White Paper on the Grounding of Titanic
Copyright © 2003, David G. Brown and Parks Stephenson
Presented for consideration by the
Marine Forensic Panel (SD-7)
chartered by the
The Society of Naval Architects and Marine Engineers
Gibbs & Cox, Inc., Suite 700, 1235 Jefferson Davis Highway, Arlington, Virginia
Thursday, May 31, 2001
Updated (addition of images only): February 6, 2003
1.0 Purpose The purpose of the paper is to set forth the argument that Titanic grounded on an underwater shelf of the iceberg, compromising her double bottom structure. The combination of direct impact damage suffered along the ships bottom and subsequent racking damage which parted plates along her starboard side allowed enough water into the hull so that the internal subdivision was overwhelmed.
The definitions for nautical terminology of relevance to this discussion can be found in Appendix I.
1.1 Assumptions For purposes of this discussion, it is assumed that Titanic was turning towards the iceberg at the time of collision and that her reciprocating engines were stopped. The rationale for this assumption is detailed in Appendix II.
1.2 Descriptions A reference for Titanics structure and internal subdivision can be found in Appendix III. A physical description of the iceberg is detailed in Appendix IV.
The most significant aspect of Titanic's iceberg encounter was that most people on the ship did not realize anything particularly unusual or important had happened. The majority of passengers slept through the most fateful seconds of their lives. Aside from those located deep within the forward portion of the ship, no one felt a great impact, or heard a deafening roar. There was only a slight tremble or a distant noise:
"It is best described as a jar and a grinding sound. There was a slight jar followed by this grinding sound....then thinking it over it was a feeling as if she may have hit something with her propellers....There was a slight jar followed by the grinding--a slight bumping...naturally, I thought it was from forward...[the grinding noise] lasted a matter of a couple of seconds..."
C.H. Lightoller, Second Officer, Officer's Quarters
"Well, I did not feel any direct impact, but it seemed as if the ship shook in the same manner as if the engines had been suddenly reversed to full speed astern, just the same sort of vibration, enough to wake anybody up if they were asleep...Not as if she hit anything straight on - just a trembling of the ship."
Able Seaman Joseph Scarrott, Forecastle Head
"At the time of the collision I was awake and heard the engines stop, but felt no jar. My husband was asleep."
Emily Bosie Ryerson, Passenger, Cabin B-63
"I was dreaming, and I work up when I heard a slight crash. I paid not attention to it until I heard the engines stop."
C.E. Henry Stengel, Passenger, Cabin C-116
"There was just a small motion, but nothing to speak of."
Pantryman A. Pearcey, 3rd Class Pantry, F Deck
Anecdotal evidence of this nature is normally treated with deserved circumspection by forensic accident examiners. However, in this instance, we have more than a single random observation. Many of the eyewitness descriptions of the impact contain common key elements: the event lasted only a few seconds, there was no strong jolt, a faint noise (sometimes described as a grinding of metal) emanated from the bottom of the ship. Equally significant are the details that are universally lacking from eyewitness descriptions. There were no tales of people being flung from the upper bunks by the force of the crash. No first-class passengers were pitched headlong down the famous Grand Staircase. Tables remained upright and drinks did not spill in the smoking rooms. Overwhelming agreement of survivors was that the meeting of Titanic's 53,000 tons (displacement) of steel with probably hundreds of thousands of tons of ice was a soft event.
Ship collisions with icebergs are usually not soft events. Three days prior to Titanic's fatal accident, another ship ran into the same field of ice. The French passenger liner Niagara ran headlong into an iceberg on the evening of Thursday, April 11, 1912. That accident occurred while passengers were enjoying dinner. The result was devastating, if press accounts, such as the following from the New York Herald, can be believed:
Passengers were hurled headlong from their chairs and broken dishes and glass were scattered throughout the dining saloons. The next instant there was a panic among the passengers and they raced screaming and shouting to the decks..."I thought we were doomed," said Captain Juham yesterday. "At first I feared we had been in collision with another vessel as I hurried to the bridge. But when I saw it was an iceberg and that we were surrounded by ice as far as we could see through the fog, my fears for the safety of the passengers and the vessel grew....I am sure Captain Smith had a similar experience in practically the same locality when the Titanic went down."
