These photographs were taken by Jimmy Lee Slover at Miraflores Locks in the Canal Zone while he was working as a Senior Control House Operator. The New Jersey is shown in the upper east chamber, going south to the Pacific Ocean. This is about the last time the USS New Jersey navigated the Panama Canal under her own power.
All photos — click to enlarge.
If you look in the center between the tracks you will see a rack gear which is about 8″ wide. The Mules have a corresponding round gear centered between the drive wheels on both the forward and rear drive wheels. This gear is mounted on the shaft that drives the wheels and is also driven by the electric motors. Although the Mule looks the same from either direction, either end can serve as the front.
This rack and pinion system locks the Mule to the track so it cannot slip forward or backward under the load of the ship it is pulling. It also allows the Mules to go up and down the incline between the locks when the lock heights differ.
If you look at the right-hand rail in the picture, you can see a slot or opening between the rail and the concrete, centered between the rails. In that slot, below the rails, is a set of three copper bars approximately 1″ thick by 3″ wide. These copper bars carry the current and voltage to power the Mules. A bar attached to the bottom of each Mule has brushes that make contact with the three copper bars to pick up the power needed to run the motors. There are four sets of these bar-and-brush pickups on the bottom of each Mule.
Another view of the gear rack centered between the rails for the Mules.
