AS THE crumpled hull of the Costa Concordia rolled slowly upright, Nick Sloane breathed a huge sigh of relief. A few hours earlier, the South African salvage expert had admitted to journalists that even after 14 months of preparation, he was still unsure if the wreck would remain intact during the recovery operation or split open, spilling a soup of rotting food, clothes and furniture into the sea.
The 50,000-tonne Costa Concordia was one of the largest cruise ships in the world. Its grounding and capsize off the Italian island of Giglio on 13 January 2012 resulted in the most expensive wreck-recovery operation ever staged, estimated at more than $1.5 billion. The operation was a huge challenge: it involved untested methods, and more than 500 people who installed 18,000 tonnes of concrete and steel on the seabed, and attached giant ballast tanks – each the size of an 11-storey building – to the hull to refloat the ship. And if that wasn’t difficult enough, it all had to be done in an environmentally sensitive marine park.
Though successful, the operation highlights concerns felt by engineers like Sloane, who ran the project for US-based firm Titan Salvage. “We’ve been at the edge of the comfort zone on this one,” he says. “For a couple of years now people have been worried, and this one really shook them up.”
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See some of the big moments in salvage history: “Up she rises: Five monstrous moments of wreck salvage“
Sloane and others in the salvage industry are concerned that future disasters at sea may simply be too big to cope with. The largest cargo ships in the world, of which the Maersk Mc-Kinney Møller is the flagship, stretch to 399 metres long – some 40 per cent longer than the Costa Concordia – and this Maersk vessel is the first of a fleet of 20 mega-ships. These are being joined by the next generation of giant bulk carriers, and even larger container ships are on the horizon.
Should any of these run aground or sink, the resulting chaos could block a major shipping lane and create an environmental disaster that could bankrupt ship owners and the insurance industry alike. With vessels of this size, Sloane warns, conventional salvage will be all but impossible. So the race is on to come up with alternatives. It’s a challenge that entails more than just new salvage techniques: it is also forcing the shipping industry to rethink vessel design from the keel up.
Despite a steady rise in air and road transport, our reliance on shipping remains overwhelming: ships move roughly 90 per cent of all global trade, carrying billions of tonnes of manufactured goods and raw materials, along with millions of passengers, every year. Yet the industry is coming under pressure from rapidly rising fuel costs and regulations that aim to limit air pollution.
To cope, ship designers are paying close attention to fuel efficiency. Along with better engines and new hull designs, they are chasing economies of scale by constructing ever larger vessels that burn less fuel for each tonne of cargo they carry.
These monsters are already plying the seas. There are 29 bulk carriers about 360 metres long, for instance. Designed to feed Brazilian iron ore to furnaces in China and Europe, each is capable of carrying up to 400,000 tonnes. More are on order. The cruise industry is also trading up – Royal Caribbean International’s latest Oasis class are the largest passenger vessels ever built, at almost twice the weight of the Costa Concordia, yet even they will be surpassed by RCI’s 227,000-tonne Fragrancy of the Seas when it launches in 2016.
Eye-watering costs
The most rapid increase in size has come with container ships. In the 1990s the largest carried about 5000 shipping containers; the Maersk Mc-Kinney Møller can carry 18,000. Shipyards will soon begin work on the next generation, some 40 metres longer and , and there are rumours of even larger vessels to come (see diagram).
But with record-breaking size comes the risk of eye-watering costs should anything go wrong. Roughly 1000 serious shipping incidents occur each year, and according to , the costs of repair – or in the worst-case scenario, wreck salvage and clean-up – are set to rise rapidly. The value of a single mega-ship’s cargo, for instance, can easily exceed $1 billion, while stricter environmental legislation in many parts of the world means that should a wreck create pollution, those liable can expect to be hit with mammoth clean-up bills.
In part, this is where the problems began for the Costa Concordia salvage team. “The easiest and cheapest way of removing the Concordia would have been to cut her up in situ and take her away in pieces,” says Mark Hoddinott, from the International Salvage Union. However, the island of Giglio, where the Costa Concordia came to grief, is part of a marine park on one of Italy’s most environmentally sensitive coasts. As a result, the authorities insisted she be moved in one piece.
“The authorities insisted the ship be moved in one piece, setting up the biggest salvage challenge to date”
That demand, deemed unrealistic by many in the industry, set up the biggest salvage challenge to date. The liner had settled on two pinnacles of reef that prevented it from sliding into the deep. But any movement could have led to disaster, so after survivors were evacuated and the vessel’s 2380 tonnes of fuel had been removed, Sloane’s team set to work.
First they filled the gap between the reefs with bags of concrete to stabilise the seabed, before building a giant undersea platform to roll the Costa Concordia onto. Next they “tied” the vessel to the shore with 16 cables to stop it slipping, and welded 15 giant ballast tanks to the hull. Finally they attached a row of huge computer-controlled hydraulic “strand” jacks, giving 13,800 tonnes of pulling capacity to haul the ship upright, allowing it to float on the ballast tanks.
When the moment came on 16 September, the operation went without a hitch. Filthy and battered, the Costa Concordia will be towed to a shipyard next year and broken up. Meanwhile all signs of the disaster will be erased: the site will be returned to as near a pristine state as possible, with platforms and cables removed and sea grass replanted around the reefs.
In some ways, though, the location of the wreck was fortunate. The site is close to some of the biggest shipyards in Europe, so the salvage equipment could reach the wreck quickly. It is also relatively sheltered, making the key step of fuel removal easier, and since the Costa Concordia was designed for short cruises, it only carried small amounts of fuel.
