A full-size iceberg10 has hundreds of times more mass than Titanic. Each cubic yard of berg is roughly a ton of solid ice. The ship was a hollow metal structure filled mostly with air. In a head-on collision, there would not have been enough time for the energy of Titanic to overcome the inertia of the ice and push the berg sideways. But, the ship didn't hit the berg. It spent those seven seconds grinding across the top of an underwater ice shelf. There was plenty of time for the berg to move a bit under the ship's weight. Ice felt the ship as much as the ship felt the ice, and the berg rolled ever so slightly toward Titanic.
It rolled because icebergs are notoriously unstable. Just as Captain Smith told his New York friends, the upper part extending into the atmosphere melts at a different rate from the underwater portions. This upsets the equilibrium of a berg, which often compensates by suddenly capsizing. "Icebergs that are in the process of disintegrating may suddenly capsize or readjust their masses," warns Bowditch. When the ship rode onto the shelf, the berg was forced to support increasing tons of steel, rivets and passengers well outboard of its center of gravity. Like any other floating object, the berg tipped toward this extra weight.
As it tipped, the upper portions of the berg brushed against the ship's topsides at the forward end of the well deck. This contact precipitated the famous mini-avalanche of ice. Brushing against the top of the berg probably didn't scratch the liner's fresh paint. During the middle 1990s, scientists studied the impact of icebergs against iron or steel objects.11 This research was aimed at developing offshore oil rigs for use on the Grand Banks near the spot where Titanic now lies. Experiments have shown that ice above a berg's waterline can be relatively soft and often crumbles upon impact. Crumbling produced the broken pieces of ice that littered the ship's forward well deck.
"There was quite a lot of ice on the starboard part of the ship," 26-year-old Olaus Abelseth told the U.S. investigation. The young Norwegian was sleeping in the Third Class open berthing area on Lower Deck G near the bow of the ship. Also near the bow was Frank O. Evans, a 27-year-old Able Seaman. "I was sitting at the table reading a book, and all of a sudden I felt a slight jar," he testified in New York. "I did not take any notice of it for a few minutes until one of the other able seamen came down with a big lump of ice in his hands."
Although passengers were largely unaffected by the brush with the iceberg, the black gang in the boiler rooms was not so lucky. After seven seconds of screaming metal, they now found themselves in a fiery twilight caused by a temporary electric blackout. A few men were dispatched from each stokehold to make the long climb to E Deck in search of portable lights. That turned out to be unnecessary as the main electric power came back on after a few dark minutes and the stokeholds were flooded with light again.
Stokers and trimmers probably feared for their lives as water poured into Boiler Room #6. Most likely, however, everyone survived the initial scramble to escape the freezing water. "We heard a crash," Fireman Frederick Barrett recalled. "The engineer and I jumped to the next section (Boiler Room #5)." Barrett became one of the few people to survive after seeing first-hand the damage done to Titanic by the iceberg. He told the U.S. Senate that a horizontal opening:
...ran past the bulkhead between sections 5 and 6, [Boiler Rooms #5 and #6] and it was a hole two feet into the coal bunkers. She was torn through Number 6 and also through two feet abaft of the bulkhead at the forward head of Number 5 section.
-- Frederick Barrett, U.S. Senate Hearings, May 25, 1912
In London, Barrett told essentially the same tale. "Water came pouring in two feet above the stokehold plate; the ship's side was torn from the third stokehold to the forward end," he testified12. (The "third stokehold" in Barrett's testimony was the forward end of Boiler Room #5.) The fireman's experience was as frightening as his testimony is illuminating. He did not mention Boiler Room #6 as suffering any great structural damage despite the tremendous noise and sudden deluge of freezing sea water. Most important, he did not report that mythical dagger of ice ripping open the side of the ship.
Barrett placed the open seam at "two feet above the floor plates." Those plates were light metal decking to give stokers easier access to the furnace openings. The stokers actually worked standing a few feet above the tank top deck, the upper side of Titanic's watertight double bottom. This means the open seam was about four feet above the tank top. On the outside of the ship it would have been in the single-thickness vertical side plating just above the turn of the bilge. Barrett's observation confirms that the opening in the side was confined to the very lowest portion of the hull, no more than ten feet above the keel.