New York Herald
April 17, 1912
Despite their hair-raising experience, all passengers aboard the French liner survived, and the ship made its way to port. Perhaps because of Niagara's survival, it has become fashionable to blame First Officer Murdoch for not hitting the berg squarely on the bow. This, of course, is not a practical solution for a deck officer, no matter the imagined benefits. The discussion about a head-on collision, though, brought out an interesting point about the effect of a collision against the bow of a large ship, such as Titanic. Edward Wilding, the senior Naval Architect under Thomas Andrews at Harland & Wolff, testified during the British Board of Trade (BOT) Enquiry that in the case of a head-on collision, the bow of Titanic would have deformed much like the "crumple zone" of a modern automobile. This crumpling would have dissipated much of the force of the blow by spreading it out over several seconds. According to Wilding, telescoping of the ship in this manner would have reduced injuries among passengers and crew who were lucky enough not to have been trapped in the compacted sections of the bow.
While less dramatic than a head-on impact, the more-often invoked "glancing blow" at 22.25 knots would have created its own kind of havoc. At impact, the deck would have jumped sideways relative to anything not riveted to it. This "rebound effect" would have been as disruptive to people in the forward third of the ship as a major earthquake is in a large hotel ashore: sleeping third-class passengers in the bow would have been tossed out of their bunks; personal items would have been sent flying; people walking in the corridors would have been thrown to the deck. Either type of impact head-on or glancing would have been an unforgettable experience. None of the more than seven hundred survivors recalled such a dramatic event. Except for the men in the stokeholds, the survivors recalled the accident as a slight tremble of the ship...a distant rumble.
What a sailor might call "rebound" is otherwise known as "impulse and momentum." The sideswipe scenario envisions the hull striking the ice, then rebounding to strike again... and again...for nearly 300 feet along the bow. Second Officer Charles Lightollers description of the collision in his 1935 autobiography is typical of the view held by most:
"The impact flung her bow off, but only by the whip or spring of the ship. Again she struck, this time a little further aft. Each blow stove in a plate, below the water line, as the ship had not the inherent strength to resist."
Charles H. Lightoller
The Story of the Titanic, 1935
In theory, Titanic could have been so unlucky that her side was thrown against an underwater ram with exactly enough force to significantly deform her steel shell plating, but not enough force to throw people out of bed. This seems highly unlikely, though, considering that the ship maintained 21 knots or more throughout the collision event. More typically, a single sideswipe impact oftentimes produces a substantial hole at the point of contact, with little damage elsewhere.
If the ship did not sideswipe the berg, though, what could account for the damage so obviously suffered? It is the contention of the authors that Titanic struck on an underwater shelf of the iceberg as she attempted to port around the portion that was visible above the surface. In other words, Titanic grounded briefly on the ice.
"...It seemed almost as if she might clear it, but I suppose there was ice under water."
