# 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:** 20\ **Page:** 1
**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 21, 2012, 8:45pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/1 "2012-04-21T20:45:11Z")
According to [Wikipedia](http://en.wikipedia.org/wiki/Sinking_of_the_RMS_Titanic): > [@](#): > > Although the watertight bulkheads extended well above the water line, they were not sealed at the top. If too many compartments were flooded, the ship’s bow would settle deeper in the water, and water would spill from one compartment to the next in sequence, rather like water spilling across the top of an ice cube tray. 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? ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [April 21, 2012, 8:56pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/2 "2012-04-21T20:56:47Z")
Money. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [April 21, 2012, 9:03pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/3 "2012-04-21T21:03:37Z")
Getting around on the ship would have been difficult. If you are down on one of the lower levels and you want to go to the back of the ship, you would have to go all the way to the top, then go back, and then go all the way back down again (you can’t have hallways going through your watertight bulkheads or they aren’t watertight bulkheads any more). And besides, no one really thought that they would puncture that many of the compartments. Trying to convince them to make the bulkheads go all the way to the top would have come across as silly and paranoid. They didn’t think it was a very realistic scenario. ---
**Author:** ![Weaver](https://avatars.discourse-cdn.com/v4/letter/w/3d9bf3/32.png) [@Weaver](https://boards.straightdope.com/u/Weaver)\ **Post date:** [April 21, 2012, 9:09pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/4 "2012-04-21T21:09:24Z")
Because they wanted a grand and impressive staircase and the bulkheads got in the way. ---
**Author:** ![Eve](https://avatars.discourse-cdn.com/v4/letter/e/9e8a1a/32.png) [@Eve](https://boards.straightdope.com/u/Eve)\ **Post date:** [April 21, 2012, 9:18pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/5 "2012-04-21T21:18:07Z")
- sigh \* No, the OP is not asking why the watertight bulkheads did not extend to the top of the _Titanic_, he is asking why the bulkhead had spaces above them down in the basement–whatever it was called–of the ship. ---
**Author:** ![Morgenstern](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@Morgenstern](https://boards.straightdope.com/u/Morgenstern)\ **Post date:** [April 21, 2012, 9:28pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/6 "2012-04-21T21:28:03Z")
Apparently they felt the possibility of the water rising above the level of the bulkhead was too remote to justify the extra expense of building taller bulkheads. ---
**Author:** ![Simplicio](https://avatars.discourse-cdn.com/v4/letter/s/c37758/32.png) [@Simplicio](https://boards.straightdope.com/u/Simplicio)\ **Post date:** [April 21, 2012, 9:32pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/7 "2012-04-21T21:32:33Z")
> [@engineer\_comp\_geek](#): > > Getting around on the ship would have been difficult. If you are down on one of the lower levels and you want to go to the back of the ship, you would have to go all the way to the top, then go back, and then go all the way back down again (you can’t have hallways going through your watertight bulkheads or they aren’t watertight bulkheads any more). The bulkheads had watertight doors, so this wasn’t the reason. > [@](#): > > And besides, no one really thought that they would puncture that many of the compartments. Trying to convince them to make the bulkheads go all the way to the top would have come across as silly and paranoid. They didn’t think it was a very realistic scenario. This is the reason. If only a few compartments were punctured, they would fill to the waterline and stop. Since the bulkheads went above the waterline, they were deemed to be sufficent. They would only fail if enough compartments were breached so that enough water got in to force the bow of the ship to sink below the height of the bulkheads. Apparently whomever did the designing didn’t consider that likely enough to make it worth the cost of building higher bulkheads. Note they did build them higher in the bow and stern, presumably because a hit on the bow or stern was considered more likely then a hit on the side. > [@Eve](#): > > No, the OP is not asking why the watertight bulkheads did not extend to the top of the Titanic, he is asking why the bulkhead had spaces above them down in the basement–whatever it was called–of the ship. I don’t read it that way. ---
**Author:** ![Snnipe\_70E](https://avatars.discourse-cdn.com/v4/letter/s/b5a626/32.png) [@Snnipe\_70E](https://boards.straightdope.com/u/Snnipe_70E)\ **Post date:** [April 21, 2012, 9:58pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/8 "2012-04-21T21:58:27Z")
Water tight bulkheads are expensive. The higher above the water line they go the more expensive they become. Putting water tight hatches in the bulkheads would add to the expence. ---
**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 21, 2012, 10:02pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/9 "2012-04-21T22:02:25Z")
To clarify what I meant (hopefully), as I understand it, the “bulkhead” walls looked like this: * * * ## Deck this and that ## Deck this and that ## | “Compartment” | “Compartment” | | “Compartment” | “Compartment” | [water surface?] | “Compartment” | “Compartment” | [below ship] … where the walls didn’t go to the “roof” of the lower deck, and allowed the “water spilling across the top of an ice cube tray”. ## While I would assume the walls should be like this: ## Deck this and that ## Deck this and that ## | “Compartment” | “Compartment” | | “Compartment” | “Compartment” | | “Compartment” | “Compartment” | [water surface?] | “Compartment” | “Compartment” | [below ship] … where the walls did reach the top of the deck and would isolate the water in case of leakage somewhere would be contained by the compartments. (Sorry if being somewhat incomprehensible, English is not my first language and ship engineering terms is not my speciality either.) ---
