Inside Mirabella V - the largest sloop in the world

  • Mon, 10 Nov 2003

There are 497 billionaires in the world and I need just 20 of them,"...

There are 497 billionaires in the world and I need just 20 of them," pleaded Joe Vittoria, the man building Mirabella V, the world's largest sloop which by the end of 2003 will be available for charter at US$250,000 a week. He is already eagerly seeking clients.

While most observers still find it difficult to take in the scale of the 246ft 8in long, 300ft high Mirabella V, now well advanced at VT Shipbuilding in Woolston, Southampton, Vittoria's clear underlying message is that she's first and foremost a business.
He wasn't too worried about the relative paucity of billionaires - as a fallback, he said there were 10,000 people in the world worth US$500million and with just 20 weeks' charter to fill each year he was confident of hitting targets.
Joe Vittoria, who also owns the 140ft Farr-designed Mirabella and Mirabella III, which he has been chartering successfully for several years, has done his homework and is entirely confident that blunted western economies are unlikely to deflect his potential client base. The scale of their wealth puts them above the stock market melee.
So he reckons the signs for really big yacht charter are looking good, especially as sail can now match motor yachts for speed and efficiency. That's what Mirabella V is all about. Above all, Vittoria, who made his fortune selling car rental giant Avis, appears to be relishing the experience. With a glint in his eye and the grin of a boy with a big new toy, he showed off the huge yacht with infectious enthusiasm.

Tallest rig will impress
'If you've got it, flaunt it' is society's message these days so that should ensure that Mirabella will sell well. "She might look long as she sits off the south of France at the Cannes Film Festival but it will be the size of that mast that will impress most," predicted Vittoria.

It's certainly a big one; the biggest, in fact. It's 291ft 11ft (89m) and from truck to the bottom of her keel Mirabella would 'stand' twice as high as Nelson's column (see Yachting World, April 2002). It's more than 50 per cent taller than any other mast ever built and the carbon fibre technology needed to keep it up required six months of testing at the National Physics Laboratory in west London before structural engineers High Modulus and VT's Composite Technology Centre had the nerve to start building it.

The research and development needed for this mast has been as innovative as it has been impressive. Like the yacht as a whole, the brief has been for a failsafe result. That 1.5m chord section might look spindly but it's clearly designed with a big failsafe margin. Nonetheless, hearts will undoubtedly be in mouths when the spar is lifted onto a barge at VT-owned Halmatic in Porchester, floated down to Portsmouth Naval Dockyard and, somehow, threaded like a splinter through the eye of a needle into Mirabella's bowels as she lies deep in a drained dry dock.

245ft of fun

Although only a small proportion of the interior was complete when we visited Woolston, Mirabella Yachts were keen to display a detailed cutaway drawing of what the finished yacht would look like to whet prospective charterers' appetites.
The fascinating illustration (left) shows some of the features, including the 29ft custom-built Hinckley tender with a 400hp engine stowed in what the VT boys have dubbed 'Joe's garage'. It sits neatly between the two rudderposts and is hauled up a mini slipway on a cradle.

Having a substantial tender is essential because Mirabella will be unable to moor to a dock in most harbours. "If I've learned one thing it's that you have to move your guests quickly but, most importantly, comfortably without wrecking the hairdos," said Joe. The Hinckley is flanked by no fewer than four Laser dinghies and a couple of small RIBs.

"You know, people think chartering is about anchoring, lying around in the sun and drinking a lot. It's not," claimed Vittoria. "A lot of these guys - and there are plenty around 35 - want to sail and the idea is when they stop they have the Lasers for racing - we can set up a race course for them." He's even got two 1.5m miniature radio-controlled Mirabella Vs in the 'garage' for less strenuous competition.

"Although they're banned almost everywhere in the world, we have jet skis - we have to have jet skis - kayaks, skis, scuba gear, dive compressors, four windsurfers, a banana boat . . ."

The drawing also shows two recesses in the foredeck just abaft the innermost furler, stowages for two tenders while the yacht is underway. One is a 21ft safety boat that has to have an orange cover for Maritime and Coastguard Agency (MCA) regulations; the other is a crew tender. But when the yacht is lying at anchor and the boats are launched, the recesses are each filled with 10 tons of fresh water. One becomes a vast, very deep jacuzzi, the other a wade pool. "They're deeper than we thought - we reckon one of the crew will have to be a trained lifeguard when clients use the pools," says Vittoria.