Lookout Reginald Lee, Crows Nest
Titanic's bow featured a distinct cutaway at the forefoot (Fig. 7). The keel member was straight beneath the engine spaces and boiler rooms. Just forward of bulkhead "B," it began to rise at approximately a 14 degree angle until it met the forefoot at the stem. As will be shown, the significance of this design is that Titanic did not attain its full draft until the after end of Hold #1, just before bulkhead "B." A grounding event would have brought two wedge shapes into contact: the ships angled forefoot and the sloping underwater portion of the iceberg. There would be no hard impact of a vertical wall of steel against ice. Instead, the initial contact would have been lessened by the shapes of the objects involved. Titanic's forefoot rose at about a 14 degree angle so that beneath bulkhead "A" at frame 140, it was about 8' 4" above the depth of the keel. For this reason, the bottom along the forefoot would have absorbed just a small fraction of the ship's weight during the first instant of contact. As the wedge shapes of the hull and berg came into full contact, the steel hull pressing against the ice would have immediately crushed the softest portions of the ice, revealing the harder core underneath. Sliding onto mud or sand may produce almost no sound or vibration river barge operators may not notice their tows are aground until forward progress virtually disappears. In this case, the action of Titanics steel hull striking the hard core of the ice surface can produce a sound like marbles pouring over sheet tin, or links of chain running out the hawsepipe:
"I was just sitting on the bed, just ready to turn the lights out. It did not seem to me that there was any very great impact at all. It was just as though we went over a thousand marbles. There was nothing terrifying about it..."
Mrs. J. Stuart White, Passenger, Cabin C-32
"What awakened me was a grinding sound on her bottom. I thought at first she had lost her anchor and chain, and it was running along her bottom."
Lookout George Symons, Crews Quarters ("up forward")
"A noise; I thought the ship was coming to anchor."
3rd Officer Pitman, Officers Quarters
Grounding pressure would have been relatively light as the sloping forefoot met and then rode across the underwater portions of the iceberg. At frame 118, some ten feet ahead of bulkhead "B," the situation changed. The slope of the forefoot ended and the straight line of the ship's keel began. Logically, it would be at this point that Titanic would have felt full grounding pressure. Additionally, there should have been some greater shock to the ship's structure as this portion of the hull passed onto the ice:
"I felt as though a heavy wave had struck our ship. She quivered under it somewhat. If there had been a sea running, I would simply have thought it was an unusual wave which had struck the boat."
Maj. Arthur C. Peuchen, Passenger, Cabin C-104
"During the time she was crushing the ice, we could hear a grinding noise along the ship's bottom."
Quartermaster Robert Hitchens, Wheelhouse
"It was not a violent shock not a bad jar a rumbling noise for about 10 seconds; somewhere about that "
Able Seaman W. Brice, outside Seamans Mess Room
" there was a kind of shaking of the ship and a little impact, from which I thought one of the propellers had been broken off."
Steward George F. Crowe, approximately 50 feet forward of amidships, E Deck
Sliding across the underwater ice ram could have lifted the starboard side of Titanic to some small extent. This lifting might have been virtually unnoticeable inside the hull on the lower passenger decks. On the other hand, the 90-foot height of the crows nest was the best place to detect a slight roll of the ship:
"...The ship seemed to heel slightly over to port as she struck the berg...very slightly to port as she struck along the starboard side."
Lookout Reginald Lee, Crows Nest
It appears that First Class passenger Hugh Woolner may also have noticed the slight lifting of the starboard side as the ship rode over the ice. Woolner was in the First Class Smoking Room at the time of the accident:
"We felt it under the smoking room. We felt a sort of stopping, a sort of, not exactly shock, but a sort of slowing down; and then we sort of felt a rip that gave a sort of a slight twist to the whole room."
Hugh Woolner, Passenger, 1st Class Smoking Room
3.1 Grounding of the Queen Elizabeth 2
It is as-yet impossible to confirm or deny the assertion that Titanic effectively grounded on an underwater ice shelf from an examination of the wreck. Because the bow portion stands upright and buried in the sediment, Titanics bottom is well hidden from view. To find support for the theory, the authors looked to other mishaps for similarities. One incident in particular involved a large liner that was running at high speed when she struck an underwater obstacle. The eyewitness descriptions given relating to the character of the impact of that mishap closely matches those given in the wake of the Titanic disaster. In 1992, the Queen Elizabeth 2 struck rocks 2.5 miles south of Cuttyhunk Island, Massachusetts, on her way to New York. At the time of the accident, the ship was making about 18 knots. Her bottom was ripped open by large boulders, but there was no violent impact. Just as in Titanic, the passengers of QE2 were not thrown about by the accident.
