RAKU RANGE

High Performance Sailing Catamarans


About Raku


Prologue

Raku is a range of cruising catamarans that began life as a series of concept sketches and renders in October 2008. The concept evolved into Raku 48 designed for Radim Zizka in 2011 and built in the Czech republic. We incrementally progressed the design concept and in 2016 we designed another Raku 48 for Troy Forrest, this time built on the Queensland Sunshine Coast.

It was in late 2019 that we felt confident we had all of the right fundamentals in place to create a range of cruising cats that would lay claim to a space that has been largely overlooked by the bulk of the world's catamaran designers and manufacturers. 

That space was for a range of modern cruising cats that feature light weight, minimal windage, sleek modern styling, good load carrying capacity and excellent sailing dynamics; Features that would inspire long distance voyaging and long term live aboard cruising on the world's oceans and seas. 

It was a space we had already successfully explored with the Chincogan and Lightwave Catamarans, and others before and after. A space that was ready for some fresh styling and some new ideas in construction that would allow greater design flexibility, and in most cases allow the cats to be built efficiently without the cost and infrastructure of a female moulded boat.


Raku Concept Model October 2008

The design work was a process taking the best ideas and technologies from our earlier designs including the two Rakus already built, and on creative thinking that would ensure the new designs would be up to the minute and well prepared for the journey into the future.

In the first half of 2020 we began to roll out the drawings, specifications and renderings for the range of cats we now call Raku 2020 to indicate these are new designs. In the future they will be simply know as Raku.

Raku 2020 is made up of six different models from 32' to 52' LOA, all built on comprehensive detailed electronic models.

 

We're in the process of creating plans, cutting files and design documentation for the Raku series and the process of incremental refinement in Raku design will continue as technologies evolve and as we get feedback from our customers and the professionals we work with.

With Raku we are confident that we have a range of cruising catamarans that will establish a benchmark in design well into the future for those who seek to travel at sea in multihulls.

Want to know more? Read on or email us with your questions. graingerdesigns@gmail.com

Tony Grainger, August 2020


Raku 48 Mint competing at Airlie Beach Race Week 2020. Mint was designed in 2016/17 and built on the Queensland Sunshine Coast. Raku 48 got some tweaks to the styling  in the process of creating the Raku 2020 design range but otherwise the platform is the same.

Why Raku

Raku Construction

Most of the composite surfaces that build Raku are created quickly and efficiently with large CNC panels accurately manufactured to fit the boat and curved in only one plane.

We incorporate moulded surfaces for hull shoes and where they're important to Raku's unique style. Compounded hull forms give us the freedom to use our expertise in hull design to optimise performance and comfort at sea. 

Compounded forms (curved in two planes) in the decks and cabin enhance the style and help to define Raku as boat that has been designed and built with care and attention to detail.

Producing curved surfaces does not have to be complicated, expensive, or time consuming. Compounded shapes are formed by various means including strip planking and moulding panels over temporary forms using CNC panels with just a light laminate on one side of the core that is later reinforced with an additional laminate. 

The panels and hull shoes are all created with PVC cores, fibreglass skins, and epoxy resins. Carbon fibre is used in the rudders, daggerboards, chainplates, forebeam, bow prodder and structural beam caps.



Raku Style

 We travel in search of beauty and our mode of travel should be beautiful too. In design we work with sketching, sculpting and 3D modeling to create elegant designs that express the way we feel about the ocean environment and the freedom we inherent from the power of the wind. The style of Raku is more than a shell that's wrapped around the technologies and spaces that make it a sailing boat. And neither is it a form simply designed to suit a particular build process.

It's a form created in the process of integrating the living and working spaces, the construction methodologies, and the dynamics of an efficient sailing machine, especially the passage of water and wind over the surfaces we create

Raku's lines convey the pride we take in our work as designers, and the pride you take in the design you have chosen to sail.



Raku Performance

There's no experimenting needed in this quarter. Hulls from Grainger Designs have been performing at the pinnacle of design technology on the Australian racing circuit for more than thirty years. Our designs have been the preferred choice of many of Australia's leading racing skippers and their various trophy collections are drawn from the Brisbane to Gladstone Race, the Bay to Bay, Surf to City, Airlie Beach Race Week, Hamilton Island Race Week, Marlay Point Race and various other racing series including the Australian Multihull Championships which have been totally dominated by our designs over the last ten years or so.

 

Good hull designs is a matter of spending the time and effort to optimise the forms that affect performance and sea handling.

A well designed hull will have good pitch resistance, easy penetration of waves, low resistance in a range of conditions, and the right amount of buoyancy to float on its intended lines.

For more on this topic see the article Why Hull Shapes Matter

and this one: What makes Max Fast


Mad Max on her way to winning the series at Airlie Beach Race Week 2016


Raku Engineering

Good engineering is critical to any transport vehicle. For a vehicle that functions at the interface of two very different and highly active fluids the engineering work is an exercise that must produce robust long lasting structures that are light, stiff, and don't cost too much to build.

