Call it arrogance or the boundless confidence of Victorian engineering. What now stands as a warning to future generations against the menace welcomed though unfettered self-belief, is that incredible assertion a century ago that convinced an entire society in the unsinkability of a ship – in fact the very ship that was lost to an iceberg midway into its maiden voyage.

Without mentioning its name, common awareness informs us I reference here: Titanic. And because of her the words ‘unsinkable’ and ‘ship’ are rooted in our psyche for evermore through their iconic association with this name. Be it blind hope or the glorious benefit of post-disaster hindsight, could it just be possible, however, that Edwardian shipbuilding was not, after all, indefensibly rash to believe they, through Titanic, had finally mastered the Holy Grail of marine architecture: the unsinkable ship?

Immortalised in disaster, this fleeting symbol of British accomplishment was launched 31 March 1911; named by her owners, Titanic. The largest movable manmade structure to date she was a sight to behold. Bisected with fifteen transverse bulkheads, all in their lowest sections sealed by powerful vertically-closing doors, her hull could be isolated throughout at the simple flick of a switch from the bridge, some seven decks above. The ease at which her bulkheads could stay disaster – the design intending her to remain afloat with as many as four breached – Titanic was dubbed, even by technical plaudits ‘practically unsinkable’. It was a bold claim to stake, but one enthusiastically precipitated through journalists and marketers alike to herald his mighty advertisement of British engineering and its reinvigoration of the nation’s faded dominance on the global maritime stage. But had Titanic been the ship to deserve such acclaim?

How society have scoffed at this audacious elevation of a ship’s invincibility, and at then its irony when smote in its maiden voyage. Yet make no mistake, in Edwardian times Titanic was not only among the safest craft afloat, but as we discover, the safest of the era. But first to qualify that point, because that is not to suggest, mindful of Titanic’s disastrous exit, that other liners of the period were demonstrably unsafe. Neither was she the first rightly singled out unsinkable. Titanic’s inch-thick transverse steel bulkheads divided her record-breaking 882ft hull into sixteen separate compartments – each spanning the full breadth of the ship, 92ft at its widest. Boasting more than twice the thickness of the armoured plating of a World War One battle tank, and conforming to all legal requirements of the day (the Board of Trade’s recommendations, June 1891), the heights of the walls dividing her was varied. Those at the extremities clearing her load-line as much as 30ft, whereas companions amidships clearing by as little as 11ft. And because hitherto Radar experience found the propensity for accident to afflict the bow or stern, raising the middle walls to a uniform height was widely deemed an unwarranted measure. Operative word ‘measure’, for White Star billed their first-class passenger domains as the largest afloat. Lavishing within them capacious saloons and ostentatious rooms connected by continuous and wide corridors that ran unhindered the entire length of their decks. Their hard-won passengers were King and un-hemmed by obtrusive and suffocating bulkhead divisions.

Sporting 31 doorways to afford passengers and crew access between compartments, the lowest 12 doors – communicating her five boiler rooms and two cavernous engine rooms – could be sealed electronically at the flick of a switch. Pioneered by the Norddeutscher Lloyd Line in 1897, to ensure doors to the largest spaces closed following a breach to the hull – than rely on crewmembers to crank shut by hand, an impossible expectation during emergency – the use of electronic and watertight doors by the time of Titanic could close tight the entire length of hull in less than a minute of activation: the remainder still requiring manual closure.

Held open by a powerful electro-magnet, each 1,680lb door and its closing mechanism was intended to drop under sheer gravitational weight and sever absolutely anything thought possible could hinder its fall. Gearwheels and hydraulics regulating its speed of descent guided the doors shut through pressures of 800psi, assuring the compartment’s isolation even with the doorway’s 5ft 6in fall straddled with wreckage. Furthermore, the doors would automatically close should floats beneath the flooring be triggered by rising water – any crewmember subsequently overriding them activating an alert on the bridge. Their arrangement of bulkheads enabled Titanic and her older twin Olympic to remain afloat even with two of the largest or all leading four compartments breached. Such containment of damage, to both engine rooms or all four forward compartments, encompassed serious head-on collision and broadside impact compromising the largest spaces of the ship. Such was imagined by their designers, Belfast’s venerable Harland & Wolff, the worst-case scenario possible to encounter. It was this impressive fact, the magazine and bible at the time for all ocean liner enthusiasts, The Shipbuilder, was enthralled to report.

In the event of accident the captain can, by simply moving an electric switch, instantly close the doors throughout and make the vessel practically unsinkable.

Founded in 1906 The Shipbuilder, a quarterly, had grown to a most sought-after and authoritative publication, devoting in 1911 a hugely successful and lavishly detailed summer special entirely to the newly finished Olympic and her recently launched and soon-to-be-infamous twin. Although not the first craft to be labelled with unsinkability, their owners White Star Line and architects since 1869, Harland & Wolff, were in no rush to rebuke the magazine’s celebration of their new class – its printed evaluation had not just voiced their own thoughts but echoed the opinion harboured by the regulator too.

