Lightoller's Testimony

[Peter Hurst]

I have just read Lightoller's testimony, at the UK enquiry. In it he his absolutley adamant that the ship did not break up. He even states that it reached perpendicular.

However clearly it did. How could such an experienced and senior seaman have got it so wrong ??

Any theories ??

Peter Hurst

 

[Dave Gittins]

Try swimming for your life in freezing water while observing a sinking ship in pitch darkness.

That's part of the reason. Another part is that Lightoller probably did not believe it was physically possible for the ship to break. In 1912 they were quite familiar with ships breaking when straddling a reef but I doubt if there were many examples of a large ship breaking in halves on a flat sea. According to Edward Wilding's calculations it couldn't happen.

The perpendicular part may not be far wrong. Quite a few agreed on that. My own idea is that the stern was dragged into that attitude by the still loosely attached bow and by the weight of the engines. However, the whole matter of the breakup is very speculative.

 

[Dean M.]

please Dave, explain the "weight of the engines" part, I'm curious.

-Dean

 

[Dave Gittins]

Just my instinct really. The reciprocating angines and the very heavy base they stood on were right where the ship broke. In fact the base broke under the terrific stress and the low pressure cyclinders departed. My idea is that the concentrated weight of the engines helped to turn the stern on end. The front part of the ship was still attached after a fashion and the two forces combined. Just my feel for it, no more.

 

[Dave Gittins]

Just my instinct really. The reciprocating angines and the very heavy base they stood on were right where the ship broke. In fact the base broke under the terrific stress and the low pressure cylinders departed. My idea is that the concentrated weight of the engines helped to turn the stern on end. The front part of the ship was still attached after a fashion and the two forces combined. Just my feel for it, no more.

 

[Dean M.]

Thanks Dave, for the clarification. I've seen a finite element analysis picture of the stresses in the hull just before the break up. The structural engineer who did the analysis belives, interestingly, that the ship could not have raised out of the water more than about 12 degrees before she broke, well almost broke, in two. However, he didn't indicate the angle the stern may have rose before being flooded and pulled under by the bow.

and yet, another piece of the puzzle missing....

thanks.

-Dean

 

[Dave Gittins]

I'm inclined to agree that the hull as a whole never reached an extreme angle. I haven't measured things precisely but if you remember Lightoller said he dived off the top of the officers' cabins as it was submerged. He then swam instinctively for the crow's nest, which was still above water. Those two conditions are satisfied if the hull was inclined only about 20° or so. At that point the propellers are out of the water. Then the bottom collapses under compression and the breakup begins.

A bit rough, but I think in the right ballpark.

 

[Lisa]

Here's my two cents on this matter: The stern did
not raise up perfectly straight as in the movie.
When the water filled the bow, it forced the
bow down, therefore raising the stern a little.
Therefore, the weight of the ship, & the stress
on the keel caused the ship to break.
However, the two halves didn't actually separate
until the ship was almost completely under water.
That's why some say the ship didn't break apart.
Anyone agree with me?

 

[Dave Gittins]

Several witnesses said the stern reached the vertical, or close to it. A lot depends on the angle they saw it from. I wouldn't be too dogmatic about the evidence of a lot of terrified landlubbers on a pitch dark night, especially when some were far away. Even those who said it broke did not always pick the place where it broke.

I think your general idea is about right. The hull broke about 350 feet from the stern but the stern remained more or less attached to the rest for quite some time. The weight of the bow and the engines explains why the stern section was able to remain more or less upright without toppling to one side or another.

The part that impresses me about the breakup is the force required to break the engine beds and pull the low pressure cylinders off the engines.