Charlie is the man who can tell you about driving a caterpillar tractor. He works in a city, helping to put up big buildings, and he knows how to use other construction machines, too. In fact, Charlie grew up with machines, for his father and his uncles and his grandfather were construction workers. It often happens that families pass along their knowledge of building from the older to the younger men, and they are very proud of their skills. Charlie uses the caterpillar tractor with a bulldozer blade to push heaps of earth and rock into a pile, ready for the shovel to load on a truck.

People often call the shovel a “steam shovel,” but that’s not its right name. You hardly ever see a real steam shovel any more. Years ago the big digging machines were driven by regular steam engines. Before they could start to work on a job, the men had to build a fire in the boiler and wait until they had enough steam pressure to make the shovel go. Of course, this wasted a lot of time. So, when very strong gasoline and Diesel engines came along, builders began using them for their shovels instead of steam engines.

Many shovels and other construction machines ride to work on long gooseneck trailers. They travel faster that way than they could on their own crawlers. And, in cities, the caterpillar treads might damage the pavement. To load and unload a shovel, the operator sets a short ramp of heavy planks against the trailer. Then the shovel creeps up and down on its own crawlers.

The kind of shovel that’s used on a job depends upon the work that must be done. If a basement has to be dug through hard rocky earth, Charlie may operate a crowd shovel, which crawls down into the hole. The shovel has a heavy dipper with teeth along the rim. When it digs, it crowds its teeth down into the ground. Charlie, sitting inside the cab, called the house, swings the dipper outward and up, then dumps the load into a truck.

Another shovel digs in the opposite way. It’s called a pull shovel. The teeth dig down and toward the driver. It can work from a bank and doesn’t have to go down inside the hole at all.

Sometimes Charlie uses a crane to get loose earth out of a hole. The crane has a long boom with wheels at the tip. Cables run over the wheels. Charlie fastens a kind of bucket called a clamshell to the cables. With its mouth open, the clamshell drops down over a heap of rocks and earth. Then Charlie starts machinery that pulls up on the cable. The jaws of the clamshell squeeze together and come up with a load of earth. Now Charlie swings the whole crane around till the clamshell is hanging above a truck. He pulls a cable that opens the bucket, and the earth and stone tumble out.

After the basement for a building has been dug, Charlie uses the crane for other jobs. Men hook the cables to heavy steel beams, and Charlie lifts them into position.

No matter what he is doing, he has a lot to watch out for. He must know which of four brake pedals to use at any moment and which of four hand levers to pull. One lever works the turntable which swings the whole house around. One moves the boom up and down. The other two control the cables.

At the same time, Charlie must watch what’s going on outside. A man stands on the job giving signals. Thumbs up mean “Take the boom up.” Thumbs down mean “Lower the boom.” When the signal man points up with his first finger, it means “Raise the cable.” If he wiggles the finger, it means “faster.” When Charlie is lifting a beam and has to hold it for a while in the air, he says he “takes a strain and dogs it off.” Dogging is his word for setting the brake on the cable.

Things are always likely to fall around a construction job, so the men who work on the ground have steel caps in their shoes to protect their toes. They wear steel helmets on their heads, too!

As the building goes up, Charlie’s crane lifts loads higher and higher. After a while he has to put a jib on the boom. This is an extension that makes it longer. When the building goes too high for his crane to reach, Charlie works another crane. It sits on top of the building’s framework and reaches down from there.

After Charlie lifts a big steel girder into position, other men bolt it in place then fasten it tight with rivets. A man called a heater gets the rivets red-hot in a fire. Using tongs, he tosses them one at a time to the catcher who reaches for them—not with a mitt but with a kind of cup. The catcher pokes a rivet in a hole, and two other men fasten it tight. One of them, the bucker, holds the rivet in position with a bar, and the rivet man pounds the other end flat with a rivet gun. (The gun works like a jack hammer, and it makes an awful racket.)

When you’re down in the street, it’s hard to realize that there may be a heavy wind blowing across the bare girders of a tall new building. High in the air, men have to keep their balance on narrow places and walk with sure feet. There are families who specialize in work far above the solid ground. Boys learn from their fathers how to walk safely without being afraid—although almost everyone is frightened at first. And, of course, everyone is careful. In New York a group of Mohawk Indians have worked on many high buildings where men like Charlie did the beginning work.

Once in a while Charlie helps to wreck an old building before putting up a new one. First, a crew of men go in and take away everything that can be used again or sold for junk. With specially made crowbars, they pry away floors and door frames. They take out furnaces and plumbing fixtures. Then Charlie gets to work with his crane. At the end of a cable he fastens a heavy steel ball, called a skull cracker. Then,

swinging the boom, he bashes the skull cracker into the wall of the old building. Over and over, the ball strikes the mortar and bricks. Cracks spread, and big chunks of the wall start tumbling to the ground. In a little while Charlie and his machine have made a heap of rubble out of a house that it took dozens of men to put up.