A quiet revolution in high-speed marine passenger transport is taking place in a small shipyard in Tasmania, Australia’s southernmost state. Who could fail to be impressed by the thought of a 120m catamaran carrying more than 1250 passengers and 460 cars at more than 50 knots!
Tasmania and Hobart in particular have a long and proud tradition of shipbuilding. The skills of those pioneering shipbuilders live on in a modern Hobart shipyard today, where revolutionary shipbuilder Incat builds the world’s fastest passenger ships. The kind of ship Incat builds is a Wave Piercing Catamaran (WPC). Incat developed the WPC concept and each increment in length sees even further refinement in vessel design. Incat WPCs are in active service in Australia, Europe and North America and are either in service or have been represented on all the world’s major passenger routes.
The latest generation of high speed WPCs in production in Hobart Tasmania is the Revolution 120. This ship represents the absolute latest in high speed ship design and manufacture. Beautifully constructed and finished, the Revolution 120 sets as high a standard in passenger comfort as it does in design and engineering excellence. Incat Shipbuilding Technology
Incat has a simple equation for success… light + powerful = fast. That’s easy enough to write down but slightly more difficult to turn into reality. Incat pushes the limits of shipbuilding in theory and practice. The entire ship is built completely of fabricated aluminium, welded and glued together. Its twin-hulled catamaran configuration is designed to pierce waves rather than ride up and over. A large center hull stops nose-diving in heavy seas. Because the vessel is very light, even when fully loaded, the submerged hulls can be long and slender, thus reducing drag and aiding speed and efficiency.
Power is provided by four Ruston or Caterpillar 20 cylinder marine diesel engines in the Evolution 10 class, and gas turbines in the Revolution 120 class. Power is delivered by LIPS waterjets configured for steering and reverse operation. These waterjets can throw out 18 tonnes of water every second and produce the characteristic “rooster tail” behind the ship when it is under way.
Using “unconventional” design and construction technologies in a vessel of this size and capacity carries with it a new set of engineering problems and equally “unconventional” solutions. Problems that would traditionally be matched by using bigger, heavier components must be solved with smart, lightweight designs. If there is any thing that encapsulates the Incat philosophy it is the “can-do” attitude, that is evident at every level throughout the company.
Mark Dewey, Incat shipyard liaison manager and John Ryan, VP Sales CADKEY, in the main construction shed at the Incat yard. The vessel under construction is a Revolution 120 class WPC Mark Dewey, Incat shipyard liaison manager and John Ryan, VP Sales CADKEY, in the main construction shed at the Incat yard. The vessel under construction is a Revolution 120 class WPC.
There’s more than 450 tonnes of high-strength marine grade aluminium alloy in each WPC providing the optimum strength to weight ratio. This metal is sourced in structural sections and plate from specialist suppliers in The Netherlands and Switzerland. Materials are plasma-cut using software proprietary to the cutting equipment on site. Nesting plans are generated automatically at first and then tweaked manually to extract a useable part from every stock piece of material. To get the maximum efficiency from a cutting run sometimes means including parts that won’t be need until the next vessel, but the eagle eyes of the cut planners will fit in a part where ever the opportunity arises to reduce waste.
Ride comfort is a top consideration in the design of the Incat WPC. Through a detailed analysis of sea states, routes and operating envelopes, Incat in conjunction with Maritime Dynamics, Inc have developed a fully integrated ride control system. This system incorporates aft trim tabs and an active fold-down forward T-foil.
Aluminium Fabrication and Welding
Incat is a world leader in aluminium fabrication and welding technologies. Aluminium is a notoriously difficult metal to work with. The structural components of marine craft take a very heavy battering from the sea and it is vital that every aspect of the construction is perfect. There is no point using the best materials and the best design if the workmanship in putting it altogether is not up to the task. The majority of jointing and welding is carried out manually and demands a very high level of skill and care from the people whose job it is to put the pieces together.
Inside view of aluminium superstructure in an Incat catamaran under construction. A view of the inside of an Incat WPC that few will ever see, shows the complexity and extent of construction detailing required in the ship’s superstructure.
