What is coolest hydraulic machine you have ever seen?
Mine is the Peterborough Liftlock. A hydraulic teeter-totter of grand proportions.
Here my students are taking the "wrench twister" tour.
Rod diameter: 7.5 feet
Barrel length: 75 feet
Age: 105 years
Medium: Water
Packing: Translock 29 (pictured in leaking mode)
Load: 3.2 million pounds
Number of times either rod has ever been removed from their barrel for servicing in 105 years: 0
So much for never betting your life on an o-ring - the cargo is passenger boats...