Gray, W. 20 November 2013. Don’t abandon ship! A new generation of monster ships will be even harder to rescue. NewScientist.
Should any of the new monster-sized ships 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 conventional salvage will be all but impossible.
Despite a steady rise in air and road transport, our reliance on shipping remains overwhelming: ships move roughly 90% of all global trade, carrying billions of tons of manufactured goods and raw materials.
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 meters long (1181 feet). Designed to feed Brazilian iron ore to furnaces in China and Europe, each is capable of carrying up to 400,000 tons. More are on order.
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 meters longer and capable of carrying 20,000 containers, and there are rumors of even larger vessels to come.
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 a recent analysis by a group of maritime insurers, 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.
When the Costa Concordia ran aground, “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 location of the wreck was fortunate. 2380 tons of fuel were able to be removed rather than leak into the sensitive environment.
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-meter-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 Napoli 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.
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 stern sank.
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, the 397-metre-long vessel 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 favorable 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.