That's an amazing machine purely by the efficiency numbers. When they say it's the most efficient machine built, I sort of had my doubts, because modern steam engines can approace the 50-60 percent efficiency range of converting the energy in the fuel into mechanical motion, and thus have continued to be popular for large applications. I imagine being that these engines power container ships, that space issues are a factor too. Steam engines, which are still popular on some navy ships, and passenger lines, occupy much more space for their boilers, turbines, condensers, etc...and thus also require more crew to handle.
I also thought was interesting thing that these engines directly drive the propellers. I guess simplicity has it's virtue, as the other variety of engine design for passenger liners is diesel electric. The Sun princess, a cruise liner I went on about 4 years ago, has 36 diesel generators powering 3 electric motors that can be swiveled like giant versions of minn-kota electric outboards. This allows the ship to move in any direction the captain desires. It's probably easier for the captain when "parallel parking" her at dock in Ft Lauderdale than it is to parallel park his SUV at the terminal due to this neat engine design. The only problem with this engine design I've heard is that it's not the most efficient, and is only about 35 percent efficient, and the mechanicals take up the entire bilge of the vessel.