Keel & double bottom

Ajmal Dar

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Jan 5, 2018
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Does anyone know about the detailed design of Titanics double bottom? How many sections wad it divided into, was there access into it, etc, erc

Regards,

Ajmal
 

Andrew Wood

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May 9, 2018
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My aim is to put together a set of CAD plans for Titanic/Olympics keel, double bottom and hull frames and then use those to produce a scale model as accurate as it can be of each piece.

Ive read through Bruce Beveridges book Titanic Ship Magnificent Vol 1 which is a great start but it doesnt give all the dimensions I need only some. Ive also seen the page on ET about the double bottom but I still need more detail.

Where is it possible to obtain more detailed plans? If people are prepared to help me I will make the results available to everyone.

Thanks in anticipation.
 

Andrew Wood

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May 9, 2018
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To kick things off lets start from basics with what I know already of the first few pieces- point out if Im wrong...

The piece parts were assembled in the following order:

1 Rubbing strip which went under the keel
2. The Flat Keel plate
3. The vertical keel with top & bottom keel angles to make an i beam shape

Q1. The rubbing strip was 19.5 inches wide by 3 inches deep but how long, was it one continuous piece or several? Where did it start and finish?

Q2 The Flat keel plate was 1.5 inches thick but reduced to 1.2 inches thick towards each end. This was assembed in sections, but how long were those sections, how were they joined, did they overlap? Where did the thickness reduce to 1.2 inches.
 

B-rad

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Jul 1, 2015
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Based on what I can see on the low resolution copy of the keel plate plan, I believe that the bars were 9 frames roughly long in the middle. you can get a copy of the plan itself (HOYFM 2010.73.72 Keel Plate Plan) by emailing picture.library@nmni.com, ask for a Ship Plan Enquiry Form, and its 15 pounds + VAT for High Quality picture.
 

Andrew Wood

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May 9, 2018
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Thanks, I had emailed them. Where did you find the low res image, Ive tried searching on their website but it doesnt seem very good, it gives me loads of images that are nothing to do with Titanic or Olympic, and although there are some ship photos I cant find any plans?

Is there a specific index of all the plans they have?
 

B-rad

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My low resolution is from them, you can pick low res or high res on the form. The detail on the keel plan (being that its a large plan - and incomplete due to ware and tear with time) is hard to read in low res so I recommend if you are modeling from them to use the high res- I will purchase a high res in the future but it was good for what I needed at the time. They take a while to get back to people, as they are busy (I've only gotten 1/2 of what I've requested and its been since Oct.) but the results are worth the wait. There is an index of all the plans they have, and you can request a list of the ship you desire. I would post my keel plan image but that's one of the agreements you make when getting them is to not post or copy for copyright protection. Hope this helps.
 

B-rad

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PS... sounds like a fun project, I got a CAD program for Christmas last just for the same purpose, to try to CAD a Titanic - hence my need for plans also. However, I soon realized I suck at the CAD program (LOL) so I am taking a class. (Plus professional CAD programmers can make good $, so possible career move???) I would like to make a program that one can look at the ship from any deck, or just the frame work, or just the rivets, or as a whole be ship bit by bit that holds all the information. So if you click on 'frame work' it will show all the frames their lengths, depths so on and so forth. Love the book The Ship Magnificent but thought it'd be neat to be able to see how the ship was built while reading it. Big plan, probably never do it, but its an idea. Good luck to your project though!
 

Andrew Wood

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May 9, 2018
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Sounds like we're trying to do the same sort of thing we should collaborate then check our understanding of things with each other. Only just got my copy of the book but certainly the best book Ive come across on Titanic
 

B-rad

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Indeed it is a great book. I suggest trying to get your hands on period engineering/shipbuilding books. I find a lot in book stores (used book stores) and its amazing what treasures appear. I would love to help when I can, I am not that technical and am myself slowly learning. Throw me questions or what have you I will gladly help. Again, I don't know my CAD program well enough to be of help there.

There is someone else who has done something similar if not the same already. I can't find their contact info yet, but when I do I will pass it along.
 

Lee Lance

Member
May 26, 2018
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Thanks for the hint about "Titanic's Hidden Deck".
Looking at the plans, it seems to me that if an Olympic ran aground, pressure on the outer bottom would be transmitted up the supporting members to the inner bottom, damaging the inner bottom. It seems that there was no attempt to make a "crumple space" so that damage might be confined to the outer bottom.
How are double bottoms designed in modern ships? Are they different from Titanic's? Do they work?
 
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Jim Currie

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Hello Ajmal.

