1912
· White Star Line, Harland and Wolff, Captain Edward Smith
The Titanic was advertised as practically unsinkable. The confidence shaped material choices: lifeboats for half the passengers, watertight bulkheads only as tall as the engineers thought they needed to be, a sea-trial of less than a day, an ice-warning-laden North Atlantic at full cruising speed. The iceberg was the trigger; the assumption was the cause.
The principle:
When an organisation believes the worst case cannot happen, it stops preparing for the worst case. The assumption becomes a design parameter — it shapes the lifeboat count, the redundancy, the schedule, the speed. The failure that follows is shaped by every decision the assumption authorised.