If you don’t have the ability to build the largest yacht in the world, why not build the fastest? This is exactly what John Staluppi did when he ordered a 44-meter Octopussy from Heesen Yachts, which developed a record 53 knots (1988). The owner of the flagship project Cosmos, presented at the Monaco Yacht Show 2018, went the same way – one of 13 vessels currently under construction at the Heesen plant in Oss.
We have already written about some of the unique technical innovations underlying this curious project, and now, having visited the keel tab, we will continue the story.
“Today is an important day not only for Heesen Yachts, but for the entire industry,” General Director of the shipyard Arthur Brower said at the ceremony and immediately explained what exactly gives 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 a reputation as almost the only manufacturer of fast yachts with a length of 40-60 m from light alloy. In recent years, the shipyard has been actively developing the niche of custom boats 60-80 m long (Galactica Star, Galactica Super Nova, Falcon project under construction) and, having laid Cosmos, literally ran into the ceiling: the existing docks do not allow the shipyard to build ships longer than 83 m, and bridges on the way to the North Sea also limit their height.
Arthur Brower, CEO of Heesen Yachts, at the keel laying ceremony
Caught in a similar situation, others would sit still and build standard semi custom boats, but Heesen Yachts is not one of those who give up ambition 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 tackle the daunting task of giving the aluminum chassis the strength it needed. Locked in the center of the country behind low bridges, the shipyard cannot simply raise the sides and is forced to invent something new. As a result, a specific kit was developed that absorbs all external energy, while the cladding does not bear a structural load and simply prevents water from entering.
“The longer the boat, the more it is susceptible to bending, especially if its hull is made of light alloy,” says Jos Verbruggen, Design Manager. – On tests of a scale model in the experimental pool, 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 tonnes, which would only weigh the hull if made of steel. “
The thickness of the deck floors on Cosmos will be 6 mm, the side cladding – 10-15 mm, and in areas with increased load, for example, under propulsion engines, sheets with a thickness of 40-50 mm are used. When welding elements of this thickness, special attention must be paid to their preheating, and also to monitor the mass of the sections so that they can be lifted by cranes.
“The hull has to be strong in the first place in areas of high stress concentration, which is usually found in the midship area,” explains Peter van der Zanden, CTO at Heesen Yachts. – When the ship is on the crest of a wave, it bends: the material in the bottom area is compressed, and above, 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 stress loads are transferred to the superstructure. “
Patented Backbone I-Beam Set
Lloyd’s approves all fundamental engineering solutions used in the design of Cosmos
To solve this problem, Heesen Yachts engineers worked with Van Oossanen Naval Architects to patent the Backbone, which is an integrated I-beam that runs along a keel line. It increases the fracture strength of the hull, while longitudinal twisting is not so critical for Cosmos and does not differ from that of a steel vessel.
“The yacht’s hull has FDFH lines and a bow bulb, and unlike Octopussy’s sharp-chin V-hull, it will only have a running trim of about a degree, which affects passenger comfort,” adds Peter van der Zanden. “Octopussy can be compared to Ferrari, where speed and noise are clearly felt, and Cosmos will only be slightly noisier than conventional displacement yachts due to the enormous power.”
In the engine compartment of the vessel there will be four MTU cruising diesels, coupled with shafts and a Rolls-Royce Promas propeller-steering group (two motors per shaft), where variable pitch propellers are located close to the rudders, but are not connected to them, as it might seem. This is necessary in order to increase the efficiency and maneuverability of the boat when driving both under four and under two engines.
This yacht will be the fastest in its class
Yacht interiors were developed by Sinot Design
This is what a beach club will look like
Heesen Yachts has chosen Lloyd’s Register as the supervisory authority because, according to Jos Verbruggen, the latter has much more positive experience with large yachts than ABS, which the shipyard works with on shorter boats. All fundamental engineering issues were resolved even before the signing of the contract, and now, when construction has begun, the lengthening of the pool from 6 to 8.5 m is being discussed with the customer.
“We will continue to build yachts up to 83m here in Oss and have no plans to enter 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 deliver consistently high Dutch quality, which is reflected, among other things, in the residual value of our yachts. In addition, defending our position in the market, we try to offer what other manufacturers do not have: high-speed light boats with innovative hulls and shallow draft. They can enter the shallow bays of the Bahamas, which very few yachts of similar length are capable of. I would very much like to build the Maximus project as well – unusual, standing out from the others, but apparently still too avant-garde. “