Titanic's hull


Kyle Stewart

Member
Jul 18, 2002
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Do u think if they made Titanic hull made outta of Steel instead of iron?

Cause i think it would have saved the passengers and crew of her.
 

Dave Gittins

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Apr 11, 2001
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Kyle, she was made of steel. People use the terms 'iron' and 'steel' indiscriminately in books and movies. Ships were built of iron in the early days of steel but by 1912 steel was available in large quantities. The steel in Titanic was roughly equivalent to modern mild steel. Tensile strength was about 30 tons per square inch.

An odd fact is that iron rusts much more slowly than steel. As a result, some very old iron ships survive, while steel ships disappear quickly. A steel wreck on a local beach went from a complete ship to a few scraps of rust in well under 100 years. An iron Titanic would have been weaker but the wreck would be in better shape.
 
Dec 2, 2000
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Kyle, the problem here is two fold.

1)The steel used in the Titanic was state of the art for the time and few if any competitors were any better. It's possible Krupp might have been but that's neither here nor there. When you run a mass of up to 50,000 tonnes of steel into an even larger mass that ain't gonna budge no matter how hard you shove, bad things are going to happen. The known/asserted damage would have been non-survivable even with the steels made today.

2)Questions of the quality of the steel are a late comer into Titanic forensics debates and never would have been an issue had the ship avoided the icefield in the first place. Literally thousands of vessels have been built using basically the same steel and they served just fine. The Olympic and Queen Mary for example.
 
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john skinner

Guest
the impact of titanic and the iceberg produced some pretty drastic damage to the ship.the "what if's"of steel or iron is negated by the fact that the hull was an inch thick. i even think a battleship could sustain some pretty considerable damage upon contact with an iceberg the size that titanic ran into though i dont think the damage would be as extensive.
 
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Tom Pappas

Guest
We humans have a tendency to measure the strength of things relative to our own puny size.

To think about how strong one inch steel is, imagine a 1:1000 model of the ship. The hull would be about 10.7" long, and her skin would be about the thickness of the foil that gum is wrapped in - .001". At the same scale, a typical battleship's armor belt would be .012"
 
Dec 2, 2000
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>>the "what if's"of steel or iron is negated by the fact that the hull was an inch thick.<<

No it is not.

See Tom's answer above as it covers the ground from a mathamatical standpoint that says it as well as anyone can. Scale it all down as he suggests, and you would be amazed at how puny inch thick steel is against the sea and all the hazards it has to offer.

>>i even think a battleship could sustain some pretty considerable damage upon contact with an iceberg the size that titanic ran into though i dont think the damage would be as extensive.<<

Why wouldn't it be? Don't look to the armour for an answer until you learn a thing or thousand about how capital warship armouring schemes work. Armour protection consisted of some plates of varied thickness arranged to protect vital areas such as machinary, command and controls spaces, rudder machinary, and weapons. It was not as if the whole hull was designed to be 12 inches thick throughout, and would scarcely float if it was.

Armour was provided as and only where the naval authorities designing and building the ship deemed in necessery, and everywhere else was just plain old hull plating of the usual thicknesses one would find on any vessel.

Which is to say, not very thick at all.
 
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john skinner

Guest
the hood had armor from 5" thick all the way to being 12" thick.even at 5" thick the hull would be LESS likely to buckle than a 1" hull therefore it would be a safer vessel.PERIOD.
 
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Tom Pappas

Guest
The armor on warships was arranged so as to protect the vitals from artillery fire, not underwater hazards (or attacks). The thickest plate was on the turrets, but a large belt around the magazines and fire control was also typical. This was almost entirely above the water line.

I think that regardless of whether such a ship bumped an iceberg or grounded on a spur, the damage would have been much the same as Titanic suffered (although military-style subdivision might have saved it from sinking).

My dad was on the engineering team at Watervliet Arsenal that built the Mark 7 rifles for the Iowas. He didn't talk about it much, but said that Dante could describe the shop floor adequately.
 
Dec 2, 2000
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>>the hood had armor from 5" thick all the way to being 12" thick.even at 5" thick the hull would be LESS likely to buckle than a 1" hull therefore it would be a safer vessel.PERIOD.<<

John, befor you hit people with these all encompassing "periods" I would strongly suggest that you actually take the time to study and get to know how and why ships of all kinds are built as they are.

