Watertight compartments

[Lisa Nakamura]

I am a college professor interested in giving a lecture on the Titanic in my modern British history class, and I need some help on the technology of the Titanic. I'm confused about what the "watertight compartments" really were, and why they failed, and I'd really appreciate feedback from the experts. Were the watertight compartments flawed because they had doors and hatchways that were always open? What about the large doors that were supposed to be shut in the event of a collision? Did the designers plan the compartments to be watertight because they had doors that could be quickly closed--and then FORGOT that they had put in open stairwells, etc., that had NO doors? Or did crewmen leave doors on stairwells and passageways open during the voyage that allowed water to flow out inspite of the fact that the watertight doors had been closed? When people say the bulkheads "didn't go all the way to the top" what does this mean--that they ended in mid-air?! How many compartments on the Titanic could have been totally open to the sea without sinking the ship--I've heard anywhere from 2 to 4. If the Titantic had collided head on with the iceberg, would the bow compartments have been watertight enough to keep her afloat, or was the problem that the glancing side blow damaged too many compartments to maintain integrity? I probably sound totally confused (which is true!) but my interest in the watertight compartment-problem stems from the interest I have in whether the sinking was mainly due to human error (excessive speed, the decision to reverse engines and steer away, etc) or if there were fatal design flaws? It seems to me that if the Titanic were designed to stay afloat even if 4 compartments were open to the sea (because doors or hatchways into them could be quickly closed and there were no open stairwells)then why fault the designers, especially if it was rare in collisions for more than 1 or 2 compartments to be damaged?
Thanks for helping out a confused professor!

 

[Jan C. Nielsen]

Greetings, Professor,

If you want answers about Titanic, you've come to the right place. Your issues were addressed quite impressively in Walter Lord's book "The Night Lives On," which can be purchased at your local bookstore.

1. Doors always open, supposed to shut: They were open but could be closed from the bridge. There is some conflicting testimony about whether all watertight doors were actually closed on Titanic, on April 14, 1912.

2. Forgot about stairwells, leave door wells open, didn't go all the way to top: the bulkheads on Titanic weren't watertight, in the sense that they weren't sealed, and only went as high a E deck. This proved to be the Titanic's Achilles heal. As the water flowed in, it gradually pulled the bow deeper, and water flowed over the first bulkhead, and into the next, and so on.

3. How many compartments could be open without sinking? Estimates vary, but 2 to 4 is correct. Five were corrupted by the iceberg on April 14, 1912. And you're right, the side blow finished Titanic off. There has been some speculation that if Titanic had hit the iceberg straight on, she wouldn't have sank.

Titanic also did not have a double hull, only a double bottom.

I think design is to blame for the disaster, as Walter Lord points out. The safety design in ship construction had been going backward since 1858, when the Great Eastern was launched. This ship had a double hull and survived a similar accident. Additionally, Great Eastern's bulkheads went all the way up to the top deck. So, if you wanted to move from one area of the ship to another, you had to go all the way up to the top deck.

Titanic's design focused on luxury, fancy stairwells (where, incidently, the ship broke in half during the sinking) and beautiful passenger accomodations, not safety. It was not a safe ship at all.

Nakamura, are you yonsei? My wife is a sansei. Take care and welcome aboard.

 

[Lisa Nakamura]

Thank you, Mr. Shomi! Your response does clear up a lot, although I'm still a little confused by the bulkheads, so let's see if I have this clear. The bulkheads extended up to the floor of E deck-that meant that there was NO way to pass through them below E deck? Does not being "sealed" and water flowing up and over them mean that when the water rose to the top there were open doors, hatches, stairwells at the top (maybe in the ceiling) through which the water flowed up and over the bulkhead and then down into the next compartment? I gues I'm hung up on the term "sealed"! In the case of the Great Eastern the bulkheads were better sealed than those in Titanic because they ran althe way up to the top deck and therefore could only be entered from a hatchway or door on top that could be securely closed in the event of damage to the ship? i can see why this would have been annoying to people trying to move about through the ship. It does sound as if the problem was design, but it still seems strange that those flaws weren't detected or understood. Maybe they just assumed that collisions were rare?
Thanks!
P.S. I'm not yonsei, but my husband is. I'm just plain old Scandinavian!

 

[Susan Markowitz]

Hi, Professor! I'm not-at-all a technical expert, but I believe I may be able to help, having been fortunate to have sailed on a few ships in my "younger years".

The bulkheads on a ship are basically walls that cut perpendicularly across the width of the ship; their purpose was to divide the ship into "compartments" that could be sealed off in the event of an emergency, thereby isolating whatever it was that went wrong in that area.

