A National Transportation Safety Board team said it determined that the ferry's two forward engines facing the Staten Island dock stopped upon impact but the two rear engines were still operating.
The team has interviewed the chief engineer and some crew members of the Andrew J. Barberi ferry, which was carrying 252 passengers and about 18 crew members when it crashed at the St. George Ferry Terminal on Saturday. It also has met with the management of the Staten Island Ferry.
Based on an initial interview Sunday with the chief engineer, who was in the ferry's engine control room, "there were no engine alarms prior to the accident," NTSB member Robert Sumwalt said.
"All conditions concerning the engines were normal prior to the accident," said Sumwalt, adding that there were also no previous problems with the propulsion system or electrical systems.
Alcohol and drug tests were conducted on the crew members, Sumwalt said at a news conference on Staten Island on Sunday. The alcohol tests, which were conducted by the U.S. Coast Guard, came back negative for all, and the drug tests were being evaluated, he said.
"At this point in the investigation, we're not ruling anything out," said Sumwalt, part of a seven-member NTSB team. "Everything is on the table."
The NTSB team completed its first full day of work on the investigation Sunday. It will spend as much as a week collecting information and evidence surrounding the accident, which injured up to 37 people.
After the NTSB team completes its work at the scene, it will return to Washington, D.C., where it will conduct a deeper analysis of the collected information to try to determine the cause of the accident. That could take from a year to a year and a half, Sumwalt said.
The NTSB, however, could issue urgent safety recommendations before that, he said.
City Department of Transportation Commissioner Janette Sadik-Khan has said the accident appeared to be the result of a mechanical failure.
The ferry's throttle failed to engage as it prepared to dock, she said, meaning the crew was unable to use the engines to apply reverse thrust and slow down. The cause of the malfunction is unknown, she said. The 3,000-ton, 310-foot-long ferry was moving at about 5 knots, or 5.8 mph, when it hit.
The NTSB's plans for Monday included interviews with all crew members, including the captain and assistant captain and the other members of the engine crew. The NTSB said it also will interview passengers.
Investigators on Monday also planned to meet with the manufacturer of the ferry's propulsion system, Voith Schneider.
The NTSB is looking at video security footage from several locations, including footage of the vessel, the bridge, the engine room and the Staten Island dock.
Investigators are getting information from a Coast Guard radar tracking system that followed the vessel and registered its speed as it crossed from Manhattan to Staten Island. Officials could not say whether the ferry was going too fast.
The Andrew J. Barberi ferry was involved in a 2003 wreck that killed 11 people. That accident occurred when the pilot, suffering from extreme fatigue and on painkillers, passed out at the wheel and the boat hit the terminal in St. George at full speed. The ferry returned to service after a multimillion-dollar rehabilitation.
The pilot pleaded guilty to negligent manslaughter and lying to investigators. He was sentenced to 18 months in prison. The city ferry director was sentenced to a year in prison after pleading guilty to negligent manslaughter and admitting he failed to implement or enforce a rule requiring two pilots during docking.
On July 1, 2009, a different ferry lost power and slammed into a pier at the St. George terminal, causing more than a dozen minor injuries among passengers. That accident was blamed on the failure of a transformer, which regulates power to the main propulsion engine.
The ferry runs across New York harbor between Manhattan and Staten Island. Ferries landing at the terminal approach fairly quickly, then slow down by putting the engines in reverse. The boat coasts into a U-shaped slip, and workers extend large ramps that allow passengers to exit. Most passengers assemble at the front as the ferry arrives.
