The Titanic and her watertight compartments

[Dave Gittins]

Wilding did look at whether Titanic could have survived if her bulkheads had reached C Deck. Here's a bit from a certain book. Wilding is in Mersey's court.

"An allegation, made at the time and repeated ever after, is that Titanic's bulkheads should have been substantially higher. Would higher bulkheads have saved the ship? Wilding advised that the height of the bulkheads was such that the ship met the target generally accepted by the Board of Trade and the shipping industry. Titanic, like other contemporary liners, could remain afloat with any two compartments flooded. Regrettably, if all the bulkheads had been taken as high as D deck, she would still have sunk, if the damage extended as far aft as boiler room five. If it extended to boiler room four, as appeared possible from the evidence of Thomas Dillon, even bulkheads reaching to C deck would not have saved her."

 

[Erik Wood]

The quote Mr. Gittens provides also in my opinion says something else:

It is more of a statement of knowledge. In order for you to know about the bulkheads reaching C deck you have to figure out the math. Which means Wilding and company did that math. They most likely (at least it sounds that way to me) worked out every possible solution to the problem, but couldn't find one (other then not to hit something).

Hmmm.....that's odd, if I recall rightly some other folks have mentioned something about that around here.

 

[Peter Spielvogel]

Well, yes, they worked out the math, but it's the specific numbers that interest me. I don't doubt that she would have sunk under either scenario. From what I've seen and particularly according to the research of Roy Mengot, during the second hour after hitting the berg she settled at half the rate as she did during the first hour. Maybe I'm overly optimistic but I think bulkheads up to C-deck could have slowed down the influx even more. I don't suppose that much of Wilding's actual calculations survived till today?

 

[Peter Spielvogel]

Thanks, Sam. A delay of an hour, eh? It's better than nothing (I don't see anyone arguing that working the pumps was a waste of energy). At least the collapsibles would have a proper launch...maybe even convince a few boats to return to pick up more passengers.

 

[Michael H. Standart]

>>Maybe I'm overly optimistic but I think bulkheads up to C-deck could have slowed down the influx even more. <<

It might have done just that. On the other hand, there's a widom to Murphy's 7th Law which states "Every solution breeds new problems." and in this case, what I'm wondering is how confining the water ingress forward for a longer period of time would have effected the ship's stability. Would the difference have been enough to cause a rollover? If so, that would tend to negate the value of holding the waters back in spectacular fashion. If not, then one has to wonder if it would have bought them a little extra time, say to properly set up Collapsibles A and B in the falls, get then get them loaded and launched with a reasonable load before the ship went down.

>>I don't suppose that much of Wilding's actual calculations survived till today?<<

If they did, they would represent the sort of primary source that us techies drool over. I doubt very much that they're still extant. If they're still around, my bet is that they notes are lying forgotten in a dusty archive or in a family's papers.

 

[Peter Spielvogel]

>>what I'm wondering is how confining the water ingress forward for a longer period of time would have effected the ship's stability. Would the difference have been enough to cause a rollover?<<

What's the reasoning behind that? To my mind, that scenario would promote a more even-keel straight-by-the-nose sinking. It came up in the thread where I asked about the possibility of a rollover that an experimental scenario was examined in which boiler room 3 was partially flooded and the modelling showed her capsizing. I just always thought a ship heeled more as its middle was flooded.

 

[Michael H. Standart]

>>To my mind, that scenario would promote a more even-keel straight-by-the-nose sinking.<<

Ain't nesseccerily so. It could be but it might also be something very different. With more of the nose immersed in the water, there's more of the stern hanging out and that's one whole lot of dead weight hanging out up in the air supported by nothing beyond thin air and prayer. Even as it was, there's evidence from the shifting of the list from one side to the other during the actual sinking to point to an on going loss of stability. Had the ship not broken up, it's entirely possible that she would have turned over onto her side as is the case in most shipwrecks.

It's that understanding which prompted me to ask how it would have affected the ship's stability.

 

[Erik Wood]

Remeber that confining water to any one part of the ship even if it be on the center line can cause instability. Instability can show its head in more forms than one might think.

That is to include roll over. But what I think is more likely to happen is you are going to get a "shedding" effect. If one where to think of the structure that supports the ship as an animal one could use this analogy:

quote:

As the ship weighs more and more and as pressure builds the structure will try to shed it's dead weight. Like an animal chewing off an arm to get out of a trap.

I put that in quotes because it is a quote from my paper I presented in Topeka, and the bold and underline was added for emphsis by for the purpose of this post.

In the end it won't matter the ship will still sink, but how fast it sinks then becomes more and more important as does the actual nature of the foundering.

