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."