Once docked, the ship will be idle through April. In addition to the dozen voyages canceled Wednesday, two other cruises were called off shortly after Sunday's fire.
Jay Herring, a former senior officer with Carnival Cruise Lines who worked on the Triumph from 2002 to 2004, said the ship was not problematic when he was on it.
The Triumph takes five generators — with one on backup — to power the ship, and 80 percent of that energy is needed to simply push the massive vessel through the water, Herring said.
Each of those generators is the size of a bus, so it's unrealistic to think that the ship could have enough backup power on board to run services when the engines die, Herring added.
"It's one of their bigger ships. It's certainly on the top end of Carnival's fleet," he said of the Triumph. "There are so many moving parts and things that can go wrong."
Associated Press writer Bob Johnson contributed to this report from Montgomery, Ala. Plushnick-Masti reported from Houston.