"The only thing I can compare it to, being from California, is a major earthquake."
Linda Robinson, Passenger, QE2
The passengers aboard QE2 were jostled more than their Titanic counterparts because the QE2 struck on hard rocks, instead of ice, which compacts on contact. Even so, as in Titanic, there were no injuries, no one was thrown to the deck, and panic did not ensue. According to the New York Times, passengers aboard the QE2 were more concerned about the re-opening of the ship's gambling casino than about whatever damage might have been suffered by the ship. The lesson taken from the QE2 mishap is that a grounding of a large passenger liner over a hard object at speed can still produce only a relatively mild impact.
3.2 Immediate Effects of the Grounding
Titanic's trip across the ice was anything but smooth, as descriptions of the impact when the ship came full upon the ice indicate. That first impact came just 11 feet forward of bulkhead "B" at the forward end of the Firemen's Passage. The weight and momentum of the ship must have worked in consort to cause upward movement of both the floor frames and the longitudinals in the bottom. Seventy-seven years after Titanic, the oil tanker Exxon Valdez struck Bligh Reef in Alaska's Prince William Sound. Shipyard workers who repaired that tanker's hull found numerous bent web frames and displaced longitudinals. Similar damage must have occurred to the framework of Titanic.
Referring to the Firemens Passage (lower centre of Fig. 1), it can be seen that upward deflection of the longitudinals forming the margin plates of the ballast tank in Hold #1 would have immediately been transmitted to the deck of the Firemen's Passage. This transfer damage would have caused displacement of the metal around the base of the circular stairways leading upward to the living quarters of the firemen and stokers. According to the British report, "...five minutes after the collision water was seen rushing in at the bottom of the firemen's passage on the starboard side." This is exactly the sort of flooding to be expected from a grounding. Displacement of the margin plates would have caused not only the Firemen's Passage to flood, but also the surrounding hold (Hold #2).
The official BOT report correctly linked the flooding of the tunnel and Hold #2, but somewhat implausibly attributed it to the iceberg somehow reaching deep inside the ship. In the "Description of/Extent of Damage" section of the report, it is stated that "...the ship's side was damaged abaft of bulkhead B sufficiently to open the side of the firemen's passage, which was 3 1/2 feet from the outer skin of the ship, thereby flooding both the hold and the passage." For this to happen, the ice would not only have to had penetrated the steel shell plating, but advance deeply enough into the hull to damage the passage standing away from the skin of the ship. In order to inflict this kind of damage, the ice spur had to have been dagger- or stiletto-shaped, thin enough to stay within the calculated opening size of approximately 12 square feet. In addition, the spur would had to have penetrated hull perpendicular to the hull surface (in other words, a puncture wound), as opposed to running parallel to the keel (as in a running rip or series of gashes). This runs counter to the known mechanics of the collision.
When Titanic first struck, the hull was probably nearly parallel with the long axis of the iceberg. However, the ship was not moving in a straight line. Titanic was making a right turn, which involved the overall advance and transfer of the vessel, as well as the pivoting of the bow toward the iceberg, in order to achieve Murdoch's goal of swinging the stern away. Presumably, the ice shelf on which Titanic grounded sloped upward to meet the upper portions of the berg above the waterline. This meant that as the ship's bow pivoted to her right, she had to push her way up the slope of the ice ram. From above, it would have appeared as if the ship's bow sideswiped the berg just as the well deck was passing. Indeed, some form of this interaction caused a significant amount of ice to break off the berg and deposit itself on Titanics forward well deck. As there is no evident collision damage to the upper works of the wreck from contact with the ice and no eyewitness reports of damage to the railings, mast or rigging, the exact manner in which this ice was dislodged to fall in the ship can only be surmised.
