OUTLINEINTRODUCTIONMATERIAL USED IN MANUFACTURINGFAILURE OF HULLS AND RIVETSDESIGN FLAWSTHE SINKING COMPOSITIONS OF MATERIALCONCLUSION

INTRODUCTIONo Titanic was built between 1911 and 1912 and began its journey on

10 April 1912 .

o Two days later at mid night around 11.40 it struck an ice berg which damaged the hulls of the six compartments ahead.

o These compartments got flooded which as a result caused the sinking of the ship , but the actual failure that caused the ship to sink was the material failure of the rivets being used in the sealing of the hull plates.

o The ship sinked about in 2 hours and 40 minutes.

MATERIAL USED IN MANUFACTURETitanic was constructed of :-

“Thousands of one inch-thick mild steel plates”

“Two million steel and wrought iron rivets and equipped with the latest technology”.

It was made up of low grade metals that were more brittle.

• Titanic's hull was triple riveted with using mild steel rivets, and double riveted using wrought iron, in the central length of the ship where maximum stress was assumed to be located .

• Where as the use of wrought iron and mild steel rivets instead of steel rivets caused the titanic disaster to take place .

• The steel rivets have good strength as compared to wrought iron.

• Titanic had experienced a great forcefull impact which caused the six compartments of it to be opened to sea where the used wrought iron rivets failed.

• When the Titanic collided with the iceberg, the hull steel and the wrought iron rivets failed because of brittle fracture.

• The causes of brittle fracture include low temperature, high impact loading, and high sulphur content. The water temperature was below freezing, the Titanic was travelling at a high speed on impact with the iceberg, and the hull steel contained high levels of sulphur.

• The typical high-quality ship steels mainly used are ductile an deform but never break like the wrought iron.

THE FAILURE OF THE HULLS AND THE RIVETS.

• There was CHARPY IMPACT TEST conducted on a specimen of the hull steel of titanic to find out the brittleness of it.

• The wrought iron was found to be very brittle as compared to the steel specimen .

• The wrought iron rivets that fastened the hull plates to the Titanic's main structure also failed because of brittle fracture from the high impact loading of the collision with the iceberg and the low temperature water on the night of the disaster.

• With the ship travelling at nearly 25 mph, the contact with the iceberg was probably a series of impacts that caused the rivets to fail either in shear or by elongation.

• . Normally, the rivets would have deformed before failing because of their ductility, but with water temperatures below freezing, the rivets had become extremely brittle.

DESIGN FLAWS….• Along with the material failures, poor

design of the watertight compartments in the Titanic's lower section was a factor in the disaster.

• The lower section of the Titanic was divided into sixteen major watertight compartments, after the collision with the iceberg, the hull portion of six of these sixteen compartments was damaged.

• The watertight compartments contributed to the disaster by keeping the flood waters in the bow of the ship. If there had been no compartments at all, the incoming water would have spread out, and the Titanic would have remained horizontal.

• Eventually, the ship would have sunk, but she would have remained afloat for another six hours before foundering.

THE SINKING

EXACT REASON FOR SINKING

TIMELINE OF THE SINKING OF THE TITANIC [GANNON, 1995].

• 11:35 p.m. Lookouts spot the iceberg 1/4 mile ahead.• 11:40 The Titanic sideswipes the iceberg, damaging

nearly 300 feet of the hull.• Midnight Watertight compartments are filling; water

begins to spill over the tops of the transverse bulkheads.

• 1:20 a.m. The bow pitches; water floods through anchor-chain holes.

• 2:00 The bow continues to submerge; propellers lift out of the water.

• 2:10 The Titanic tilts 45 degrees or more; the upper structure steel disintegrates.

• 2:12 The stern raises up out of the water; the bow, filling with water, grows heavier.

• 2:18 Weighing 16,000 tons, the bow rips loose; the stern rises to almost vertical.

• 2:20 The stern slips beneath the surface.• 2:29 Coasting at about 13 mph, the bow strikes

the ocean floor.• 2:56 Falling at about 4 mph, the stern strikes

the ocean floor.

COMPOSITION OF MATERIALS

Table I. The Composition of Steels from the Titanic, a Lock Gate, and ASTM A36 Steel

C Mn P S Si Cu O N MnS: Ratio Titanic Hull Plate 0.21 0.47 0.045 0.069 0.017 0.024 0.013 0.0035 6.8:1 Lock Gate* 0.25 0.52 0.01 0.03 0.02 — 0.018 0.0035 17.3:1 ASTM A36 0.20 0.55 0.012 0.037 0.007 0.01 0.079 0.0032 14.9:1

• NICKEL (Ni)• As the properties of nickel say that when added to

steel increases its toughness even at low temperatures .

• As nickel was missing in the materials being used in the manufacturing of Titanic , due to low temperature in the surroundings the materials failed .

• And hence the use of Nickel would had made the ship to float for longer period.

WAS TITANIC'S STEEL TO BLAME FOR HER DEMISE?

•Many combining factors led to the magnitude of Titanic's disaster at sea, including lack of lifeboats, flaws in the design of the ship and negligence of the crew.

• One factor that we can accurately evaluate with today’s technology is the quality of steel that was used for the Titanic, and if any shortcuts were taken during construction that may have contributed to the disastrous event.

• All three million of Titanic's rivets were driven by hand.

• Wrought iron is an Iron Alloy with a very low carbon (0.1 to 0.25%) content in contrast to cast iron (2.1% to 4%), and has fibrous inclusions, known as slag up to 2% by weight.

• If it would had been 2012 instead of 1912 about a Century after, then the failure of material wouldn’t had took place with the use of Modern steels.

• Even the techniques of riveting the hull plates would had been replaced by new techniques of Welding .

• The materials being used would also had been replaced by new composite materials , which would had satisfy the properties required.

If it would had been 2012 instead of 1912

CONCLUSION…..

• The steel used in constructing the Titanic was probably the best plain carbon ship plate available in the period of 1909 to 1911, but it would not be acceptable at the present time for any construction purposes and particularly not for ship construction.

• Whether a ship constructed of modern steel would have suffered as much damage as the Titanic .

THANK YOU….