Titanic’s “Brittle” Steel?
Olympic and Titanic were built using Siemens-Martin formula steel plating throughout the shell and upper works. This type of steel was first used in the armed merchant cruisers, Teutonic and Majestic in 1889/90. This steel was high quality with good elastic properties, ideal for conventional riveting as well as the modern method (in 1912) of hydraulic riveting. Each plate was milled and rolled to exact tolerances and presented a huge material cost to both yard and ship owner. The steel was not a new type, as already stated, but shows that yard and owner only put material and equipment into these two giants that was tried and tested. Reports of Teutonic’s and Majestic’s hull condition 20 years after they entered service showed that both were in remarkable condition. The excellent properties of this steel and resistance to corrosion made it the natural choice for the new sisters.
Yard workers at the time referred to this steel as “battleship quality.” I had several conversations with retired shipbuilders at Harland and Wolff and they confirm this. Harland and Wolff used larger sized plates to reduce the amount of butts and overlaps. The shells themselves were generally 6 feet wide and 30 feet long weighing between 2 1/2 and 3 1/2 tons depending on thickness. The double bottom plating was 1 1/2 inches thick and hydraulically riveted up to the bilge. Some of the largest plates were 6 feet wide and 36 feet long and weighed 4 1/2 tons.
White Star gave Harland and Wolff complete freedom to build the very best ships they could, adding a percentage profit to the final cost of the building. The so-called “cost-plus” arrangement was used on all but one of the company’s ships. From 1869 until 1919, it was said that there was never a single day that Harland and Wolff was not working on one of the White Star Line’s ships. White Star was Harland and Wolff’s best customer and they undertook to build Olympic and Titanic on the same basis as before, cost-plus. The ships were the largest in the world and would require numerous calculations as to the strength of hull required at this size. Much of the ships’ arrangement was tried and tested basic shipbuilding design — just larger with greater added strength. The strength was entirely provided by the ship’s shell plating and rivets. Hydraulic riveting was used for much of the 3 million rivets, in some places the hull quadruply riveted.
Titanic’s impact with an iceberg caused the rippling and springing of the joints between plates. Rivet heads ripped off would not cause massive flooding, rather the long leaking that is recorded to have happened in her forward compartments. Science tells us that in order for steel of this quality to fracture due to cold and impact would mean the steel being brought down to below the temperature of liquid nitrogen. As the water in Titanic’s ballast tanks had not frozen on the night she struck the iceberg, it’s safe to say the steel was above the freezing point of ordinary seawater.
We discovered on the Arabic (White Star liner of 1903) dive the ship’s shell plating was in remarkable condition, but the rivets had “let go.” That is to say, sprung — allowing the plates to come apart. In places the ship was like a stack of playing cards not relating to any structure. I have some of these and I’m organizing a scientific study of them and will keep you apprised of the results.
I think — and this is just a theory — the rivets were heated so they could be riveted into place by hand or by hydraulic riveter. The steel would have to be capable of easy heating, malleable, and perhaps weaker by design. Is this the Achilles’ heel of the Titanic? So much time is spent looking at the steel but I think these 3 million mild steel rivets might hold the secret.
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