Through the murk it looks like it might be a classic modernist sculpture: a blackened block of metal hangs from a huge iron armature, wreckage telling of some cataclysm of the industrial age, much as works by David Smith or Eduardo Paolozzi told of a Europe crawling from the ashes of World War Two. But this artefact testifies to an altogether different disaster. It is a two-and-a-half-ton section of the hull of the Titanic, which had lain 4 km beneath the surface of the North Atlantic since the night of 14-15 April 1912.
As we all know, the Titanic sank after hitting an iceberg which ripped a three-hundred foot hole in its hull; of its over 2200 passengers and crew, just over 700 survived, bringing with them tales of half-filled lifeboats, miraculous escapes and tragic ends, of steadfast heroism and shameless cowardice. Indeed, the event almost immediately gave rise to songs, poems - such as Thomas Hardy's 'The Convergence of the Twain' - and popular legend.
To this tangle of narratives there has since been added a heavy burden of historical pathos, beneath which the real ship has almost disappeared. The Titanic has come to embody a whole range of standard cultural tropes: the hubris of industrial man in the face of implacable elements, the complacency of class-bound society, the inexorable drifting of old Europe into the looming terrors of the First World War. The American satirical newspaper The Onion brilliantly captured this condition in its recent spoof survey of the 20th century, with the headline: 'World's Largest Metaphor Hits Iceberg'.
The Science Museum's exhibition opens in resolutely material fashion, the section of hull and meticulous explanations of the process of recovering material from the ocean floor loosening your grip on easy symbolism. But some of the sense of a lost historical period returns when you're confronted with a case of au gratin dishes, found on the sea floor intact, in serried ranks in the sand, after the wooden cupboard which had shielded them from damage had rotted away. As at Herculaneum, there's a feeling here that you've stumbled across a whole society caught unawares by disaster; indeed, it's almost as if the Titanic were a kind of inverse Noah's Ark for the Belle Epoque, gathering its flora and fauna into a single vessel in which they would forever be interred.
The artefacts gathered here all speak of a vanished world of melancholic elegance and privilege, betokened by the florid curls of the ship's wrought-iron benches or of the copper-plate calligraphy of the various calling cards. (Though the waltzes piped in over the speakers are a little too much, giving less a flavour of the age than a soundtrack for a familiar fantasy.) There are pictures here of the First Class smoking room – an oak-panelled affair with stained-glass windows - as well as a reconstruction of a First-Class cabin, which would have slept two, and was usually adjoined by a private bathroom and a parlour. At the other end of the ship's unabashed hierarchy were the Third-Class berths, with between four and six bunk beds crammed under a maze of pipes, and apparently constantly invaded by the rumble of machinery. Given that one is like a miniature high-class hotel room while the other has the air of a barracks, the price differential is not too surprising: A First-Class ticket to New York cost £500, or £27,940 in today's money, while passengers in steerage would have paid £7, or £395. The difference also found a grisly reflection in the survival rate:199 of 329 First-Class passengers, 119 of 285 in Second Class, but only 174 of 710 in Third, and 214 of 899 crew.
Along with the ship's crockery and cutlery - of three different types for the three classes of passenger - the exhibition assembles a number of personal effects that hint at the lives left behind or hoped for on either side of the ocean: postcards from Patagonia, a pot of cherry toothpaste bearing a picture of Queen Mary on its lid. There are also playing cards with the faces of the court cards washed clean, a display-case full of US dollars smudged into various degrees of illegibility, and half-a-dozen cigarrettes, flattened out like tobacco-stuffed tapeworms. There is also a solitary top-hat and bow tie, which I would like to think of as belonging to Benjamin Guggenheim, whose words are quoted on the wall towards the exhibition's conclusion: 'We are dressed in our best and prepared to go down like gentlemen.'
Several of the ship's instruments were also recovered, including its chronometer, stuck at 12.40 - exactly one hour after the lookout, Frederick Fleet, pulled the lanyard of his bell and shouted 'Iceberg!' The bell itself hangs on its own, a Foucault's pendulum around which the world ceased to turn, in a passage leading to the room in which the ship's sinking is detailed. Here you're confronted with a video reconstruction of the sinking, and a huge block of ice - presumably to give you an idea of what an iceberg might look like, or of how cold -2°C is, the temperature of the water in which hundreds of people suddenly found themselves.
The show concludes with a section on the aftermath, detailing some of the stories of those who perished and those who survived - including a man who made it onto a lifeboat by pretending to be a woman, and several sailors who, with a certain panache, confronted their doom by getting blind drunk. The inquiry into the disaster, held in May 1912, called on the expertise of figures such as Marconi and Shackleton, and concluded by blaming poor navigation and excessive speed; it exonerated White Star Lines, despite the woefully inadequate provision of lifeboats and stark inequality of survivalrates in the different classes. It also attached no blame to Sir Cosmo Duff-Gordon, who was alleged to have paid 7 crew members 5 pounds each not to allow any more people into his lifeboat, which took a total of only 12 people to the safety of the SS Carpathia. The exhibition provides a full list of passengers, separated into those who survived and those who didn't; in a fairly ghoulish gimmick, visitors to the show are given a boarding pass on entry, with the name of a passenger on the back; in the final room, you can check if your name is among those who were saved. (Luckily for me, Mr Edwin Nelson Kimball Jr made it, and so did his wife.)
In many ways the most striking aspect of the exhibition is the sense it gives of the intersection of history with personal narratives: a single event of global importance, knotting together the smaller-scale recollections of thousands of individuals. It's this multiplication of voices and memories that fills the show's final room, and that has been a key source of the disaster's poignancy for generations. But more poignant still, for me, was the testament to transience and human frailty provided by the exhibition's opening. The Titanic's hull lies rusting on the ocean floor, 80 per cent of its surface covered by 'rusticules' - iron-consuming microbes that are gradually turning this former triumph of engineering back into iron ore; scientists estimate that around 20 per cent of the hull has already suffered this fate. As the real ship turns to powder, we will be left with only the fabric of legend; though stories, too, are not unsinkable.