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Mirabella V: Stretching the Limits

October 4, 2007

Everything about Mirabella V is BIG.

At 246 feet LOA, she is the largest composite- structured yacht in the world. Her carbon five-spreader rig stands 292 feet high-the tallest mast. Everything about this 740-ton mammoth of the seas is massive-including her charter fee of $250,000 a week.

This megayacht, built by VT Shipbuilding in England at a cost of approximately $50 million, was designed by Ron Holland, but she is very much the brain-child of her American owner, Joseph V. Vittoria, formerly CEO of Avis Rent-A-Car System Inc. He already owns two 40-meter yachts, Mirabella and Mirabella III, and was driven to add to this fleet by the strong desire to develop the ultimate in status symbols. Why did he decide to push existing rig technology to new limits for a cruising yacht, with all the risks that this may encompass? “Very simple, Vittoria replied with a smile. “Someone was going to do it, so why not me? The challenge has been to build the biggest rig in the world.

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Now that she has been launched, Guinness World Records will need an additional page to include all the superlatives about this boat. The hull weighs in at a mere 85 tons and draws a little more than 6 feet, but that is without her 150-ton lifting keel, which gives her a maximum draft of 33 feet. Her structure encloses 80 tons of insulation, six luxurious double cabins for guests and a host of less welcome additions determined by the MCA and other organizations that regulate the construction of large yachts slated for the charter trade. These organizations have re-written their rule books for composite superyachts around this project.

“These rules have diluted many of the weight advantages of building in composite”, said Ron Holland. He pointed to the MCA’s insistence that all doors and frames within the yacht have to be made of steel. “We understand their concerns for a fire on board, but unlike powered yachts of this size with their multiple decks, Mirabella‘s guests and crew have only one floor to climb out on deck.”

“Everything within the boat, including the composite construction, is all made from fire-retardant materials”, Vittoria added. “We think many of these new rules are over-zealous.”

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The practicalities are that if a fire takes hold in the galley, for instance, the heat will not even penetrate to the other side of the bulkheads for an hour at least, and should have been put out long before by the yacht’s pressurized fine-spray sprinkler system. Another safety feature: There are no naked flames for the chef to flambé anything. The giant cooktop on which he prepares meals for 12 guests and 13 crew operates on energy induction, so the elements remain cool to the touch and only transfer heat to special magnetic pans.

This design has really pushed the industry to new levels of sophistication in her rig. Mirabella‘s reacher sets a record as the world’s largest sail-20,450 square feet (the equivalent of almost three tennis courts). Existing sailcloth, including the famed Cuben Fiber, proved too fragile, so Doyle Sailmakers worked with Warwick Mills to develop a special Vectran cloth specifically to meet the challenge. The furling system controlling this sail tips the scales at 3.3 tons, but this is dwarfed by the main headstay furler, which weighs a hefty 5.4 tons. Sheet sizes were another limiting factor to be overcome. No ropes on the market could cope with the loadings on the sails, so Gleistein Ropes developed a buoyant 12-strand 34-millimeter rope to provide a 110-ton safety margin. “That left us having to re-design all the winches and deck blocks to cope with the potential loading, Holland said.

Among the most innovative aspects of this megayacht is her mainsail. Weighing 1.4 tons, it was too heavy to be lifted onto the boat in one piece, so Doyle designed a clever seven-section segmented sail, in which six compression-sprung full-length battens act like curtain rods to link one loop-edged segment with the next. Because of its weight, final assembly had to take place when the sail was bent onto the rig, but should one panel require repair, this can be taken off the yacht with relative ease, leaving the rest of the sail in place.

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And the cost of these sails? “Well, I’ve already told my skipper that delivery trips will be made under power. It will be cheaper to replace Mirabella‘s two engines than to think of buying new sails”, Vittoria jokes.

