So - hoping that my sketches and mind math do me right - it seems to me that after the breakup (between the third and fourth funnels at the aft expansion point), if one considers that only 1 of 6 watertight chambers in the stern were flooded, proportionally 1/6 is less than the 1/4 needed to keep the ship - as a whole - afloat. My inquiry is concerning the happening of the stern even sinking. Might have more that just one bulkhead have been damaged during the ripping at the expansion point and the breakup more extreme than previously thought by me? Or might have the turbine engines (3: weighing 1,000 tonnes each) pulled the fore of the broken stern deep enough into the water for it to spill into the 5th watertight chamber - creating a 1/3 ration flooded; an amount exceeding the ship's sinking point. Help me anyone? Am I just going mad?