The luxury Southern Railway train that derailed in rural Virginia Sunday killing six persons and injuring some 60 others was traveling at 80 miles an hour going into a curve where the maximum speed limit is 45, federal safety inspectors at the crash site said yesterday.

At that speed, according to several authorities who examined speed recording tapes taken from two of the train's four engines, the Washington-bound Southern Crescent was going 35 miles over the posted legal limit when it jumped its tracks while heading into a downhill curve with a 5-degree bank.

"Anything over 45 mph is an unsafe speed" for that section of track, said Francis McAdams, a member of the National Transportation Safety Board who went to the scene of the crash yesterday near Elma, Va., about 35 miles south of Charlottesville.

Noting that the recording tapes have only a "small margin of error," McAdams said 80 miles per hour would be "an excessive rate of speed" for that portion of the train's route between Atlanta and Washington.

Nevertheless, McAdams told a news conference in Charlottesville last night that it is too early to conclude that the train's speed was the cause of the wreck, the Associated Press reported. "While I have no reason to doubt the mechanical accuracy of the two speed tapes, there are other factors which must be considered," he said.

The train was carrying 65 passengers and a crew of 12 when seven of its eight passenger cars and three of its four locomotives twisted off the tracks about 5:40 a.m., either overturning nearby or plunging down a 40-foot gully in mountainous terrain.

Federal officials said yesterday they still have not been able to determine the exact cause of the crash, which killed six, critically injured five others and trapped scores of passengers and crew members in the tangled wreckage.

"We do not as yet have any evidence of inadequacy of the track or malfunction or failure of equipment. I would underline the 'as yet,'" said a safety board spokesman last night.

The spokesman added that there was no evidence yet that human error played a part in Sunday's derailment.

McAdams said the train's crew members "were upset, nervous and wanted to settle down before they gave us any definitive statement."

Among those still to be questioned by National Transportation Safety Board (NTSB) investigators is the train's engineer, J. E. Smith of Alexandria, who has been described by Southern Railway officials as the crewmember directly responsible for the train's operation.

A neighbor staying at Smith's house yesterday said the engineer was in Appomattox "on a hunting trip" and could not be reached.

A board spokesman last night said the train's engineer, conductor and fireman will be interviewed this afternoon at Smith's Alexandria home.

The Southern Crescent, the last famed passenger train in America operated by a private company, resumed its daily service between Atlanta and Washington yesterday, according to Southern Railway spokesman Charles Morgret. He said Sunday's southbound Crescent was rerouted but that tracks along the regular route reopened at 4:30 a.m. yesterday in time for the regularly scheduled northbound train.

Virginia State Police yesterday released the identity of the sixth victim of the crash, Ethel Schuler, of Spartanburg, S.C., whose body was pinned under the wreck at the bottom of the gully until late Sunday evening.

Also identified as having been killed in the crash were Southern Crescent flagman Howard L. Jackson of Alexandria; Lewis Price of Atlanta, a cook; Jackson and Edith Hume, an elderly couple from Madison Heights, Va., and 14 year-old Edward F. Shaw of Wilmington, Del.

Hospital authorities said yesterday that 17 survivors remained hospitalized, five in critical condition, including one of the train's cooks, Med Haynes, who was pinned in the wreckage by a stove for more than 11 hours Sunday.

In terms of lives lost, railroad officials said the crash was the worst in Virginia since 1903, when Southern's "Old 97" derailed at Danville, killing nine persons. That accident is depicted in a wellknown ballads "The Wreck of the Old 97."

A Southern Railways official who declined to be quoted by name said there are three possible, causes for a train's derailment -- "a possible track problem, a possible mechanical problem, or something wrong in how the train was operated, the human element."

NTSB spokesman Ed Slattery said the agency has sent specialists in all three of those investigative areas to the scene of the crash, with their findings to be detailed in NTSB's accident report.

In addition to information obtained from the speed recording tapes, one federal investigator said there were other indications that the train may have been traveling at a high rate of speed when it derailed.

"Several of the draw bars connecting the couplers with the cars were sheared," said a spokesman for the investigative team. "There were severe forces involved."

Federal Railroad Administrator John M. Sullivan said yesterday that Southern Railway officials have cooperated fully in the investigation of the crash. He praised the company's safety record and the condition of the track before the accident.

'Southern Railway has a very good safety record and a good reputation for maintaining its equipment properly," Sullivan said, adding that his agency found the track to be "defect-free" while making a routine inspection of that part of the route last May 11.

He said sections of the track on both sides of the point of derailment "are still in very excellent condition."

In addition, a spokesman for Southern in Atlanta said the train itself had been carefully inspected before its departure Saturday night and found to be in good working order.

Southern's Morgret said there is "no better maintained passenger train in the country" than the famed Southern Crescent. "Nobody ever accused us of operating a second class service."

Just last year, Morgret said, the company completed the solid welding of track along the entire 1,200-mile train route, and the section of track around Elma was "completely overhauled" two years ago. In addition, he said, the whole route is inspected daily and a specially equipped electronic stress-measuring car routinely travels the line.

The company's revenue is derived almost entirely from freight transporation. Southern has been trying to discontinue its passenger service, citing a steady decrease in ridership and a deficit last year of about $7 million from the Southern Crescent. It is now appealing an order by the Interstate Commerce Commission to continue the service at least until next August.