The problem with doing so, of course, is that it prevents free horizontal movement of passengers and crew. Therefore, on each deck, the bulkheads are equipped with "watertight" doors that are generally left open in times of non-emergency. On Titanic, I believe, they operated vertically and were lowered from the ceiling; on the ships I was on, they were more like pocket-doors and moved horizontally. As Joe explained, on Titanic, these doors could be operated remotely from the bridge. He also mentioned that they were not strictly watertight, as they probably are today (but would certainly stem the flow of water).

In the event someone became trapped between bulkheads (I'd imagine alarms were sounded to alert everyone that the doors were about to close), they could generally escape up a stairway or elevator.

On the ships I was on, there was a "ledge" or "sill" at the base of the door, which one had to step over; I'm not certain about Titanic's, but I'd imagine any sort of bulkhead door would interfere with the flow of traffic.

Consequently, on a ship designed for luxury, the designers opted not to carry such "impediments" to E deck and above -- and certainly, not to break up the magnificent open spaces of the public rooms. You can think of it as a kind of cost/benefit analysis: the risk of collision or other emergency in their minds was not sufficient to necessitate such interference with the passengers' enjoyment of the ship.

On Titanic, it was believed that so long as the damage was limited to a certain number of compartments, or in certain places, any water that did enter would not reach high enough (i.e., the angle of the bow, for instance, would not become steep enough) for the water to flow over one bulkhead and into the next compartment.

Hope that helps!
All the best -- Susan

 

[Jan C. Nielsen]

What a coencidence . . . I'm Scandinavian and my wife is sansei! With respect to the bulkheads, one could pass through them by going through the watertight doors. But you're correct, water could seep above the bulkheads and over into the next compartment. The theory of construction was that the ship wouldn't go down at such a steep angle with only 2 compartments corrupted, and thus, they didn't need the bulkheads to go higher, or a hatch. They weren't "sealed" in the sense that there would have been a hatch that closed at the top of them. But I think Great Eastern may have had such a feature.

I'm sure you're right that the designers assumed that a collision with an iceberg would be rare. However, cost was clearly at issue here. In the British Board of Trade Inquiry, architect Edward Wilding admits that the double hull construction was evident on other (particularly British navy) ships, but not cost effective for passenger ships such as Titanic. After the disaster, I believe I'm correct in saying that the double hull was extended up above the waterline on both the sister ships, Olympic and Britannic.

It's not strange, though, that such flaws were not detected. Given that Great Eastern was designed in 1858, well before Titanic, I think that many of them were known, and that (as with the double hull) the designers chose luxury, convenience, and saving costs, over safety of passengers. One of the designers, Carlisle, I think, purportedly designed for Titanic to have more lifeboats - - but was overruled, or some such.

There are many factors at work here, as members on this board will attest, i.e., the design, the conduct of the bridge and captain, the conduct of the wireless room, etc. Some of these are fleshed out in Lord's book. Lord is so disgusted with Titanic's bridge that he says: "It's a wonder they lasted as long as they did."

Finally, I think the fact of the ship breaking in half where the weak structure of the aft grand staircase was, is ironic - - and almost a slap in the face to Titanic's designers. Unfortunately, they never knew it - - because the fact Titanic broke in two wasn't widely accepted until 1985, when the wreck was discovered.

 

[Maureen Zottoli]

Joe and Lisa,
Joe. You stated that a double hull was extended on the Britannic and Olympic, is that true for Olympic? How does one extend a double hull after a ship has already received its final fittings and has set sail? I am curious more than anything...do you know?

Lisa. This is a great question Lisa!
maureen.

 

[Maureen Zottoli]

Michael,
please bear with me. I think I understand the bulkheads being raised and have seen that in print elsewhere. Didn;t know about the water tight doors enhancements though. But if a ship is not doubled hulled in the first place, and it has been fitted and set off to sail, how does one double hull it above any line, if it were not double hulled to begin with? How can one do that in retro-fit mode?

And I agree with you, Titanic withstood an aweful lot!
Maureen.

 

[Maureen Zottoli]

I am no technical expert or even an apprentice, but my feeling is that the ship would have foundered, but perhaps in more of one piece. But given all the other scenarios as being true, such as the water tight doors and bulkheads only to E Deck...I think that the staircase omission would merely have made it more likely to sink...just in one piece and a lot more suction and proably loss of life,...like those closest to the ship as it sunk.

Just a poor opinion.
MAureen.

 

[Michael H. Standart]

Joe, the fact that it broke in two is no indication of a defect in design. NO ship today...not even a welded one...could survive the weight that was put on the keel when the stern rose up into the air. A fact which Dan Deitz made clear in his artical "How Did The Titanic Sink" which was published in Mechanical Engineering, Aug98 Vol 120, Issue 8 on pg 54.

