These large engines are designed to power the world's super oil tankers and large container ships. They are built to the ship owners' preferences. They usually request an engine construction of a single unit and single propeller design for ease of maintenance, and not surprisingly any later troubleshooting. A single unit and single screw design has also proved over time to have a longer life span than double or even quad screws.

These engines are built in 6, 8, 10, 12 and 14 cylinder configurations. All the engines are straight or 'inline'. The diameter of each cylinder is 3 foot 2 inches with a stroke of 8 foot 2 inches. The 12 cylinder version weighs in at 2000 metric tons and delivers 90,000 Horsepower at 100 Revs per minute, with best fuel economy at 53,244 HP at 90 Rpm. When I mention economy, the 14 cylinder engine for example with a displacement of 25,480 Liters ( 1.56 million cubic inches ) burns up 1,660 gallons of crude ("bunker") oil every hour. 

 $2,844 every hour the engine runs or 27.6 gallons, which is $46.00 every minute or 76 cents a second! That is, of course, if the ships buy oil at trade price...if not, then these figures are the absolute minimum. ( * at time of publishing ) 

In the image below a worker at the plant is finalizing work on the cylinder block. This image shows the piston sleeves. The worker could quite easily have a nap inside one of the bores and no one would notice!