# Titanic: Why wasn't the watertight bulkheads extended to the top **URL:** \ **Category:** Factual Questions\ **Created:** [April 21, 2012, 8:45pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533 "2012-04-21T20:45:11Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![CannyDan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cannydan/32/548_2.png) [@CannyDan](https://boards.straightdope.com/u/CannyDan)\ **Post date:** [April 23, 2012, 5:20pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/21 "2012-04-23T17:20:53Z")
Not only “extended to the top” but “sealed at the top” would have been much better. As stated above, the water tight compartments were really open topped boxes. Submerge them enough and water would indeed pour from one to another like a giant ice cube tray. But if they were sealed boxes (or sealable – water tight bulkheads and doors on the top as well as the sides) then water could enter but would stop when it could no longer displace air. The water level would rise, probably above the level of the leak, but once compression of the air balanced the water pressure, no more water would flood in. Any passengers and/or crew trapped inside would have been able to breathe and survive for a considerable time. Those people could even have congregated at any watertight hatch above the interior water line, opened it briefly to exit _en mass_, and shut it again. Some water would have entered, but would again have stopped once pressures equalized. Of course, the costs in inconvenience (to both loading and within-ship movement) as well as capital outlay would not have been trivial. But the ship might actually have been unsinkable. ---
**Author:** ![ExTank](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@ExTank](https://boards.straightdope.com/u/ExTank)\ **Post date:** [April 23, 2012, 7:06pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/22 "2012-04-23T19:06:55Z")
> [@Wakinyan](#): > > According to [Wikipedia](http://en.wikipedia.org/wiki/Sinking_of_the_RMS_Titanic): > > As an amateur, I can’t help asking the question: Why on earth were the walls in between the compartments _not_ extended to the roof? Even though they couldn’t have foreseen the particular damage Titanic suffered, it just seem so obvious to me that “compartments” whose whole point (as far as I understand it) are to contain water from a leakage should be separated by walls from bottom to top of the deck. What am I missing in my ship building logic? If I’m understanding you correctly, you’re under the same misconception my father was. Is what you’re asking is why, for example, the E Deck watertight bulkhead didn’t extend all the way up to the “roof,” which would be the underside of “D” Deck? As if the “wall” (bulkehead) had an actual gap at the top? Or are you asking why the watertight bulkheads didn’t extend all the way up to A deck? Or even the Boat Deck? **CannyDan:** the kind of compartmentalization you describe is fairly standard on warships, and it’s still no guarantee against sinking. If you build a ship out of steel, and then poke enough holes (or a big enough hole) in it, it will, sooner or later, sink. ---
**Author:** ![Wakinyan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wakinyan/32/352_2.png) [@Wakinyan](https://boards.straightdope.com/u/Wakinyan)\ **Post date:** [April 23, 2012, 7:41pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/23 "2012-04-23T19:41:06Z")
> [@ExTank](#): > > Is what you’re asking is why, for example, the E Deck watertight bulkhead didn’t extend all the way up to the “roof,” which would be the underside of “D” Deck? As if the “wall” (bulkehead) had an actual gap at the top?. Yes, this is what I was asking, where “E” deck would be the lowest (the “compartmens” deck in my illustration above). ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [April 23, 2012, 7:51pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/24 "2012-04-23T19:51:42Z")
You can get great deals on souvenirs in the Alamo basement. Just ask one of the docents. ---
**Author:** ![Mk\_VII](https://avatars.discourse-cdn.com/v4/letter/m/5f9b8f/32.png) [@Mk\_VII](https://boards.straightdope.com/u/Mk_VII)\ **Post date:** [April 23, 2012, 8:12pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/25 "2012-04-23T20:12:31Z")
In warships, which can expect to sustain battle damage, there is much greater compartmentalisation and a good deal of effort is devoted to damage control, both in the form of active measures to shore up bulkheads, fight fire and counter flood, and passive ones like phoning the damage control centre for permission to open hatches and confirming that they are dogged down again after you passed through the compartment. Passengers won’t stand for being treated like that. They will leave doors open, will think of themselves before the ship, and won’t obey orders that might seem a bit dangerous. They’re paying for a pleasant sea voyage, not to re-enact _Two Years Before the Mast_. They will pretty well negate any design features that might save a ship full of disciplined sailors. ---
**Author:** ![ExTank](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@ExTank](https://boards.straightdope.com/u/ExTank)\ **Post date:** [April 23, 2012, 8:19pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/26 "2012-04-23T20:19:06Z")
> [@Wakinyan](#): > > Yes, this is what I was asking, where “E” deck would be the lowest (the “compartmens” deck in my illustration above). Then in that case, yes, the bulkheads did extend all the way to the “roof,” with the “roof” being the underside of the next deck up. [What they did _not_ do is extend all the way up to A Deck,](http://www.encyclopedia-titanica.org/discus/messages/6584/114137.gif) the last enclosed deck before the Boat Deck, which was a “weather deck;” an open-air, unprotected deck exposed to the weather. ---
