Back in 1973, we were doing a project out in the Northwest Hills Area of Austin. We had just acquired a new C14 Hein Werner Excavator, much like the one below.
To make it travel the 2 shorter levers (with the black grips) in the picture below would be pushed forward or back depending on the direction you wanted to travel. Of course only pushing or pulling one lever would cause the machine to turn.
If you were traveling for a far distance they could be snapped in, so you didn’t have to hold them.
At the end of the day late one afternoon as we were all preparing to leave the job site, a few of us were standing out at the street making conversation. That machine was left parked a couple of hundred feet inside the project. Suddenly we heard the engine start up. When the operator stepped off of the machine earlier, he snapped the travel levers in the forward direction, to allow for better clearence when getting off.
As the engine started, the excavator started slowing walking across the project, toward a newly completed row of very expensive homes. At first it seemed like a prank, but as we all ran to get closer, it was obvious that the machine was traveling without the aid of an operator.
We found out later that those machines had a problem with the starter shorting out and the engine starting all on thier own. The factory recommended that the user unhook the battery cable each night so it wouldn’t happen. They eventually made a fix that cured the problem.
Very likely if we hadn’t stopped for some after work chit chat, that machine would have found its way to do 100s of thousands of dollars damage to the neighborhood homes.