SUPPORT

I am not approaching this as a commercial venture: I simply want to sail faster Raceboards and see the Raceboard class develop. To this end, I have contacted several of the leading sailboard manufacturers to try to make this design a reality. I have shared my design concept with them. In addition, I have even offered to co- ordinate further design / development and construction / testing of prototypes (effectively outsourcing their R&D for this board), while allowing them to retain commercialisation rights.

The feedback from the manufacturers has been positive regarding the design concept. However, they have not been interested in developing this board with me, generally stating that the Raceboard / lightwind market is too small and is considered a niche. This response is disappointing but understandable: they are operating a commercial enterprise.

While the big manufacturers may not find it attractive to invest in Raceboards, such investment might suit a niche or boutique sailboard manufacturer. I’m interested to talk to such parties and I would offer to co-ordinate further development if they’re interested.

Alternatively, perhaps an individual will take these design concepts, and build and race a board competitively. Unfortunately, the Raceboard class production rule discourages such innovation.

The Author

Richard Reatti (AKA ‘yagon’) is an avid sailor of Raceboards at Dobroyd Aquatic Club in Sydney, Australia. His sailing background includes extensive racing of skiff Moths and 18 foot skiffs, achieving top 5 placings in their respective world championships and he was the world junior champion in the Moth class. He is also an engineer specialising in fluid dynamics.

Richard can be contacted at: richard @ reatti.com.au

⁽¹⁾ I expect that eliminating the hump in the curve will not be possible for a craft as small as a sailboard, but I believe that this design will reduce the hump significantly.
⁽²⁾ Unproven in sailboards, however, this design concept has been proven in dinghies such as: Moths, 18 Foot Skiffs, 49ers, 29ers and others.

Kona 380 Elite

This pure raceboard is an evolution of the Exocet Warp X380, a proven concept and top contender in the Raceboard class.

The “blueprints” inherited from the prominent Warp X380 was key when developing this exiting concept. All the positive characteristics of the previous design have been preserved and the conclusion is outstanding.

The Warp X380 was a board with astonishing speed and stability upwind, – yet we have succeeded in adding to the performance by moving all the appendices (fins and dagger ) further back. As a consequence the footstrap and mast track positions have been moved as well – giving the board a free feeling and blistering up wind speed. Although working well, the step tail was eliminated in the process – which admittedly makes the board better suited for today’s upwind -downwind courses.

With the fin positioned far back into a standard set up we also managed to decrease the size – adding speed both up and downwind. The Kona 380 E rides high and effortless through chops in rough conditions.

The volume has been increased by 15 litres and the VE has been altered to coincide with this innovative concept. A complete new package, delivering uncompromised speed and pointing abilities, being produced in a new high tech construction and delivered with a top of the line racing daggerboard.

We hope you will enjoy the board as much as we enjoyed developing it.

This press release was taken from kona-windsurfing.com

Specs;
Volume 310 litres
Length; 380 cm
Width; 65 cm
Weight; 13 Kg
Fin size and box; 40 cm Tuttle box
Mast track; Adjustable
Sail size; 6.5 to 9.5

Raceboard Design

A recent thread in the forum prompted me to think about the future of raceboard design and articulate my emerging opinion on this topic.

Raceboard Designs

The IMCO was originally designed for a minimum wind strength of 15 knots (ie not really in displacement mode).  It was the best course-racing, high-wind (planning) design at the time of its creation (pre the wide tail revolution).  Even today in high winds (>20 knots), it is a very competitive design compared to the modern high volume raceboards.  The IMCO “works” in light winds, but it was never really designed for such conditions.

The IMCO offers great one-design course racing across the wind range, but its original mandate (>15 knots) and its dated design limits its application for heavyweights and delays the onset of planning.  A great board, but it needed to be replaced as the Olympic board, especially in today’s media / spectacle driven world, which gravitates towards fast planning action.

When Formula boards evolved, they offered spectacular planning racing (albeit a different type of racing to traditional IMCO/Raceboard racing) in relatively low winds (>8 knots), although they are not all-wind, real-world racing boards.  It was not surprising that the Olympics wanted to get a piece of this exciting action, although they needed a board for all conditions.  In the end they adopted the RSX, which is (in my view) a formula board with a centreboard.