This project began to form in Vittoria’s mind five years ago, but he says that his wife, Luciana, who manages the family’s charter fleet and strongly influenced Mirabella‘s interior design and styling, vetoed everything he came up with. In the end, Vittoria called Ron Holland, whom he’d first met in 1974 when he bought one of the designer’s race boats. “He came around to our house with four drawings and asked the family to vote on them”, Vittoria said. “My three sons and I voted for the most racy-looking design. My wife and daughter chose the final design with the dark blue line along the coachroof…. I’ve got used to it now.”

The design began as a 60-meter yacht, and simply grew as the project developed. Holland and Vittoria chose VT Shipbuilding (formerly Vosper Thornycroft), because it specializes in very large composite structures. “They build 65-meter minesweepers here so they had the expertise in composite engineering, and they think big”, Vittoria explained.

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Ron Holland’s Vision

Prior to Mirabella‘s launch, we had the opportunity to sit down with her designer, Ron Holland, for a little technical talk, and came away with a deeper understanding of just how groundbreaking this yacht is, and what a design and engineering challenge she had been. Holland said the first design discussions took place in 1999, and it seems that was none too early, for there was a great deal of detailed engineering to do before construction ever started.

Very little on Mirabella is off the shelf, from the top of her mast, whose height prevents her passage through the Panama Canal, to the tips of her twin rudders, designed as a pair to get enough surface area for steering without excessive draft. The main boom is 90 feet long and big enough to allow the sail to drop into it for storage, dimensions which qualify it for superyacht status on its own. The intermediate booms-what Holland calls “mega-battens”-are bigger than many masts.

In order to carry the anticipated 40-ton loads, the running sheets had to be designed for 110 tons breaking strength and still be pliable enough for self-stowing. Once that hurdle was overcome, then the custom winches could be designed, and only then, finally, the deck layout.

Mirabella is the first composite yacht to achieve MCA 500-ton certification, and is the largest composite structure ever to be classed by Det Norske Veritas. Because her parameters exceeded all the published rules, design calculations had to be done from scratch, entirely by “proof of concept,” and approvals gained by negotiation with the regulators.

Finally, there were the many little things not ordinarily in a yacht designer’s brief. As an example, custom watchmaker Arnold & Son is handmaking Mirabella watches, one model for the charterer and a different one for his guests. The design, of course, required input from Holland and his approval of the finished product.

-Dudley Dawson

Initial sailing trials saw Mirabella sailing upwind at 8 knots in 14 knots of apparent wind. “It took a bit of time to get her up to speed, but once in the groove, she sails very easily”, Vittoria reported. Holland predicts that she will reach 20 knots broad reaching in a good breeze, but Mrs. Vittoria, who has a dislike for sailing at any sort of angle, has insisted on a safety system that pays out the sheets automatically whenever the yacht exceeds 20 degrees of heel.

What do you get for $250,000 a week? Apart from the six-star accommodations and a crew who among them speak five languages, the yacht has two swimming pools sunk into the foredeck, one filled with sea water, the other doubling as a freshwater Jacuzzi. Then there is the giant open-air movie theatre on the main deck and an entertainment and barbecue area aft. The stern garage houses a 29-foot Hinckley launch, personal watercraft and diving equipment, but the pièce de résistance is a ride in the three-man crow’s nest that whisks you at elevator speed, 200 feet up the mast.

The toughest task during this three-year project was,”convincing the wife”, Joe Vittoria said emphatically.

How Big is Mirabella V?

Compared to a J-Class yacht, above, the scale of Mirabella V is obvious. Just consider the size of the mast. At 290-feet, and taller with antennas and instruments, she can not fit under the Golden Gate Bridge, which stands 220 feet above the water. A Hudson River cruise is off limits since she will not make it under the Verrazano Narrows bridge either.

The mast is more than half the size of the 555-foot Washington Monument, one of the tallest masonry structures in the world, and would reach to about the 24th floor of the Empire State Building. It supports nearly 40,000 square feet of sail, or nearly an acre. That’s canvas, not grass. From the keel tip to the top of the mast, she measures 328 feet.

Mirabella‘s mast isn’t the only item that will drop jaws. Consider that the keel alone weighs nearly as much as 100 SUVS! And the hull has so much volume that you could drop in several double-decker buses. That’s big.

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