Why did the number 1 funnel collapse


May 9, 2001
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As Titanic sank down by the head, the angle of the boat deck began to tip forward. At about 2:00am the sea reached the boat deck and the bridge began to flood. Moments later, the forward funnel collapsed and fell into the sea, crushing the bridge and killing many people swimming in the water.

I've seen animation of the sinking, and I've played with the angle of the ship during the sinking myself, and I still can't understand why the forward funnel suddenly collapsed.
The funnels were not top heavy that I'm aware of, and they were all secured to the superstructure with 6 heavy cables. (I think its 6, but not positive about that)
Even though the angle of the deck reached about 20 degrees, thats not unusual for a ship to endure especially during rough weather, right?
And why didn't the other three funnels also collapse at that point?

So what was different about the forward funnel?
Why did it tear loose?

Yuri Singleton
 

Paul Rogers

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Nov 30, 2000
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Hi Yuri.

May I have a stab at this one? No. 1 funnel was sited in front of the forward expansion joint. However, some of the cables supporting the funnel were afixed aft of the expansion joint.

When the expansion joint began to open as the bow sank under the sea, the cables were stretched to breaking point. When they finally snapped, the weight of the funnel caused it to collapse, as it was no longer supported from behind.

I read somewhere that the anchoring points for the #1 funnel cables on Britannic were moved forward of the expansion joint after Titanic sank, as their original siting was seen as a (minor) design flaw.

Hope this helps.

Regards,
Paul.
 
Mar 3, 1998
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Paul,

I hate to contradict you, but I have run some modeling on this. It wasn't the failure of the guy wires that caused the funnel to collapse, but rather the differential of pressure between the water around the base of the funnel uptakes and the air inside. Think of an inverted empty glass being pulled under the water as an over-simplified example. There was enough slack in the guy wires to accommodate movement in the expansion joint; otherwise, you'd be snapping cables during heavy weather. I believe the wires failed when the funnel was swept off its base.

Parks
 
May 12, 2005
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Gentlemen,

Couldn't the stress on the decks owing to the weight of the water in the bow (which culminated in the breaking away) have at least partly caused the funnel to fall? What Paul has said seems quite reasonable to me. Not that the other factors Parks suggests weren't there too. But the stresses on the submerged portion of the ship, if they were as great as is believed, could not be compared to that caused by a normally heavy sea. It just seems that the wires, after the slack was taken out by the bending decks, would have finally snapped.

Randy
 

Paul Rogers

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Parks,

Thanks for your post. Yet again I have to learn the lesson not to believe in everything I read, but to go back to the source and check, check, check! I wish I could remember where I read that info on the cables now...

Was I wrong that the Britannic had her cables moved to forward of the expansion joint? (I'm sure I read this somewhere!) If so, what was the given reason for the change?

Perhaps Randy has got it right. One question I have, which touches on what Randy says, is as follows:

When I believed the "snapping cables" theory, I was working on the assumption (careful!) that when the funnel collapsed, the expansion joint had opened A LOT further than the original design had envisaged - thus causing the stress and final failure of the cables.

I based this assumption on the state of the expansion joint as we see it today. After all, the ship was near breaking when the funnel collapsed and, after she did break, there should have been a reduction in the bending force on the joint. Thus, the expansion joint must have opened a LONG way by the time the funnel fell....further than the cables could stretch, perhaps?

What do you guys think?

Regards,
Paul.
 
Mar 3, 1998
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Randy,

I think you're alluding to the same forces I am, but instead of decks, think of the comparatively weaker steel of the superstructure and funnel uptakes, rather than the decks themselves. The "weight" (I think in terms of pressure) of the water building around the empty (air-filled) uptakes as the bow filled and submerged pressed in until a portion of the uptake gave way, allowing water down the uptakes and causing the upper structure of the funnel to collapse. The wires finally snapped when the funnel fell forward.

Could the funnel have fallen of its own weight had the funnel stays snapped? I count 4 out of 12 wires supporting the funnel straddling the expansion joint break. So presumably, if those four wires broke, the funnel is free to fall forward. Or is it? Normally, the funnels has an aftward rake of about 8.5 degrees (I'm pulling that number off my protactor. According to the model presented in the Hackett/Bedford analysis of the sinking, the ship trim was somewhere between 7 and 12 degrees at the time the funnel collapsed (between Conditions C-6 and C-7 in their analysis). This means that the funnel was either perpindicular or even leaning a little forward. Let's say those aft 4 stays failed because they didn't have enough slack to accommodate the opening of the expansion joint. That leaves two more stays which, given the new angle of trim, are supporting the funnel from falling forward. Why would the funnel fall? There was no extreme angle forward...at most, the funnel was leaning forward 4 degrees or so. With 8 stays supporting it, I just don't see the funnel falling due to simple gravity.