A standard "trick" for getting small ships away from a quay is to "push" the bow against an upright while motoring forward with the helm toward the quay (this trick would work with large ships, but it is hard to find uprights of sufficient size and strength). Although Murdoch did not plan to do this maneuver, that is exactly what he accomplished. Contact between the side of the ship and the berg helped pivot Titanic's stern well clear. This rapid pivoting also brought the forepeak into contact with the iceberg, just before the hull slid sideways off of the ice ram. By the time the iceberg came abreast of Boiler Room #6 (slightly abaft of the bridge), the ship was free. Possibly, the full weight of the ship was sufficient to break the ledge on which Titanic was riding, or the geometry of the intercept was such that she quickly rode off the edge of the berg. The whole accident from first to last touch had taken no more than 10 seconds and more likely 8 seconds, based on the time it would take a 22.3 knot vessel to travel approximately 300 feet.
It is not the purpose of this paper to discuss the overall damage to Titanics hull girder as a result of grounding upon an underwater ice shelf. However, in making the assertion that Titanic grounded on the berg, instead of the conventional view that she brushed against it, a variety of questions are raised regarding the damage immediately sustained during the collision (actually, the conventional collision scenario does not adequately explain how the forepeak and Firemens Passage were compromised, or the character of the collision as described by witnesses, but the burden of proof is always on the less conventional theory). The authors acknowledge that the type of damage expected as a result of a grounding accident must match the actual damage sustained by Titanic, as evidenced by eyewitness accounts and observations of the wreck. If grounding damage is not consistent with those realities, then the theory must be discarded. Two types of damage must be accounted for: (1) direct from the ice; and (2) racking of the hull.
4.1 Direct Damage
Sliding thousands of tons of steel across an underwater ice shelf must have caused a great deal of damage to the shell plating, as well as to the underlying frames and longitudinals. The first hard impact would likely have caused crushing of the double bottom. This damage can only be imagined, as it is confined to a portion of the ship that is not accessible with modern echo-sounding equipment. Photographs taken of QE2's bottom after her grounding give a hint of the type of punishment suffered by Titanic's more brittle shell plating. Much of this damage was likely inconsequential, because it would have simply opened to the sea the ballast tanks beneath the watertight tank top deck. The most serious direct damage flooding probably occurred at the after end of Hold #1 and the forward end of Hold #2 by way of bulkhead "B."
4.1.1 Steel Versus Ice
Since the discovery of the wreck in 1985, it has become possible to study the actual steel from which the ship was constructed. Samples of both the shell plate and the rivets which held the vessel together have subsequently been subjected to laboratory analysis. That analysis by Dr. Timothy Foecke of the Metallurgy Division, National Institute of Standards & Technology, and others, was conducted to test the assertion that Titanic's steel was "brittle" by modern standards for shipbuilding materials. The findings seem to indicate that the steel in Titanic's hull had adequate strength, but very low fracture resistance at (or near) the freezing temperature of seawater, which was the situation on the night of the disaster. However, there is not enough evidence to say that embrittlement played a significant role in the initial flooding of the ship.
The truth of what happened when ice met steel on April 14, 1912 must take into account the character of the ice itself. The impact of icebergs against iron or steel objects was investigated during the 1990s, during development of offshore oil drilling rigs for use on the Grand Banks. These experiments showed that the typical berg is a mixture of both soft and hard ice, and as such, presents a significant hazard to floating platforms. Dr. Stephen Bruneau of the Center for Cold Ocean Resource Engineering (C-CORE) in St. John's, Newfoundland, has stated that ice cubes in the normal home freezer (the kind used in soft drinks) are only about 10% as strong as steel. That would make them a poor adversary against a steel ship. However, ice deep inside a medium-sized iceberg, such as the one struck by Titanic, can be as cold as -25 degrees Celsius. At that temperature, the core of an iceberg is nearly ten times stronger than the average ice cube, strong enough to challenge the steel plate of an ocean liner. Typically, the crushing strength of ice is only about 1% that of steel.
