World Superyacht Review

New and innovative solutions for the development of large, fast luxury craft

Gary Grant, Gary Grant Advanced Maritime Systems Limited

Since the advent and proliferation of high-speed ferries, commercial, special purpose vessels and offshore race boats, our understanding and knowledge base for large, high-speed private craft has evolved into the high art/science of yacht design.

Designs made with the new generation of imaging tools can be viewed from any angle.

Much like the acceleration of the digital economy, we now enter the world of virtual design and engineering. Current technologies, human resources material and equipment can now be integrated and orchestrated more efficiently and solutions perfected more rapidly. More often than not, the independent design and engineering firm can compete favorably with large organizations offering in-house services. This unique situation frequently allows for greater flexibility, innovation, ability to network and find solutions quickly and more efficiently.

Form
Designs for ultra high-speed craft must, with few exceptions, be developed around the prime movers, drive systems, ancillary and mechanical systems' requirements. Fuel load also has a significant impact on the required mission profile of the vessel. Since the goal is to achieve trans-Atlantic capability at maximum speed, we opted to go with two prime movers and a faster vessel to avoid the fuel barge. Numerical models of the loaded hull form are tested and optimize for efficiency and prior to physical model testing. Physical model testing is as important as ever in large high-speed craft. There are many excellent facilities available for such work in North America, Europe as well as Russia with their high level of experience with fast surface and surface effect craft.

If we consider that our 86 meter [282 foot] vessel is an indicator of the future for this simple and elegant form, then it is easy to see that aerodynamics play an important roll in the testing phase and that this element of the design should be addressed in detail. After all, we are battling resistance and this is a 70+ knot vessel.

A well-known architect once told me that "to get a large yacht to plane is a matter of luck". There are a few excellent high speed vessel designers in the world today (who I will not name here) and I am sure that they will agree with me when I say that the ability to develop an efficient high speed hull form is not a matter of luck, it is a matter of knowledge.

For this particular design, steps are designed into the deep-V mono hull bottom surface to induce a layer of friction-reducing air. These steps are shaped and placed based on more extensive computer modeling and tank testing to maximize their effectiveness. As steps are fixed features of a vessel's hull shape, they require no special maintenance and add very little to the vessel's construction complexity.

Gary Grant-designed 86m Superyacht detail with two Fino 30-ft classics for scale.

COGOG Power System
By using the combination of primary and secondary gas-turbine engines, the operational factors of vessel speed, duration, range and maneuverability can be fully exploited. Diesel-fueled gas turbines produce an extremely high amount of power for their weight, have a very high reliable factor and require no special starting procedure or warm-up before producing full power. In a COGOG power system two small secondary gas-turbine engines are used for low speeds, extended range and for maneuvering; and two large primary gas-turbines are always at the ready for high speed operation. A proprietary combining gearbox transmits rotational energy from the gas turbines to the vessel's drive shafts. The drive system incorporates controllable pitch hubs which are fitted to surfacing-piercing drive units. A computer system detects torque at the output drive shaft, hydraulically adjusting the pitch angle of the seven (7) forged stainless blades, continuously producing optimum thrust. This drive system, along with the aerodynamic envelope and the elements described above, allows for sustained speeds of 70+ knots.

The geometrically-correct image of the vessel being designed can be set into any context.

Our 86 meter is powered by some of the largest available gas turbine power plants in the known world. It is imperative to address the issues of gear housing size and offset, combustion and cooling air trunks as well as exhaust plenum space from the beginning of the design process. By networking with the engine manufacturer and the design team of the reduction gear manufacturer we were able to develop the combined gas turbine or gas turbine system. All of the components mentioned here are long lead items and therefore will be instrumental in establishing milestones in the construction process.

Speed = Safety & Security
A colleague and engineer in the Netherlands had this thought, "It may be safe to assume that an individual, company or nation that spends over USD 100 million on a vessel values the safety and security of themselves and their guests more than their money." This statement rings true in regards to foul weather avoidance as well as foul play and makes practical sense when it comes to protecting the vessel as well as the occupants in an unfriendly environment. Another positive attribute is the ability to transit from port to port while avoiding running at night. There is also a simple and attractive logic from a recreational point of view when you are spending less time in transit and more time at your desired destination. What is exceptional about the propulsion system on the 86 meter previously mentioned is the ability to run continuously and efficiently at displacement speed without rotating the main engines. However since there is virtually no warm-up time required for the mains, you always have 112,000 shaft horsepower on demand.

