I wonder how big those actually are? I mean, they're BIG but the perspective makes them look HUGE!

Looking at some of the fasteners and thru-holes makes them seem a little smaller than they appear.

 

they must be for a big diesel tug boat or something.

 

They're for a giant container ship, and yes it's a diesel. Just search world's bigest diesel and you can see pics of the engine and everything. The head studs are like tree trunks, and you could literaly sleep in one of the main bearings.

 

Forget J-Lo, I've got wood from that pic!

 

Id hit it.