Aargghh, Stu, thank you including me in the contest.
Now, you are plainly wrong about the speed at which your car would have to ride to dissipate the same energy: 0.5*18²*45000000=0.5*V²*1500 gives 3117 knots (4.7 Mach). To give a more common equivalent in the same domain, it can be compared with 33 ton falling on the bow of Titanic at the speed of sound.
Of course, this huge energy is dissipated in the ship, and not in the car. With the same energy per ton, it could be compared with a car having a mass of 1500kg crashing on a wall at a speed of ... 18kts.
Commonly, the collision bulkhead had to be placed at no less than 1/20th of Lbp from the bow, and from 1949 on, passenger liners above 800ft must be four or more compartment ships. But if flooding could have had various origins, collisions at the bow were to happen against the beam of other vessels, ie soft targets.
Except for Niagara, I don't remember any front collision above manoeuvring speed against piers or quays being cited, and if that had happened, land would not have been far away: That is surely why there is such an international watch for icebergs or growlers.
Unlike cars, there are no front collision tests made with passenger liners (or any ship that I know of, but I am not sure). Well, is crumble zone not a specific word for cars? The implementation of a bow dissipating the energy of the collision purely by crushing came together with welding on a large scale, I think.
Now, my feeling also is that a front collision with the iceberg could have been also lesser catastrophic, and I can completely follow the ideas presented in http://www.encyclopedia-titanica.org/item/1511/
Also, I completely agree that if the speed had been consistently lower, and if Mr Ismay... and if 1st Officer Murdoch..., and if the steel..., and if the rudder ..., and if the weather messages..., and if the marconists..., and if the bulkheads..., and if ... if... perhaps Titanic (or was it disguised Britannic?) wouldnt ... what?
What can be expected from the study of such an accident, is how to improve safety at sea. New ideas or suggestions are very welcome, but what can be said about the Titanic drama that has not yet been repeated hundreds of times?
The fascination for such a tragedy cannot hide the fact that such a blame game is at the verge of depreciating (?) the memories of these seamen, who surely knew much better than anyone today what they had to do, the more they were deeply involved, to say the least. Who dares to say his personal judgment is better than Murdoch's?
Regards,
Luc