What is the most POWERFUL engine you have ever been behind?

This may not count, but it's still a heck of a something to be around. I was inside here once trying to get a job. The pilings that this building in the center attaches to (generation area) are rebar cages that are inside of an 8 foot diameter 2-1/4 inch wall casing welded together as they're installed into the earth and bedrock to a depth of 80 to 120 foot deep (I know because I had a friend that worked for a subsidiary of Case Foundation who was on the crew welding them together). 668 MW (895,000plus HP!) Hitachi steam turbine and generator assembly on the fourth floor. They sound a siren off before they start the generating and five seconds later (protocol to let everyone stop what they're doing) you feel the whole building in the center of the picture moving back and forth until everything evens out. The person I was interviewing with told me it was engineered for up to one and a half inch of lateral movement during start up.
Virginia City Hybrid Energy Center - Wikipedia