* New public relations disaster for global cruise line

* Ship due into port around midnight

* Angry mother rejects cruise line executive's apology

The Carnival Triumph cruise ship is towed towards the port of Mobile, Alabama, February 14, 2013. The 893-foot (272 meter) vessel, notorious for reports of raw sewage from overflowing toilets, has been without propulsion and running on emergency generator power since Sunday, when an engine room fire left it adrift in the Gulf of Mexico. [Photo/Agencies]

MOBILE, Ala. - Reeking of rotting food and sewage from overflowing toilets, a crippled cruise ship carrying more than 4,200 people was limping into Mobile, Alabama, on Thursday as passengers awaited the end of a vacation voyage some described as hellish.

The Carnival Triumph was being towed into port by tugboats as the drama played out live on US cable news stations, creating another public relations nightmare for cruise giant Carnival Corp. Last year, its Costa Concordia luxury ship grounded off the coast of Italy, with 32 people killed.

Passengers described an overpowering stench on board the ship four days after an engine room fire knocked out power and plumbing across most of the 893-foot (272-metre) vessel and left it adrift in the Gulf of Mexico.

After the mishap, toilets overflowed, soaking many cabins and interior passages in raw sewage.

"Let's just say that I had a pair of shoes that I will not be bringing home with me," Julie Morgan told CNN.

"It is revolting," Morgan added, referring to the smell aboard the ship. "It's a mixture of sewage and rotting food."

But Terry Thornton, a senior Carnival Cruise Lines vice president, told reporters in Mobile that additional provisions were laid in on Wednesday and the ship was now "in excellent shape."

Passenger Donna Gutzman said those aboard the ship were treated to steak and lobster for lunch on Thursday afternoon.

"Our basic needs are being met. For the most part, they are making us happy," Gutzman told CNN.  

The ship was expected to arrive in port around midnight CST (0600 GMT on Friday), Carnival said. A senior Carnival official said it could take up to five hours to remove all the passengers from the ship, which has only one functioning elevator.

Carnival Corp spokesman Vance Gulliksen said a tow line on one of four tugboats helping the Triumph get into port snapped on Thursday. But the tug was later reattached to the vessel.

Operated by Carnival Cruise Lines, the flagship brand of Carnival Corp , the ship left Galveston, Texas, a week ago carrying 3,143 passengers and 1,086 crew. It was supposed to return there on Monday.

A Coast Guard cutter has been escorting the Triumph on its long voyage into port since Monday, and a Coast Guard helicopter ferried about 3,000 pounds (1,360 kg) of equipment including a generator to the stricken ship late on Wednesday.

Earlier in the week, some passengers reported on the poor conditions on the Triumph when they contacted relatives and media before their cell phone batteries died. They said people were getting sick and passengers had been told to use plastic "biohazard" bags as makeshift toilets.

'VERY CHALLENGING CIRCUMSTANCES'

Carnival Cruise Lines Chief Executive Gerry Cahill said in a statement late on Wednesday that the company had decided to add further payment of $500 a person to help compensate passengers for "very challenging circumstances" aboard the ship.

"We are very sorry for what our guests have had to endure," Cahill said.

Mary Poret, who spoke to her 12-year-old daughter aboard the Triumph on Monday, rejected Cahill's apology in comments to CNN on Thursday, as she waited anxiously in Mobile with a friend for the Triumph's arrival.

"Seeing urine and feces sloshing in the halls, sleeping on the floor, nothing to eat, people fighting over food, $500? What's the emotional cost? You can't put money on that," Poret said.

Carnival Corp Chairman and CEO Micky Arison faced criticism in January 2012 for failing to travel to Italy and take personal charge of the Costa Concordia crisis after the luxury cruise shop operated by Carnival's Costa Cruises brand grounded on rocks off the Tuscan island of Giglio. The tragedy unleashed numerous lawsuits against his company.

The cruise ship mogul has taken a low-key approach to the Triumph situation as well, even as it grabbed a growing share of the US media spotlight. His only known public appearance since Sunday was courtside on Tuesday at a game played by his Miami Heat championship professional basketball team.

"I think they really are trying to do the right thing, but I don't think they have been able to communicate it effectively," said Marcia Horowitz, an executive who handles crisis management at Rubenstein Associates, a New York-based public relations firm.

"Most of all, you really need a face for Carnival," she added. "You can do all the right things. But unless you communicate it effectively, it will not see the light of day."

Carnival Corp shares closed down $0.11 at $37.35 in trading on Thursday on the New York Stock Exchange. The shares closed down 4 percent at $37.46 on Wednesday after the company said voyage disruptions and repair costs related to Carnival Triumph could shave up to 10 cents a share off its second-half earnings.

The Triumph is a Bahamian-flagged vessel and the Bahamas Maritime Authority will be the primary agency investigating the cause of its engine room fire.

For all the passengers' grievances, they will likely find it difficult to sue the cruise operator for any damages, legal sources said. Over the years, the cruise industry has put in place a legal structure that ring-fences operators from big-money lawsuits.

Rules for seeking redress are spelled out in complex, multi-page ticket contracts that have been the subject of decades of court battles. Victims are often required to proceed with any litigation in remote jurisdictions.