Big Loads - Post Photos Number 2

I don't know if either truck even got on the brakes. They're geared so low it looks like they were just getting pushed/pulled. Wheels were turning for most of what I could make out.

 

The controller guy or the remote failed then.

 

Could be, it’s been a long time since I worked with one and it was self propelled. The control unit is on the first truck but I’m not sure who’s controlling it. I think it was to steep of a grade and got away from them.

 

The puller truck definitely had on brakes, and the trailer pushed him into a tractor jackknife. I was wondering about the trailer, because if the trailer had skid, it would have went sideways.

 

You're right. I replayed it with sound and I can hear the air fanning down on the lead truck.

 

There are some job sites that are so steep that you may skid. I’ve had the axles bounce... especially on a steep gravel road. When that started, I let off the brakes to regain steering control.

JD says that the trailer doesn’t have brakes, but it can be slowed by the drive motors. That being the case, if the trailer was creeped down the grade and lost traction, it would still display the same signs as brakes.... it would slid sideways. Especially the heavier loaded axles. In other words, the back end of the trailer would have stepped sideways. This doesn’t happen.

 

Looked to me like the trailer started pushing the pull truck because the platform wheels were still spinning while the tractor was locked up. If you look at about the 30 second mark you can see that the draw bar has mechanical links to the wheel groups. That platform is steered by that draw bar on the pull truck. Uses the mechanical links to steer the first axles and then proportional hydraulic steering from those to auto steer the rest. It would then turn in a big arc from front to back. When the pull truck broke traction and the back started sliding right it made the entire platform steer right. If they had let it roll instead of smashing the brake pedal through the floor board might have saved it.

There still would've been the issue of the truck at the bottom of that hill but they might have had a chance of controlling it and getting that guy to move quick.

As usual they ran out of traction long before overcoming the brakes or drive power.

Slope was too steep with loose material on the surface.

I do agree that some how the trailer braking system failed to work. If they are unpowered platforms maybe they do still use air brakes. There do appear to be lines between both tractors and the platform connected with standard glad hands.

Also, what the hell was that guy thinking trying to outrun the load in a straight line. It's sliding right he should've gone left. Instead he runs directly into the path of an uncontrolled piece of machinery.

 

Same page, friend. The guy that’s running, he’s wearing a harness of sort. My gut instincts tell me that he’s in control of the trailer. And he panics and makes poor choices.