Titanic rivets high concentrations of slag found

by William Broad - New York Times on 1 May 2008 Scientists have discovered that the builder of the Titanic struggled for years to obtain enough rivets and riveters and ultimately settled on faulty materials that doomed the ship, which sank 96 years ago and took with it more than 1500 passengers.

The builder's own archive, the two scientists say, harbours evidence of a deadly mix of low-quality rivets and lofty ambition as Harland & Wolff laboured to build the world's three biggest ships at once - the Titanic and its two sisters, Olympic and Britannic.

When the safety of the rivets was first questioned 10 years ago the builder ignored the accusation.

Historians say that the new evidence, uncovered in the archive of Harland & Wolff, in Belfast, settles the argument and finally solves the riddle of one of the most famous sinkings. The company insists the findings are deeply flawed.

The team collected clues from 48 Titanic rivets recovered from the wreck, modern tests, computer simulations, comparisons with century-old metals as well as careful documentation of what engineers and shipbuilders of that era considered state of the art.

Harland & Wolff's colossal work-load forced it to reach beyond its usual suppliers of rivet iron and include smaller forges, as disclosed in company and British government papers. Small forges tended to have less skill and experience.

Adding to the threat, the company relied on cheap materials, scientists say.

They found many rivets riddled with high concentrations of slag, a glassy residue of smelting, that can make rivets brittle and prone to fracture. The company also faced shortages of skilled riveters, according to archive papers.

Shipbuilders of the day were moving from iron to steel rivets, which were stronger. And machines could install them, improving workmanship and avoiding labor problems.

The scientists discovered that Harland & Wolff only used steel rivets on Titanic's central hull, where stresses were expected to be greatest.

Iron rivets were chosen for the ship's stern and bow. And the bow, as fate would have it, is where the iceberg struck. Studies of the wreck show that six seams opened up in the ship's bow plates. And the damage, one of the scientists noted, 'ended close to where the rivets transition from iron to steel'.

The scientists argue that better rivets would have probably kept the Titanic afloat long enough for rescuers to have arrived before the icy plunge, saving hundreds of lives.

The New York Times http://www.nytimes.com