>My thoughts exactly. I was surprised when Hal said the ship >was under power. My original thought was that the mules pulled >the ship through, as I figured the ship would be bouncing of >the sides of the lock under its own power. The ship's throttle >must be barely cracked open. Maybe just enough to assist the >mules?
The ships engines are certainly running to provide A/C, electrical power, run the pumps and hydraulics, provide steering control and so on. But no cargo ship normally traverses the panama canal locks under its own power. Some inattentive skipper or helmsman would have the entire system jammed up in no time. Traction engines - sometimes several ganged together on each track running parallel to both sides of all locks in the system - tow and navigate ships through the locks. In several of Hal's shots you can plainly see the rail tracks and various traction locomotives lined up and ready for use.