A DEEPEST LOOK INSIDE MY K23 Agosto 2023
A star is born: M/Y Stella di Mare ready to set course
The design of the new Explorer M40 is an example of the Hydro Tec holistic design package including exterior design, engineering and naval architecture all developed in complete harmony.
This new mega yacht was designed for an experienced Owner whose previous yacht was also an Explorer designed entirely by Hydro Tec.
His contribution to this project were extremely valuable and widely implemented in the design of the M40. The owner's contribution, however, was not only aesthetic, but also addressed the practicality of use and the behaviour of the yacht, having foreseen, already in the initial phase of the project, spending long periods of time on board.
One of the main points was that Stella di Mare should be a real “Explorer”.
From a technical point of view, Stella di Mare has all the characteristics of the successful Explorer lines designed by Hydro Tec.
The steel hull, optimised with CFD methods and tank tests in order to reduce fuel consumption as much as possible, is characterised by a round hull, a generous bulbous bow and flat and raised stern sections.
The hull form were designed trough an iterative optimization process where results from hydrodynamic optimization carried out using CFD analysis were continuously compared with trim and stability checks and with the design of the propulsion system to keep the correct propeller diameter and shaft inclination. Once the final hull was defined, using the CFD we found the optimal shape and arrangement for the appendices such as engine exhaust scoops, V brackets, fin stabilizers and rudders.
The final hull was finally tank tested at MARIN Research Institute to confirm the data collected during the optimization phase.
The sea trials confirmed the good behavior of the hull in terms of seakeeping, maneuverability, andin terms of performances. At the trials, the yacht reached a top speed of 15 knots using the two engines Caterpillar C32 746 kW@1600-1800 rpm and registered a fuel consumption of 79 lt/hr that allowed for an operative range over 7000 nm.
The forward sections, above the waterline, of Stella di Mare are wide and flared, making them very classic, from an aesthetic point of view, but also very effective in keeping the deck dry and the superstructures sheltered from splashes in windy conditions and rough seas.
The relationship between beam and immersion has been brought to an optimal value and the stern sections have been shaped so as to allow the adoption of high diameter propellers to achieve optimal performance values.
In line with the initial request for a “real” ship, the ease of the crew to carry out the various operations for navigation and maintenance, even with the yacht underway, was also taken into consideration during the design phase.
For this purpose, the double bottom of the hull, in addition to the various tanks, houses a gallery that runs under the deck, allowing the crew a protected passage between the bow area, which houses the crew cabins, and the engine room and the lazarette.
Furthermore, this tunnel is crossed by all the main lines of the on-board systems, which are, therefore, always easy to inspect, as well as allowing the installation of visual levels and the various manholes for inspection.
The part of the double bottom in correspondence with the crew area provides ample space for refrigerators, freezers and a galley.
In addition, the yacht has 8,000 litres of fresh water and a total fuel capacity of 75,000 litres, which translates into a range of over 7,000 nautical miles and transatlantic capacity easily.
The yacht is also equipped with a large lazarette aft of the engine room which houses the various water games, a professional work bench and tools for any minor repairs that may be necessary during long journeys.
Electricity generation is provided by three Caterpillar C4.4 generating sets of 86 kW each, arranged in parallel, with a combined power of 252 kW.
The yacht is designed with an arrangement of three closed decks plus a huge sundeck, sheltered by a large hardtop topped by a “crow’s nest” with 360° views, designed to be an excellent observation point during exploration.
The large flybridge offers space for self-supporting sun beds, a covered space for a gym, alfresco dining with barbecues and refrigerators and a complete command post which is a rather rare feature for a yacht of this size.
The lower deck offers a comfortable space for four suites and for the crew area, with three double cabins, laundry room and a real dining space. On the main deck you will find the large living room, with dining room, the galley, the main hall and the owner’s suite, with a large space for the bathroom and dressing.
The upper deck offers space for the family/TV room, the hall on the upper deck, the captain’s spacious cabin and the large wheelhouse, with sofa and office space
The outdoor spaces are very large, according to the owner’s wishes, suitable for sailing in the Mediterranean.
The stern area of the main deck is very spacious and can be sheltered with sliding panels hidden in the fashion plates.
The stern area of the upper deck is also very large and protected by the overhang of the flybridge and the transparent protective panels on the sides.
The forward area of the wheelhouse, in addition to the large sunbathing area that hides the tender and its crane for handling, also offers a pleasant lounge area for guests or crew.
The forward and aft directional propellers are hydraulic, and the stern propeller is inserted in the large skeg in the stern skeg for optimal performance. The manoeuvrability of the yacht is optimal also thanks to the adoption of an independent rudder system that can be oriented so as to produce an adequate transverse thrust.
The air conditioning system offers full control of the climatic conditions inside the yacht, including the possibility of using a thermoelectric unit powered by diesel for extremely cold climatic conditions.
Stella di Mare is a true ocean-going yacht, ready to face all conditions and explore the entire globe.
The hull form designed to match the above requests was a round bilge hull with bulbous bow, concave sections aft and full central body. The hull form were designed trough an iterative optimization process where results from hydrodynamic optimization carried out using CFD analysis were continuously compared with trim and stability checks and with the design of the propulsion system to keep the correct propeller diameter and shaft inclination. Once the final hull was defined, using the CFD we found the optimal shape and arrangement for the appendices such as engine exhaust scoops, V brackets, fin stabilizers and rudders.
The final hull was finally tank tested at MARIN Research Institute to confirm the data collected during the optimization phase. The sea trials confirmed the good behavior of the hull in terms of seakeeping, maneuverability andin terms of performances. At the trials, the yacht reached a top speed of 15 knots using the two engines Caterpillar C32 746 kW@1600-1800 rpm and registered a fuel consumption of 79 lt/hr that allowed for an operative range over 7000 nm.
• Huge fuel capacity of 75.000 lts, uncommon for yachts of this size, to make the planning of the cruises flexible;
• Adequate flared bow to not only for aesthetic purposes, but specially for helping to keep the deck dry in rough seas;
• Aft sections designed to allow for high diameter/high efficiency propellers and for suitable clearance to keep noise and vibrations level very low even during the cruising;
• Wide interior volume for accommodations and storage;
• Easy access to machinery and technical spaces for easy maintenance;