Quite a few of the people here have done exactly that and the body of expertise here includes a metallurgist, professional historians, sailors of every patch from deckplate seamen such as myself to fully licensed ship captains, engineers, and mathmaticians. You might want to think about that befor you try to talk down to anybody here. It won't be kindly recieved and rightly so!


The armour figures you gave for the HMS Hood are for the armour belt which protects only a limited section of the ship's side from hostile shellfire. the Armoured deck would tend to be low down so as to avoid topweight problems and stil protect the vitals from plunging fire.

The rest of the ship would be unarmoured and plated in normal hull plating no more then an inch thick depending on what the construction specifications called for. In point of fact, there's really no way one can build a ship with extrodinary thicknesses throughout as even if the beast could float, it would take enormous amounts of power just to move it, and there is no way a ship so overweight could ever carry a useful payload.

Now if you want to see the actual armour specifications for the HMS Hood, then you would do well to click on This Hotlink. You will see that by no means was the whole hull 5 inches thick.
 
Mar 3, 1998
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<font color="#000066">the hood had armor from 5" thick all the way to being 12" thick.even at 5" thick the hull would be LESS likely to buckle than a 1" hull therefore it would be a safer vessel.PERIOD.

You picked a strange example. Hood was as much a victim of her anticipated operating environment as Titanic was of hers. Why not pick a ship that didn't sink for your comparison? You know, Titanic had an older sister that survived more than a few mishaps...

Parks
 
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john skinner

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the reason i gave the example of the Hood was to point out that she had protection in the areas titanic was most severely hurt.and michael,i havent had a reason,at least a justifiable one to talk down to anyone yet.it just seems to me that an inch or two more protection on cruise ships in general would be a good thing.it seems to me you like to trounce on people for giving their oppinion.if you dont want me to share my opinion,than take me off the list with everyone else you dont prefer the input of.
 
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robert s hauser

Guest
Uh, this is my first one. Can anyone help me understand the plating scheme used on the Olympics? I've read about how rows of plates were arranged in overlapping "strakes" and I can see this in photographs, but I don't quite get how the plates were joined end to end. They don't look like they overlap the same way as the strakes, it almost looks like some kind of bulge going on where they are joined end to end. Also, was anykind of caulking or waterproofing used between the overlaps, or were they riveted so perfectly as to be totally watertight?. One other thing, I notice this on the Queen Mary as well, why were the rivits so much more numerous on the top edge of the hull, like around C deck on Titanic? Thanks. Rob
 
Dec 2, 2000
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>>the reason i gave the example of the Hood was to point out that she had protection in the areas titanic was most severely hurt.<<

No she did not. The Hood's armour belt didn't extend a good twenty feet below the waterline and all the way around to the underbelly of the ship where the damage would have actually occurred.

>>and michael,i havent had a reason,at least a justifiable one to talk down to anyone yet.<<

And you still don't and never will. So let's get away from that.

>>it just seems to me that an inch or two more protection on cruise ships in general would be a good thing<<

1)Running into an iceberg at 21 to 22 knots would have rendered it quite irrelevant. Remember you've got your own mass working agianst you and you're running into something that's not going to give ground for you no matter how hard you push.

2)The best evidence and opinion seems to point to a combination of cracked plates, split seams, and rivets which failed under the stress. And again, the thickness of the plates would have made little real difference on this.

3)You might want to check on the sort of weight penalty you would be imposing on a vessel by going from an inch in thickness to 2 inches of thickness. The sheer mass added would have been of little real protection in most situtations and would have made the ship unacceptably costly to run.

>>it seems to me you like to trounce on people for giving their oppinion.if you dont want me to share my opinion,than take me off the list with everyone else you dont prefer the input of.<<

In a public access forum, anything you post is fair game for any one of the registered members or any one of the moderators who happens to take an interest. If you post something that others believe or know to be in error, you're going to hear about it and you'll have to defend it.

Just remember that in this group, a number of the people here are trained in the diciplines you have an interest in so they actually know what they're talking about.

You do have a right to your opinion.

You do not have a right to have it go unchallanged.

If you cannot deal with those realities, then forum participation of any kind may not be for you.

