I had the pleasure of attending the Lusitania Centenary Conference at Clydebank Town Hall, 13th May 2015 and thought it might be of interest to members if I share my understanding what was said by some of the most excellent speakers.
1] She was designed with the provision that she could be converted to an Armed Merchant Cruiser. This required warship standard bulkheads and flood prevention doors and thus to be able to take shell fire and be expected to survive a torpedo attack. The torpedo tack was spotted and the doors automatically shut from the bridge.
2] The torpedo penetrated the hull but did NOT detonate due to a fault in the detonator. It passed through the hull plating and THEN on landing exploded within the empty bunker causing the bulkheads on either side to collapse.
3] Although the instruction had been given early in the morning for all portholes to be closed it is estimated that 40% were open by the time of the sinking in the early afternoon. This is important as the explosion caused a list which placed these open portholes below the waterline, allowing water to flow into the third class section of the ship, through the stairwells into the large volume of the third class dining room, at the bow of the ship.
The hypothesis is that she would have remained afloat, with a 15 degree list, the incoming water being contained by the flood prevention doors and bulkheads, if the portholes had remained closed.
The speaker for this session was Ian E Winkle.
4] The call up merchant seamen interfered with the manning of some of the larger ships compounded by recruitment and retention problems and the dilution of training given to seamen.
The above is in line with log of Schwieger, Captain of U-20: “Shot hits starboard side right behind bridge. An unusually heavy detonation follows with a strong explosion cloud…” and later “”great confusion on board… they must have lost their heads.”