Titanic's stern did not implode.

[Arun Vajpey]

I find the conjecture that the sinking stern of the Titanic 'imploded' soon after sinking rather difficult to comprehend, particularly in relation to the sinking stern. Why would the air pockets "burst inwards"?

I am a retired scuba diver and have visited over 25 ship wrecks around the world. Some, like the San Francisco Maru in Truk Lagoon, lie 50 metres deep. Most wrecks that I have seen are due to war damage - torpedoes and bombs - while others are due to collision with reefs, intentional scuttling etc. Most would have had large air pockets within them when they went down but none showed any signs of explosion or implosion due to pressure build-up. AFAIK, the wreck of the Lusitania, around 100 metres deep, does not show such damage either.

I realise that the wreck of the Titanic is far, far deeper and that there is some evidence of implosion but my question is at what stage of the sinking - more precisely at what depth - could it have occurred? When the ship split in half, the deck spaces in the unflooded stern section would have been exposed, yes. But there still would have been a few intact bulkheads between the split section and the extreme stern of the ship. My thinking is that it would have taken the flooding sea some time - perhaps as much as a minute - to traverse all those remaining bulkheads and other obstructions to reach and flood the rearmost spaces after the stern sank. During that time the trapped air in the stern would have been compressed and built-up pressure, which in theory might have resulted in an explosion rather than implosion. In reality, it is probably likely that the water rushing in through open portholes and other spaces equalised the pressure changes to some extent and so the implosion would not have occurred till the stern sank to perhaps 200 metres or more before the outside water pressure became too much for the hull.

That is my conjecture, anyway. Can someone with more knowledge of the physics involved please explain this further?

 

[Kyle Naber]

I think Cameron and his team estimated that the implosion took place within the first couple hundred feet. This means that it was pretty soon after the stern disappeared for good. I forget where, but there is some testimony about hearing explosions after the ship completely sank from underneath the surface.
It was probably something like this:

 

[Arun Vajpey]

Cameron et al might have estimated that way but how does it explain the fact that the Lusitania, over 300 feet deep, did not implode? Or other similar wrecks? I know that the Titanic split in two, but why would flooding through opened-up deck spaces hasten implosion? If anything, the water inside would reduce the pressure gradient with the water outside and delay implosion, as far as I can understand.

 

[Kyle Naber]

It’s possible that the weakened structure made is more vulnerable to pressure damage. A pop can with some gashes in it is easier to be flattened than an untouched can.

 

[DarrenC]

So this one is bugging me. A lot of people seem to think the stern of the Titanic imploded after being dragged down by the bow (thanks James Cameron, Titanic expert extraordinaire!), but it is just physically impossible!:

An underwater implosion occurs when a structure designed to withstand water pressure (ie: a pressure vessel) catastrophically fails. This kind of thing is usually associated with a submarine exceeding its crush depth, but the Titanic was not a submarine!

Here's a thought experiment (or a real one, if you choose). Take a glass tumbler and turn it upside down. Now immerse it into a bath of water open-end first. As the tumbler enters the water, the air inside the tumbler gets slowly compressed by the increasing water pressure, taking on less volume and allowing more water to enter the tumbler. The deeper you push the tumbler, the more the air gets compressed and the more water will enter.

The 'problem' is, it will never implode. It won't implode because the pressure inside the tumbler is equal to the pressure outside; the air inside is continually compressed (increasing its pressure) to "make room" for more water, but the air and the water are always at the same pressure.

Now, if you were to completely seal the open end of the tumbler, you would have a different story. Water would not be allowed to enter, so the pressure inside the tumbler would remain static whilst the pressure outside the tumbler increases as a function of depth. Eventually, the the pressure differential would exceed the strength of the glass walls and the tumbler would fail catastrophically (implosion).

But, again, the Titanic was not a submarine, nor was it made of glass! Even if there were trapped air pockets, the hull of the Titanic was not a pressure vessel! Even assuming the non-damaged sections of the hull were air-tight and contained trapped air pockets, the steel would deform long before any internal pressure differential could build up. She was a strong ship, but she was not designed to submerge.

Just wanted to get that one off my chest! Thank you for humoring me.

 

[Cam Houseman]

So this one is bugging me. A lot of people seem to think the stern of the Titanic imploded after being dragged down by the bow (thanks James Cameron, Titanic expert extraordinaire!), but it is just physically impossible!:

An underwater implosion occurs when a structure designed to withstand water pressure (ie: a pressure vessel) catastrophically fails. This kind of thing is usually associated with a submarine exceeding its crush depth, but the Titanic was not a submarine!