Your call.
 
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Trevor William Sturdy

Guest
Tom,
Enjoyed your post regarding the hull thickness and the gum wrapper, goes to show that even though these were huge vessels, in the scheme of things they did very well to hold up to the everyday stresses we placed on them.

Robert,
For your "first one" I think you have raised some really good points probably worthy of their own threads. I had a quick look around the topics on this site and could not find an answer to your questions - nor could I remember seeing any posts regarding the plating arrangement or how you make 2 or more overlapping steel plates watertight. I guess I was just taking it for granted that if you stick enough rivets through these plates and let the cooling of the rivets pull the plates even tighter that you will hold back the water, although I think that no ship is ever really watertight and relies on ite bilge pump system to offload any invading water...not an expert just my landlubber opinion...
 
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David Haisman

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Hi Robert Hauser,

I may be able to help you but purely from what I've seen and experienced and from a practical standpoint.
British built ships were always noticeable in my day by their overlapping riveted plates and German ships especially, by that ''bulge'' you were talking about.
In the ship yards and dry docks I've visited, bottom plates especially were treated with a mixture of boiled oil and red lead. We always used this concoction on all bare metal up on deck after chipping and scraping bulkheads etc.
Today I suppose things are much different but I would hazard a guess that something similar took place in Titanic's day.
The hot rivets being hammered in just inches apart would have had quite a sealing effect I would imagine, along with plenty of primer and boot topping being slapped on after the exercise. However, all ships leak!

The heavy riveting seen on the superstructures of huge ships is there for the stresses and strains being caused when ships endure heavy weather conditions. The higher you go on the upper works of a pitching liner, the greater the movement. This can also be easily seen by the fore stays and back stays slackening and tightening quite visibly in those conditions.
On the boat decks of Royal Mail ships and Union Castle liners and many others, the ship moves between it's expansion plates quite considerably, a few inches in fact, when pitching in heavy seas.
Some passengers would be quite alarmed to see the ship moving in this way but we would assure them that all they have to do is make sure they're on the right half when she breaks in two!
Seriously though, seaman have a saying that '' when she surges,groans, creaks and squeaks,then she's a good 'un!''
The above applies to riveted ships.
I mention expansion plates in the Atlantic Daily Bulletin if they decide to publish the article.

I hope this is of some help to your question,

All the best,
David
 
Dec 4, 2000
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Riveted ships were "caulked," although not quite the way of old wooden vessels. Sometimes bituminous materials were placed in the faying surfaces between the plates. This worked well until those materials dried and cracked. A later technique was to splay out the exposed edges of the top plate against the underlying plate. This was done with a cold chisel and hammer or latter an air tool. A watertight fit could be obtained in this manner.

There are many ways of plating. Seams run horizontal. A line of horizontal plating is known as a "strake." Strakes were usually overlapped on an in-and-out basis. That is alternating strakes would appear to be "on top" from the outside. There were other plating schemes, but in-an-out was the easiest for the yard.

Butts are the vertical joints between plates. These can be made in a variety of ways, just like seams. One common way is to put a "butt plate" on the inside. This is a smaller piece that covers the butt and to which both adjoining outer plates are joined. Above the waterline the butt plates were sometimes placed on the outside of the hull to provide a smoother interior.

Shell plates (the big exterior plates) could also be formed with a sort of recess to accept an overlapping plate. This was more expensive and time consuming.

A major problem in plating a ship was to make sure the butts were staggered. That is, one butt joint could not be in a vertical line with the joints on the plates above and below. In fact, you wanted several strakes between aligned butt joints. So, great care was used in calculating the size of plates to avoid "overlapping butts." (I can hear the chuckles now.)

The big problem with plating a ship was getting the plates to lie flat against the underlying framework. As near to 100% contact between vertical frame and plate as possible was desired. In-and-out plating caused gaps the thickness of the plate at the "out" strakes. American yards often inserted spacer pieces as needed. British yards more often "joggled" the frames. That is, they made the frames shaped to fit the in-and-out plating. This was more expensive and time-consuming, but joggled ships were stronger.

Techniques used to plate ships varied not only from yard to yard, but also from country to country. As David H. points out, it was often possible to tell the country of origin of a ship by the way its plates were put together.

