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.