Peter Wadhams is one of a group of present-day scientists who determined that solid ice below a berg's waterline is quite different from that projecting into the air above. His team found that the crystalline structure of submerged ice is much denser, with smaller trapped gas pockets. Individual ice crystals making up the underwater portion of a berg have also been found to be much larger and stronger than ice crystals exposed to the air. Conversely, the above-water portions are made of softer ice with larger gas pockets.
"While ice strength depends upon temperature, differences above and below the waterline would depend on the relative temperatures of air and water and the recent history of the iceberg with regard to rolling and calving. Steel is typically a lot stronger than ice. Most of the time very little happens when steel-hulled ships hit ice. Thin steel plating can be dented and the supporting frames bent. High speed vessel collisions have caused perforation of hulls that are not designed for ice impacts."
Dr. Richard McKenna, Ph.D., P. Eng,
Director of Ice Engineering for C-CORE
Based on Dr. McKenna's observations, and those of other researchers, certain generalizations can be formed for use in examining Titanic's collision with a medium-sized iceberg. The steel in the ship's hull was strong enough to withstand impact with the relatively softer ice often found above an iceberg's waterline. In addition, the ship's steel probably faired well against the high-speed impact that occurred. However, the colder (and therefore harder) ice found below the berg's waterline was much more likely to have caused damage to the ship. Significantly, a high-speed impact with an iceberg in this manner could explain the breach in Titanics shell plating and consequent flooding through the double bottom.
4.2 Racking Damage
As the ship rode across the ice ram, her bow would have been flexed upward in a manner never intended by its designers. This lifting would have been confined to the starboard side, which could have considerably racked the hull (Fig. 6). Movement of riveted plates against each other can cause the seams to lose watertight integrity, or shear the rivets, especially if the rivets were weakened by a significant slag content, as samples of Titanics have proven to be (refer to this Panels previously-published report, Titanic, The Anatomy of a Disaster). The former condition would only allow a slow seepage of water. The failure of a number of rivets along a horizontal seam, however, would have allowed a significant length of that seam to open, resulting in a large ingress of water.
Racking damage may also have caused the automatic watertight doors to close imperfectly. These cast iron doors slid vertically in tracks. Any distortion of those tracks would likely have caused a door of this design to stop their descent before closing the opening. Not only is deflection of the iron guides a possibility, but because the doors drop by gravity, their freefall is controlled by hydraulic arrestors. The entire door assembly is 16 feet tall from the bottom of the door sill to the top of the arrestors and the various components are not mounted on a common bed plate, but instead bolted directly to the bulkhead. The slightest deflection of the bulkhead out of plane will disturb the alignment of the arrestor rods, with the possibility of the door binding before reaching the bottom of its stroke. It is also important to note that there were no feedback circuits, so it was impossible for bridge personnel to determine whether or not the doors were secure. There is some evidence that the racking of the watertight door assembly in the vestibule at the aft end of the Firemen's Passage (Fig. 2) was a significant contributor for the loss of Titanic's sister ship, Britannic. The authors of this paper suggest that the failure of the automatic watertight door assembly in the Firemen's vestibule also contributed to the flooding in Titanic.
4.3 Damage by Compartment (Fig. 3)
4.3.1 Forepeak not damaged during the initial grounding. The forepeak did not contact the ice until the ship came against the iceberg when the berg was approximately opposite hold #3. Sideways motion of the bow as it rotated to the right scraped the forefoot on the ice shelf at that time, causing the loss of watertight integrity to the peak tank. Water entering this tank was prevented from moving elsewhere inside the ship by bulkhead "A" and the lower Orlop deck.
4.3.2 Hold #1 hold and tankage beneath were opened by crushing damage caused by hard impact with the ice. This impact took place approximately 11 feet ahead of bulkhead "B." Water was free to rise in Hold #1 to the Orlop deck, which was watertight except for the hatch tower to the forecastle deck.