Had it been a mega-ship it would have been a different story, even in such sheltered waters, says Sloane. Such vessels carry more than 20,000 tonnes of fuel, so removing it is a major operation. And since fuel must be removed first, any delay will exacerbate the disaster. “I don’t think there’s many places in the world where you could do an operation on this sort of scale,” Sloane says.
In many ways removal of cargo containers is even harder, as these 6-metre-long boxes can be stacked up to nine deep above and below deck. The lower decks often include built-in metal guideways designed to speed up loading and unloading in harbour, but with the hull at an angle, these can jam containers together. Several recent salvage operations have sent a shuddering warning through the industry.
In 2007, for example, a container ship called ran aground in Lyme Bay on the UK’s south coast after her engine room flooded. The cold conditions meant the vessel’s 3500 tonnes of fuel had to be warmed before it could be pumped out, so almost three weeks passed before the salvage teams could begin to remove the 2300 cargo containers. Even then, salvors had to man-handle lifting chains around each cargo container before removal so it took three and a half months to recover them all. Still unable to refloat due to damage, the hull was eventually blown apart with explosives and removed for scrap.
Mission: impossible?
Worse came in 2011, when the container ship Rena ran aground off the coast of New Zealand. It was 11 days before salvors could begin controlled oil removal and a further month before the first container was removed. Eventually a giant crane was brought in but it was still slow going – just six containers per day were salvaged. Hit by bad weather, the wreck eventually broke up and the .
Compared with the latest ships, the Rena was a tiddler capable of carrying just 3351 containers, yet only 1007 were recovered in an operation that lasted more than a year. “Offshore, in a remote location, when the ship has anything over a 5-degree list, it’s almost impossible,” says Sloane. “You have to have bigger and bigger cranes, on barges, and it’s very slow and very challenging. The big ones are going to be a nightmare.”
In fact the gigantic Emma Maersk container ship has already hit trouble. In February this year, lost power off the Egyptian coast. Luckily it was brought safely to port where almost 13,500 containers were unloaded in a two-week-long shore-based operation while the hull was repaired. In less favourable weather conditions and in a more remote location, things could have been very different. Industry experts suggest that unloading the cargo of a mega-ship in the open sea could take up to three years to complete, if indeed it can be done at all.
“Unloading a mega-ship in the open sea could take up to three years, if indeed it can be done at all”
Even safety features on modern ships may hamper salvage efforts. An industry-wide move towards double-hulled tankers that reduce the risk of oil spillage has created new challenges for salvors – the space between hulls can fill with water, adding weight and making it difficult to refloat a vessel. In addition, fuel tanks on cargo vessels are sometimes positioned amidships, beneath the accommodation block. This makes them less likely to rupture in a collision, but it is also more difficult for salvage teams to reach them and pump out their contents should the vessel run into serious trouble.
To tackle many of these problems, politicians in Europe are calling for new efforts to make salvage more effective, and to reduce the risks of pollution. The result is the concept of the “salvage-friendly” ship, equipped with technology that accelerates operations and helps mitigate any environmental consequences. New safety systems include fast oil-recovery connectors, which offer easy access to fuel tanks through standardised piping and valves. Future plans include equipping ships with suites of sensors that feed reports of the vessel’s condition back to salvors should the craft sink.
Meanwhile, Norwegian engineering firm Miko Marine has been part of a European collaboration to develop a , attached remotely and then deployed to stabilise the ship. Miko Marine has also designed heavy duty that can be applied to holes in the hull like giant sticking plasters. Available in sizes up to 5 metres across, they can be positioned using Miko Marine’s pneumatically powered , which cling to steel hulls using magnetic feet.
Perhaps the most pressing problem – how to remove containers from a mega-ship – is still a work in progress. “Though containers have standard mounting points and positions, taking them off a stranded ship is a very risky operation and is likely to damage the structure of the ship,” says Gilles Longueve, president of the .
Sloane believes something he used on the Costa Concordia could be the answer. “The strand jacks are relatively light and they give you a large pulling force,” he says. But they would need to be mounted on portable frames that could be flown to a wreck by helicopter. “They’re slow, so there would have to be some R&D to speed them up, but it gives you options,” he says.
Video: Built-in balloons could help salvage sunken ships
But perhaps the most ambitious plan could see sunken vessels lifting off the seabed and emerging from the waves on their own. A European Union consortium has been awarded €2.65 million to develop based on technology that provides emergency buoyancy in submarines. In subs, these systems harness fuel to blast water out of ballast tanks in a matter of seconds. The modular uses large volumes of gas, generated rapidly by the catalytic breakdown of hydrazine fuel, say, to automatically inflate large Kevlar-reinforced balloons.
The nine European universities and organisations behind the system have devised ways to install these balloons on the side of hulls to help right listing or capsized vessels, across vehicle decks on ferries to provide instant bulkheads, as well as in the spaces within double-hulls. Simulations suggest the system can even be used to raise vessels from the seabed, and trials in 2012 using 11-tonne hull sections from a tanker proved the balloon system is up to the job.
One day this system could prevent a repeat of the Costa Concordia disaster. At a meeting last year, the researchers sketched out a plan that would place a ring of flat-packed balloons around the hull of a cruise ship. Located just above the waterline, they would provide enough buoyancy to support a 50,000 tonne ship with a hole in its hull. After 2016, when this technology is finally commercialised, it won’t be just the passengers and crew that inflate their life belts when disaster strikes.
This article appeared in print under the headline “Abandon ship!”