Remember, this is something like 17,000 tons, give or take a few, which is supported by nothing. Part of the support for any ships structure is provided by the water in which it floats. Substituting a bulkhead for the staircase would have made little if any difference at all. When you put more weight on the keel and hull girder then it can stand, it will break

When I spoke about the Titanic being IN SOME RESPECTS(Caps for emphisis) being safer then some ships today, I was referring to watertight integrity and protection which hasn't really improved much, at least not in the merchentile service even though there's no technical barrier to doing so.

Mo, all that you need to make some major structural modifications to a ship is a good plan, a lot of steel and a lot of time and trained manpower. It's difficult, particularly if tyhe modifications are internal rather then external, but it can be done.

In the case of the Olympic, they were adding to the existing structure and not really taking anything away from it and that simplifies things. All the shipfitters had to remove would be stuff like furnishings, panaling decor and so on...in other words, nothing that impacts the strength or integrity of the structure itself.

Cordially,
Michael H. Standart

 

[Maureen Zottoli]

Thnaks Michael, you are always so patient with me with my questions and kind in your answers. I am grateful to you in that. I am thinking that they had to somehow alter the structure, but they were adding to existing structures. Now I understand better. Thanks.
Enjoy your day.
Maureen.

 

[Jan C. Nielsen]

I take back my point about a "design defect" relative to the Titanic's crack up - obviously, the ship wasn't "designed" to maintain a level of integrity as it sinks. It was "designed" to prevent it from sinking. So you're saying that the weight and angle were so much that no comparable ship could withstand it. Thanks for the feedback Maureen and Michael.

 

[Maureen Zottoli]

Dear Joe,
Think that Michael Standart's feedback is always more valuable and more valid than mine when it comes to anything technical, so please listen to him.

Also, he is a better resource for advice on how to get help from one's mother as well, he recommended crunch and munch and I suggested a single rose. Who knew?
Maureen.

 

[Michael H. Standart]

Hi Joe, and I beleive you're quite right in what the Titanic was designed to survive. Unfortunately, nothing can be so well designed so as to survive human error, even the momentary ones. In this case, the math is one iceberg(sideswiped) opening six compartments to the sea + an initial flooding rate of 7 tons a second over 2 hours 40 minutes adding 39,000 tons of water to the bow pulling down on the hull with a stern full of air upending to an angle of 20 to 25 degrees leaving 17,000 tons unsupported - enough lifeboats for all=1515+or- dead and three peices of hull on the bottom of the North Atlantic.

Mmmmmm...don't forget too the very best steel at the time in water at a temperature of -1 or -2 celsius=brittle steel fracture.

Pretty lousy numbers when you get right down to it.

Cordially,
Michael H. Standart

 

[Lisa Nakamura]

All these responses have been really informative, although prompting even more questions! So one crucial factor is the angle of the bow, meaning if the inflow of water can be stopped or slowed (by using pumps) then the bow won't sink low enough to allow water to flow from one compartment to another? I gather from the discussion that Titanic was taking on a huge amount of water very fast which overwhelmed pumps or attempts to block the holes in her side, so it was never possible to stop water from coming in and eventually filling compartments completely. I also see a debate about the quality of design of the Titanic going on, so I want to be sure that if I tell my students that Titanic was INTENDED to be watertight but in practice proved not to be, I won't be far off the mark?
Thanks to all-
Lisa

 

[Maureen Zottoli]

Dear Lisa,

I think that the term "watertight" is the speedbump here. The titanic was not tupperware or rubbermaid. (he he) I think that kids can understand that concept. But what they had were water tight doors that would prevent a huge direct flow of water, but I do not think that I would refer to them as water proof as say the submersibles that go down to visit the wreck have to be water proof.

And also these "water tightness" features went longitudely from bottom to near top and not lateral from side to side, as in a capping off of the tops of the water tight bulkheads. Sort of like an icecube trays that fills with water. As it fills water begins to flow over into other spot of the tray. There was nothing to cover the water to keeo it from rising.

In regards to the pumps, they were a tad slower than the water coming in, so it was a losing proposition. Plus the water fille dthe bow rather quickly. I am no expert on any of this. But maybe my limited imagination helps in trying to explain this to your students. And someone can helpout with the wuestion regarding the speed of the pumps.
Good luck in your class Lisa.
Maureen.

