Without wishing to launch into a tedious lecture, that would never do in a blog devoted to whimsy, there are several ways that airbrakes can fail. The most spectacular shouldn’t ever happen. Overheated brakes leading to runaway trucks are down to bad driving, no more, no less. But a leak in the air line can happen to anyone and it depends a little where you are, and how catastrophic the leak is, what happens next. The normal brake-pedal brakes work by compressed air being pumped into the brake chambers, but the emergency/parking/handbrake thingy works when air is taken out. That one’s called a spring brake, because, well, it’s got a spring in it for leaping into action when required. Trouble is, when things are faulty and the air pressure drops, the spring brake can pop on anyway. It’s a safety feature, but you don’t want it happening all of a sudden on the highway. That’s why a warning alarm goes off before things get that drastic.
I’d noticed, about a mile or so from Guelph, that my low air warning had started to go off at traffic lights. I’d put it down to being tired and using too much welly on the brakes instead of judging my approach from a distance. But, while the truck sat on the dock being unloaded, whatever was leaking air must have got worse. With pressure dropping in all the tanks, the trailer spring brakes wouldn’t release when I tried to leave. Still in blaming-self rather than blaming-vehicle mode I checked all the stupid, tired-person mistakes I could have made. Like trying to pull away while the dock clamps still had hold of the back bumper. Or forgetting to take the chocks out from under the wheels. But an air issue it was. I switched the engine on and sat for a while as the gauges registered an illegally slow build-up. The truck would be going off the road for repair. But I was in the way, other people were waiting to get onto the dock, unload and go home. This was a very antisocial spot for a breakdown. Finally I built up just enough air to release the brakes; if I didn’t use the brake pedal for the scant kilometre back to the yard I could maybe park up and declare the truck out of service somewhere convenient. I still had some freight in the trailer, I could use its weight and the gears to slow me down.
I turned off the dock, left in front of the other trucks, ready to make another left turn, past the dumpsters, through the car park and out onto the road. But the car park was full of people in cars, in a hurry to get home. One of them zoomed out in front of me and I had to brake sharply. The trailer springs sprung again and I was now stuck at an angle across the car park. I had one more go at revving like mad to get some air pressure going. Then I released the clutch to see if I could get the truck to move. It leapt forwards, and a spot to the left, whereupon I twigged that I’d taken the turn round the dumpster a little tight. Under normal circumstances I’d have had time to correct it.
I had no idea what to do next. I just stood there, nonplussed. What do you do with a trailer door on the ground? Apart from wishing that the last 10 seconds could be rewound. That I’d closed the doors before trying to release the springs, that I’d looked at my mirrors instead of my air gauges. Fortunately (in a manner of speaking) I had an audience. A couple of avuncular Linamar drivers took over. They regaled me with tales of how many times everyone they knew had ripped a trailer door off and how it wasn’t a big deal really. They picked the door up, popped it in the back of the trailer and strapped it to the inside wall so that a forklift could still get in and unload the rest of the freight in the morning. They followed me slowly back to the yard in case the brakes gave trouble again. Back at dispatch, more people told me that everybody does it. But I was devastated, exhausted, hungry and miserable. With my tractor off the road for repairs for a couple of days, there would be time to think about how exhausted, hungry and miserable I actually enjoyed being.