The Queen Mary 2 is the biggest passenger ship ever built. Three times bigger than the Titanic, it breaks all records. It is the tallest, longest, widest and fastest of all liners. It is also the strongest and most expensive, costing almost a billion US dollars to complete. Weighing in at 150 thousand tonnes, its design must be revolutionary to keep it afloat. Despite all this, it is also the most manoeuvrable - able to turn unaided a full 360 degrees, in port.