Super Yacht Prepares To Set Sail

JSYD's Adastra is a striking 42.5-m trimaran that is capable of traveling 4,000 miles while cruising at 17 knots.

Adrasta

Adastra is a culmination of more than five years of design to build a yacht that provides a level of comfort and style that would be expected in a yacht of this class and size.

Based in West Sussex, off the south coast of England, John Shuttleworth Yacht Designs (JSYD) specializes in the production of stock plans and custom designs of sail, power, and sail-assisted power catamarans and trimarans -- both for racing and cruising. A trimaran is a multi-hulled boat that consists of a main hull and two smaller outrigger hulls. In a typical trimaran, the outrigger hulls are attached to the main hull with lateral struts.

Company owner and chief designer John Shuttleworth has a worldwide reputation for designing fast, strong, and safe boats. With a background in engineering and computer-aided design, he first developed his new approach to yacht design in the 1980s, which resulted in boats that were lighter, stiffer, and stronger than any previous multi-hull designs.

Today, Shuttleworth is using structural design technology and his fast, aerodynamic hull shapes to design both power and sailing multi-hulls, and develop sail-assisted power boats that are capable of significant fuel savings and increased range.

Described by the boating press as "one of the world's most amazing super yachts that could spell the future for efficient long-range cruising," JSYD's Adastra is a striking 42.5-m trimaran that is capable of traveling 4,000 miles while cruising at 17 knots.

Adastra is a culmination of more than five years of design to build a yacht that provides a level of comfort and style that would be expected in a yacht of this class and size. JSYD worked directly with its Hong Kong-based clients to discuss the features required to meet the needs of such experienced seafarers.

The challenge of turning the concept into a reality has led JSYD to conduct years of testing, research, and analysis. In the first year of research and development, the company performed extensive tank testing and radio-controlled model tests. For example, the staff filmed a two-meter model on waves to analyze Adastra's stability and performance at sea.

"Adastra is the first luxury super yacht trimaran in the world," says Orion Shuttleworth, lead designer on the Adastra Project. "She takes the power trimaran concept further than ever attempted before. Previous trimarans, like the Earthrace [broke the global circumnavigation record in 2008 by two weeks] and Cable and Wireless [first to circumnavigate the globe by motor-powered vessel in less than 80 days, in 1998], were stripped-out, record-breaking machines, only. The challenge of turning this concept into a viable luxury yacht has led us to further research and develop new thinking on stability and comfort at sea for this type of craft."

Combined with the extensive tank testing and model tests, the outrigger height has been optimized for ease of motion at sea and JSYD developed and a new outrigger shape to increase stability in waves. The crew performed state-of-the-art structural analysis of all the major components in the yacht in order to achieve the light weight required for low fuel consumption.

Structurally Unique

If the tank is barren, Adastra weighs 49 tons, but with 15,000 liters of fuel the weight reaches 64.8 tons. For the occasional long ocean passage, the yacht can hold up to 32,000 liters of fuel and reach a total weight of 77 tons. According to Shuttleworth, virtually every aspect of the boat is custom built to help reduce weight. With a top speed of nearly 26 miles per hour (22.5 knots), Adastra only reaches its maximum range of 4,000 miles when cruising at 17 knots, and will churn through 120 liters of fuel per hour along the way.

Among the many challenges the super yacht posed along the way, one of the most menacing for JSYD involved the windows. Inge Strompf-Jepsen of Hong Kong-based Jepsens Design is credited with Adastra's luxurious interior design, but Shuttleworth first had to engineer the structure to be able to include such accoutrements as the panoramic windows in the saloon.

The superstructure and interior structural parts are designed using a carbon fiber with a Nomex honeycomb core. The hull is created from a combination of glass and Kevlar -- essentially a glass/Kevlar foam sandwich -- and the interior consists of lightweight oak cabinetry using honeycomb panels. JSYD carried out extensive impact testing on the hull laminate to ensure the design is robust while maintaining the required light weight.

"The whole boat is unique, structurally," says Orion. "It is the most challenging and complex structure that John [Shuttleworth] has been involving in engineering in over 30 years of multi-hull design."

As far is cost is concerned, Adastra is a bit too unique for Orion to quote a price point. Anyone who is seriously interested should contact JSYD.

Anchors Away

The anchoring system consists of three anchors individually driven by carbon fiber drum winches run by hydraulics. The primary anchor is a custom 130-kg Bruce-style anchor that deploys out of the starboard wing. "Bruce-style" refers to the claw-shaped anchors designed by Peter Bruce in the 1970s. Claw-type anchors set quickly in most sea beds and have the reputation of not breaking out with tide or wind changes. Instead, they slowly turn in the bottom to align with the force.

