The Titanic ship was switched with the HMS Olympic and deliberately sunk as part of an insurance fraud scheme
Gardiner and van der Vat's theory runs like so: The Titanic did not sink. Rather, her damaged and almost identical sister-ship the Olympic was substituted and deliberately sunk in her place as part of a gigantic insurance fraud. [...] This, the theory continues, was accomplished with a simple switch. To the untrained eye, the Olympic and the Titanic were almost identical, and so a clandestine slight-of-hand was accomplished while the two ships were in dock together at the Harland and Wolff yard at Belfast in March, 1912. Name-plates, life-belts and so forth were secretly swapped. The Olympic" now disguised as the Titanic, was patched up and deliberately sailed into a known ice-field... The authors stress that this is not a mass murder conspiracy, but "an insurance fraud which went horribly wrong." The plan, they speculate, was that the "Olympic/Titanic" would indeed hit an iceberg, but that her water-tight compartments would keep her afloat for long enough for other ships of the same line safely to take off all the passengers and crew before the great ship went down. Unfortunately for all concerned, they claim, the liner's "ever-impetuous" Captain Smith got it "wrong" and hit the ice-field early, resulting in massive and terrible loss of life.