The RSX’ attempt to bridge the gap between planning and displacement was skewed to the planning end of the spectrum to the massive compromise of displacement sailing.  The current proposed next Olympic designs are for even larger formula boards that can plane in ~6 knots, but these are still not all-wind real-world boards because they are pigs in displacement mode.

Displacement-focused designs, such as the Lechner and Serenity, offer outstanding performance in light winds.  However, they too are not all-wind real-world boards and do not offer the spectacular high wind performance of a planning design.

Raceboard designs after the IMCO (eg Pan-Am, Phantom) did not have the 15 knot minimum wind strength, and thus had high volume rails and tail, making them better all-wind boards and better suited to heavyweight sailors.  However, they are variations of the IMCO concept and have not yet (in my view) adopted some of the design insights of the wide-tail revolution of the past 10 years.  At the moment, I believe that they are the best available compromise between displacement and planning sailing.

The Dream Raceboard

The approach I’d like to see for future raceboard designs and future Olympic designs is to start with a true all-wind course racing board, then improve its planning abilities in lower wind strengths through wider tails and bigger rails.  In addition, I’d like to see a design that minimises the force required for transition from displacement mode to planning mode, following the lead of efficient skiff designs such as the 49er.

Reviewing some first principles of hull dynamics helps to understand the compromise that board designers face.  The illustrative diagrams below (adapted from “Higher Performance sailing” by Frank Bethwaite – highly recommended reading) show the relationship between board speed and drag for several different hull designs.

Some observations:

• The drag of displacement hulls is initially low, but rapidly increases with speed – at high speed, they are relatively slow and difficult to control

• The is a significant “hump” to the speed-drag curve for most raceboards – this reflects the effort required to move from displacement to planning mode (”getting onto the plane”)

• The 49er hull does not have this “hump” – there is no discontinuity between displacement and planning modes

The dream would be to have a “humpless” raceboard hull design like an 18 foot skiff or 49er.  The image below clearly shows the hull design of the 49er, incorporating a fine displacement-like bow and a broad flat planning stern.  This is the hull design that allows the remarkable “humpless” performance.

Given the light weight, small size and universal joint of a raceboard, a skiff-like design with a “humpless” drag curve may not be possible.  However, I believe that it is in this direction that future raceboard development should focus.

Prompting Progress

It appears difficult for manufacturers to justify investment into the raceboard class because the market is relatively small (albeit a fast growing segment).  In many ways, the raceboard community has recently been relying on competition between Star-Board and Mistral to progress raceboard design, but with the Equipe 3’s future in doubt, there may not be any incentive for Star-Board to invest in new designs.  However, the recent success of the Pan-Am at the world championships (beating the Phantom) may prompt further development.

Although the raceboard class is a development class, its rules are relatively restrictive and prohibit further development.  In particular, I believe that the thickness limit (which I understand was introduced to prevent the use of displacement hulls) and the production board registration requirements limit further development of the class.  The size restrictions on centreboards, fins and sails can also be considered to be deterrents to development.

As an ex-sailor of Moths and 18 Foot Skiffs, I appreciate the progressive environment created by few rules.  We used to joke that in 18s that there were (basically) 3 rules: maximum hull length was 18′; the race starts at 2pm; and the first across the line wins.  Moth rules were similarly simple.  It is no wonder that these classes led the most stunning developments in sailing design: apparent wind sailing; and foiling.

Although such free-wheeling rules prompt development, they come with a penalty: potentially higher cost and fewer participants.  The raceboard class can hardly afford to turn away participants.  However, Moths and 49ers (an 18 derivative) are now two of the fastest growing sailboat classes in the world – catering for the high performance segment of recreational sailing.

For Discussion

I don’t have the answers, but I’m interested in creating a discussion around the following questions:

• In what direction should raceboard design evolve, particularly in regard to the compromise between displacement and planning sailing?

• What should be the future of the Olympic sailboard class?

• What design direction would be in the best interest of the class?

• Should the raceboard class rules be changed to prompt further progress the class?

Share your thoughts.

The Author

Richard Reatti (AKA ‘yagon’) is an avid sailor of Raceboards at Dobroyd Aquatic Club in Sydney, Australia.  His sailing background includes extensive racing of skiff Moths and 18 foot skiffs, achieving top 5 places in their respective world championships and he was the world junior champion in the Moth class.  He is also a civil engineer specialising in fluid dynamics.

