What happens when a huge ship sinks? A step-by-step guide to averting disaster
At 3:24am in the Atlantic Ocean, a catastrophe unfolds across the moonlit waters. The MS Seascape – a 200-metre, sixstorey cargo vessel carrying 4,000 new electric vehicles – is pushed by swells into a coral reef. The ship grinds to a sickening halt, begins listing violently to the side and capsizes on to the reef a few kilometres from port.
The coastguard receives the distress call. Helicopters lift the flailing crew members to safety, while support boats unload any cargo that hasn’t already tumbled into the sea. It’s urgent – lithium ion batteries in electric cars risk exploding and most of the vehicles are stored in the hold. If fire breaks out, the vessel will become a giant pressure cooker.
Although our MS Seascape is a hypothetical ship, its situation is far from uncommon. In 2021, 54 large vessels either sank, ran aground or went up in flames and these behemoths are more likely to cause catastrophe when things go wrong.
Abandoning the ships is rarely an option. The risks of oil and fuel leaks mean it is now standard practice to try to salvage them and fix any environmental damage. But the costs are astronomical: the Costa Concordia, which ran aground off Genoa, Italy in 2012, became the most expensive wreck removal in history, costing more than $1bn, and taking 350 salvage workers almost three years.
There’s no cookie-cutter approach to salvage: each operation will vary depending on location, water depth, weather, equipment and sensitivity of the surrounding environment.
So what to do with our hypothetical MS Seascape? Let’s get started.
Step 1: Contain spills and remove fuel
The risk posed by MS Seascape, loaded with potentially explosive car batteries, is not dissimilar to that of the 200-metre Felicity Ace, which caught fire in the mid-Atlantic before sinking to an unsalvageable 10,000ft: it is suspected that the 281 EVs onboard may have sparked, or at least accelerated, the blaze.
To avoid this fate, a local salvage company gets involved, one of a few dozen operators around the world poised to rush to the scene of a maritime disaster. Its first objective is to save the vessel and return it to service.
A vessel’s location has a huge bearing on how quickly the operation unfolds. The Rena, a container ship that grounded off the coast of New Zealand, had to wait several weeks for equipment to arrive from Singapore – during which time the hull broke apart.
At this stage it is too early to tell how much impact the MS Seascape hull has sustained. In the morning, in calmer conditions, the salvage crew traces a skirted boom around the vessel to capture any fuel and hazardous wastes.
In the meantime, a specialist team begins bleeding its 20-plus tanks of more than 300,000 gallons of fuel, as well as potential pollutants such as lubricants, gases and oily water and sludge.
They drill through the ship’s exposed double-walled steel exterior into the fuel bunkers below, inserting pipes to pump out waste to a waiting vessel. Divers are dispatched to enter the ships’ interior to drain the remaining submerged tanks. This is a delicate task: removing fuel can destabilise the already precarious ship, so this process can take days, possibly weeks.
Suddenly, a crisis: after days of being strained against the reef by the current, stress fractures appear along the hull. They could break the ship apart. This dashes hopes of returning the MS Seascape to service – the cost of recouping would now be more than the value of the ship itself.
The mission transitions from salvage operation to wreck removal and the real work begins.
Step 2: Slice the ship apart
After 10 days, the ship’s fractures threaten to split the wreck. The team of hundreds of engineers, crane operators, firefighters, labourers, divers and architects, must move quickly.
They cut away the accommodation block to declutter the deck and simplify the process. One option to break the ship is to use explosives, such as those applied to the MSC Napoli, a giant container vessel grounded off England’s south coast in 2007 and blasted into two sections. But this would be catastrophic for the fragile coral ecosystem beneath the wreck.
Instead, the removal team opts for a thick cable of diamond-encrusted wire that can slice through inches-thick steel. The saw is fitted into a custombuilt frame lifted by cranes and ferried to the wreck site. Over two days, its two legs are rigged into the seafloor on either side of the wreck. Within the frame, the wire is cycled at high speed through a system of pulleys and lowered, guillotine-like, into the metal hulk, shearing through it with an earsplitting roar.
It can take up to 12 hours to cut a single cross-section, but the saw’s surgical precision means it only grazes the reef below. It can also slice between parked cars in the lower decks so that fewer tumble out into the sea, and around the fuel tank.
Fuel isn’t the only environmental threat: ships contain an extraordinary load of hazardous material, such as antifouling chemicals and lead embedded in paint, asbestos in the walls, and mercury and polychlorinated biphenyls (PCBs) wound into the electrics of older ships. These pollutants will gradually ooze out of hulks left to rot in the ocean. One sunken German warship is still leaching chemicals into the North Sea after more than 80 years.
Step 3: Remove sections and take them ashore
The MS Seascape is now encircled with vessels and equipment ready to