Luxury line Crystal Cruises announced plans in February to bring the historic SS United States back to its earlier glory — pending a feasibility study.

Now that the study is done, the cruise operator says that plan is impossible.

While the 1952 ship is “structurally sound,” according to the evaluation, Crystal Cruises said updating it to meet current standards for oceangoing vessels would be too challenging and force too many changes to the original structure. The ship has been docked in Philadelphia for 20 years.

Edie Rodriguez, the CEO of Crystal Cruises, said earlier this year that the company would be willing to invest at least $700 million in renovations to turn the SS United States into a modern luxury ship if the purchase deal went through. Crystal spent more than $1 million on studying the possibility and will donate $350,000 toward preservation.

“Over the past six months, Crystal has conducted an extensive feasibility study to restore ‘America’s Flagship’ to oceangoing service,” Rodriguez said in a statement. “Unfortunately, the hurdles that would face us when trying to bring a 65-year-old vessel up to modern safety, design and international regulatory compliance have proven just too great to clear in both a technically and commercially responsible manner.”

Crystal public relations diretor Paul Garcia said the cost could have easily neared a billion dollars, but that wasn’t the biggest issue.

“We reached a point where the multitude of needed changes would have led to a loss of the ship’s character and that was more of a driving factor,” he said in an email.

The SS United States Conservancy owns the vessel and will try to find a partner to redevelop it for stationary use.

“America’s Flagship continues to hold enormous potential as a stationary mixed-use development and museum in New York or another urban waterfront setting,” Susan Gibbs, the conservancy’s executive director, said in a statement.

Tom Basile, who oversees media relations for the conservancy, said in a phone interview that the ship’s interior was “essentially a blank canvas” for developers to repurpose however they see fit. He said that could include office space, lodging, a conference center,  performance space, and cultural areas, and the conservancy hopes a museum would also be included.

“There are a lot of different options when you’re dealing with a ship that is three blocks long and basically the size of the Chrysler building,” he said.

In the meantime, the organization is raising money to continue paying the cost of keeping the ship in the water. That is necessary to avoid having to “pursue a scrapping scenario,” Basile said, though he said the ship is “not in immediate danger.”

Crystal Cruises has been expanding rapidly since it was acquired for $550 million last year by Genting Hong Kong, a casino giant that also owns Asian lines Star Cruises and Dream Cruises. Just a two-ship line when it was bought, Crystal has added or announced plans to add more ocean ships, river boats, yachts, and aircraft.

Photo Credit: An evaluation ordered by Crystal Cruises found that the SS United States, shown docked in Philadelphia, is "structurally sound" but cannot feasibly be returned to service. Don Robson / Flickr