**Author:** ![CannyDan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cannydan/32/548_2.png) [@CannyDan](https://boards.straightdope.com/u/CannyDan)\ **Post date:** [April 23, 2012, 9:03pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/27 "2012-04-23T21:03:12Z")
**ExTank** , warship compartmentalization is exactly what I had in mind. I admitted that it had costs, even insurmountable costs, in convenience and treasure, as **Mk VII** points out. Nit pick regarding a “big hole”- one can in theory remove the entire bottom of a floating hollow steel container (a ship, say, or a simpler shape like a tin can) without it sinking, as long as an air bubble of sufficient buoyancy remains to float the weight of steel. (Capsizing is a whole different issue.) Water inside at or below the water line doesn’t constitute “weight” and won’t “pull the ship down”. Adding another hole, no matter how large or small, that allows the air to escape will indeed inevitably lead to sinking though, as water replaces the air. And fighting ships are certainly subject to multiple holes 🙂 ---
**Author:** ![mlees](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@mlees](https://boards.straightdope.com/u/mlees)\ **Post date:** [April 23, 2012, 9:39pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/28 "2012-04-23T21:39:57Z")
(Using the link in post #11 as a guide.) It appears that all of the bulkheads go up as far as “E” deck, with the bow and stern areas having bulkheads that go up to “D” deck. I’ve always assumed that the bulkhead “F” (between boiler rooms number 4 & 5), for example, does indeed reach the underside of “E” deck, meaning that flooding cannot proceed fore and aft until it gets above “E” deck, and that “E” deck itself was not watertight (meaning there were ladder/stairwells down from “E” deck into boiler room 5 that were not watertight). To make “E” deck watertight would have added a lot of weight (and cost) high up in the ship, as well as constricting crew, cargo, or passenger traffic. How do we find similar drawings for modern cruise ships? 🙂 ---
**Author:** ![Guinastasia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guinastasia/32/5751_2.png) [@Guinastasia](https://boards.straightdope.com/u/Guinastasia)\ **Post date:** [April 23, 2012, 9:53pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/29 "2012-04-23T21:53:47Z")
> [@AK84](#): > > I think what doomed the Titanic was the failure of its hull plates not the lack of watertight till the decks. The steel was of inferior quality – is that what you’re talking about? It became especially brittle in colder water. ---
**Author:** ![Mk\_VII](https://avatars.discourse-cdn.com/v4/letter/m/5f9b8f/32.png) [@Mk\_VII](https://boards.straightdope.com/u/Mk_VII)\ **Post date:** [April 23, 2012, 10:11pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/30 "2012-04-23T22:11:28Z")
The brittle qualities of steels at freezing (and not so freezing) temperatures were not well understood at this time. The ship was not the only on with this problem. ---
**Author:** ![Wakinyan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wakinyan/32/352_2.png) [@Wakinyan](https://boards.straightdope.com/u/Wakinyan)\ **Post date:** [April 24, 2012, 8:53pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/31 "2012-04-24T20:53:30Z")
> [@ExTank](#): > > Then in that case, yes, the bulkheads did extend all the way to the “roof,” with the “roof” being the underside of the next deck up. > > [What they did _not_ do is extend all the way up to A Deck,](http://www.encyclopedia-titanica.org/discus/messages/6584/114137.gif) the last enclosed deck before the Boat Deck, which was a “weather deck;” an open-air, unprotected deck exposed to the weather. Thanks, **ExTank** , that’s the answer to my original question (thanks everyone else too for an interesting thread)! ---
**Author:** ![MinisterFarrigut](https://avatars.discourse-cdn.com/v4/letter/m/e19adc/32.png) [@MinisterFarrigut](https://boards.straightdope.com/u/MinisterFarrigut)\ **Post date:** [December 6, 2016, 11:09pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/32 "2016-12-06T23:09:25Z")
> [@gunnergoz](#): > > That isn’t quite the case as I understand it. There is no evidence I’ve seen or read of that the hull plates failed. The iceberg impact would have damaged almost any steel-hulled vessel in much the same way, with the possible exception of a naval dreadnaught (battleship) with fully armored and blistered hull sides…and those didn’t come along until a bit later. > > The problem was that the damage compromised several compartments, leading to their flooding, and the ship’s floatation was no longer assured. > > The miracle was that she didn’t capsize before going under. That fact allowed the lifeboats to at least be launched. Most big ships that flood, do capsize at some point before finally sinking. Yah…true. The bulkheads were a HUGE factor in the sinking. But it was also the hull plates and the rivets that were used. From what I’ve read and seen, especially from Dr. Robert Ballard, the rivets used were cheaper than the ones that were actually going to be used. Being cheaper made them more brittle and inseffiecient. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [December 6, 2016, 11:21pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/33 "2016-12-06T23:21:09Z")
Remember the engineers who designed the Titanic class said they were “Virtually Unsinkable”. The press didn’t like weasel-words, so they printed “Unsinkable”. This was the first civilian ship to have ANY anti-flooding compartments. Best laid plans of mice and men… (these lessons need to be considered in the great rush to autonomous cars…) ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [December 7, 2016, 12:05am UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/34 "2016-12-07T00:05:04Z")
I saw a documentary the proposed a theory that the rivets used on the hull were substandard, and that this what the reason the plates parted. ---
**Author:** ![rbroome](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@rbroome](https://boards.straightdope.com/u/rbroome)\ **Post date:** [December 7, 2016, 3:06am UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/35 "2016-12-07T03:06:34Z")
> [@bob\_2](#): > > I saw a documentary the proposed a theory that the rivets used on the hull were substandard, and that this what the reason the plates parted. I remember it as the rivets were more brittle than the plating but they were as planned. Substandard implies that they didn’t meet spec. I believe the problem was the spec for the rivets was different than that of the steel. Which has already been mentioned suffered from unexpected brittleness in cold temperatures. The rivets apparently failed even before the plates did, at least at the collision points. [Previous page](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533.md?page=1)