Part 112

Such rapid work is not unusual with the steel foundation method. On another contract, work was completed not in the three months stipulated, but in exactly one month and a half, during which brief time all the excavation had been done, including sheeting, shoring, pile-driving, the mounting of concrete girders to carry the wall and capping of the piles ready to receive the grillage.

Sometimes difficulties are encountered which would prove all but insurmountable and certainly hopelessly expensive with other methods. Thus in carrying out the one contract, water was found 12 feet from the curb. Two running streams had intersected at that point. The piles were simply sunk through the stream to rock bottom without any difficulty.

The excessive cost of open-pit work has sometimes made it impossible to build twelve or fourteen-story buildings in many sections of the city of New York. The steel pile has, however, made steel building construction profitable.

The carrying capacity of a steel pile is enormous. On a single 12-inch steel pile one hundred tons can be safely maintained. Piers containing sixteen piles have been used, and loadings up to 1300 tons are not unusual.

Naturally the question arises: Do the steel piles deteriorate in time? The question has been answered over and over again by the piles themselves. After a service of fifteen years the steel foundation piles were removed from the site of a building which now stands at the northwest corner of Wall and Nassau streets, in New York City. They showed practically no deterioration. The oxidation on the outside was almost negligible.

CLEANING OUT A HOLLOW STEEL PILE BY MEANS OF COMPRESSED AIR A GEYSER OF MUD ALWAYS APPEARS.]

The Story in a Glass of Water

How Does the Water Get into the Faucet?

It is easy for you boys and girls who live in the city to run into the kitchen or bathroom when you are thirsty and by a simple turn of the faucet tap secure a glass of cool and refreshing water, but did you ever stop to think how many men must constantly work and how great and perfect arrangements must be made before it is possible to supply a great city with water to drink, to bathe in, and for cooking and washing?

No one who has never had the experience of being in a town or city from which the water supply has been cut off, for a day or a number of days, can realize how necessary water is in our daily lives. We are so used to having all the water we want at any time that we even complain when in summer we are asked to drink water which is not iced. Drinking ice-water is very much of a habit. In tropical countries where there is no ice, people drink the water just as they find it, and if you were to go there and drink the waters for a few days, you would soon find that the water slakes your thirst even when quite warm, so it is not the ice in the water that quenches your thirst, but the water itself, and the ice-water is not good for you, as the doctor will tell you, because it chills the stomach.

Where Does Our Drinking Water Come from?

The best way to find out where the water in the faucet comes from is to follow it back to its source. Let us see. Here we are in the kitchen and you have just had a drink of water taken from the faucet above the sink. The faucet, you will notice, is attached to a small pipe which is fastened to the wall back of the sink. We look under the sink and see that the pipe goes through a hole in the floor, so we reason that the water must come from the cellar. Let us go down cellar and see. Yes, here is the little pipe that comes down through the floor under the sink and we follow it along the wall toward the front of the house, and well, well, there it goes right out through the stone foundation of the house. So we conclude that the water comes from somewhere outside of the house, and that the little pipe we have been following is only a means of getting it from the outside into the house. We now mark the place in the wall where the pipe goes through and run around to the front of the house to see where it comes out, but we don’t see it. It must be buried in the ground, so we get a spade and pick and begin to dig a hole in the ground, and pretty soon we find the little pipe pointing straight out toward the street. We keep on digging the dirt away, and thus open a little trench from the house to the middle of the street and when we get there after a great deal of digging we find our little pipe attached to a larger pipe which seems to run along the ground in the middle of the street; so we are still in the dark as to where the water comes from, excepting that so far as our own home is concerned we know that it gets into the house through a little pipe which is attached to a big pipe in the middle of the street. By this time we know we have a big job on hand.

BUILDING OLIVE BRIDGE DAM TO FORM THE ASHOKAN RESERVOIR.