**Author:** ![Kenm](https://avatars.discourse-cdn.com/v4/letter/k/bc79bd/32.png) [@Kenm](https://boards.straightdope.com/u/Kenm)\ **Post date:** [April 21, 2012, 10:17pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/10 "2012-04-21T22:17:39Z")
Penny-wise, pound-foolish head slaps kicked in only [**_after_ Titanic sank**](https://en.wikipedia.org/wiki/HMHS_Britannic). > [@](#): > > Following the loss of the _Titanic_ and the subsequent inquiries, several design changes were made to the remaining _Olympic_-class liners. With _Britannic_, these changes were made before launching. (_Olympic_ was refitted on her return to [Harland and Wolff](https://en.wikipedia.org/wiki/Harland_and_Wolff).) The main changes included the introduction of a [double hull](https://en.wikipedia.org/wiki/Double_hull) along the engine and boiler rooms and raising six out of the 15 watertight bulkheads up to ‘B’ Deck. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [April 21, 2012, 10:27pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/11 "2012-04-21T22:27:30Z")
[Here’s a picture](http://upload.wikimedia.org/wikipedia/commons/5/5d/Titanic_side_plan_annotated_English.png). The red lines are the bulkheads. I’m thinking “not sealed” just means they aren’t watertight between the bulkhead and ceiling so if there’s hydraulic pressure it’ll be able to push through the crack if it makes it up to that point. ---
**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 21, 2012, 10:46pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/12 "2012-04-21T22:46:20Z")
> [@Simplicio](#): > > pparently whomever did the designing didn’t consider that likely enough to make it worth the cost of building higher bulkheads. [Thomas Andrews](http://en.wikipedia.org/wiki/Thomas_Andrews_%28shipbuilder%29) I seem to recall as well that some of the bulkhead doors were left open that night, to make passage between easier for the crew. ---
**Author:** ![Alka\_Seltzer](https://avatars.discourse-cdn.com/v4/letter/a/c89c15/32.png) [@Alka\_Seltzer](https://boards.straightdope.com/u/Alka_Seltzer)\ **Post date:** [April 22, 2012, 9:59am UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/13 "2012-04-22T09:59:14Z")
**Simplicio** has it right. Raising the bulkheads wouldn’t have made a great deal of difference in the case of Titanic. Water only started to spill over the top of them in the latter stages of the sinking, when the bow was very low in the water. If they’d been higher, the ship would have only stayed afloat for a few minutes longer. > [@Simplicio](#): > > Note they did build them higher in the bow and stern, presumably because a hit on the bow or stern was considered more likely then a hit on the side. The bow and stern bulkheads are higher because flooding at the ends of the ship changes the angle it sits in the water. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [April 22, 2012, 10:00am UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/14 "2012-04-22T10:00:45Z")
I think what doomed the Titanic was the failure of its hull plates not the lack of watertight till the decks. ---
**Author:** ![gracer](https://avatars.discourse-cdn.com/v4/letter/g/8e7dd6/32.png) [@gracer](https://boards.straightdope.com/u/gracer)\ **Post date:** [April 22, 2012, 10:46am UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/15 "2012-04-22T10:46:10Z")
[Wikepedia](http://en.wikipedia.org/wiki/Thomas_Andrews_%28shipbuilder%29) does say though, that: > [@](#): > > Unfortunately Andrews was overruled to have 36 more life boats and a double hull and water tight bulkheads that went up to B deck. So the ship’s architect clearly thought it would’ve been a good idea, just like the OP. Poor Andrews, I always felt so sorry for him. ---
**Author:** ![Alka\_Seltzer](https://avatars.discourse-cdn.com/v4/letter/a/c89c15/32.png) [@Alka\_Seltzer](https://boards.straightdope.com/u/Alka_Seltzer)\ **Post date:** [April 22, 2012, 11:13am UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/16 "2012-04-22T11:13:12Z")
> [@Alka\_Seltzer](#): > > Water only started to spill over the top of them in the latter stages of the sinking, when the bow was very low in the water. If they’d been higher, the ship would have only stayed afloat for a few minutes longer. I might be misremembering this. Looking at the Britannic article, it states that due to the design changes she could stay afloat with the first six compartments flooded, which would have been enough to save Titanic. ---
**Author:** ![bluezooky](https://avatars.discourse-cdn.com/v4/letter/b/e8c25b/32.png) [@bluezooky](https://boards.straightdope.com/u/bluezooky)\ **Post date:** [April 22, 2012, 11:33am UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/17 "2012-04-22T11:33:57Z")
Technically speaking the ship might not sink however as soon the bow slipped below the waterline sealed bulkheads would not prevent rolling over or even flipping upside down. ---
**Author:** ![gunnergoz](https://avatars.discourse-cdn.com/v4/letter/g/e95f7d/32.png) [@gunnergoz](https://boards.straightdope.com/u/gunnergoz)\ **Post date:** [April 22, 2012, 10:53pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/18 "2012-04-22T22:53:44Z")
> [@AK84](#): > > I think what doomed the Titanic was the failure of its hull plates not the lack of watertight till the decks. 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. ---
**Author:** ![Rich\_G7subs](https://avatars.discourse-cdn.com/v4/letter/r/85e7bf/32.png) [@Rich\_G7subs](https://boards.straightdope.com/u/Rich_G7subs)\ **Post date:** [April 23, 2012, 4:49pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/19 "2012-04-23T16:49:25Z")
> [@Eve](#): > > - sigh \* > > No, the OP is not asking why the watertight bulkheads did not extend to the top of the _Titanic_, he is asking why the bulkhead had spaces above them down in the basement–whatever it was called–of the ship. The Titanic had a basement!? ---
**Author:** ![Number](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/number/32/242_2.png) [@Number](https://boards.straightdope.com/u/Number)\ **Post date:** [April 23, 2012, 5:00pm UTC](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533/20 "2012-04-23T17:00:53Z")
Yes, just like the Alamo. [Next page](https://boards.straightdope.com/t/titanic-why-wasnt-the-watertight-bulkheads-extended-to-the-top/619533.md?page=2)