Incat has developed a close relationship with Hobart Institute of Technical and Further Education (TAFE). The results of this collaboration are training courses where employees receive off site theoretical studies and part of their practical training experience on site. This enables workers to develop the highest level of technical skill in aluminium fabrication and welding skills with training modules directly matched to Incat construction needs. The purpose-built TAFE College of Aluminium Training has been constructed adjacent to the yard for even greater convenience.
Incat Design Office Technology
Designing high-tech ships requires high tech design tools. Of particular importance is that the design tools allow designers the freedom to work in the mode most appropriate to the part or assembly being designed. CADKEY’s abilities in this area are exceptional, allowing designers to work in wireframe, surfaces or solid modeling mode at will. The Incat design office uses CADKEY exclusively to design and document ship designs. There are 30 designers in the office and all are equipped with CADKEY.
CADKEY was first introduced at Incat when designers moved to CAD several years ago. At the time the decision was made, CADKEY was selected on the basis of its total 3D approach; its ability to work with wireframe, surfaces and solid models; its built-in aptitude for mechanical design and manufacturing and the ease of use for designers. At the time, there was nothing else available under a million dollars that matched CADKEY feature for feature and the economy of choosing the perfectly capable CADKEY did not require a second thought. Even today, now that there are some very capable 3D design tools around, it is not possible to match CADKEY’s capabilities for under A$40,000 per seat. CADKEY can be deployed for much, much less than this.
As the Incat design team pushes design ideas to the limit with their ships they also push their software tools to limit as well. To say that members of the Incat design team are all CADKEY enthusiasts is an understatement. The team also comprises a significant number of power users who often test the capabilities of CADKEY. A few also regularly participate in CADKEY’s online technical discussion forums and provide the CADKEY development team with significant constructive feedback for further enhancements.
Additional stand-alone software tools are used for specialist engineering analysis and presentation purposes. All CAD work is done on Pcs. Paper output is generated through a Xerox large format printer that runs virtually continuously providing drawings for the fabrication shop and fitters. Manufacturing Community
No business operates in isolation. Building a world-beating ship requires a significant contribution from world-beating suppliers. A significant manufacturing community has grown up around Prince of Wales Bay primarily to service and supply Incat with materials and components. Each supplier makes an important contribution to Incat. Most also operate a thriving independent high-tech engineering business fostered by association with Incat and a shared commitment to manufacturing specialized products for the world market.
Local manufacturer Skeels & Perkins machines T-foil components for US company Maritime Dynamics, Inc. These T-foils are also used in Incat ride control systems. Tasmanian marine products manufacturer Skeels & Perkins machines T-foil components for the US designer. These T-foils are also used in Incat ride control systems.
Several suppliers of engineered components to Incat have adopted CADKEY as their main design software. Initially the strength was to simplifying the transfer of information between companies. While ease of data exchange is still a convenient factor in using CADKEY, it is more of a side-benefit now. CADKEY users quickly discover that it is a powerful and flexible design tool that is perfectly suited to manufacturing applications. It is easy to operate and does not break the bank to get set up and maintain.
The future holds even more exciting developments for Incat. The design team will face even greater responsibility soon when it begins supporting three construction yards building Incat WPCs. And if that does not sound challenging enough, consider that two of these yards will be supported remotely, being in different countries on a different side of the globe. Gone are the days of designers and detailers nipping down into the yard to check a dimension or measure a bracket.
It is vital that Incat is able to manage multiple simultaneous ship construction projects by remote control. Every aspect of the structure is designed and analyzed with the goal of reducing weight and the design process also proceeds on a parallel track, revising and refining throughout construction. This is no mean feat when you consider that every member, every joint, every bracket, even every weld is fully documented and referenced in drawings models and supporting documentation relating to each ship. This process calls for powerful and efficient software tool and document management strategies. The success of the entire business depends on designers having tools that are accurate and reliable. They must have tools through which they can confidently create first class designs and communicate ideas to the people and machines that will turn their vision into reality.
CADKEY is cornerstone software tool in Incat’s current design and documentation system and will play an even more critical role in systems to be used in the future.