As some of you know, this runs counter to the argument that is presented in the final report on the disaster from the Marine Forensic Panel. This is an example of an area where, even though I am a member of the Panel, I take an alternate view.

Parks
 

Bill Sauder

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Dec 19, 2000
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The idea that differential flooding caused the collapse of the funnel was first put forward by Edward Wilding, a naval architect for Harland & Wolff at the BOT Inquiry in 1912. Like Parks, he proposed that the outside of the funnel and casing flooded faster than the inside, the water pressure causing the structure to collapse and bring the funnel down.

The broken stays/expansion joint theory was first put forward by one of the surviving deck officers (Lightoller I think — G. Behe would know for certain) and was given wide circulation by Walter Lord’s “Night to Remember”.

Between the two, I prefer Wilding’s partial flooding theory. Aside from his qualifications, the theory has better reasoning behind it and a non-spectacular ring to it.

The broken stays theory has several difficulties. First, funnels have to withstand extreme inclinations while rolling and pitching in a storm. (although funnels have broken off in storms, the cause was attributed to extreme acceleration on account of the ship’s cargo being loaded to make her very “stiff”, not degree of roll). Second, funnel guys are rigged to allow for the natural expansion of the funnel with heat, plus normal working of the ship. I feel that there was more than enough slack in the guys to accommodate deflection of the structure as the ship sank. Parks has already made the case for objections based on surviving stays afore the expansion joint supporting the funnel and the possibility that the trim for the bow section was not as dramatic as shown in movies for the sake of its horror factor.

Bill Sauder


20919. (Mr. Laing.) There is evidence that certainly one, and I think two, of the funnels fell? — (Mr. Wilding) Yes.

20920. I think the evidence is that the forward one and the after-one fell? - Yes.

20921. What would account for that? - The funnels are carried from the casings in the way of the comparatively light upper decks - that is, the boat deck and A deck. When these decks became submerged and the water got inside the house, the water would rise outside much faster than inside, and the excessive pressure on the comparatively light casings which are not made to take a pressure of that kind would cause the casing to collapse; would take the seating from under the funnel and bring the funnel down.

Testimony excerpts from the Board of Trade Inquiry curtsey of The Titanic Inquiry Project -- http://www.titanicinquiry.org/
 

Bill Sauder

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A few notes on expansion joints and funnel guys.

The Olympic/Titanic’s superstructure was constructed with two expansion joint. This number was increased to three joints for the Britannic and the placement of the joints rearranged to equalize their spacing.

I suspect that this may have been done for one or both of the following reasons:

1. When the new gantry davits were designed for Britannic, it was realized that the superstructure needed to be strengthened to accommodate the additional load and so the weight of the deckhouse reduced as much as possible to reduce top hamper. A deckhouse built of even lighter material will require the introduction of additional expansion joints, to limit the fore-and-aft run of the deck house side and to prevent overloading and deformation in any one section.

2. It is possible that deformities / cracks were showing up in the deckhouse on the Olympic from ordinary working of the structure in a sea way, suggesting that an additional joint would help contain local failures with out resort to heavier material.

It should be noted that Titanic was unusual in that she had only two expansion joints leaving a midship section of about 220 feet — that’s a tremendous length for a midship’s deckhouse as the following small table will show. Cunard liners typically had three joints (as well as Britannic) and this helps reduce the midship’s sections of deck length considerably.

Mauretania midships deck section length : abt 100 feet each
Aquitania midships deck section length: abt 100 feet each
Britannic midships deck section length: abt 126 and 159
Titanic midship deck section length: abt 220 feet

I would also point out that even after the redesign on the expansion joints, Britannic’s funnel guys cross over them to adjacent deck sections. This was also the case on the Mauretania, Aquitania, and Queen Mary.

Bill Sauder
 
May 12, 2005
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Parks & Bill,

I stand happily corrected and convinced. Thanks for the details. Those of us without the technical knowledge need it explained; at least I do. So thanks again.

Randy
 

Paul Rogers

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Parks and Bill,

I echo Randy's words. And Bill, thanks for the additional info on Britannic's expansion joints. Fascinating stuff!