Engineering is not just material science, it involves the geometry of the platform, determining the loads, and the way the loads are distributed throughout the structure.

 We work with structural considerations and engineering as an integral part of the design process, making use of the best available knowledge to find reliable cost effective solutions in the choice of materials and the engineering details that are critical to the structural integrity and longevity of the craft.

Custom engineering packages are available for light weight optimisation, CE compliance and other certification requirements.


Raku Design Options


Accommodation Layouts

We provide a range of interior layout options, but you're free to create your own so long as changes don't adversely affect the outer form or move the position of bulkheads and other components that are integral to the structure.

The bulkhead between the cockpit and the saloon provides two options. The first we call the "classic" with a fairly conventional opening that provides shelter and a range of options for the galley and settee arrangement. The second we call the "open layout". It features a wide opening between the saloon and cockpit, and it can feature a continuous floor between the two spaces if suitable drainage and reinforcement is provided for the wing deck structure.


Layout Options for Raku 40 and Larger Models

Raku 40 with Classic Layout provides maximum galley space and central bathroom in Stbd hull. Owner's bathroom forward to port.

Open layout with 2.3m opening in the Saloon bulkhead. This layout shows bathrooms forward in each hull and an occasional berth forward to Stbd.



Raku Cockpit Design

Step aboard any Raku and access the cockpit without ducking your head, or even worse, risking an injury.

All Rakus from 40' up feature a walkway at wing deck level at least 450mm wide and a minimum of 1.9m head clearance between the aft helm station and the aft beam.

The cockpit shade roof is self supporting with beams that extend forward into the cabin leaving the cockpit free of support columns,



Raku Helm Options

Standard Raku has twin helm wheels aft in the cockpit. If you like to be up high for better vision you can move the helm up the BH and this gives you the option of just one helm station. And if you like to steer with a tiller that option is available as well.

At right; Tiller and kayak seat helm setup for the Raku 40. A similar arrangement is available for the other Rakus



Dagger Boards or Fin Keels

Dagger boards provide optimum upwind performance and reduced wetted area for downwind performance.

Raku's fin keels are fuss free and well proportioned for good all round performance.

The choice is yours with Raku



Standard Bow Prod or Extended for more Power


Standard Bow Prod is same length as hulls so you don't get lumbered with berthing fees for a longer boat.

You can add a detachable extension to increase sail area and increase the gap between the gennaker and the working headsail.

 

Extended Bow Prod provides added sail area upwind and cleaner flow over the headsails.

It can be made from a one piece beam incorporating the transverse forebeam, or alternatively an extension piece that fits a socket in the end of the main beam.

Extended Bow Prod provides added sail area upwind and cleaner flow over the headsails.

It can be made from a one piece beam incorporating the transverse forebeam, or alternatively an extension piece that fits a socket in the end of the main beam.


CNC Panels for Raku Construction

A number of panel systems are available for Raku construction including the

Duflex kit system available from ATL Composites in Australia and VDL Composites in Germany. These kits are from 1.2m x 2.4m pressed pressed panels which are joined to full length on site using a convenient scarf join built into the panel.

 

 

Full length one piece CNC panels are also currently under development. The panels can be up to 12110mm long to fit  a 40' container (Raku 40 is exactly 12m LOA). For longer hulls we can add a joining piece and make a rebate in the panel for the taping. 

Contact us for availability and pricing.

graingerdesignss@gmail.com




Building Raku

 Depending on your skills, your motivation and your financial resources you can build your own Raku with or without a kit, manage your own Raku project with your own employees and contractors, or commission a professional yard to bring your project to life.

You are welcome to contact us for advice on how to go about the project. Contact us for plans prices, kit prices, and for builders who may be able to price a custom build.

graingerdesigns@gmail.com

 

 

OPTION 1. Build from detailed plans and electronic cutting files sourcing your own materials.

 

OPTION 2. Purchase a kit for panel construction. There are two main options;

(i) A CNC Duflex kit from VDL Composites in Germany if you are based in Europe, or a Duflex Kit from ATL Composites in Australia if you are outside of Europe. The Duflex kits are delivered in a container in 1.2m x 2.4m panels. The panels are joined on site using a scarf join built into the panel edges.

You can see a step by step description of the Duflex build process described on our web site.

(ii) A one piece CNC panel kit which is delivered in panels up to 12m long with no joins required. For longer boats the hull topsides panels can be joined on site and a rebate can be manufactured into the panel for this purpose. More details on these one piece panels coming soon.

 

OPTION 3. Order your Raku from a Professional yard built to composite structure stage to finish yourself, or fully completed ready to sail away. Select your own builder or contact us for builder recommendations.



Raku Builder Support

Every set of plans comes with a Copy of the Guide to Yacht Construction in PDF format

Our goal is to create pathways that simplify the process, and we welcome feedback suggestions from our builders to help us know what kind of experience you are having in the build process.

If something in the plans is not clear or you have a suggestion for improvements in our documentation we encourage you to get on the phone or send an email to let us know.



Raku 48 Mint sailing on the Queensland Sunshine Coast