Panama Canal lock masters employ specialized electric locomotives known as mules to physically pull colossal cargo ships through the narrow concrete locks because the vessels cannot safely steer themselves.

A closer look

Panama Canal lock masters employ specialized electric locomotives known as mules to physically pull colossal cargo ships through the narrow concrete locks because the vessels cannot safely steer themselves. These incredibly powerful, low-profile trains ride on specialized rack-and-pinion tracks alongside the water, attaching massive tension cables to the boats to keep them from smashing into the walls. You have hundred-million-dollar maritime super-freighters completely surrendering their navigational autonomy to a bunch of stubby little electric tractors that look like they belong in a children's television show. It is a wildly stressful tug-of-war where a single snapped cable means an entire global supply chain gets severely backed up, all because a cargo ship the size of a skyscraper is completely helpless in a tight space