What amendments in regards to expansion joints and/or funnel guys were made to Olympic, BTW? Or did WSL just live with the cracks in the superstructure?

Regards,
Paul.
 
Dec 2, 2000
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FWIW, I don't think the Olympic's basic structure was really altered. At least not to the point of adding an expansion joint. Such a modification would have required a nearly complete(Meaning expensive) rebuild of the superstructure and a prolonged dockyard period.

Of course, there were internal modifications, after the Titanic's loss, but that involved adding things to what already existed. Raised watertight bulkheads for example, double hull, extra lifeboat provisions and so on.

I'd go into greater detail if I had a more reliable source

Cordially,
Michael H. Standart
 
Mar 3, 1998
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It's too long to go into here, but I can point you to Simon Mills' "RMS Olympic: The Old Reliable," which recounts the sad tale of Olympic's material decline during the late 1920s-early 1930s.

Parks
 
Mar 3, 1998
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Michael,

I can't say if THS carries that book, but I got my copy from iBS.

Olympic was placed on the BOT's Confidential list as early as 1927. In 1931, the BOT only granted a seaworthiness certificate for a six-month period while repairs were effected. In 1932, White Star itself informed the BOT that Olympic would be restricted to 21 knots.

Total replacement of the topside shell plating was required, and with a price tag of over 100,000 pounds Sterling, the work could not be justified for a liner of Olympic's age.

Parks
 

Bill Sauder

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Paul and Randy:

Thanks for your recent kind comments about my notes on the Titanic's expansion joints and funnel rigging. There were a few loose ends that I wanted to tie down.

Paul asks "What amendments in regards to the expansion joints and/or the funnel guys were made to Olympic? Or did WSL just live with the cracks in the superstructure?"

I was only speculating about cracks showing up in Olympic's deck house because of metal fatigue through an insufficient number of expansion joints, but given the ship's history late in her career, I don't think it's unreasonable. Any cracks would most likely show up at the lower corners of the deck house windows and possibly where the deck channel passes through the deck house side (Its covered by a cast iron shoe in most photos).

Any cracks in the deck house side would be mostly a cosmetic concern, and so a small patch or "doubling" could be welded over to help arrest its advancement and hide the fault.

If you look at the side of the QE2 you will see dozens (maybe a hundred now) of similar patches on her promenade deck side screen windows (the large square windows on the sides of the ship, right under the Boat Deck). Either Cunard or John Brown decided to do away with expansion joints and make the entire superstructure cooperate in the overall hull strength. That meant that these square windows are BELOW the strength deck -- a major Bozo no-no. Square windows have a tendency to focus stress in their corners and cause cracks radiating from them in the metal. That's why portholes are round and shell doors have generous radii in the corners and heavy doublings at the top and bottom. There were several witless moments in the QE2's design, this is one of the more obvious.

Parks said : "the funnels has an aftward rake of about 8.5 degrees."

Close, but not quite. The Titanic's funnels had a rake of 2 inches in 12 or 9.5 degrees.

Also: "It's too long to go into here, but I can point you to Simon Mills' "RMS Olympic: The Old Reliable," which recounts the sad tale of Olympic's material decline during the late 1920s-early 1930s."

A summary from My Friend Simon's book (Did I really say that?):

1926 stem frame replaced
1926 number of small cracks starboard side of Bridge deck.
1927 similar cracks discovered on port side, Olympic placed on BOT's Confidential list.
1929 new stem frame heavily pitted
1930 pitting had advanced alarmingly and stem sheathed in white metal.
1930 cracks detected in 1927 in bridge deck advancing. Extensive welding and fitting doublers over the affected areas.
1931 strain deterioration in A deck support girders forward of Number 2 funnel -- large number of slack rivets near the aft expansion joint. BOT grants a certificate of seaworthiness for a period of six months; renewed six months later.
1932 Olympic limited to 21 knots to mitigate hull stresses
1932 cracks found in Olympic's engine bedplates, thrust block foundations and part of the crank shaft.

Mike writes: I don't think the Olympic's basic structure was really altered. At least not to the point of adding an expansion joint. Such a modification would have required a nearly complete (Meaning expensive) rebuild of the superstructure and a prolonged dockyard period.

I agree. Post IMM White Star was in serious financial difficulties. The money was not available in the depression for anything more than Band-Aids.

