The Underpinnings of the Country

I am fascinated by the Knife River plant. The sheer size of it is spectacular. They make pre-stressed concrete. Here is a link to a short explanation of what that is.  It's not long and it's interesting.  Without pre-stressed concrete, our infrastructure would be very different.
The truck is getting a load of concrete.  You can see it being dumped into the hopper in the back of the truck.

The day we were watching this, they had two trucks running back and forth between the above and the concrete form.  One would fill the form while the other one went back for more concrete.  It's about a quarter of a mile drive.

There is an auger in the hopper in the truck.  It moves concrete onto the conveyor belt.  As the concrete goes into the form the employees smooth it out.

Look at the guys on the right, they're using a board to level the concrete in the form.  It's surprising how manual the process is.

When they are done, we have one of these.  If you look carefully, you can see the curve in the beam.

This is a major payroll in Harrisburg.