2009 Raceboard Worlds Wrap

Press Release
The record entry of 114 surfers from 15 nations in the Raceboard World Championship 2009 sailed 12 races during the Championship. “This is the biggest fleet in a World Championship of the Raceboard Class, we have seen for more than 20 years”, Murat Tueten from the German Windsurfing Association, who organised the event, raved.

It was a tight finish before the world title in the Raceboard class was decided on Saturday June 11, 2009. Maksimilian Wojcik could defeat the German challenger Moritz Martin in a tight finish. Martin became second, followed by the Slovakian Patrik Pollack. “In these very changing conditions only all-rounder like Martin or me could win the series and I am very happy about the title in the end”, said the 25 year old surfer from Poland. “I was very nervous before the last races started and the pressure was enormous. It is my biggest success so far to win the championship after a world title in the youth class at the age of 16. I love the atmosphere in the Raceboard class, it is pure amateur sport and very different to the Olympic RS:X class in which I train as well”, raved the polish surfer, who started for the first time during the Warnemuende Week. The beaten competitor from Germany was happy about his vice title in the end as well: “I could win the last race, which was good for my motivation and my goal was to be among the top three, so it is a great success for me. I had some spin outs on Saturday due to fin problems, which have cost me some deciding points, as it was really tight”, Martin said. Patrik Pollack from Slovakia won Bronze. Gabi Schlotmann from Germany won the women’s title clear ahead in front of Martina Hruba and Jana Slivova, both from Czechoslovakia.

Results Men
Results Women

Photo album 1
Photo album 2

Event Website

Competitor equipment list

Minimum board weights – are they too low?

Those of you that have read my other Journal entries on LBWS know that I am an avid raceboard sailor.  Over the years I have had many different boards some more successful than others.  In recent times I have owned the last F2 lightning and Mistral Pan am that came out of the Cobra Factory in Thailand as well as the recent Starboard Phantom also from the Cobra factory.

Generally speaking all of these boards have been great boards in their own right.  They have pointed and railed well, been quick and a pleasure to sail.  However, they also share a common and similar construction that delivers a board to a set weight.  That is as light as possible.

“Great” I hear you saying, “light is king”, it makes boards faster.  Yes this is true, but at what cost?  More on this later…….

Like most raceboard sailors I sail at a local sailing club and race against other Raceboards, Windsurfer One Designs and dinghy classes such as Lasers.   Those of you that know Windsurfer One Designs (WOD) no that if you have an incident on the water, such as a port and starboard challenge, that the raceboard will come of second best to the WOD.  This board is a solid construction that is very durable.  Yes I know, it weighs more.  Equally, running into a Laser will not do your raceboard any good and little to no damage to the Laser.

I am sure that you can see where I am heading with this one.  Modern Raceboards are fantastically light but very fragile.  The manufactures have traded long term durability for weight savings.   This is great if you are going to get a new raceboard each year.  But if like most of us you do not have that much cash you provably would expect to get at least 5 years out of your new raceboard.

Some of the old Raceboards in the fleet that I sail in are late 80’s and early 90’s models.  These boards have lasted well beyond 5 years and are still going strong.  Interestingly they are not that much heavier if at all.  I suspect that when these boards where made more reinforcing (carbon) was used.  This of course has a price.

So, I see a situation where we have pushed the manufactures to make boards as light as possible and as cheap as possible.  Surely this is a recipe for a 1 year life span boards that are fragile but quick.  Is this what the majority of us want?  Perhaps I have oversimplifies the situation here?

I do not blame the manufactures for this situation.  I am sure that you have seen in our sport this never ending diatribe of drivel about board weights.  Check out the starboard forum for many examples.  I recall when the RSX first came out there was a huge outcry that it was too heavy and that people could not lift it off their car.  Really, what a load of shit.    Yes the board may weight more than your slalom board…but its not a slalom board and is built for a different purpose.