4.3.3 Hold #2 opened at forward end in way of bulkhead "B" by crushing damage caused by hard impact with the ice. Enclosure of firemen's stair tower displaced by upward movement of structure. Water flooded firemen's passageway, firemen's stair tower, and Hold #2. Water could rise in Hold #2 until it reached the Orlop deck, which was watertight. Above that level, it could rise in the hatch tower to the well deck. Water in the firemen's stair tower was free to rise to the level of G Deck, where it could flood the spaces in front of bulkhead "B" above Hold #1.
4.3.4 Hold #3 may not have been opened directly by the ice. This hold would have been largely protected from direct contact by the double bottom. The turn of the bilge beneath the extension of the tank top deck covering the bilge brackets may have been damaged by crushing as the iceberg reached its closest point of approach. Flooding of mail room on the Orlop deck may have been caused by an open horizontal seam. If the automatic watertight door in bulkhead "D" did not fully close, then water in Firemen's Passage could have entered hold #3 through the open bunker doors located in the vestibule at head of Boiler Room #6 (see "Firemen's Passage" in Appendix III).
Note: The BOT report on the sinking suggests that water in Hold #3 had reached the height of 24 feet above the keel within the first ten minutes after the accident. This is based on the flooding of the mail room on the Orlop deck. However, an open seam in Hold #3 above the Orlop would have produced the same appearance, even if the hold beneath the Orlop deck was still essentially dry.
4.3.5 Boiler Room #6 probably did not receive direct ice damage; instead, water entered through a seam in the shell plating opened by racking damage. The speed with which this compartment flooded has been disputed. Leading Fireman Barrett claimed at the BOT Enquiry that the water in the space was 14 feet above the tank tops inside of 10-15 minutes. However, quick flooding can be anticipated if the automatic watertight doors in the vestibule (see "Firemen's Passage" in Appendix III) did not fully close. Open seams, caused by the racking of the hull on the ice, likely contributed water to that entering this compartment from elsewhere.
4.3.6 Boiler Room #5 only a small portion of a seam was reported opened, about 2 feet off the deck. This seam was apparently an extension of seam parting that began in Boiler Room #6 and continued across bulkhead "E" (water was also noted coming into the bunker separating the two compartments). Distortion of the supporting longitudinals might have compromised the integrity of bulkhead "E," leading to a subsequent failure along the starboard side.
Flooding resulting from a grounding would have immediately filled Holds #1 and #2. Water rising in the Hatch #1 tower would have caused the canvas cover to bulge upward and produce the sounds described by eyewitnesses. Water in Hold #2 was contained by the Orlop deck, but water rising in the stair tower quickly began to flood onto G Deck forward of bulkhead "B." This is the water that forced the greasers and firemen sleeping on G Deck to evacuate before midnight. If Boiler Room #6 was flooded as quickly as the BOT report indicates, the water likely came through partially-closed watertight doors in the vestibule at the after end of the Firemen's Passage. After midnight or so, secondary flooding through scuttles, hatches, ports and other ordinary openings in the liner's structure became the primary source of water.
5.0 Summary Through a reassessment of First Officer Murdochs final maneuver, a compilation of eyewitness descriptions regarding the character of the collision, a revaluation of the damage reported by witnesses and observed on the wreck, the authors have come to the conclusion that Titanic grounded briefly on a projecting underwater shelf of the iceberg. This strike was hard enough to open portions of the hulls double bottom to the sea and transmit shock damage up supporting members so that watertight integrity in the immediate area was compromised. In addition, as the ships momentum carried the starboard side of the hull up farther onto the shelf, racking damage distorted shell plating on the starboard turn of the bilge, shearing rivets and opening seams. Water entering from below and alongside the forward holds and boiler rooms eventually overcame the hulls internal subdivision, causing the ship to founder.
David G. Brown
Parks E. Stephenson