Completed, Titanic supplanted her sister as world’s largest ship, and credence to her unsinkability was not only bolstered by the technical proficiency of her builders but their proven track record of safety. In the ten years preceding 1912, of the 2.1 million passengers travelling aboard White Star’s ships only two passengers had been killed through accident. The likelihood of disaster involving a Harland & Wolff vessel was becoming inconceivable, and with her design centred upon safety Titanic encapsulated this record like none other. The assertion of the press to this record would not only feed the public psyche, but Titanic’s arrival was politically an excellent time to boast and put the full stop to a decade of German dominance of the mercantile marine: ended with rivals Cunard’s Lusitania reclaiming Britain the coveted Blue Riband in 1907, with Titanic British shipping could lay its demons to rest.

Fitted with a cellular keel – an arrangement developed by Isambard Brunel, discovering that through flattening the hull could incorporate this model within a keel to build his progenitor of the first true long ship, Great Eastern – the arrangement within Titanic and Olympic measured almost 6ft deep. Deepening further beneath the engine rooms to give additional support to the machinery above, the double keel ran not only above the bilges but the entire length of the ship, honeycombing the keel into 44 smaller compartments. Rising above these, double-lined sidewalls separated with a 10in void, enclosed a secondary layer of plating around the hull. Clearing the load-line by 2ft 6in the walls ran 447ft encasing the full exterior flank of the ship’s six boiler compartments and two huge engine rooms, the hull’s most vulnerable areas. Boasting also a frame tensile strength as high as 22,400 pounds per square inch, their clinker-plated hulls would prove remarkably resilient; surviving relatively unscathed even as Olympic rammed and sunk a German U-Boat, May 1918.

The heights of the bulkheads within the Olympic-Class were based to a concept that would not allow water rise above the ship’s natural surface line as long as the undamaged compartments adjoining them counterbalanced the burden by redistributing this load. With each wall rising clear of the waterline this arrangement, upper extents varied as they were, was considered by the Board of Trade proficiently watertight – permitting the Olympic-Class no continuous upper deck with which to cap them. Transverse divisions were believed better suited to disperse the floodwater collected within a damaged hull. Yet, segmented by 13 transverse and 2 longitudinal bulkheads Cunard’s 790ft Lusitania formed of 175 watertight compartments sealed by 61 doors; 38 electrically activated from the bridge. On paper, she was superiorly subdivided; “with the most stringent regard to making the vessel unsinkable,” prophesised The Shipbuilder magazine, 1906 (Titanic aggregating 62 compartments throughout her cellular keel and protruding transverse walls). In 1915 however, the longitudinal configuration would compound Lusitania’s own downfall, capsizing her within a mere 18 minutes when breached by a torpedo. She lingered a fraction the almost three hours transversely divided Titanic held upright and afloat post-collision with the iceberg, opening five compartments to the sea.

Insistent at maximising interior protection within their Dreadnought fleet, the Royal Navy’s sponsorship of longitudinal bulkheads quickly expanded into the grandiose merchant cruisers of the day; replicating the formations with zeal into the greyhounds of White Star and Cunard vying for Blue Riband and glory. The former, however, would soon grow to disfavour the formation, even removing the longitudinal divisions completely by 1890. It was a dislike was driven by experience. For when longitudinal compartments flooded, the inflow confined to the damaged side of hull. Although honeycombing the sides of the ship to meticulous extent offered clear benefit to battleships, having them proved too impractical for passenger vessels. Mindful when designing Titanic to curtail such settlement of water – its tendency to increase the hydrostatic weight to the damaged side of hull – Harland & Wolff denied the Olympic-Class similar longitudinal formations. This decision would soon be vindicated. The causalities of notable Dreadnoughts during World War One demonstrated longitudinally divided vessels were far more susceptible to capsize opposed contemporaries compartmented entirely transversely.

During its deconstruction of the Titanic disaster The Shipbuilder continued its preference toward the enhanced containment offered by longitudinal configuration. Attesting the arrangement within Lusitania the more effective against disaster than transverse compartmenting that had failed to save Titanic, it also proposed enhancements to the longitudinal system to abate the problematic list. Sporting just transverse walls Titanic had indeed yielded entire compartments to incoming torrent of water, settling it the full width of hull in a single moment. But, filling symmetrically, the transverse system would afford Titanic its resilience to remain upright and afloat markedly longer the Admiralty specification would eventually offer Lusitania. This measured intake had indeed given the crew of Titanic the time to launch eighteen of the twenty lifeboats carried (the poor stowage of two of four auxiliary canvas boats proving disastrously impractical for crew to launch). In contrast, half Lusitania’s boats were rendered inoperable through her rapidly developed 18 degree list.

Here, and at the moment of her disaster, the footnote of Titanic is rewritten, for history perceives her as the doomed ship, the failed product of an industry’s fervent disinterest with safety. Indeed, who today would book travel on a ship named Titanic? Built to survive headlong collision into obstruction – had she done would most have probably survived – her sideways glancing blow left history to diminish Titanic to a byword of failure, and mankind’s quest for unsinkability: delusional folly. Earlier refusal to increase the allocation of lifeboats for Titanic, as early as 1910, found White Star’s chairman Bruce Ismay become a figure of hate in the wake of the disaster. Confident Titanic was instead her own lifeboat, and that his company had realised the unsinkable ship, a cowed Ismay would later lament her loss had encapsulated “the futility of that hope.” And though our post-Titanic hindsight cautions us to cede such unbridled trust toward the super-liners of today, Ismay’s vision of unsinkability had, just maybe with Titanic, teetered closer to fruition than we care to believe.