The second anchor, which weighs 80 kg, deploys out of the bow with a carbon fiber arm, and the third anchor, which is used as a stern anchor, weighs 60 kg and deploys out of the port wing.

Operating System

Adastra has a helm station with a conventional steering wheel, but it can be controlled from a lower navigation station situated in the saloon. The captain also has the ability to control the vessel remotely via an Apple iPod or iPad using Palladium's SiMON2 software.

SiMON is the single-point resource McConaghy Boats chose for the integrated ship's operational data. The software collects and organizes real-time information, non-stop, from sensors monitoring the ship's critical systems -- alerting crew members to potential problems before they become a crisis. The ship's monitoring system watches the security systems, pump sensors, and the electrical systems -- among others. The vessel also includes a fully-automated fuel management system that includes a method for cleaning the fuel.

Well-organized displays show the current state of engines and generators, navigation instruments, tanks, pumps, hydraulics, air conditioning, electrical systems, hatches, bilge pumps, and alarms, as well as fire alarms.

According to CCS Services of VA, an authorized representative for SiMON Integrated Ship Systems, a glance at the screen allows the captain to see if an engine is running too hot, if a pressure is too high or low, or if a pump has been cycling too often for the level of a tank.

Under the Hood

Adastra's main propulsion comes from a Caterpillar C18, which can generate 1,136 Bhp (1 boiler horsepower unit is equal to a boiler thermal output of 33,475 BTU/h (9.811 kW) at 2,300 rpm in the central hull. The yacht also has two Yanmar 110 Bhp engines in the outriggers that are used for running the two main generators. The Yanmar engines are used for maneuvering and as a safety backup in case of a main engine failure.

Full Integration of the Design Process

The design process for all of JSYD's yachts starts with hand sketches, Photoshop renderings and a very basic GA and profile created in AutoCAD to roughly define the theme of the vessel. Maxsurf Pro and Hydromax Pro, specific naval architecture and structural engineering CAD software packages by Formation Design Systems (FormSys) are then used by Shuttleworth to model a preliminary hull shape. Maxsurf Pro offers specialized tools for modeling high quality fair hulls using trimmed NURB surfaces and also includes parametric transformation, on-the-fly hydrostatics, and curvature evaluation.

Once designs have been modeled using Maxsurf, their stability and strength characteristics can be assessed using the Hydromax analysis module. Hydromax provides a range of analysis capabilities to handle stability and strength calculations. Precise calculations are performed directly from the trimmed Maxsurf NURB surface model without the need for offsets or batch file preparation.

The model is then imported into AutoCAD, which is used to further develop the general arrangement and profile drawings.

The 2D plans and profile, as well as the 3D hull, are then imported into Siemens NX 7.5 PLM software where JSYD develops a preliminary 3D model.

Majenta PLM was contracted by JSYD to provide NX 7.5 because, from a design angle, it offers greater design control, speed, productivity, and throughput, with a set of flexible shape creation, manipulation, and analysis tools for design and styling, according to Orion.

Luxion's KeyShot rendering software was then used to create photo-real images of Adastra and help JSYD further refine the styling.

At this stage Richard Oliver of ASTA Ltd carried out a preliminary Finite Element Analysis (FEA) of the structure. The FEA model was put together and meshed in Femap, laminates added to the various zones, constraints and loads applied. This file was then exported to Nei Nastran to do all the number crunching. The resultant file was then brought back into Femap for the post-processing, viewing of results and creating images.

Once a well-developed concept was defined, Shuttleworth conducted a full weight study using Microsoft Excel. The process enabled JSYD to estimate the vessel's center of gravity and then return to Maxsurf to make adjustments to the hull.

"We make the necessary adjustments to ensure that the boat will float as intended," adds Orion. "We then analyze the stability and hydrostatics using Hydromax." Once the final hull is defined, it is re-imported into NX 7.5 to create a fully detailed deck and hull model suitable for CNC tool manufacturing.

Another FEA study was carried out on the final design to insure every aspect of the vessel is structurally sound.

The completed model was imported back into KeyShot for the final presentation renderings and AutoCAD was used to create the final plans that McConaghy Yachts uses to build the vessel.

As Adastra nears completion at McConaghy in Zhuhai, China, the nautical world continues to wait in anticipation in order to see the super yacht set sail.

In the future, Orion Shuttleworth predicts a push towards more efficient eco-yachts. "We are already working with researchers on alternative propulsion systems, which include hybrid solar systems and kite power," he adds. "Our engineering knowledge and methods of analysis are under constant development, which will result in lighter more efficient hull and deck structures."

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