pneumatic

The special effects department had to rig everything with pneumatic closers that are electrically operated so they can kind of open and close on cue.

In a pneumatic caisson, the air pressure is maintained equal to or higher than the water pressure at the bottom of the structure so that seepage and soil instability can be avoided.

You have an electromechanical actuator that's driving a pneumatic cylinder, which is pumping air to a valve so that you can control the input to both cylinders at the same time.