Back when I first started posting here in the year 2000, David Brown and I where calling it a stress fracture, that evolved into "bent ship". It was called this because I couldn't come up with a better phrase. All of that research was based on different information and data (mainly concerning the heights of the bulkheads as it relates to the discussion). However the outcome is the same: A serious loss of stability from the onset.

It should be again pointed out that just because you loose stability it does not mean the ship is unstable. The word "stability" is relative. Any captain will tell you that when the ship takes on water it becomes unstable, even if there are no other signs to point in that direction. The question becomes is the ship stable enough to continue to hold passengers and crew, or is it time to abandon the vessel. If the latter becomes the case, you then need to ask if the ship is stable enough to launch lifeboats and the best way to accomplish a massive evcuation at sea safely.​

 

[Scott R. Andrews]

Kelly and Bill,

I just happened across your discussion and thought I might be able to add some information to help you along. Bill's figures for the weight of water in the boilers aren't very far off the mark. According to the H&W drawing office notebook for the Olympic, the weight of water in each of the D.E. boilers was 48.5 tons, while the weight of water in each of the S.E. boilers was 29 tons. The empty weight of these boilers was 91.5 tons and 57.38 tons, respectively. In all cases, 1 ton = 2240 lbs.

Regards,
Scott

 

[Bill West]

Scott -thanks for the check, you’ve brought out that strange old custom of giving boiler capacities “filled to the brim”. When I upped my estimate figures to the top, I coincidently got the same 48.5 Long tons. I don’t know why they do this, yes the boiler is full once a year for the hydrostatic test and so that’s the structural weight to be supported but for all other purposes the contents to mid glass would be more useful -ship’s trim, steam system calculations, etc. Anyway, I guess that’s part of why I like to redo other people’s figures myself, the math is precise enough but sometimes the English around it has multiple meanings so the designer starts teaching me things. My numbers are still a bit loose for now though, I haven’t refined them with the Brittanic info yet and I did find that I’ve expressed the water level at the bottom of the glass, not the middle.

Bill

 

[Scott R. Andrews]

Hi Bill,

I'm glad the drawing office figures were able to provide you with a check against your volumetric models. Even though I didn't go to the trouble you went to in calculating the internal volumes, I was suspicious of these numbers because they just seemed way too large, and suspected that they might be figures given for a fully filled vessel rather than one filled to the maximum proper level for steam production. Your analysis has evidently proved these suspicions to be well-founded! Of course, as always, this now brings up a new question to explore: I wonder what the optimum nominal fill height above the tubes was for these boilers, as well as the minimum and maximum operating levels.

Regarding the structure of Olympic and Titanic boiler versus those of the Britannic as shown the drawings published in "Engineering" and in "Verbal Notes...", I have compared the information presented with all of the information I have available to me, photographic and otherwise, and other than the one foot increase in length, all other features appear to be the same between the earlier D.E. boilers and those of the Britannic. Based on the figures provided for grate surface, the additional length seems to be added wholly to the furnaces, fire bars, tubes and stays, with the depth of the combustion chambers remaining the same. I don't have figures for the S.E. boilers on the Britannic, but given their primary purpose, I doubt that there was any change made in the design of these boilers.

Regards,
Scott Andrews

 

[Scott R. Andrews]

"...Based on the figures provided for grate surface, the additional length seems to be..."

Oops! Sorry about that -- what I meant to say was "...based on the figures provided [period], the additional length seems to be added wholly to the furnaces, fire bars, tubes and stays, with the depth of the combustion chambers remaining the same." Just prior to writing that reply, I was reading a question emailed to me regarding the grating surface, so I apparently typed what I was preoccupied with, rather than what I meant to say!

Regards,
Scott Andrews

 

[Bill West]

Hi Scott, -I’m afraid I’m going to have to pull back on this subject. I copied The Sothern dwg into CAD and started measuring areas but darn, the more I figured the messier it got. I kept finding uncertainties big enough to swing the answers all over and at no point could I get good matches to Sothern’s tabulations, so it seemed unwise to continue without more collaborating facts. The original idea of raising Kelly’s candid guess one notch is fine but, for a push onwards to a calculated basis, I’m looking too close without having laid out a proper ground work.

Bill

 

[Brent Holt]

I have not seen it mentioned that Titanic moved "slow ahead" for a good 15 minutes or so after she had glided to a near stop after the impact. This is frequently ignored in most disaster accounts, but there is testimony to back it up. This must have caused additional damage that sped up the flooding process and may have sealed the ship's fate; or at least made her sink much sooner.

Brent

 

[Samuel Halpern]

quote:

I have not seen it mentioned that Titanic moved "slow ahead" for a good 15 minutes or so after she had glided to a near stop after the impact.

The amount of time attributed to this is highly debatable. A few minutes is probably the best we can say. The impact of any movement has been addressed in other threads on this site.​