Bill Sauder
 
Mar 3, 1998
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*Close, but not quite. The Titanic's funnels had a rake of 2 inches in 12 or 9.5 degrees.*

Bill,

I was hoping you would chime in with the actual figure. Mine was a WAG...I pulled a protractor from my son's school supplies and took an eyeball measurement off that big blue picture hanging on the wall over my desk. Close enough for government work, as we like to say at work. :)

And to think it's guys like me whom the Navy depends upon for its highly sophisticated weaponry. :)

Parks
 

Erik Wood

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Apr 10, 2001
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Hello All,

I have some small experience in this. The STC cables are brought or used to be as some one pointed out they are not used anymore they are brought tight to keep even tenision around the entire stack. As someone also pointed out cables are fitted with extra wire. But basically it is bolted and spot welded to the base of the Sun Deck, Boat Deck whatever the case may be as well as beeing fit into the top side of the boiler casing. So to keep the stack from moving from side to side in heavy weather they attach the guide wires or STC cables to keep it in place. As someone else also pointed out expanison joints for the most part are a thing of the past. I am in now way a naval engineer but I have seen them attach many a stack in my day and I THINK that it is the combination of both the bolts welding and stuff with the guide wires that keep it in place. Now days they just weld and bold and the stack in reenforced into the inside of the exhaust casing.

To be honest I have never really thought on why the ships forward funnel fell. One would think that it was a combination of the internal air, the bending and breaking of the joints and the extreme tension on the aft set of guide wires which I am sure probably snapped. Plus you have the natural downward angle of the ship.

Not that long ago a emergency steam release valve basically exploded and sent part and rather large chunks through the boiler casing and ripped three giant holes in the stack shell cutting in half three of the forward guide wires. The Captain (not me) ordered the ship stopped and the steam taken out of the that stack. The engines then used box patches on the stack and reattached (using mooring cable)cables to the deck.

Just some thoughts and insight.

Erik
 
May 9, 2001
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When the funnel collapsed, it fell forward, sending out a great wave in the water, and crushing the bridge and officers' quarters. This damage is seen on the wreck today.

Since the funnel was of a light construction, it would naturally have flattened out upon impact with the water, as the water would have received the majority of the momentum from the falling object.

So why didn't the collapsed funnel, settle down softly onto the roof of the bridge and remain there, doing little damage?
The fallen funnel would still have been attached to the superstructure by the remaining cables.

If it had continued to settle forward and slide off of the bridge as the bow tilted down, it should have fell onto the well deck and became entangled on the forward cargo cranes, where we should see it today.

But today, we see little damage to the cranes, and no trace of the funnel in the well deck. So what happened to the funnel after it fell? What destroyed the bridge?

I think this is one possible explaination. Its based solely on my own imperfect understanding of all the facts and details of shipbuilding and of the construction of Titanic, and mostly on my vivid imagination. So take it for what its worth.

2:10am April 15th, 1912. The funnel is standing upright, but under increasing strain as the ship tips forward to an angle of about 20 degrees nose down. This puts the funnel at a true tilt angle of about 10 degrees relative to the surface of the water. The support cables aft and abeam the base of the funnel are taught but the ones forward of the base are slack.

Sea water is flooding the ship's superstructure from above C deck through windows and open doors, spilling into the cabins of A deck and B deck and washing down the stairways to meet the water coming up from below. The bridge is submerged under about 15-25 feet of water, and the base of the forward funnel is awash in about 5-10 feet of water. Second Officer Lightoller is struggling to get free from the air vent where inrushing water has pinned him against the vent screen.

Then, something happens. Some occurance that is yet unknown. Whatever it is, it causes a violent rush of air up the boiler casing and out through the vents, freeing Lightoller. It also causes damage to the boiler casing walls in the upper decks and rattles the forward funnel violently. This causes the aft support cables to snap.

The funnel now is supported only by its weakened base of thin metal. Its tilted forward at about 15 degrees. As the base of the funnel is further submerged the water pressure increases until the sides of the funnel implode. This implosion creates a buckle, or weak spot that serves as a pivot point for the funnel to twist on. Sort of like when you cut down a tree. You cut the base away and create a pivot point which guides the direction of the fall.

The funnel's top leans and falls almost straight forward as it is guided by the remaining support cables. On its way down, the support cable running from the top of the funnel to the forward mast is given slack and then powerfully snapped tight as the funnel finally hits the water. The mast is jolted backward by this tug and buckles at the base on the forecastle. Yet it remains standing for a few moments supported by its own support cables and the marconi antenea.

The funnel smashes into the water. Its internal framing is destroyed on impact and all the pipes inside the funnel are torn apart from their fittings.

