When you think of steel giants, the Titanic is one of the first to come to mind. It was an incredible feat of marine engineering for its time to build such a gigantic vessel, and her sinking on 15th of April 1912 was one of the most shocking events of the early 20th century.
Steels got that sinking feeling…
Considering most of us have seen Titanic, there were quite a few contributing factors that lead to the magnitude of the disaster including a lack of sufficient lifeboats, flaws in the design and negligence of the crew and captain who continued to power at full steam despite warnings of ice in the area. But did you know that the quality of the steel used on the “unsinkable ship” would have contributed to the disaster?
According to a study conducted in 1998 and published in 2008 by Dr. Phil Leighly, a professor of metallurgical engineering at the University of Minnesota Rochester, the steel that was used in the construction of the Titanic did play a role in its destruction.
The Titanic was built between 1911 and 1912. She was constructed of thousands of one-inch thick mild steel plates and two million steel and wrought iron rivets. In the 21st century, ship plates are welded together using oxyacetylene torches, but this technology wasn’t available in Titanic’s time. Instead, Titanic’s overlapping steel hull plates were held together by rivets that were hammered in by hand.
Luckily, Professor Leighly was able to access a large recovered plate of steel from the Titanic’s hull to determine what made the hull so vulnerable. At the University of Minnesota Rochester, chemical and stress test of the metal samples from the hull and bulkhead show that the steel used to build the ship was incredibly inferior to modern steel. In fact, it was 10 time more brittle than modern steel when tested at freezing temperature, which was the estimated temperature of the water at the time Titanic struck the iceberg.
“Tests of the steel’s chemical composition also showed a high content of sulphur, oxygen and phosphorus. High levels of those elements cause steel to be more brittle” said Leighly is his findings.
The chemical analysis of the hull plate revealed low level of manganese, which is another symptom of brittle steel.
Inadequate iron rivets played a part
That’s not where the story ends, however. Historian Jennifer Hooper McCarty, who studied the archives of the builder, Harland and Wolff, in Belfast, Northern Ireland, shortages of steel rivets peaked during the Titanic’s construction.
“The board was in crisis mode,” said McCartey in an interview. “It was constant stress. Every meeting it was, ‘There’s problems with the rivets and we need to hire more people.”
To build quicker, Harland and Wolff started reaching beyond their usual suppliers of rivet iron and employed smaller forges, who at that time tended to have less skill and experience.
Their ability to cut corners saw the company order No.3 bar, known as “best”, instead of No.4, known as “best-best”. Shipbuilders of that time typically used No. 4 iron for anchors, chains and rivets.
Many of the rivets recovered and studied by scientists were found to be riddled with high concentrations of slag, which is a glassy residue of smelting that can make rivets brittle and prone to fracture.
Given that the iron rivets were not as strong as steel rivets, Harland and Wolff decided to use the steel rivets only on the Titanic’s central hull, where stresses were expected to be greatest. Iron rivets were used for the stern and bow.
And so, history dictates, the bow is where the iceberg struck. Approximately six seams opened up in the ships bow plates. Scientists argue that had the rivets been better quality, Titanic might have stay afloat long enough for rescuers for arrive, saving hundreds of lives.
Many argue that welding seams would have proven more effective and could have saved Titanic, however welding was in its infancy at this time in history and metallurgy wasn’t as advanced.
Luckily modern ship building technology and standards have come a long way to ensure it is capable of surviving disasters at sea.
The team at ShapeCUT are all about using the best steel for the right application, and have extensive experience in using the latest steel cutting machines to get the job done right. No matter the size, shape or complexity of the task, ShapeCUT have the tools and knowledge to help you. Talk to ShapeCUT today to find out more.