The 41-metre, full-aluminium Dynamiq GTT 135 Stefania has been launched from the Dynamiq shipyard in Massa, Tuscany. Photo: Dynamiq YachtsSuperYacht Times was invited to tour the yacht shortly before her launch. Sitting in the build shed, the striking exterior design by Dobroserdov Design and dazzling metallic gold paintwork certainly set her apart from most other yachts on the water. Fitting out of the artful interior by Miami-based Giuseppina Arena was in full flow during our visit.
As the latest in the Dynamiq’s series of round-bilge superyachts, in many ways the Dynamiq GTT 135 represents the culmination of the ethos that company founder Sergei Dobroserdov has proposed from the beginning: ocean-going, fast displacement cruisers that are carefully engineered and easy to order or customise.
“Stefania is the evolution of our full-aluminium Gran Turismo Transatlantic concept that began with 39-metre Jetsetter,” says Dobroserdov. “The difference is that the design and engineering has now been developed to the utmost degree.”
Dynamiq has continued its collaboration with Van Oossanen Naval Architects, but this time they were also engaged as project engineers and worked closely with the brand’s other international consultants and suppliers. This has resulted in specific technical solutions to enhance the comfort, liveability and operation of the GTT 135.
Like Jetsetter and the GTT 115, a Fast Displacement Hull Form by van Oossanen provides remarkably low resistance and fuel consumption. The addition of a Hull Vane further improves hull efficiency and motion comfort. A double spray rail and tweaks to the reverse bow shape at entry ensure the foredeck will remain dry. Photo: Dynamiq YachtsVery low noise and vibration levels were a priority for the owner. Dynamiq and Van Oossanen consulted with Intersona, noise and vibration specialists in the Netherlands with over 45 years’ experience in the marine field. Intersona analysed the hull structure and noise-emitting components to achieve the contractual levels.
Intersona recommended Rubber Design, another Dutch company specialised in anti-vibration technology for propeller shaft installations on yachts, and the GTT 135 is fitted with a Torque Compensation System that reduces structure-borne noise by more than 25dB. Consisting of two rubber spring elements supporting the gearbox and two air springs that produce a counterforce to compensate for torque displacements, the TCS control unit works by adjusting the air spring pressures to maintain the engine gearbox in a neutral position and reduce the excitation forces transmitted to the hull structure. Photo: Dynamiq YachtsTo reduce engine exhaust noise, Dynamiq specified 2.8-metre mufflers by UK-based Halyard that provide noise attenuation of more than 40 per cent. Cavitation is another source of noise and vibration and the GTT 135 is equipped with SIP Marine propellers. The Dutch firm uses CFD analysis, proprietary software and VR technology to reduce pressure fluctuations on the hull and shaft for cavitation-free prop designs that still provide optimal thrust and energy consumption.
The design team chose to install curved Vector fins from Side-Power by Sleipner Motor. These generate more vertical net force than flat fins that operate parallel to the angle of the hull’s deadrise, creating an anti-roll force that is more efficient that that of straight fins. Photo: Dynamiq YachtsEven the HVAC system by Termodinamica is more efficient. Using a gas refrigerant instead of chilled water, the air handlers work at a very low temperature to offer better dehumidification, less condensation and power consumption is reduced by at least 50%.
“Yacht builders are like chefs – we use the same machinery or ingredients but in different combinations and proportions,” says Dobroserdov. “Yes, we have some exotic components aboard Stefania like the Torque Compensation System, but more comfort and efficiency gains can be made by refining hull lines, props, rudders, and so on, than by installing the latest space-age technology.” Photo: Dynamiq YachtsThe project also drew on the operational know-how of Captain John Scullard as shipyard captain. Formerly captain of the GTT 115, his input included rerouteing the mast ventilation for the grey and black water tanks to avoid back pressure, improving the position of the mooring gear in the stern for faster and safer operation, and making sure the engine room layout provides easy access for maintenance.
Stefania is equipped with aerosol firefighting equipment that uses non-conductive dry powders in areas where applying normal extinguishing agents, such as water or foam, might cause more damage than the fire itself, especially around electrical systems.
Unusual for a yacht of this size, the GTT 135 has a forward garage so the tender and toys are stored as far away as possible from the guest areas. Unlike a transom garage, it also means the 5.3-metre tender can be deployed at any time, even when docked stent to in port. Photo: Dynamiq Yacht DesignTwin MAN V12 1650 engines provide a maximum speed of 20 knots with an ocean-going range of 3,500 miles at a cruising speed of 12 knots. Her shallow draft of 1.8 metres is ideal for cruising the cays and shoal waters of the Bahamas.
The yacht is built to RINA Commercial Class, Comfort and Green Star Plus certification. Once the fitting out and sea trails are complete, following delivery the yacht will be based in Monaco and available for charter through Arcon Yachts. Photo: Dynamiq Yacht Design“It’s always exciting to see a yacht on the water that was first sketched some years ago,” concludes Dobroserdov. “We’re very happy with how the GTT 135 looks: she’s modern, fresh and elegant with lots of design details and interesting elements. We‘re now looking forward to the sea trials to check how her many technical innovations take performance and comfort to the next level.”