The impact of the funnel into the sea displaces the water between the surface and the roof of the bridge below with emense force. While the funnel never directly contacts the bridge at impact, the force of the displaced water beneath it crushes the roof of the bridge and splayes out the walls. Anything inside the wheel house is completely destroyed.

The wreck of the funnel sinks onto the wreck of the bridge and comes to rest. The funnel is still attached to the ship by a few shards of metal at the base of the funnel and by the remaining 6 support cables.

Water whirlpools into the open hole left at the base of the collapsed funnel. Eventually filling the boiler casing along with the rest of the forward sections of the ship.

As Titanic sinks further, its tilt angle increases until the stern of the ship breaks away and the bow section then drops to almost 90 degrees nose down. When this happens, the forward funnel trys to slide off the ship but is held on by the support cables. It slides around on top of the bridge area. It mows down both wing bridges as it moves around.

The second funnel has now broken away and smashes the top of the grand staircase, destroying the dome and making an opening for the remains of the grand staircase to wash out of the ship as it sinks.

As the bow section begins to plunge down to the bottom the lighter funnels try to drift away from the ship but are held by the remaining support cables.
The funnels drag along the top of the ship for a moment or two when the final cables snap and they are swept clear of the bow section by the rushing water currents.

The main mast is swept aft by the rushing water and falls down against the crushed port wing bridge. Where is stays to this day.

The remains of the funnels are never found, so far as I know, although the steam whistles are discovered in the debris field and recovered.

This theory is 99% speculation. But I think it fits the evidence that we see at the wreck site. It also explains the paradox of damage to the bridge area when it was submerged. The Funnel did not directly destroy the bridge. The force of the water, displaced by the funnel falling caused the bridge enclosure to explode outward.
This theory also covers the damage to the roof of the grand staircase. Both areas were destroyed and both are directly forward of the two forward funnels.

Yet the initial event that caused the forward funnel to break its support cables so early is unknown. What was it that caused the aft support cables to snap? I speculate that they should have remained intact until the bow section broke away. For them to snap so early indicates that something else happened to cause them to fail.
The collapse of the forward funnel happens immediately after Lightoller is blasted free of the boiler vent by an explosion of air as he describes it. That leads me to think that there was a bubble of hot air somewhere below in the ship that finally burst free and exited the ship upward through the boiler casing. That could easily cause serious damage to the funnel. So I point to that event as the key to the failure of the aft cables. Of course I could be wrong.
For all I really know the funnel could have collapsed because people swimming in the water over the bridge tried to climb up the forward sides of it to get out of the water and overloaded it until it fell. Who can tell for sure.

Anyways, my final thought on this is that when the forward funnel fell, it didn't just vanish. It was still an active participant in the destruction of the ship. When the funnel fell, it caused changes to occur. Is this when Capt. Smith finally perished, when his cabin was laid flat by the impact forces? Was the log book blown out of the ship to be lost in the ocean? What would have happened to Mr Lightoller and the rest on the overturned collapsible if the funnel had not fell with such force?

Some things seem almost to defy reason when considering Titanic. Like the ship's wheel mount. How is it that it survived when everything else around it was flattened? Why is the forward mast still attached and not utterly swept away? Why do the forward cranes show almost no damage when only two decks above them is devastaion?
Questions beget more questions.

Titanic, ship of questions.

Comments....?

Yuri
 
Mar 3, 1998
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Yuri,

A well-thought scenario, but I have some questions:

Where did you get the number of 20 degrees of bow trim when the forward funnel fell? The Hackett-Bedford analysis puts it at somewhere between 8-12 degrees.

Why do you say the funnel stays snapped early?

Why do you call the line running from the funnel to the forward mast as a support cable? I was not aware that that cable was used for support of either the mast or the funnel and therefore would have had any major impact on the mast when the funnel collapsed.

Why should the forward funnel remain on the ship any longer than the three remaining funnels?

I do agree with you that the falling funnel (or the pressure transmitted through the water) damaged a high-interest area of the ship and therefore could have been the end for some of the more well-known personages.

Parks
 
Dec 2, 2000
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Sparks, I checked the THS website last night and they do have the title available. It's a 64 page book, but very highly regarded from what I've heard. I'll have to get it.

That 100,000 pound sterling price tag for the job you mentioned must have caused some faces to go white on the Cunard-White Star Board of Directors. Not much of a surprise though. she was pretty well worn by that time.

Cordially,
Michael H. Standart