It is just short of 110 years since the tragic sinking of the unsinkable ship, the RMS Titanic.

First, I would like to acknowledge all who have been involved in the investigation of the fateful event. They have all sacrificed their time, knowledge, investigative facilities and capabilities to bring what could only be stated as logical conclusions to the sinking.

During construction, some 2,000 hull plates were used along with approximately 3 million rivets to join the hull plates together. The hull-plate steel was to have been produced to AISI 1018 analysis specification. However, it was reported after the vessel was located and during the investigation that analysis anomalies and contamination in the plate were present.^[1]

It was decided during the design stage and construction planning of shipbuilder Harland and Wolff that the major stress points on the vessel keel would be at approximately the second 1/3 of the hull keel, and there would be no requirement to protect the bow and stern assemblies of the vessel. Therefore, wrought iron was the material of choice. When reviewing the hull layout drawing, the steel alloy rivet failure occurred at a point just forward of the third funnel. It was also contaminated and not a “fully clean steel.”

Fig. 2. Example of hull rivet head

Bow and Stern Rivets

The bow and stern rivets were manufactured from wrought iron, which was badly contaminated. I have been unable to locate a steel specification identification (those rivets were simply identified as alloy steel). I estimate that the rivets at that location were simply low-alloy mild steel, which exhibited higher mechanical values than the wrought-iron rivets. NIST metallurgist Dr. Timothy Foecke, however, confirmed that the steel of choice for the central-hull keel areas was made from an alloy steel and that it also exhibited contamination.

More next time in part 2 on the rivets and riveters.

Fig. 3. The head of two rivets. This photograph shows the “randomness” of the contamination. (Dr. Tim Foecke, NIST)