Megayachts
55-Knot Superyacht Makes Euro Debut
Earlier this year a technically sophisticated 37m superyacht -- Ermis2 -- was shipped to the Mediterranean. The ground-breaking vessel was entrusted to three leading names in the industry; designers and naval architects Humphreys Yacht Design, builders McMullen & Wing and composite engineers High Modulus. Ermis2's apparently simple design brief of 'safety, seakindliness, speed and comfort' understates the fact that the owner was looking for a superyacht capable of speeds normally reserved for the powerboat racing circuit; the capacity to be driven hard in the kind of weather conditions that see most other owners remaining in port, and yet with all the comfort needed to entertain family and friends. In an owner-driven quest to minimize the weight of the yacht without sacrificing strength and toughness the three parties pursued an aggressive weight audit of all aspects of the vessel. After detailed investigation of the construction options McMullen and Wing were tasked to build the boat in advanced carbon composites, and they rose to the challenge by electing to build a one-off female mould for the hull to allow for efficient vacuum-infusion, a process which is designed to ensure excellent laminate consolidation. A significant amount of analysis, test-panel manufacture and destructive testing was carried out to optimize the structure, and a particularly significant decision was to go with a sandwich bottom shell panel rather than a solid carbon panel -- not only a lighter choice but as it turned out a tougher one as well, giving the boat significantly more resilience.
ERMIS2 Specifications Length, o.a. 37.6 m Beam 6.4 m Draft 1.6 m Displacement (lightship) 107,000 kgs Water Capacity 2,000 liters Fuel Capacity 55,000 liters Engines 3 x MTU16V4000 Gearboxes Twin Disc WaterJets Kamewa Generators Northern Lights Top Speed 55 knots Cruising Speed 35 knots Designer Humphreys Yacht Design Builder McMullen & Wing Engineers High Modulus
Ermis2 is a 55-knot, 37-m Superyacht. (Photo Credit: Chris Lewis)
In their extensive tank testing and R&D work, the Humphreys office felt that the commercial standard vertical acceleration of 1g was not adequate to define this particular vessel and its usage -- with a top speed of 55 knots and a cruising speed of 35 knots -- and through wave-testing analysis they
established a design threshold of 2.2g which Humphreys instructed Germanischer Lloyd to use as their planapproval benchmark. So the term 'light but strong' gained an added, self-imposed poignancy, amplifying the challenge posed to the composite engineers and the builder. Given
this, the achieved lightship displacement of less than 100 tons represents a huge success and the general approach has been spectacularly vindicated in recent trials, with initial speeds in the 55+ knot range being achieved and promise of further increase given more optimiztion time.However, even despite this performance, Ermis2 has proved to be extremely comfortable and surprisingly quiet even at speed and the systems are configured to allow the boat to remain absolutely silent through the night, free of generator hum. Humphreys worked to develop an external style that sat well with the utilitarian aspects of the brief -- with form essentially following function -- and knowing that the boat was capable of exceptionally high speeds was enough without making the inference of speed a flamboyant style statement as well. This understated philosophy was carried through to the interior design, with Jo Humphreys working closely with the owner and his family to come up with a really comfortable, light and bright interior, with carefully crafted white-painted timber paneling emphasizing the natural light and creating an easy backdrop to the more vibrant colours of the fabrics and furnishings Despite some very ambitious intentions Ermis2 has delivered, and the owner's observation on completion of his acceptance trials was a measured, "All our objectives have been exceeded."
Humphreys Yacht Design design@humphreysdesign.com McMullen & Wing Ltd info@mcmullenandwing.com High Modulus info@highmodulus.co.nz
Pershing 115 GT Powered by Turbine
ZF Marine debuted a special reduction gear designed to match Vericor Power System's TF 40 and TF50 marine turbines. The HSMT 410/730 reduction gear is available in reduction ratios ranging from 9.5 to 20:1, designed to meet the demand for larger and faster high-speed yachts. Vericor's aero-derivative engines are designed to run on diesel fuel and can deliver power up to 5,600 shp. Marine Turbines are typically used for booster propulsion on 78-to-165-ft. high-performance luxury yachts. The package weighs 2,800 kg (6,172 lbs.), and is suitable for various waterjet and propeller sizes and types because the available ratio range permits shaft speeds between 800 and 1,700 rpm to be selected. In addition, rotation direction can be defined as well as gearbox output flange arrangement, either under the turbine (C configuration), or on the opposite side (Z configuration). The multiple disc hydraulic clutch is designed to ensure smooth transmission engagement with minimal mechanical stress and a comfortable changeover when boost power is engaged. The gearbox is also equipped with two PTOs for auxiliary services, each with a maximum torque capacity of 650 Nm (480 lb ft) at 2600 rpm with the turbine running at full power. ZF Marine also provides the turbine's electronic controls, complete with a wide range of control levers, or a new joystick control system.
20 Maritime Reporter & Engineering News