The man who located the wreck of the Titanic has revealed that the discovery was a cover story to camouflage the real mission of inspecting the wrecks of two Cold War nuclear submarines.
When Bob Ballard led a team that pinpointed the wreckage of the liner in 1985 he had already completed his main task of finding out what happened to USS Thresher and USS Scorpion.
Both of the United States Navy vessels sank during the 1960s, killing more than 200 men and giving rise to fears that at least one of them, Scorpion, had been sunk by the USSR.
Dr Ballard, an oceanographer, has admitted that he located and inspected the wrecks for the US Navy in top secret missions before he was allowed to search for the Titanic.
Only once he had used his new underwater robot craft to map the submarine wreck sites was he able to use it to crisscross the North Atlantic seabed to pinpoint the last resting place of the luxury liner. It meant he had only 12 days to find the Titanic.
"I couldn't tell anybody," he said. "There was a lot of pressure on me. It was a secret mission. I felt it was a fair exchange for getting a chance to look for the Titanic.
"We handed the data to the experts. They never told us what they concluded - our job was to collect the data. I can only talk about it now because it has been declassified."
Dr Ballard said what he had seen during the inspection of the wrecks gave him the idea of finding a trail of debris that would lead to the main sections of the Titanic. Thresher, had imploded deep beneath the surface and had broken up into thousands of pieces and Scorpion was almost as completely destroyed. "It was as though it had been put through a shredding machine. There was a long debris trail." Dr Ballard developed a robotic submarine craft in the early 1980s and approached the US Navy in 1982 for funding to search for the Titanic, which sank in 1912 with the loss of 1,500 lives after hitting an iceberg.
He was told that the military were not willing to spend a fortune on locating the liner, but they did want to know what had happened to their submarines. The military were anxious to know how the nuclear reactors had been affected by being submerged for so long.
During the 1980s the nuclear submarine fleet was reduced after the Salt II (strategic arms limitation talks) agreement and one option was to sink unwanted reactors at sea. Dr Ballard said that samples taken from the reactor sections of both submarines showed that there was little risk to the environment from radioactivity.
The oceanographer was given the funding to embark on two expeditions, one to find the wreck of Thresher in 1984 off the eastern coast of the US and another to find Scorpion in the eastern Atlantic.
Thresher, the US Navy's most advanced attack submarine at the time, sank with all her 129 crew in April 1963 while undergoing seaworthiness tests after dockyard repairs.
A surface ship, Skylark, was in contact when the submarine's crew reported that a high-pressure pipe supplying the nuclear reactor with cooling water had blown. The accident 1,000ft down, caused the vessel to lose power. It then sank so deep that the pressure hull imploded.
Scorpion disappeared with 99 crew in 1968, and there had been speculation that it was sunk by Soviet forces. Dr Ballard's visual examination of the wreck site showed that the most likely cause of its destruction was being hit by a rogue torpedo that it had fired itself.
♦ Titanic: The Final Secret will be shown on the National Geographic Channel at 9pm on June 8.
© 2008 - Times of London