Sitting in a truck stop in Ohio, waiting for a mechanic. The sky is blue.
This is the second time I've had this trailer fixed today. The first breakdown happened as I was on my way here to get this fixed. Does that make this the first?
I was moving quietly down a busy little road, minding my own business, when the rig abruptly slowed, making a hissing sound. Before I could get off onto the shoulder, it stopped completely. Dragged to a halt.
The hissing continued, but now I recognized it. Air, moving past the valve on the dash that controls the flow through the trailer's air lines. I had suddenly developed a massive leak, and the trailer's brake system was losing air much faster than the compressor could put it back.
When I was a kid, I saw a movie where David Jansen* played a tough-as-nails trucker delivering a cargo the bad guys really wanted to stop. At one point, some nefarious fellow cut his brake lines, sending him careening down a mountain road with only his skill and manliness to save him.
I was disgusted. Even at that age, I knew better.
Cars have a hydraulic brake system. Step on the pedal, and you compress hydraulic fluid, which pushes pistons attached to your brake pads (calipers or shoes, it matters not). If you cut the brake lines, the fluid runs out and the brakes stop working.
On a semi, when you step on the pedal, you open valves, that open other valves, that dump high-pressure air into similar pistons. That air is stored in tanks on truck and trailer. Cut the lines, and the air no longer goes to the pistons.
But the people who build semi's worry about such things. And they apply the same solution train-builders and (after a fashion) elevator designers use.
Also attached to the brake pads are a set of powerful springs. And those springs are set up to keep the brakes locked up. Always. One of the other things all that high-pressure air is doing is--holding those springs back. Cut the air lines, and the pistons that apply the brakes become useless. So do the ones that hold those springs at bay.
And the brakes lock down.
Like this afternoon.
The police and the street department were very polite. They directed traffic around me for a couple of hours, until the mechanic finally got there.
Fifteen minutes later I was rolling along as if nothing had happened. And got here to get the trailer fixed. Again. Maybe they'll get to me sometime tonight.
The sky is dark.
-----
*The original “Fugitive", chasing the one-armed man across TV screens before cops had computer assist…
No comments:
Post a Comment