Structure
With the vessel envelope somewhat fixed, and the main propulsion and equipment installed in the design, the structure must be optimized. High strength steel, alloy, titanium, fiber-reinforced epoxy and other materials are integrated for the optimum strength and weight advantage. With the ability to analyze the structure both globally or element by element, the design and engineering team can find the best solution for maximizing strength, eliminating harmonics, noise, vibration and ensuring survivability of this complete and self contained luxury life support system in its daily use or in a possible hostile environment. At this juncture, the safety requirements and the space required as outlined by DNV, MCA and other societies are accommodated in the structure of the vessel and interfaced with the general arrangement. The prime focus here is fire and smoke protection, escape and evacuation as well as watertight integrity.

Advanced visulation tools allow the owner and designer to envisage the completed craft.

Advance visualization tools
These tools and this technology are critical not only to refine the new vessel design but absolutely necessary to provide the owner and builder with the information that they require. Here is a list of some of the benefits.

Photo-Realistic imaging before construction

Visualization from any viewpoint

Geometrically-correct: perspective, shadows, reflections, site location

Single image with multiple views

Side by side design comparison

Addition or subtraction of design elements

Unlimited "what if" design possibilities

Create: walk throughs, fly-bys, panoramas, animations suitable for interior, exterior and machinery spaces

Produce client specific sales tools

Reduce time cost transition to production

CNC cut scale model construction

Mock-ups and scale models
Mock-ups and models are useful tool from aero-hydro testing and owner acceptance of interior space planing. The designer can use anthropometric software to assist in the optimization of wheelhouse design. This allows for the placement of the owner, captain or crew at the helm detailing the pilot’s field of vision for optimum eye rotation. It is within this area that all primary operational displays are placed. Grab and safety rail locations and control reach is also addressed. A full size mock-up follows and is made available for acceptance by the owner or owner's representative and reviewed by the trades involved in the construction. The benefits far outweigh the initial cost by reducing change orders and providing clarification to the assembly technicians, master joiners, mechanical systems installers and other interfacing trades. Again, the responsibility lies where it should be, in the hands of the design and engineering team not the shipyard technicians. Scale models of the exterior of the craft can be quickly and accurately fabricated to any size from the same data used to create photo-realistic renderings and made available for customer approval and acceptance.

Fabrication
We saw the precursor to today’s technology a decade or more ago when overhead pin routers were used to cut flat panels for interiors and some framing systems. Today metal parts and frame kits are routinely made using plasma cutting machines and female molds are machined and assembled for fabrication of parts well over 100 feet [30m] in length. These tools are suitable for one to six units and have all the advantages of hard production type molds in terms of accuracy and dimensional control. The advantages to this type of CNC-cut tooling are numerous, some of these are:

Modular and off site construction

Class "A" automotive quality part finish [no inherent waviness]

No added weight from fairing material more stable coating system

Guaranteed fits on compound and single element window installations

Minimal waste and added weight where adhesive and chemical bonds are used

No lofting or layout and reduced production time to name a few

The responsibility for the success of the product from assembly to aesthetics remains that of the designers and engineers. Much of the above technology is now being used to construct our design of the 136 foot [41.4m] x 50-knot MV ADLER. One of a kind vessels can now be constructed to exacting standards accomplished through constant control over sourcing, sub-assembly and fabrication. This high degree of control assures that proper design accuracy is maintained resulting in optimum levels of performance and build quality.

Imaging and design software is enabling the yachtbuilding industry to make real progress in the speed at which they work.

Elegant Solutions
The general arrangement of the interior of an exotic high-speed craft is only a close second to the propulsion and mechanical systems and running close 3rd behind is the exterior envelope. The exciting aspect of this is that every component is strongly influenced by its relationship to some form of functionality. This may seem obvious to some but is even more pronounced if the ultimate goal is make simple and elegant what is complex by nature.

The hallmark of great design solutions seems to be in their simplicity. Although the road to the best solution may vary, it is generally not an expressway. The good news is that this new high speed luxury yacht industry will be more forward thinking and take full advantage of the tools at hand to help it find the best solutions and provide the quality that the customer expects and deserves.

This article was featured in the Millennium Edition of World Superyacht Review 2000 beginning on page 83.

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