Two cinemas, equipped with wireless headsets for the audience, a three-man crow's nest which will whisk people 150ft up the forward face of the mast (don't forget that's only halfway), sauna, gym and sophisticated entertainment system for the seven guest cabins, add up to a very big yacht full of fun. Satellite phones and Internet are available in all cabins.

Charter options
The two traditional theatres of charter, the Caribbean and Mediterranean, will be favoured. "People want Cannes, St Tropez, Elba, the Costa Smeralda - maybe if we could get two charters we could move round to Croatia - that's a great coastline," said Joe Vittoria. But even now he sees the downtime for the delivery trip being a problem.
Jacqui Beadon, who used to head up Camper & Nicholsons' Charter Management Division, has been given the marketing and central booking responsibilities for the new yacht along with Mirabella and Mirabella III.

But there is still a long way to go. There have been slight hold-ups at VT because of the failure of one of the main interior fit out sub-contractors - Nicholson Interiors went into liquidation - and there have been inevitable alterations. But the aim is to start sailing trials in September 2003.

A visit to Greenwich was, we understand, being toyed with, but as the air draught of the Queen Elizabeth II Bridge at Dartford is just 54.1m at mean high water springs it's out of the question with the mast up - Tilbury is about the closest they'll get. From there the plan is to head for the Caribbean and the Antigua Charter Show in early December.

Redefining 'big'
In the meantime, VT continue to face up to the task of what composites consultant Damian Byrne referred to a 'redefining big'. Mirabella V is due down the ways of her building shed in May. It will be a traditional launch down greased runways and, as one of the last vessels to leave VT's Woolston site before they up sticks and move the entire production to the Royal Naval Dockyard at Portsmouth and their Porchester site, it will undoubtedly be an emotional moment.

As we walked directly beneath the vast 130-ton fibre-reinforced plastic structure with much of its MDF mould now removed, a remarkably fair hull could be inspected. The timber rails down which Mirabella will slide with just 80mm clearance between her portside and the building shed doors - don't worry, there are 250mm to spare on the other side - are already being built and there is already a sense of expectancy as the New Year approaches.

Wandering underneath the 75m (245ft) yacht revealed another of her startling features. There's a 6.09m (20ft) long hole where the lifting keel will locate. Designer Ron Holland publicly pleaded with VT project manager Mike Carter not to refer to the 150 tonne keel as a 'drop' keel. But drop or lower it will, to extend Mirabella V's draught from a manageable 3.9m (12ft 10in) to 10m (33ft). In the up position it will draw the same as the existing Mirabellas so V will be able to follow in their wake - literally - despite being 100ft longer.

The lift keel is the most complex piece of the engineering jigsaw. VT, High Modulus, project manager Paul Johnson and Ron Holland have had to work out how to marry the enormous steel keel box, extending from the bilge to the deckhead, to the 70mm (3in) thick polyester vinyl foam and carbon hull structure. It's not easy to integrate such totally dissimilar materials but that's the least of their problems.

Designer Ron Holland and Det Norske Veritas and the MCA, the certification authorities, want Mirabella and, in particular, her keel structure, to survive a 90° knockdown with the keel in the fully down position. When you think there will be 91 tons of lead in the bulb alone, you begin to appreciate the size of the calculation. The fin and bulb are so huge that the former will have to be lowered into the keel box from above while the latter is slid underneath the hull (having been topped up with lead) and then offered up to each other.

The keel is pushed and pulled up and down by a 10m (33ft) long hydraulic ram, set inside the keel, with its own dedicated pump. Massive pins lock the fin in fully up, fully down or halfway positions.

750 tons at 20 knots
In spite of Mirabella's bulk (750 tons loaded), there has been a genuine attempt to make her a good sailing yacht. And when you look at the proportion of the rig, the depth of the bulb and the relatively shallow hull you could be persuaded she may well top 20 knots.