Sprung seams also must have occurred in the four compartments forward of Barrett's position. Recent dives to the wreck have brought back evidence of six or more horizontal openings in the ship's side in the area from Boiler Room #6 to the bow.
Unfortunately for the hypotheses of modern researchers, however, the ship's crew did not believe the open seams in the side of Titanic allowed significant amounts of water into the hull. Surviving crew members knew the more exact location of their vessel's mortal wounds: the bottom beneath their feet. Seaman Edward J. Buley was precise about where the fatal water entered the hull. It was not coming through the side, but up through the bottom. When the interrogator made a mistake on this, Buley pointedly corrected him.
MR. BULEY: ...down where we were there was a hatchway, right down below, and there was a tarpaulin across it, with an iron batten. You could hear the water rushing in, and the pressure of air underneath it was such that you could see this bending. In the finish I was told it blew off.
SENATOR FLETCHER: What part of the ship would you call that?
MR. BULEY: The forecastle head.
SENATOR FLETCHER: How far was that from the bow?
MR. BULEY: About 20 yards, I should think.
SENATOR FLETCHER: That condition could not have obtained unless the steel plates had been torn off the side of the ship?
MR. BULEY: From the bottom of the ship. It was well underneath the water line.
U.S. Senate Hearings, Thursday, April 25, 1912
The ice was cruel. Rivets must have been stretched and even ripped out of the plating. Seams would have been forced open and butt joints misaligned. Damage on the outside undoubtedly was random. Although horrible to look at (if that could have been done), it is unlikely that this exterior ice damage was life-threatening to the ship. The most immediate result of damage to the exterior was flooding of the starboard side tankage located beneath the tank top deck.
There is one place where there was evidence of direct internal damage from the ice. This is at the forward end of Hold #2 directly above the spot on the keel where the ship would have first felt full grounding pressure on the ice shelf. According to the report of the British inquiry, the impact smashed a metal enclosure around the foot of the double spiral staircase used by firemen to go from their quarters on D, E, and F Decks to the stokeholds. This damage was followed by substantial flooding of the Holds #2 and #3, and the passageway. Hold #3 filled rapidly to the vessel's waterline.
Ice damage to the shell plating of the bottom forced the ship to rely on its double bottom to stay afloat. Rending of steel plates on the outside of the outer bottom did not allow significant amounts of water to enter the inside of the hull because the tank top deck was there to stop it. If that deck had remained totally watertight, Titanic might have stayed afloat just as QE II did eight decades later when it ran arground off the U.S. Atlantic coast. Unfortunately for more than 2,200 people aboard Titanic, (most still warm in their beds) the tank top deck was no longer watertight after the ship came off the ice. The Atlantic Ocean was boiling up in the forward cargo holds. It was also rising in Boiler Room #6, but at a markedly slower rate.
Rents in the horizontal tank top deck would be expected as a result of upward deflection of longitudinal girders running parallel to the keel within the double bottom. These longitudinals acted much like snow skis carrying the ship over the ice. And, just as skis flex over moguls, Titanic's hull flexed upward as it passed across the ice ram. Upward movement may have created random strained rivets, sprung seams, or cracked plates in the overlying tank top deck. This movement of the ship's structure was greatest at the point where the keel reached its full depth at the base of the spiral staircase. Damage to the metal around this staircase and the rapid flooding of Holds #2 and #3 likely resulted from upward displacement.
Seventy-seven years after Titanic, the oil tanker Exxon Valdeze struck Bligh Reef in Alaska's Prince William Sound. The resulting oil spill continues to make headlines. Shipyard workers who repaired the tanker's hull found numerous bent web frames and displaced longitudinals. Similar damage must have occurred to the framework of the passenger liner as a result of crossing the ice shelf.
Although Titanic was not cut open by a knife of ice, Barrett's eyewitness account has often been cited as proof of a long slice in the ship's side. The importance of what he saw was misunderstood. When the seam opened, it released the stress created by the ship squirming off the ice. This release prevented rivets from popping any higher on the ship's side. Plates in the side above this single horizontal seam remained undamaged and watertight. Barrett's description of a horizontal opening has distorted nearly every discussion of Titanic's demise. Based on what he saw, it has generally been assumed the berg tore a horizontal gash the length of the first four compartments and into the fifth. Crew members on duty that night did not think that was what happened.
