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Poor choice of materials made Titanic more vulnerable

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By Bob McDonald, Quirks & Quarks

 

Studies of the steel that made up the hull and rivets of Titanic have shown that the ship was made with lower-grade metals that were more brittle, suggesting that lives might have been saved had the vessel been constructed with better material.

 

As memorial services this weekend mark the 100th anniversary of the famous disaster at sea, scientists who have studied samples of the hull brought up from the wreck have found the ship was built with sub-standard steel. They suggest that there might have been less damage from the collision with the iceberg had the ship been made with a higher grade of metal.

 

Titanic might have stayed afloat longer if the damage has been less severe, allowing more time for rescue ships to arrive before the ship slipped beneath the waves.

 

The problems with steel quality arose from the attempt by the builders of Titanic - Harland and Wolff - to construct two other vessels of equal size at the same time, Britanic and Olympic, intended to be the largest passenger ships in the world. But this massive feat of construction was hard on suppliers of steel and rivets, causing shortages that were greatest during the construction of Titanic.

 

When pieces of hull were brought up from the famous wreck on the ocean floor, laboratory tests in the 1990s showed the steel contained higher levels of sulfur than was customary for ship construction at the time. It made the metal more brittle, especially in the icy waters of the North Atlantic. The edges of the steel fragments were also jagged, indicating that it had shattered on impact, rather than being bent and torn as lower-sulfur steel would have been.

 

In addition to a shortage of steel plates for the hull, there was a shortage of steel rivets and expert riveters to piece the hull together. The company was forced to use lower grade wrought iron rivets which, under impact tests, also turned out to be more brittle.

 

Ironically, there were enough higher-quality steel rivets to build the central section of the Titanic's hull, which is still intact today. The only places where the lower-quality rivets were used was on the stern, which broke off, and the bow, exactly where the impact with the iceberg took place.

 

The result, according to engineers, is that when Titanic grazed the iceberg, the brittle steel plates broke rather than bent, while iron rivets popped instead of holding on. This produced a larger hole and more separation between hull plates, allowing water to more easily rush in.

 

Higher quality metals could have absorbed more of the shock of the iceberg impact by bending inwards, then tearing in a thin line, rather than breaking. And stronger rivets would have kept the seals between hull plates tightly closed.

 

Might this have prevented Titanic from sinking?

 

Probably not. The gash along the side of the hull exposed too many watertight compartments for the ship to remain afloat. But the slower influx of seawater could have kept the vessel afloat an hour or two longer.

 

The engineering lessons learned from Titanic include better materials for shipbuilding, double hulls, ice patrols, electronic navigation, and even Canada's own RADARSAT to monitor the movement of ice in the oceans from space.

 

But the one thing science cannot provide for is hubris and human error.

 

Had the shipbuilders not tried to impress the world by constructing the three largest ships at once, higher quality steel would have been available. Had the crew of Titanic not ignored the ice warnings from other ships in the area and not continued on at 22 knots, perhaps for the sake of setting a trans-Atlantic speed record on a maiden voyage, the collision could have been avoided. 

 

As clearly demonstrated by the recent wreck of the Costa Concordia in the Mediterranean, where the Captain was showing his ship to a friend on shore, and the Queen of the North in British Columbia, where the crew on the bridge was reportedly not paying attention to the ship's course when it struck land, hubris is still a prime factor in disasters today. Even most air crashes are due to pilot error.

 

We tend to build comfort zones made of metal around ourselves to protect us from the forces of nature. But we can never become too complacent in the security of that technology. As long as bad human decisions are involved when building and using it, nature always wins.