I presume that the bulk of longboard sailors out there, weather they be raceboard or other will agree with me on this one?  So how do we rectify this situation?  Firstly as the people who use these boards we need to tell the manufactuers that we want our boards to last longer and that we are happy for the boards to weigh a little more.  So this universally affects everyone we could raise the minimum board weight in the Raceboard Class rules.  Yes, I said rise the minimum weight.  Perhaps a little controversial but maybe the boards will last longer.

Boards that last longer will ensure that there is a greater supply of second hand boards on the market.  This is essential for our sport as a “entry platform” for new sailors who are not ready to make the financial commitment associated with buying a new board.

Perhaps another solution is for manufactures to make two models of their new boards.  So for example you could get the “Standard” Phantom and the “Race” Phantom.  The Standard has more carbon and reinforcing and will consequently last longer.  The race Phantom is stripped back, weighs less and will consequently not last as long?  The Standard may weigh a little more, but in the scheme of things that weight is irrelevant for most of us weekend warriors.   One less beer and meat pie before the race would also achieve a weight saving, but I am not willing to give that up.

So what do the rest of you think on this topic?  Please let us know…

09 Phantoms hit Aussie shores

At last the 09 replacement Phantoms have arrived in Australia.  In accordance with the warranty instructions my friend and I took our 08 model Phantoms to our local Starboard retailer to pick up our new boards.  With much excitement we swapped over centreboards, foot straps and mast tracks from the old board to the new.

Ok so I have not used the new board yet but it looks good.  I really appreciated the new shape and lines that appear to be more subtle than the previous.  In particular, I liked the ridges on the deck that travel for a good portion of the length.  While these were perhaps a weight saving and strengthening feature I think that they will be great for light wind railing as a foot hold.

On first inspection the reduced rocker appears interesting as does the increased vee that runs through the board.  It is quite pronounced particularly when you compare it to the original phantom. No doubt this will be advantageous for railing and reducing wetted surface area up wind?

Starboard claims a completing new construction method for this years board….

The new 2009 Phantom Race 380 is built deck and bottom in full PVC sandwich and unidirectional 80g carbon. Flat-weaved and unidirectional, the UD80 carbon iber is the most eficient iber ever used in the construction of a windsurf board, weighing a mere 80g per square meter and providing extremely high stiffness. A new oversized side-plate holds the 78cm daggerboard, spreading the load evenly and ensuring total reliability, durability and functionality.

I hope that all of this means that the boards will be more robust and last for many seasons as Raceboard sailors generally tend to keep their boards for many years.  All of the old Equips out there is evidence of this.

While it is winter in Australia at the moment my local club has a winter race this weekend.  So I will get some better photos of the board in action and give you my feedback.  I would love to hear from others who may have used the new board.  What do you think?

Starboard’s website is www.star-board.com

UK Raceboard Class launched

The successes of our Olympic sailors has inspired many new windsurfers to take up windsurf racing. ‘Raceboard’ is already an official class with very simple kit rules based on length, width and production registration. Quite simply the board is a performance longboard – a true racing class. One that is not inhibited by wind strength or location. It is also provides the fairest racing when considering a sailors size/weight or age. At National level the class has been a little dormant primarily due to board manufacturers being focused on the development on ‘planing’ boards’ (like Formula) and the media spotlight being on RSX (the Olympic Class). These racing divisions now have their niches – the Raceboard class has the opportunity and desire to once again thrive and become the biggest National and International windsurfing racing class. [Read more]

Australian Longboard Festival

The Australia Day Weekend, 23rd-26th January, will see the inaugural Longboard Windsurfing Festival happening on the East Coast of Australia.  This event includes the Raceboard Oceanic Championships, which will be held at Illawarra Yacht club and the National Windsurfer One Design Championships which will be held at Port Stephens Sailing and Aquatic Club.   On the East Coast of Australia seabreezes prevail from the North East consistently and a cool Southerly change usually once a week in the month of January. It’s a fairly safe bet that we will see a daily average of 12-15knots at both locations, however this summer the ‘Black’ Nor-easter (25-30 knots) has reared it’s head on a number of occasions which could make things interesting. Both of these events will cater for all levels from elite to beginners and will be a heap of fun. If your local, make sure you grab your longboard and get down for a sail and join in the fun. If you can’t make it, enjoy an online experience through LBWS.com.au, showcasing results, photos & video. Further information on the Festival and the two locations can be also found at LBWS.com.au.

[Read more]

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