The great Ashokan reservoir is situated about fourteen miles west of Kingston on the Hudson River. Its cost is $18,000,000, and it will hold sufficient water to cover the whole of Manhattan Island to a depth of twenty-eight feet. The water is impounded by the Olive Bridge dam, which is built across Esopus Creek, and also by the Beaver Kill and the Hurley dikes, which have been built across streams and gaps lying between the hills which surround the reservoir.]

The dam is a masonry structure 190 feet in thickness at the base, and 23 feet thick at the top. The surface of the water when the reservoir is full is 590 feet above tide level. The total length of the main dam is 4560 feet, and the maximum depth of the water is 190 feet. The area of the water surface is 12.8 square miles, and in preparing the bottom it was necessary to remove seven villages, with a total population of 2000. Forty miles of highway and ten bridges had to be built. In the construction of the dam and dikes it was necessary to excavate nearly 3,000,000 cubic yards of material, and 8,000,000 cubic yards of embankment and nearly 1,000,000 cubic yards of masonry had to be put in place. The maximum number of men employed on the job was 3000.]

~HOW THE PIPES RUN THROUGH THE STREET~

We are pretty tired of digging by this time, so we call in all the boys and girls in town to help us dig so that we may see where these pipes come from, and we have a regular digging carnival. We follow the big pipe along our own street until we come to the corner. Here we find that our larger street pipe is connected with a still larger pipe, so we think we had better follow the larger pipe. We keep on digging, getting more of the boys and girls to help, and we follow that big pipe right out to the edge of town where we see it runs into another stone wall which you knew all the time was the reservoir, but concerning what it was for you were perhaps never quite clear.

Right near the place where the pipe goes in is a stairway which leads up to the top of the wall, so the whole crowd of boys and girls climb the steps and you are at the top of the reservoir; and there spread out before you, you see a big lake surrounded with a stone wall and you see where the water comes from--the reservoir--at least so you think. But you are wrong. You really haven’t come anywhere near the source of the supply. For soon as you walk around the broad top of the wall which surrounds your reservoir, you meet a man who asks you what you want, and you tell him that you have been finding out where the water in the faucet came from, but having found out you thought you would go back home.

The man smiles at you, but, as he is good-natured and sees you are really trying to find out where the water comes from, he tells you that since you have gone to all the trouble of digging up the streets to follow the pipes, you might as well learn all about it.

He first tells you that the reservoir is not really the place where the water comes from but only a tank, so to speak. He explains to you that most of the faucets in the city are higher than the real source of the water, which is out in the country miles away, and as water will not run up hill, it is necessary to keep the city’s daily supply in some place that is higher than the highest faucet in the city, so that it will force its way into and fill to the very end all of the large pipes in the streets and the small pipes which go into the houses, so that the water will come out just as soon as you turn the faucet.

Then he takes you over to a large building near the reservoir which you have always called the water works, but never knew exactly what it was for. He takes you into a large room where there is a lot of nice-looking machinery working away steadily but quietly, and tells you that these are the great pumps which lift the water from the great pipes which bring it from far away in the country, into the reservoir we have just seen, from which the water runs into and fills all of the pipes into the city.

He also tells you that in some cities it is impossible to find a place to build a reservoir which is higher than the highest places in the city. In such places, the pumps in the water works pump the water direct into the city water pipes and force the water to the very end of all the pipes and keep it there under pressure all the time.

From the pumping station he takes you down stairs in the water works and shows you the huge pipe which brings the water to the water works from the country. It is quite the largest pipe you ever saw. You see it is not really an iron pipe, but built of concrete, which is quite as good. You will be surprised to have our friend, the water-works man, tell you that three average-sized men could stand up on each other’s shoulders inside the great pipe.

OLIVE BRIDGE DAM; ESOPUS CREEK FLOWING THROUGH TEMPORARY TUNNEL.]

