Building a Highway (1948)

Driving along a wide, smooth highway is something we all enjoy. But building a highway is a big job. It takes many men, a lot of machines, and a lot of materials. First of all, men have to decide just where the highway should go. They have to measure the land and mark the path the highway is to follow. That's what these men are doing. They are surveyors. After the surveyors finish their work, other men clear the ground. They cut down trees that stand in the way, and they burn away the brush. And then come the machines. First, the mighty bulldozer. Its work is to make a wide path or trail for the highway. This machine can move tons of earth along at a time. The driver moves a lever, and a wide steel blade drops down. Other levers make the big machine move ahead. It would take dozens of men to do the work this machine is doing. As the bulldozer moves along, it pushes the earth ahead of it. Over the bank goes the earth from the hillside, making a good wide trail. This is done so that even bigger machines can take up the work. Giant road scrapers go into action. The tractor has caterpillar treads on its wheels, so it won't get stuck in the loose deep sand. The huge rubber tires on the scraper help keep it from getting stuck, too. One big tractor is pulling the scraper and two others are pushing it. A scraper like this acts like a giant shovel that scoops up the earth in great buckets full. The big scraper bucket soon fills with earth. When it is full to the top, the tractor pulls it away to a low spot. So, the earth scraped from the hillside goes to fill in low places in the road. The scraper bottom opens and out falls the earth. Earth that builds up the roadway and helps level it out. So, now the land has been cleared and a level roadway has been made. Next, we will see how the roadway is paved. To begin with, workmen set up a heavy steel track along each side of the road. Big steel stakes hold the track in place. These tracks will hold in the wet concrete until it hardens. Also, the wheels of the paving machine will run on these tracks. Now, the road gets a final leveling to make it ready for the concrete paving. Any high spots that still remain have to be leveled off. And any low spots have to be filled in. It would be wasteful to use concrete to fill in the low places. High spots would leave the pavement thin. And thin pavement cracks too easily when heavy traffic runs over it. Now, the road is all ready to pave with concrete. While all this is going on, another part of the job of road building is taking place nearby. Here, more big machines are getting ready some of the materials needed for concrete pavement. Truckloads of rock and sand are carried to crushing and screening machines. The crushing machine breaks up the big rocks. The screening machine separates the sand and the small rocks. Two sizes of rock are often used to make concrete paving. This is one size. But, it takes other materials to make concrete. One of these is cement. Here, cement from railroad cars is hoisted into the elevator and dropped into the paving trucks. Each load of paving material gets the right amount of the gray powdery cement. We need sand, too, to make concrete. Small rocks and clay have been washed out of this sand. Now, a big scoopful of clean sand goes to the loading hopper. Down from the hopper drops the sand into the truck. It falls on top of the cement and rock already there. Now, the paving truck has a full load of paving materials. The driver heads it out toward the highway where the paving machine and a crew of men are working. The paving truck backs up to the front of the paving machine and onto a large scoop. Paving men call it a skip. The paving materials fall into the scoop. A little pounding loosens any cement or sand that sticks in the truck. Water trucks haul in the water to make concrete. The water runs out of the truck and into a pump on the side of the mixer. The pump forces the water on into the mixer. The mixer man watches everything going on around the paving machine. At just the right time, he moves some levers and up goes the scoop with another load. Into the mixer drops the batch of raw materials. The mixer spins round and round until all of the water, sand, rock, and cement are mixed into concrete. This big bucket carries the mixture along to the right place and dumps it. At once, men begin to spread it out over the road. Heavy wire screens help strengthen the center of the pavement. This wire will help keep the center from cracking after the pavement dries. More and more concrete goes into place on the roadbed. After the concrete is spread out over the road, it is leveled down until it is just right. This machine cuts grooves across the pavement. Men put a strip of heavy fiber in each groove. This will help keep cracks out of the pavement later on. Machines do most of the leveling, but the final smoothing is done this way. Roughening now will help stop the glare of light shining off the drier pavement later. Rounding with a trowel will keep the edges from breaking. Now it's time to cover the paving. The men wet it down and cover it with heavy paper. All of this makes the concrete dry slowly. And that's a good thing because slow drying helps make strong concrete. Now the concrete paving is finished, but the highway is not yet completed. Later on, we find guardrails alongside grades and curves, and stop signs and stop and go lights to protect cars at crossroads. Now the roadway has become a highway. It leads into other larger highways. Highways that join together all parts of our country. Highways that let us travel quickly and safely if we're careful wherever we want to go.