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Once Charlie worked on a road-building job. There he used a crane and a
shovel and many other machines besides. This particular road had to
cross a big swamp near the ocean. So the first problem was to fill up
the swamp with something solid. In order to get enough earth and rock
for the fill, men would have had to tear down a whole mountain. Instead
they called in suction dredge machinery for the job. The huge pumps
sucked sand from the bottom of the sea and poured it through pipes onto
the swampy ground. When the water drained away, millions of tons of fine
white sand were left.
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Charlie helped level the sand off with a bulldozer. Then he moved on to
a place where a hilly spot had to be leveled. There he drove a carrying
scraper, a machine with a scoop between its front wheels and its rear
wheels. The sharp scoop scraped up a load of earth, and Charlie drove
off to dump it in a low spot. When he got there, a pusher blade at the
back of the scoop pushed the earth out. Round and round he went,
without having to stop for loading or unloading.
Other men used a different machine like the one in the picture. This
earth mover carried more in one load than the motor scraper, and it was
better for hauling earth longer distances. For very short hauls, Charlie
drove a fast little tractor. At least it looked small compared to the
giant machines. It pushed a scoop in front of it like a shovel, then
lifted a load, turned swiftly and dumped the earth where it was needed a
few yards away.
Charlie’s road was going to be a special highway for speedy traffic. In
order to make it as safe as possible, the crossroads had to be lifted up
over the new highway. Crews of men built these overpasses. First they
used the huge earth-moving machines to make little hills on each side of
the highway. Then they built bridges of concrete and steel between the
hills.
At one place, there were two houses on the exact spot where the hill for
an overpass had to be made. Instead of tearing the houses down, moving
men just carried them away with the furniture still inside. First they
raised the houses off the ground with jacks. Next a tractor backed a
wide, low trailer up close to each house. Using special machinery and
rollers, the men
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eased the whole building onto the trailers. That same night, the houses
were set down on new foundations, and the people went right on living in
them.
At one place, a big ledge of rock was in the way of the new road. Men
called powder monkeys blasted the ledge to smithereens with explosive.
Then Charlie came in with his caterpillar tractor and a rock rake.
Unlike a garden rake, which you pull, Charlie’s rock rake scratched up
rocks and pushed them ahead of it. He shoved all the loose chunks of
stone away, but several big ones were too far underground for the rake
to pry them loose. So Charlie put a ripper on behind his tractor.
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The ripper had strong prongs that could dig down deep and get a good
hold on a boulder. The frame that held the prongs was hollow. For very
heavy work, Charlie filled the hollow frame with sand to give it a lot
of weight so the prongs wouldn’t slip. To pry out the very largest
boulders, Charlie sometimes got another driver to hitch his caterpillar
onto the ripper. Then the two tractors, chugging together, did the job.
After the bulldozers and scrapers and rakes had built a rough bed for
the highway, Charlie helped to smooth it down and get it all ready for
finishing. He used a long six-wheel motor grader for the job.
The motor grader had its Diesel engine in the rear, above the four
wheels that did the pushing. The guiding wheels were way off at the
front, and in between was the scraping blade, placed where Charlie could
watch it.
Charlie could set the blade at almost any angle, just as a barber can
tilt a long-bladed razor. And Charlie was proud of the way he had left
the road almost as smooth as a barber leaves a man’s face.
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Charlie could play tricks with the motor grader’s front wheels, too.
Besides steering them in the ordinary way, he often made them lean over
toward the right or the left. To look at them, you’d think they were
broken, but they were only tilting to do a special job. They were
actually in a tug-of-war with the blade and the earth it was pushing.
The weight of the earth against the blade pulled the grader toward one
side. But the leaning of the wheels pulled in the opposite direction. So
the two pulls balanced each other. Charlie could guide the grader in a
straight line without having a wrestling match with his steering wheel.
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Charlie leaned his wheels when the grader went around a bend in the
road, too. They helped the long machine to turn easily. If he had to
back into a ditch,
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he didn’t worry. The great wheels adjusted themselves to the sloping
earth. All six wheels stayed on the ground, and the machine never got
hung up the way a four-wheeled automobile would.
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When the earth had been smoothed down, it was time to put the hard
surface on. Trucks brought in crushed rock to make a solid bed. Concrete
mixers covered the rock with concrete. And asphalt spreaders put a coat
of asphalt on top.
Wherever the asphalt wasn’t spread evenly, men with rakes finished the
job by hand. Then came the tandem roller to pack it down and make the
surface smooth.
A Diesel engine moved the roller’s great weight quickly back and forth
over the asphalt. In no time the road was as smooth as a table top. If
the driver wanted to, he could turn his seat sideways. Then he could
easily see whether he was guiding the roller straight forward and
straight back.
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Many people call road rollers “steam rollers.” That’s because the first
ones really were driven by steam engines. Men have a lot less fuss and
bother with a modern Diesel-engined tandem. There’s no need to start the
fire or shovel coal to keep steam up. You can still see some steam
rollers at work, though, because they are strong machines that last a
long time. But when one wears out, it is replaced with a modern roller.
After the roller finished smoothing all the asphalt down, Charlie’s road
was ready for traffic, but the job still wasn’t quite done. All along
the highway the machines had left bare banks of earth. These had to be
protected from the weather--just the way a house is protected with a
coat of paint. The best coat for the earth is grass of one kind or
another. So Charlie turned gardener. In some places he used the motor
grader again to prepare the soil so that seed could be planted. With the
blade of his grader hung away out at the side and pointed up in the air,
he smoothed off the steep banks. Running along the edge of the road, he
filled in the soft shoulders.
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Then a seed-planter sowed the grass. And finally Charlie used the
strangest machine of all. It chugged and puffed and spit out great
mouthfuls of hay, which fell over the newly-planted grass! The hay
protected the grass seed and kept it moist until its roots were growing
strongly in the soil.