DBs today are much like the ones fitted to Titanic.

If a ship grounds, she rarely does so on a single point unless it is an underwater mountain peak.

Double bottoms should be viewed as a 'system' rather than treated as a series of tanks sandwiched between an inner and outer bottom.
The system is cellular in nature...each adjoining 'cell' helping to share and redistribute the pressure on a ship's bottom due to grounding.
In most cases of grounding, the ship settles or rubs along a flat seabed. Consequently, the load on the bottom shell plating is transmitted to and borne by the immediate internal structure such as the transverse "floors" and intercostals.
In most of the grounding surveys I have made, the damage was usually distortion to the outer bottom plating being set up between the deep floors of the DBs. In cases of raised seabed hard points, the internals would also be buckled.

In fact, one of the original ideas was not a double bottom, but a double skin. Leonardo. (Da Vinci...not Di Caprio) had that idea a very long time ago. Here's the proof:
Italy trip 2013..1 014.jpg
 
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A. Gabriel

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Jun 13, 2018
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It appears that there does in fact exist particularly detailed plans that are of relevance -- the only trouble is first identifying the type and provenance and then figuring out a way of obtaining them. In the National Geographic five-part series "Rebuilding Titanic" (a.k.a. "We Built Titanic"), the very first episode features what appears to be extremely detailed plans of the ship, seen here from 4:13 to 5:00. The ten seconds from 4:50 to 5:00 seem to show incredibly meticulous hull plans, as there appear to be diagrams depicting the shape of one end of the keel, as well as the profiles of hull frames, as well as the stem of the bow up to the 36' water mark.

The stem diagram appears to show the height of the stem at each frame, as well as the distance from the forward perpendicular at different water marks. Similar measurements accompany other diagrams on the plans in question. If these can be identified and copies obtained, it would be a veritable goldmine of accurate data for modeling the Olympic-class liners.

A second source may be Robert Hahn, if still active. Mr. Hahn is, to my knowledge, the only source for the "hull lines" and shell plating plans of the Olympic-class liners -- the shell plating plans supposedly show the plating for the ship's bottom, though I cannot confirm for lack of possessing them as of yet.
 

B-rad

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That is the shell plating plan. I don't see that on my list of plans provided at the museum, so IDK where to obtain a copy (I'll do some digging, and if you find out - if you could let me know). Other plans that may be of interest is the 'Keel Plate Plan' (HOYFM.2010.73.1) and Tank Floors and Brackets (HOYFM.2010.73.19) Hahn's is a good choice! Also check out the book RMS Titanic A Model Maker's Manual by Peter Davis-Garner.
 
Hello everyone,


Transversally framed double bottom.jpg

Since a while, I'm trying to understand the construction of those great liners and I got through many web sites.
I have found some schemas (like the one I put here, of transversally framed bottom's ship) but I really need someone to explain it to me. Here is few questions.

1) Between the bottom plating and the tank top is there was stokehold or bunkers in Titanic ? I mean is there any human being in those spaces or was it just for rats if you know what I mean ?

2) The bracket floor seems to be open between the two dark grey parallels : when the Titanic hit the berg, water could have got through that opening : what's the point to do it like that ? Would not have doomed ships built like that in case of collision ?

3) The holes that are on the white parts (girders and web frames, I think ???) are that Watertight doors ??

4) The round part just behind the the bottom plating is that the bilge ?

5) The average height between the bottom plating and the tank top is of what ? I mean is a man can stand?

Here is the web site where I found that schema if you need to go : 4. Construction - Transport Canada

Thank you very much to those who could help me out with it.
 

Tim Aldrich

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Jan 26, 2018
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I'll answer your questions the best I can.

1) The area between the bottom plating and tank top were tanks, or could be used as tanks. Fresh water could be stored there, oil for ships with oil fired boilers or oil engines, ballast. That space is also the bilge(s) and I would assume that moving the fluids around, adding or subtracting to the quantity, could be used to help trim the ship. On the Titanic there was about five feet (1.5m) of height. It was not a space where crew would normally be.

2) That space does appear to be open but remember, the tank top was water tight. The open spaces allowed these areas to be used as tanks.

3) The holes you speak of are not water tight doors. They are simply holes that allow passage of the fluids stored in those tanks and also allow access for maintenance.

4) The rounded part of the bottom plating is called the "turn of the bilge".

5) The average height is about 5 feet (1.5m). A man could get in there and they were in there on occasion for inspections and maintenance such as painting. I believe that trimmers who were not needed for trimming coal would be sent into the bilge.
 
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