Pieces of a Photographic Mosaic
June 2, 2004
Drawn on a 1987 mosaic (originally published in National Geographic Magazine) of the bow section of the Titanic are many small boxes. They are the guides for a new mosaic of the bow section being made from images collected by the ROV Hercules.
Photograph by Bert Fox © National Geographic Society
Two still-frame digital imaging cameras aboard the ROV Hercules on Tuesday began taking the first in a series of photographs that will be stitched together with computer software to form a complete mosaic of Titanic on the ocean floor. Comparison with a similar but low-resolution monochrome mosaic, produced in 1987, will help scientists assess damage to the ship and its rate of decay.
"I want to sit here, and go back and forth, back and forth, and do some mosaicing," Return to Titanic expedition leader Dr. Robert D. Ballard told his crew as Hercules hovered a few meters above the bow.
"I want to go down the center axis of the ship, and out past like you're Leonardo DiCaprio standing on the bow," he added, drawing chuckles from those running the cameras and motors of his two exploration vehicles.
Dwight Coleman, sitting in the control van on the deck of the NOAA ship Ronald H. Brown, fired the mosaic cameras' flash every few seconds as Herc glided above anchor chains, captstans, winches, and bow railings.
Meanwhile, high-definition video cameras aboard the ROV and its relay vehicle, the towed sled Argus, sent hours of live images to the ship 2.25 miles (3.63 kilometers) overhead.
A crowd watching a monitor in the main lab gasped as Hercules pilot Tom Orvosh flew the remotely operated vehicle along the collapsed mast. Lookout Frederick Fleet had been up the mast when he spotted the fatal iceberg in 1912.
"Follow the mast. Rise up," Dr. Ballard quietly told his crew.
The third voyage of Hercules and Argus to the sea bottom proved to be the charm. Heavy seas cut short the first trip. A second journey, which began late Monday, proved frustrating when the signal from Herc's high-definition camera cut out just as the ROV approached the bow.
Dr. Ballard explained that the tether joining Hercules and Argus, which must remain slack to be effective, had been jerked taut too many times. The "bullwhipping" damaged the ends, he said.
Hercules lost telemetry and had to be recovered "dead stick." A winch operator reeled in the long cable connected to Argus, and as it rose, it pulled up Hercules by its fiber-optic tether.
Engineers and technicians declared the tether a loss. Two of its three optical filaments would not pass a signal from end to end.
They spent Tuesday morning replacing the 98-foot (30-meter) tether and strengthening its ends with reinforced rubber tubing and what ship's Bosun Bruce Cowden called a "Chinese finger puzzle" of interwoven cords.
In addition, engineering support worker Dave Wright polished the fiber-optic cable connectors and aligned the embedded fibers to strengthen a weak signal that had been compromising data transmission.
Dr. Ballard acknowledged that there are always surprises during an expedition at sea but emphasized that "failure is not an option."
The repairs apparently worked. Hercules performed as advertised during a third mission that began when it and Argus went into the water at noon Tuesday.
Three hours later, they arrived at Titanic's bow.
The control van crew moved the vehicles along the port side, collecting startling video images: Portholes, still containing glass. Red paint on the keel. Rusticles and pitted iron in swirls of turquoise and orange, looking like nothing so much as a Jackson Pollack drip painting.
The vehicles headed north toward the bridge, pausing to allow the crew to photograph five memorial plaques left in front of the telemotor by earlier expeditions. The lettering was easy to read under the lights, and a tiny American flag was clearly visible.
Return to Titanic, an hourlong National Geographic Channel program, will be broadcast at 9 p.m. ET/PT Monday, June 7.
(Note: nationalgeographic.com does not research or edit dispatches.)
