I think we’ve found as much as we can about the breakup as far as the wreckage. The biggest thing now is de-coding what we’ve observed and trying to figure out what it means.This is one for the all the technical experts on here.
I know that in the mid-late 1990s there was a considerable amount of investigation conducted upon the wreck that looked into the breakup but do you think they missed anything ?
Is there anything specifically about the breakup still to learned from careful investigation of the wreck or has this went as far as it can conceivably go ?
I'm unsure why you're counselling me on the topics of a conspiracy theory and an expansion joint. I didn't talk about either of them. You must be thinking of the person ApwbD1912, who posted before me.The V break is not a conspiracy, Bill. If we carefully examine the evidence of eyewitnesses and know the main strength parts of the ship. we can build a minds-eye picture of what happened.
First: a ship is designed like a girder with a top and bottom flange. The top "flange" is the heavy strake (line ) of shell plating, which in the case of Titanic ran from bow to stern at the deck-edge of Deck C. it is called the "sheer strake"
The bottom "flange" was a little more complicated. it consists of the vertical plate keel the plate on top of the keel, the plate on the bottom of the keel and the two bottom shell plates (Garboard strakes) running from bow to stern on each side of the keel. Do you visualise this?
When a ship's stern rises out of the water.... even by a small amount, the bow dips and a stress called the "hogging stress" is imposed on a point on the upper edge of the sheet strake...the top edge of the plate is in huge tension. Consequently, the bottom "flange" is in compression.
If the tension on the upper edge of the sheer strake is great enough, it will break violently and vertically at the point of greatest stress...and usually with a very loud "BANG".
However, if the ship is up right, without a list to port or starboard, the hogging stress is shared equally between the port and starboard top edges of the sheer strake and the plates will stay intact much longer...perhaps even long enough for the ship to sink intact.
Now imagine what would happen if the ship was not only tipped by the bow but heeled over to port.
I suggest to you that in this case, the greatest stress would be on the upper edge of the starboard side sheer strake and it would part with a loud BANG. This would immediately transfer the load to the port side sheer strake and at the same time, allow a massive volume of sea water to enter the hull as the starboard side break propagated downward.
Thus, the sequence of events would be:
1...Starboard side sheer strake breaks and the hull cracks vertically downward at the break location allowing huge volumes of sea water to enter the compartments in way.
2... Ship sinks faster and port side heels even more to port imposing full stress on the port side sheer strake which then breaks with a BANG
3.... The sudden added weight in the area of the forward end of the engine room causes the bottom "girder to fail in 2 places and a sectio of the Double bottom tears free from the hull... The hull is now in two parts...the aft part returns to the upright position while the forward part continues to heel to the left and spirals bow downward toward the sea bed.
To answer you questions:
There was most certainly a V break but the Expansion Joints played no part in the main hull failure.
When the bow started down ward it did so with a forward as well as down ward movement, this gave the impression of a wave passing along the boat deck from bow toward the stern.
When the internal parts of the hull were suddenly inundates at the moment of initial failure, the flood water displace air trapped inside the compartments being flooded. In the case of the engine rooms and boiler rooms the sudden escape of trapped air through ventilator shafts would expel anything in the way such as soot, coal or Lightoller and Colonel Gracie.
The antics of the forward section as it broke loose and rolled would also confuse thos looking in the direction of the funnels visible above the surface.
Just a few thoughts.
This is how I see the first part of the hull failure sequence, Sam...a wee bit inaccurate but i'm sure you will see what i'm getting at.V-break theory? Two views of what could be considered a V break: A break that looks like the letter \/ or a break that looks like an inverted letter /\.
So which one?
Jim's description appears to be /\ caused by hogging stress failure. (I happen to agree with this view.)
The other V break would be a sagging stress failure in the double bottom and look like \/. (I see no physical reason why this would happen.)
Probably right about mixing-up postings.I'm unsure why you're counselling me on the topics of a conspiracy theory and an expansion joint. I didn't talk about either of them. You must be thinking of the person ApwbD1912, who posted before me.
I understand the construction of the ship, and how structures fail.
In your rendition of events, it isn't clear why the keel broke into pieces and tore free from the hull. Water in the engine room would not do that. Flooding into a ship compartment below sea level simply equalizes that part of the ship with the sea around it. Flooding takes away buoyancy, leaving the dead weight of the iron. The iron there could support itself and more. Maybe you're saying that the top-down break went all the way down to and through the keel?
Also, I wish that people would clarify when they are talking about a "V" break. Is it the shape of the opening that forms, or the shape of the ship once it breaks? From descriptions that people have given, it usually sounded as if they were talking about the shape of the ship: bow up, stern up, and down in the middle, like a V. Your description sounded the opposite.
If you're asking about witnesses in the lifeboats, I don't know that level of detail. I will say that it was a few women, and the women's testimonies are mostly rubbish because they were clueless about ships, sea life, etc. It is the men's testimonies that I rely more upon...although some of them are pretty bad, too. "Consider the source" is a good thumbrule for listening to people's testimonies.Do we know which sides of the boat deck those who claimed that it rose were situated?
If you're talking about net pressure acting on the hull, that it true. But if you look at the bending moments on the hull girder, the flooded compartments would create increased stresses on the sheer strake, the same as if weight was added to those flooded compartments equal to the volume water that flooded in. And that can easily be proved.A flooded compartment actually has less stress on it.