MR. BULEY: ...according to where the water was, I should say the bottom was really ripped open altogether. SENATOR SMITH: The steel bottom? MR. BULEY: Yes, sir.
-- U.S. Senate Hearings, April 25, 1912
The pattern of flooding during the first ten minutes after the accident shows how the upward curve of the keel toward the bow influenced where damage occurred. Titanic's keel ran straight for most of the ship's length, but swept upward in a gentle curve beneath Hold #1 and the forepeak. This upward curve protected these first two compartments from the full force of the grounding on ice. The brunt of the impact was reserved for the after portion of Hold #2, particularly beneath the double spiral staircase, and the forward portion of Hold #3 where the keel first reached full depth.
The report of the British inquiry found that following the accident the forepeak was dry above the orlop for more than an hour. Hold #1 was awash to seven feet, but Holds #2 and #3 were quickly flooded13. Water rose 24 feet within the first ten minutes in Hold #3, indicating it received considerable damage.
Boiler Room #6 was protected by Holds #2 and #3. While flooding here was immediate, water does not seem to have driven out the majority of stokers and trimmers until they had raked their fires and vented the 215 pounds of steam pressure from their four double-ended boilers. Boiler Room #5 remained nearly dry despite a high-pressure fan of water cascading through a sprung seam at its forward end14. Significantly, the space beneath #5 was apparently dry enough for engineers to open a manhole into the tankage below. There are no reports of ice damage to compartments aft of Boiler Room #5.
Depending upon the point of measurement, Titanic's tank top was six to eight feet above the keel in the area of the ice damage. The British report noted that damage reported by men in the boiler rooms did not appear more than a few feet above this deck. This means that the observed damage was low on the hull.
The Crow's Nest Heels
Titanic's steel bottom absorbed just a few ounces of the ship's weight during the first split second of the accident. This weight continuously increased to pounds, and finally to hundreds of tons while the hull was fully on the shelf. However, steel plates in contact with the berg did not carry the total mass of Titanic even when the maximum amount of ship was on the ice. The bottom would have supported only that portion of the hull extending deeper than the top of the shelf. Grounding pressure on the vessel's structure may not have exceeded a minor percentage of the ship's mass. This, too, contributed to the soft impact.
Men standing watch on Titanic's bridge knew they had gone across a submerged ice shelf and had not run into the iceberg. "During the time she was crushing the ice, we could hear a grinding noise along the ship's bottom," Quartermaster Hitchens confirmed during the U.S. Senate hearings. Note that he stated "along the ship's bottom," and not "along the ship's side." Hitchens believed the damage was located on the underside of Titanic's bottom, and he said so. He also used the phrase "crushing ice," an unlikely way to describe a glancing blow against the side of the bow. "Crushing ice," however, is a perfect description for what happened as the ship slid over top of the underwater ice shelf.
Sliding across the underwater ice ram would have lifted the starboard side of the ship to a small extent. This lifting would have been virtually unnoticeable inside the hull on the lower passenger decks. The men on the bridge might have noticed it that except their attention was focused on dodging the berg and closing the watertight doors. There were two men, however, who were perfectly positioned to observe the lifting of the starboard bow: lookouts Fleet and Lee. The 90-foot height of the crow's nest would have magnified this small roll, which is just what Lee experienced.
"The ship seemed to heel slightly over to port as she struck the berg," Lee recalled in London. "Very slightly to port as she struck along the starboard side."
Eerily, Captain Smith appears to have predicted Titanic's accident to some American friends, Mr. and Mrs. W.P. Willis and a Dr. Williams. His prediction was made about 1910 while he was in command of the White Star Line's Adriatic prior to taking command of Olympic. "The big icebergs that drift into warmer water melt much more rapidly under water than on the surface, and sometimes a sharp, low reef extending two or three hundred feet beneath the sea is formed," Smith explained after a meal in the doctor's Flushing, New York home. "If a vessel should run on one of these reefs half her bottom might be torn away." Should that happen, the Captain said, "Some of us would go to the bottom with the ship."15 16
David G. Brown
Cite this page David G. Brown (2001) The Last Log of the Titanic Titanica! (ref: #1515, accessed 27th November 2015 08:54:33 PM)
URL : http://www.encyclopedia-titanica.org/last-log-of-the-titanic.html