The water is conducted from Ashokan reservoir as a huge, underground, artificial river. The aqueduct is ninety-two miles in length from Ashokan to the northern city line, and it should be explained that it is built on a gentle grade, and that the water flows through this at a slow and fairly constant speed. The aqueduct contains four distinct types: the cut-and-cover, the grade tunnel, the pressure tunnel, and the steel-pipe siphon. The cut-and-cover type, which is used on fifty-five miles of the aqueduct, is of a horseshoe shape and measures 17 feet high by 17 feet 6 inches wide, inside measurements. It is built of concrete, and on completion it is covered in with an earth embankment. This type is used wherever the nature of the ground and the elevation allow. Where the aqueduct intersects hills or mountains, it is driven through them in tunnel at the standard grade. There are twenty-four of these tunnels, aggregating fourteen miles in length. They are horseshoe in shape, 17 feet high by 16 feet 4 inches wide, and they are lined with concrete. When the line of the aqueduct encountered deep and broad valleys, they were crossed by two methods: if suitable rock were present, circular tunnels were driven deep within this rock and lined with concrete. There are seven of these pressure tunnels of a total length of seventeen miles. Their internal diameter is 14 feet, and at each end of each tunnel a vertical shaft connects the tunnel with the grade tunnel above. If the bottom of the valley did not offer suitable rock for a rock tunnel, or if there were other prohibitive reasons, steel siphons were used. These are 9 feet and 11 feet in diameter. They are lined with two inches of cement mortar and are imbedded in concrete and covered with an earth embankment. There are fourteen of these pipe siphons of a total length of six miles. At present one pipe suffices to carry the water. Ultimately three will be required for each siphon.]

Our water-works man sees how earnest you are in seeing just where the water comes from, so he proposes that we go find out. We go outside and there is an automobile all ready to go and we jump in and the machine starts off along quite one of the nicest roads you were ever on. Soon you exclaim, “Why, this is the aqueduct road,” and so it is. The great pipe through which the water comes to the city is an aqueduct and they have built the road right over the place where the aqueduct runs. Away we go as fast as the car can carry us, sometimes ten, or twenty or perhaps fifty miles, according to what city you are in. The city goes as far as it must to find a supply of pure water and plenty of it and spends millions upon millions of dollars to make its supply of water good and certain. Occasionally we come to a little stone house along the way where we can go down and see the sides of the great stone pipe. After a while, however, we find our aqueduct road comes to an abrupt stop before another great stone wall. It is the great dam which has been built out there in the country to form one end of a great tank that catches and holds the waters from the creeks and rivers that flow into it. Usually the dam is built up right across a river. They simply build the dam strong enough to stop the river from going any further. Then, of course, the water piles up on the other side of the dam and occasionally this tank, which is simply another huge reservoir, gets so full that the water flows over. It does not really overflow the top of the dam, because underneath the top the engineers have left openings here and there for the water to get through. If it were not for these loopholes, so to speak, the great wall of water within the reservoir, piled against the dam, would break down the wall no matter how well built, by the great pressure it exerts.

~THE REAL SOURCE OF THE WATER~

We are now near to the real source of the water. We take a trip around the top of the great reservoir. Around at the other end we find what looks like a river, excepting that there isn’t any current to speak of. It is a river, but a much deeper one than it would have been but for the dam which has been built across it, and originally its surface was quite far down in a valley. Sometimes man makes his water dam at one end of a lake, which has been formed by streams flowing into a valley which has no opening for the water to run out of. In these cases the lake will be high up in the hills and man simply builds his dam at one end, lets the end of his aqueduct into the bottom of the lake and the water flows. In other cases he picks out a valley where there is no lake at all, builds his dam and then drains the water which he finds in small lakes higher up in the hills into the one big valley and makes a very large lake. But the water in the lakes comes originally from the creeks, rivers or springs which run into it, and so we will follow our original river back into the hills. Here and there along its course we find a little stream flowing into our river and, as we go up higher and higher into the hills, we find our river getting smaller and smaller. Now it is only a creek and, if we go far enough, we find its source but the tiniest kind of a tinkling brook with the water dripping almost noiselessly between the rocks as it makes its path down the side of the hill. There is the source of the water in the glass you have just enjoyed.