The working of a ship in a seaway as David H. so vividly described caused rivets to loosen and begin "weeping." (water came through) In Titanic's day (before welding) these rivets were removed and new ones fitted. Later, it was common to run a bead of weld around the head to seal this sort of minor leak.

Steel shipbuilding in Titanic's time was really an extension of wooden ship construction. That is, frames were set up just as in days of yore and strakes put hung to form the hull. The result was a very tightly woven basket. Like a basket, the individual pieces (reeds in the basket, plates and frames in the ship) remained discreet. Only during WW-II did welding begin to change things. Today's welded ships are best thought of as one-piece hulls.

What has been overlooked even by modern scientific analysis of Titanic's accident is that the rivets in the seams were not the only fasteners which held the plates together. Each plate was also riveted to the underlying frames. Thus, if a seam rivet was knocked loose, the plate remained in poisition and the seam might not open at all. I can show proof of this on an existing 1911 hull. The strength and watertightness of a riveted hull comes from more than just the butts and seams. It is the totality of the construction--just like a well-made basket.

One-piece containers break under strain while baskets can bend and "give." Well into living memory many sailors avoided welded ships in favor of riveted hulls for this reason. The idea was that the riveted hull would be more able to hold together because of the nature of its construction. And, there was some truth to this. Many early welded ships broke apart at sea. This was the case of many Liberty ships during WW-II.

Back to the butt joints for a final note. On Titanic they were arranged so that any vertical edges faced aft. This was thought to provide a "smoother" surface. Only later with the development of aerodynamics was it discovered that this method actually created "burbles" in the water flowing past the hull. These burbles rrobbed speed and increased fuel consumption. It was learned that butt seams should be reversed. Unfortunately, by then welding had become the way of shipbuilding.

--David G. Brown
 
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David Haisman

Guest
Yes, quite interesting detail and as mentioned, my information comes from observing repairs in shipyard slipways and dry docks in Southampton.
When red lead and boiled oil ''goes off'' it appears like a thick plastic skin. When this is between riveted plates, it makes a good seal. I've seen new plates set up in dry dock for ships being altered for stabilisers and insurance jobs and this appeared to be the procedure.
Perhaps not being a shipwright or builder, I may have been missing something, however an informative post and thank you for that.

All the best,
David
 
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Scott R. Andrews

Guest
Here's what I have been able to learn about the practices employed to form the plate connections on the Olympic-class ships, and on other large riveted steel ships built by H&W. While in smaller vessels, the materials used in the construction of the hull were light enough to permit the joggling of the frames to make a solid connection between all surfaces, with ships the size of the Titanic this wasn't found to be practical. The "In" strakes were riveted directly to the frames while spaces remaining between the "Out" strakes and the frames were filled by steel strips, called "liners", having the same thickness as the adjacent "In" strake.

In the "clinker" style shell plating used between the keel and the turn of the bilge, H&W got around having to use tapered liners by riveting the plates to angle-bar frames of relatively thin section that had been machine-joggled prior to being attached to the tank floors. (For those unfamiliar with the term, the tank "floors" are the transverse, vertical deep frames of the double bottom.)

H&W formed the corners of their butt laps in the following manner. Where the lands of the "Out" strakes passed over the raised butt lap of the adjacent "In" strakes, the corners of the raised edge of the butt under the landing were planed off in a manner creating a tapered scarf, allowing the outside strakes to bear tightly on the inside strakes. The inward-protruding edges of the butt laps of the outer strakes were finished in the same manner, only with the scarfs being planed into the corners of the inboard forward edge of each plate. Without these scarfs, a tapered aperture would have remained, each one requiring small tapered pieces of packing iron to fill them. Some builders employed the latter method rather than incur the penalty in both increased cost and time that came with scarfing the corners of all of the butt laps. Tapered packings tended to produce a maintenance and repair nightmare for the owner down the road, in the form of premature failure of seams from the accelerated corrosion experienced in the thinner edge of the packing piece.

Where the plating was of thinner section, such as with the deck plates, joggling of the plate seams was adopted instead of plating on the "in-and-out" or "clinker" systems. In the areas above B-deck where the scantlings were much lighter in general, joggling of the vertical frames for the deckhouses of the superstructure was employed.

Best regards,
Scott Andrews
 

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