You can discount any claim that she will benefit from a lightweight construction by using composites instead of aluminium. Steel bulkhead doors and 60 tons of fire insulation specified by the MCA - at 500grt she is classed as a ship - have cancelled that out, despite the use of a very compact (but expensive) form of ceramic insulation material. The real benefit from composites is reduced maintenance and with a charter boat that means less downtime.

Biggest sails in the world
But it is the rig, the spars and sails for Mirabella V which continue to intrigue more than anything. Peter Holloway, who is project managing the construction, has spent six months testing various carbon matrices first using a test rig on site at Porchester and then sending samples to the National Physics Laboratory at Teddington. Then the team built a 100m (328ft) long mould in which the 89m (292ft) 10-ton five-piece mast tube will be built.

The mast comprises a forward section made in three parts and an aft section made in two parts with the top part of the front moulding forming a taper. The wall thickness is about 20mm for most of the length but increases to 50mm at the bury. Before the fore and aft half are glued together, compression bars will be built in internally to take spreader roots (there are five sets) and other fittings.

'Dry' carbon cloth, pre-impregnated with resin supplied by Cytec Engineered Materials, has to be vacuum-bagged onto the mould and then uniformly baked in stages up to 70°C. The final heat cure lasts for several hours.
Building an oven that big was out of the question so Peter and his team have constructed a mould fitted with more than 200 thermo couplers which monitor the temperature as the laminate is gradually heated to 70° by heater blankets. A Dasylab 6 computer software package controls the heat, which can be monitored every metre or so along the entire mould from both sides of the carbon structure.

It is crucial to maintain an even temperature and a uniform vacuum, a process requiring five pumps running simultaneously. "It's taken us six months to get this far but the cost is cheap when you consider the scrap value of just one section if we get it wrong!" said Peter. The tube alone costs £500,000.

The boom is a wet lay-up so doesn't need the heated mould but the laminate is consolidated by vacuuming. At almost 92ft long (28m), 6ft 6in wide (2m) and almost as deep, the two halves of the boom mould look like aircraft wings. The Park Avenue design will allow the 1.4 ton battened main to flake into a vast trough.

The other big moulding task involves the ten spreaders. They are so big a man could lie on top of one and not be seen from the deck, although he would have to avoid the three uplights and three decklights fitted to each - so 60 spreader lights in all! By the time this story is published lamination for the mast will have started - the team is still working out how to sling the tube and when to attach the 20 tons of rod rigging from Ocean Yacht Systems. A further 500kg of cabling will run inside the mast. Another brain teaser is how to move and fit the three Bamar furlers, the biggest one of which stands almost 10ft above the deck (see drawing) and weighs five tons.

Mainsail segments
Mirabella's reacher at 20,450ft2 (1,900m2) will be the biggest sail in the world and will be made by Doyle Sailmakers, who have been commissioned for three sails, including a working jib. Together they weigh a staggering 3.5 tons. They have also been experimenting with what they call a segmented mainsail. Instead of one piece of cloth, the main will be divided into seven segments and attached to six full-length battens.

The sail is so big that the only way to handle it in the event of repairs being needed will be by dividing it into manageable parts. Doyle are still experimenting and have tried a prototype on Ron Holland's 70ft sloop Golden Opus in the Mediterranean. Each segment, the largest of which will be 315m2 (3,390ft2), is attached to the batten by a series of loops (see diagram above).
The battens, too, are a new development with hydraulically spring-loaded inboard ends to prevent damage in tacks and gybes. The sprung ends are designed to act as shock absorbers in an attempt to prevent battens from breaking. The main halyard captive winch - all the winches have been supplied by Egon Sander in Germany - is capable of pulling eight tons and operates a continuous-line halyard. It should take between three and five minutes for the hoist.
Particular attention has been paid to the Harken batten car system which runs on a track split in two above the gooseneck so the cars can stow in two stacks.

Ironically, despite the performance predictions for Mirabella, when she crosses oceans she is likely to make the passage under power using her twin 788kW MTU main engines driving Rolls Royce Kamewa Ulstein controllable pitch propellers. "It's probably more economical to replace an engine than it is the mainsail," said Joe Vittoria.
Mirabella V is simply that sort of yacht.

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