Here's a thought experiment (or a real one, if you choose). Take a glass tumbler and turn it upside down. Now immerse it into a bath of water open-end first. As the tumbler enters the water, the air inside the tumbler gets slowly compressed by the increasing water pressure, taking on less volume and allowing more water to enter the tumbler. The deeper you push the tumbler, the more the air gets compressed and the more water will enter.

The 'problem' is, it will never implode. It won't implode because the pressure inside the tumbler is equal to the pressure outside; the air inside is continually compressed (increasing its pressure) to "make room" for more water, but the air and the water are always at the same pressure.

Now, if you were to completely seal the open end of the tumbler, you would have a different story. Water would not be allowed to enter, so the pressure inside the tumbler would remain static whilst the pressure outside the tumbler increases as a function of depth. Eventually, the the pressure differential would exceed the strength of the glass walls and the tumbler would fail catastrophically (implosion).

But, again, the Titanic was not a submarine, nor was it made of glass! Even if there were trapped air pockets, the hull of the Titanic was not a pressure vessel! Even assuming the non-damaged sections of the hull were air-tight and contained trapped air pockets, the steel would deform long before any internal pressure differential could build up. She was a strong ship, but she was not designed to submerge.

Just wanted to get that one off my chest! Thank you for humoring me.

Titanic's Stern did implode, its why she's in she's in super bad condition. I will explain later.

 

[Jim Currie]

So this one is bugging me. A lot of people seem to think the stern of the Titanic imploded after being dragged down by the bow (thanks James Cameron, Titanic expert extraordinaire!), but it is just physically impossible!:

An underwater implosion occurs when a structure designed to withstand water pressure (ie: a pressure vessel) catastrophically fails. This kind of thing is usually associated with a submarine exceeding its crush depth, but the Titanic was not a submarine!

Here's a thought experiment (or a real one, if you choose). Take a glass tumbler and turn it upside down. Now immerse it into a bath of water open-end first. As the tumbler enters the water, the air inside the tumbler gets slowly compressed by the increasing water pressure, taking on less volume and allowing more water to enter the tumbler. The deeper you push the tumbler, the more the air gets compressed and the more water will enter.

The 'problem' is, it will never implode. It won't implode because the pressure inside the tumbler is equal to the pressure outside; the air inside is continually compressed (increasing its pressure) to "make room" for more water, but the air and the water are always at the same pressure.

Now, if you were to completely seal the open end of the tumbler, you would have a different story. Water would not be allowed to enter, so the pressure inside the tumbler would remain static whilst the pressure outside the tumbler increases as a function of depth. Eventually, the the pressure differential would exceed the strength of the glass walls and the tumbler would fail catastrophically (implosion).

But, again, the Titanic was not a submarine, nor was it made of glass! Even if there were trapped air pockets, the hull of the Titanic was not a pressure vessel! Even assuming the non-damaged sections of the hull were air-tight and contained trapped air pockets, the steel would deform long before any internal pressure differential could build up. She was a strong ship, but she was not designed to submerge.

Just wanted to get that one off my chest! Thank you for humoring me.

You are right, Darren. Unfortunately. many folks treat movies like encyclopedias of fact with Documentarys coming a close second. We all forget that those who procuce them do so to make money and we watch their efforts to be entertained. Unfortunately, truth takes a back seat and sensation does all the driving. Worst of all. individual reputations can be stained for all time.

I got that one off my chest.

 

[DarrenC]

You are right, Darren. Unfortunately. many folks treat movies like encyclopedias of fact with Documentarys coming a close second. We all forget that those who procuce them do so to make money and we watch their efforts to be entertained. Unfortunately, truth takes a back seat and sensation does all the driving. Worst of all. individual reputations can be stained for all time.

I got that one off my chest.

Thanks, Jim.

It was re-watching James Cameron's 'The Final Word' which made me want to vent. I just find it frustrating that some people can give themselves a global platform to espouse their 'gut feeling' ideas which even a basic understanding of the physics involved can call into question (if not outright disprove) and, in the meantime, well-researched evidence-based ideas such as the work done by the late Roy Mengot - and many contributors to these boards - get lost in the noise.

