If you do not have the opportunity to build the largest yacht in the world, why not build the fastest one? This is exactly what John Staluppi did in his time, ordering a 44-meter-long Octopussy for Heesen Yachts, which developed a record 53 knots (1988). The owner of the Cosmos flagship project, presented at the Monaco Yacht Show 2018, is one of the 13 ships currently under construction at the Heesen factory in the city of Oss.
We have already written about some of the unique technical innovations underlying this interesting project, and now, having visited the keel tab, we’ll continue the story.
“Today is an important day not only for Heesen Yachts, but also for the entire industry,” said the general director of the shipyard, Arthur Brower, at the solemn ceremony and immediately explained what exactly gave him the right to make such a loud statement. The fact is that with a length of 80.7 m the vessel will be able to develop at least 30 knots and will become the largest and fastest aluminum motor yacht in history in its class. Heesen Yachts went to this step by step, over the years creating the reputation of almost the only manufacturer of high-speed light-alloy yachts 40–60 meters long. In recent years, the shipyard has been actively developing the niche of custom boats 60–80 m long (Galactica Star yachts, Galactica Super Nova, the Falcon project under construction), and laying Cosmos, literally rested against the ceiling: the existing docks do not allow the shipyard to build ships longer than 83 m, bridges on the way to the North Sea also limit their height.
The interior of the yacht was developed by the studio Sinot Design
Once in a similar situation, others would sit straight and build typical semi custom boats, but Heesen Yachts are not among those who give up ambitions under the influence of pessimistic critics: she sets a goal, goes her own way and achieves what she wants. In the case of Cosmos, engineers had to solve a very difficult task of giving the aluminum body the necessary strength. Being locked in the center of the country for low bridges, the shipyard can not just raise the side and forced to invent something new. As a result, a specific set was developed, which assumes all external energy, whereas the skin does not carry a constructive load and simply prevents water from entering.
“The longer the ship, the more susceptible it is to bending, especially if its hull is made of light alloy,” says the design department manager Jos Verbrügggen. “On tests of the scale model in the test basin, we were able to evaluate the forces acting on the hull and then calculate the shape and strength of the structure. As a result, the total weight of the hull and superstructure will be 325 tons – only the hull would weigh so much if made from steel. ”
The thickness of deck ceilings on Cosmos will be 6 mm, side plating – 10–15 mm, and in areas with increased load, for example, under the main engines, sheets 40–50 mm thick are used. During the welding of elements of this thickness, special attention should be paid to their pre-heating, as well as to monitor the mass of the sections so that they can be lifted by the taps.
“The hull must be durable in the first place in areas with high concentration of stresses, which, as a rule, fall in the area of the mid-section,” explains Peter van der Zanden, technical director of Heesen Yachts. – When the ship is on the crest of a wave, it bends: the material in the bottom area is compressed, and at the top, in the superstructure, on the contrary, it stretches. In the pit between the waves, everything is exactly the opposite, and if the hull is not rigid enough, then the stress loads are transferred to the superstructure. ”
To solve this problem, engineers, Heesen Yachts, together with the design office Van Oossanen Naval Architects patented the Backbone design, which is an I-beam integrated into the set, passing along the keel line. It increases the strength of the hull for fracture, while the longitudinal twisting for Cosmos is not so critical and does not differ from that of a steel vessel.
Arthur Brower, CEO of Heesen Yachts, at the keel laying ceremony
This is the patented Backbone set with an I-beam “spine”
“The hull of the yacht has FDFH contours and a nasal bulb, and, unlike the sharp V-shaped hull Octopussy, its running trim will be only about a degree, which affects the comfort of passengers,” adds Peter van der Zanden. “Octopussy can be compared to Ferrari, where speed and noise are clearly felt, and Cosmos will be only slightly noisier than conventional displacement yachts due to the enormous power”.
In the engine compartment of the vessel there will be four propulsion MTU diesel engines associated with the shafts and the Rolls-Royce Promas propeller and steering group (two motors per shaft), where the variable-pitch propellers are located close to the handlebars, but not connected with them, as it may seem. It is necessary in order to increase the efficiency and maneuverability of the boat when driving under both four and under two engines.
Lloyd’s has endorsed all the fundamental engineering solutions used in the design of Cosmos
Heesen Yachts chose the Lloyd's Register as supervisory authority, since, according to Jos Verbruggen, the latter has much more positive experience with large yachts than with ABS, with which the shipyard works on shorter boats. All fundamental engineering issues were resolved before the contract was signed, and now, when construction is started, the customer is discussing the extension of the basin from 6 to 8.5 m.
“We will continue to build yachts up to 83 meters long here in Oss and do not plan to go into the 90+ m segment,” says Arthur Brower. – If we talk about the segment of aluminum vessels with a length of 50–70 m, then we dominate in it and issue a consistently high Dutch quality, which is also reflected in the residual value of our yachts. In addition, in order to protect our positions in the market, we try to offer something that other manufacturers do not have: high-speed light boats with innovative hulls and low draft. They can go into the shallow bays of the Bahamas, which very few yachts of similar length are capable of. I would also like to build the Maximus project – an unusual one that stands out against the background of others, but apparently still too avant-garde. ”
Text Anton Cherkasov-Nisman Photo by Dick Holtis, Heesen Yachts