 

[Michael H. Standart]

Hello Lisa, getting a few written sources may be more helpful in this, and i'm hoping you have access to a library of some really good archives. "The Birth Of Titanic" written by Michael McCaughan would be a good place to start. Also, Titanic, An Illustrated History by Don Lynch and Ken Marschal as well as Titanic,Triumph and Tragedy(second Edition) by John P. Eaton and Charales A. Haas.

None of course are entirely lacking in faults, but they are good sources and Eaton And Haas 's work includes deck plans which identify staterooms by number. If you can get your hands on them, The Shipbuilder articals as well as the report issued by the British Board OF Trade are excellant sources of technical information, and the transcripts of both investigations is a must have. There's a link to the Titanic Inquiry Project which has the transcripts and reports which you can access through the links section here on ET.

If you prefer a vidio, the Discovery Channal offers two that you would find useful. One is Titanic, Anatomy Of A Disaster, and another is Titanic, Answers From The Abysss. I have both and I highly reccomend them.

In regards to the pumps, the total capacity of the pumps was 1700 tons per hour. When the Titanic sideswiped the iceberg, six compartments were opened to the sea at depths ranging from near the waterline to 15 feet below it. This opened only 12 square feet to the sea, but at the pressures which increase as the depth increases, the initial flooding rate was 7 tons per second. The watertight bulheads only went as high as E deck, and the deck was not watertight at all, so this allowed water to come up through deck openings, through bulkheads which had no watertight features and down through deck openings into the next compartments. The simple way of describing would be a nasty variation of the Domino Effect. As the mass of water inside the ship increased, the accumulated weight served to pull the bow down ever deeper until it was heavy enough to drag the whole ship down.

As to blocking the holes, no attempt was made nor could it be. When you have the equivalant of a 47 inch wide watermain blasting water in under full pressure, there was no way they could have pulled it off.

I hope you're not in any great hurry to give this lecture as this is a subject which is going to take some time to really do a good job of researching. Getting a hold of a naval architect or marine engineer would be a good idea. If there is any further way I can help, let me know.

Cordially,
Michael H. Standart

 

[Andrew Rogers]

Hi All,
Titanic had watertight bulkheads but not watertight compartments. I think it is important to make the distinction between the two. The Great Eastern, as mentioned, had watertight compartments, which means it had watertight bulkheads that were topped by a watertight deck, thus creating a watertight compartment.
I have seen a cross-section of the GE (somewhere) and as well as the double hull that Joe mentioned I think it had 5 compartments, but the cross-section did not show how many latitudinal (is that a word?)divisions these compartments had.
In comparison to the GE the Titanic was actually very "sinkable". It is amazing when you consider the GE was built about 50 years before Titanic.
So Lisa, I think it is important to draw the students attention to the difference between bulkheads and compartments.
On the subject of compartments; the other day I was looking at a copy of the US senate hearing into the T disaster and Senator Smith is questioning Lightoller about the watertight compartments as though they were a place to seek refuge!! I think he said " did the passengers and crew know about these compartments" "did they seek out the watertight compartments as a last resort or an alternative to taking their chances in the open ocean"
I suppose he didn't have the ET message board to set himself straight!
By the way, what is Sansei and Yonsei?
I'm an Aussie, is that similar?

Andrew

 

[Lisa Nakamura]

Things are indeed becoming much clearer, thanks to everyone's very helpful comments. As Michael Standart recommends, I should also find myself a naval architect, although that may be difficult here in central Texas! And Mr. Standart, your reference to the failure of E deck to be watertight really explains a great deal of the problem. As you say, I'm trying to investigate the Titanic thoroughly before giving a lecture on it--it's a fascinating event for a wide variety of reasons, but also very complex, and I want to do it justice.
Thanks everyone!

 

[Jan C. Nielsen]

Andrew,
"Sansei" is third generation Japanese-American, and "yonsei" is fourth generation. You may have heard of "issei" and "nisei," which is first and second generation. In Los Angeles, there is a huge "Nisei Week" celebration every year in the Little Tokyo area. Issei and Nisei were the ones interned in concentration camps during World War II, and there is much written about their experience. In 1990, each of them received $20,000 and an apology from then President George Bush. By the way, as an "Aussie" - - do you have any comments on the "S.S. Success" (see thread under "other ships and shipwrecks")?

 

[Michael H. Standart]

Hi Lisa, and I'm sure you'll do fine. You don't become a professor at a collage without knowing how to check sources. BTW, Andrew is quite right about the decks not being watertight and the difference between watertight bulkheads and watertight compartments. Think of the bulkheads as being something of a dam, complete with an upper level over which the water may (and did!) overflow when it came up through the deck openings, then through bulkhead openings and down through more deck openings which weren't watertight at all.

Cordially,
Michael H. Standart