I wish people like Cameron, who have such a reach, would consider the impact of their reach and think twice before claiming something as fact. Even a simple throw-away line such as 'Titanic was called the ship of dreams' can pollute the already-overflowing disinformation pool. Now it is a part of popular culture and, ergo, fact.

...Though at least it has inspired me for a new a signature line! Would you believe I spent most of the day today researching if there were any prior-1997 references to 'ship of dreams'? I wish I had better things to do with my time than trying to prove a negative. Damn you, COVID-19!

 

[Jim Currie]

Thanks, Jim.

It was re-watching James Cameron's 'The Final Word' which made me want to vent. I just find it frustrating that some people can give themselves a global platform to espouse their 'gut feeling' ideas which even a basic understanding of the physics involved can call into question (if not outright disprove) and, in the meantime, well-researched evidence-based ideas such as the work done by the late Roy Mengot - and many contributors to these boards - get lost in the noise.

I wish people like Cameron, who have such a reach, would consider the impact of their reach and think twice before claiming something as fact. Even a simple throw-away line such as 'Titanic was called the ship of dreams' can pollute the already-overflowing disinformation pool. Now it is a part of popular culture and, ergo, fact.

...Though at least it has inspired me for a new a signature line! Would you believe I spent most of the day today researching if there were any prior-1997 references to 'ship of dreams'? I wish I had better things to do with my time than trying to prove a negative. Damn you, COVID-19!

Excellent post, Darren. - I wish I had written that.

I have something on the 'deawing board' which, if I ever finish it, will, I hope, go a long way to satisfying a need for the plain truth. At least that one thing I can thank Covid for...giving me something to do during this endless lockdown.

 

[Cam Houseman]

Excellent post, Darren. - I wish I had written that.

I have something on the 'deawing board' which, if I ever finish it, will, I hope, go a long way to satisfying a need for the plain truth. At least that one thing I can thank Covid for...giving me something to do during this endless lockdown.

Titanic’s Stern did implode. The air that was trapped within her hull built pressure. Think of when you’re washing the dishes, and you flip a cup of bowl down and press it on the bottom of the sink. There’s an air pocket!

See, the deeper you go, the more pressure that air pocket is subjected to. Think of how much pressure the Stern’s remaining air pockets had to deal with, within the first 300-400 feet. Boom! The subsequent implosions blew out Walls and supports, explaining why when the Stern landed, everything pancaked. And, there’s huge mounts of Hull, and superstructure that’s missing. Basically, when the Stern landed and broke her back, the job was finished.

how else do you explain the Stern’s appearance? The Bow retained its entire structure!

 

[Jim Currie]

Titanic’s Stern did implode. The air that was trapped within her hull built pressure. Think of when you’re washing the dishes, and you flip a cup of bowl down and press it on the bottom of the sink. There’s an air pocket!

See, the deeper you go, the more pressure that air pocket is subjected to. Think of how much pressure the Stern’s remaining air pockets had to deal with, within the first 300-400 feet. Boom! The subsequent implosions blew out Walls and supports, explaining why when the Stern landed, everything pancaked. And, there’s huge mounts of Hull, and superstructure that’s missing. Basically, when the Stern landed and broke her back, the job was finished.

how else do you explain the Stern’s appearance? The Bow retained its entire structure!

Hello Cam.
When a ship sinks, air trapped in compartments is at sea level pressure. As the ship sinks in salt water, the sea water pressure increases by 64 lbs./ cu ft. for ever foot it sinks. very soon, the outside pressure pushes every last vestige of surface air out of the ship. That is what saved Lightoller and Colonel Gracie.
When all the air was pushed out and replaced by sea water, then the pressure outside and inside equalised. Consequently, there was no differential of pressure in any compartment. Not even a tank since all tanks would be ventilated.
As for the damage you see? Think of a multi-story car park falling from the sky onto the dessert...what do you think would happen? Also, what do you think caused the side-way displacement of the shell plating in the forward section of the wreck?
Think "telescope"

 

[Cam Houseman]

Hello Cam.
When a ship sinks, air trapped in compartments is at sea level pressure. As the ship sinks in salt water, the sea water pressure increases by 64 lbs./ cu ft. for ever foot it sinks. very soon, the outside pressure pushes every last vestige of surface air out of the ship. That is what saved Lightoller and Colonel Gracie.
When all the air was pushed out and replaced by sea water, then the pressure outside and inside equalised. Consequently, there was no differential of pressure in any compartment. Not even a tank since all tanks would be ventilated.
As for the damage you see? Think of a multi-story car park falling from the sky onto the dessert...what do you think would happen? Also, what do you think caused the side-way displacement of the shell plating in the forward section of the wreck?
Think "telescope"

