Wärtsilä 14RT-flex96C engine. This is the smaller six cylinder engine version of the 14 cylinder engine described in the article.
MSN/SlashGear has a post about what they report as the largest marine diesel engine, “How Big Is The World’s Largest Piston Engine? And How Much Power Can It Deliver?”
There is a large element of “Gee Whiz” here, but it may be something more Coast Guard members should know about. Marine Inspectors are certainly aware. The post is a five-minute read and there is a short video of “Top Gear” presenter Richard Hammond getting a literal inside look at a smaller, but still very large, marine diesel.
In addition, since the Coast Guard has an implicit requirement to be able to forcibly stop any ship, regardless of size, think about how hard it will be to hurt one of these massive engines. Large explosions are going off inside 1400 times a minute. A 25 or 57mm projectile exploding in the engine room may not have much effect.
Chuck Hill's CG Blog 
A large containership will have 2 of these which weigh about the full load of an NSC when they are dry. You either stop it by boarding or assume the level of force will need to possibly be enough for it to eventually sink. https://en.wikipedia.org/wiki/W%C3%A4rtsil%C3%A4-Sulzer_RTA96-C
The engine in the photograph is not the 14-cylinder behemoth but a smaller six-cylinder unit. I don’t know which make and model it is, but it has been misidentified as the “world’s biggest engine” since at least 2011. Nonetheless, it serves well as a generic illustration for the size of these low-speed engines that power most of the world’s commercial shipping.
Thanks, I will caption the photo accordingly.
I also added a video.