You have a point, but not the lower decks, like cabins and things. How would the Propeller shaft vent it’s air? Or the Third Class cabins? The Bow was able to force the air out, but not the Stern. Where would the air go once the Stern went under? The air had nowhere to go. Thus, she imploded, probably within 400 feet.

had the Stern not imploded, it probably wouldn’t have been forced into a helicopter spin, and slam 40 miles an hour into the sea bed.

Oh, and the damage to the Hull plating? That was a result of the impact. The impact caused the entire Starboard hull to be blown outwards, like how the Bow’s number one hatch was blown forwards. Water can’t be compressed.

EDIT: not the entire Starboard Hull, as the Hull On the Fantail is still there, but it begins to splay out from the Well Deck— or what used to be the Well Deck.

Speaking of that, the Well Deck was blown outwards as well, and that’s why only the Starboard Crane remains. So, the Well Deck is now D-Deck

 

[Jim Currie]

You have a point, but not the lower decks, like cabins and things. How would the Propeller shaft vent it’s air? Or the Third Class cabins? The Bow was able to force the air out, but not the Stern. Where would the air go once the Stern went under? The air had nowhere to go. Thus, she imploded, probably within 400 feet.

had the Stern not imploded, it probably wouldn’t have been forced into a helicopter spin, and slam 40 miles an hour into the sea bed.

Cam.

Every ship's cabin had ventilators of some kind. Otherwise, passengers would have suffocated like those poor unfortunates who were recently locked in a shipping container. Additionally, cabin doors and ally-way doors would also have been left open when the occupants went up on deck.
At the moment of impact with the sea bed. water within compartment would try to displace. However, unlike air, it could not displace the water out side, so the vertical structures such as side frames, shell plating would simply buckle downward and outward. The internal compartmental framing which would have been light and part wood part steel would also have buckled
The propeller shafts were solid and mounted within stern tubes which would have had little or no air in them. Any air which had been in them would have long since been pushed out through the shaft bearings by sea water. Incidentally, sea water acting on lignum vitae bearings was used to lubricate the stern tubes.

 

[Cam Houseman]

Cam.

Every ship's cabin had ventilators of some kind. Otherwise, passengers would have suffocated like those poor unfortunates who were recently locked in a shipping container. Additionally, cabin doors and ally-way doors would also have been left open when the occupants went up on deck.
At the moment of impact with the sea bed. water within compartment would try to displace. However, unlike air, it could not displace the water out side, so the vertical structures such as side frames, shell plating would simply buckle downward and outward. The internal compartmental framing which would have been light and part wood part steel would also have buckled
The propeller shafts were solid and mounted within stern tubes which would have had little or no air in them. Any air which had been in them would have long since been pushed out through the shaft bearings by sea water. Incidentally, sea water acting on lignum vitae bearings was used to lubricate the stern tubes.

You got me there, Jim. Guess we’ve arrived at that point where we’ll disagree

I am still of the mind the Stern imploded! The Bow, was full of water. Barely anything tore off, excluding the Lifeboat Davits and Vents. But yet, the Stern is missing a 70 foot section. Lifeboat davits and after davits, gone. The Poop Deck is folded back, a result of the implosions loosening rivets, “like a deck of cards caught in the wind”

and, the Survivors reported hearing booms, after the Stern left the surface. It’s scientifically impossible the Stern did not implode, with the amount of air still within the Hull. If the Stern did not implode, why doesn’t the Bow like the Stern? The Forecastle deck didn’t fold back! The impact would not cause the Smoking room and smoking room roof to be gone on the Stern.

as for the occupants, there’s ample evidence passengers were still inside.

 

[Cam Houseman]

But, again, the Titanic was not a submarine, nor was it made of glass! Even if there were trapped air pockets, the hull of the Titanic was not a pressure vessel! Even assuming the non-damaged sections of the hull were air-tight and contained trapped air pockets, the steel would deform long before any internal pressure differential could build up. She was a strong ship, but she was not designed to submerge.

If the ship did not implode, where did the air go? Air cannot simply vanish and be replaced with water.