Wonders of World Engineering

 © Wonders of World Engineering 2014-22 |  contents  |  site map  |  info@wondersofworldengineering.com

Mobile Site

The first telephone line across America was opened by Graham Bell, the inventor of the telephone, in 1915, when he conversed with San Francisco from New York. Engineers had to carry the pioneer lines over prairie, desert, swamp and mountain ranges. One of the great landmarks in the history of the telephone was the building of the first transcontinental telephone line, between new York and San Francisco, a distance of about 3,400 miles


ACROSS THE MOUNTAINS between San Francisco and Sacramento, in California, the steepness of the grades presented serious problems to the engineers who built the first transcontinental telephone line. In these regions they suffered severe hardships from the wintry conditions.

THE building of the first transcontinental telephone line between New York, on the Atlantic, and San Francisco, on the Pacific, called for pluck, determination, skill and patience on the part of engineer and scientist. The line, some 3,400 miles long, crosses no fewer than thirteen States, and traverses vast stretches of prairie, hundreds of miles of desert, great mountain ranges, broad rivers, miles of swamps and lakes.

The telephone is in such common use to-day that we are apt to forget that it was invented and perfected within living memory. On March 10, 1876, in his laboratory in a boarding house in Boston, Alexander Graham Bell, a young Scotsman, put his mouth to the telephone and called: “Mr. Watson, come here: I want you”. Thomas A. Watson, listening at the other end of the wire in a room near by, heard the first sentence ever transmitted by telephone and, full of excitement, burst into the room, exclaiming: “Mr. Bell, I heard every word you said — distinctly”.

Thirty-nine years later, on January 25, 1915, Bell again called up Watson, using, in a light-hearted way, the same words. This time, however, Graham Bell was in New York, and a whole continent separated him from his former colleague. In place of the hundred feet of line that had carried the feeble, ill-formed electrical pulsations of the first spoken message, 6,800 miles of hard-drawn copper wire brought New York and San Francisco within talking distance of each other. Thus was the first transcontinental telephone line introduced to the world.

Since the completion of the first transcontinental telephone line three other transcontinental lines have been built. The aim of the telephone engineer is to provide the public with an uninterrupted service. However well designed and soundly built a single line may be, it is liable to be temporarily interrupted by storm, tornado, fire, flood and other causes. To maintain communication at all times it is desirable, wherever practicable, to have more than one line and to have the lines so located that storms or accidents which affect the one are unlikely to interrupt service on the other at the same time. These additional lines are known as alternative routes.

With the exception of a few short lengths of cables underground in the main cities, the first transcontinental line was entirely overhead. In the early days of telephony it was found impossible to hear at any distance on underground lines. This drawback was overcome and to-day in all the leading cities the telephone engineer lays his lines underground. Of some 12,000,000 miles of telephone wires in Great Britain only about 1,000,000 miles are overhead, the remainder being underground. In large stretches of open country, however, the overhead system is still favoured, the laying of lines underground in such conditions being impossible because of the cost.

At first only a single conversation could be carried on over a pair of wires. To-day twelve conversations or more can be conducted over the same pair of wires on what are termed telephone cables. Then by the use of telephone and radio it is possible now to talk to almost any part of the world. The message travels by wire to the radio station and it completes the remainder of its journey through the ether.

A pioneer line had to be built, however. The problems that faced the telephone engineer at that time were many. Yet it was the minuteness of some of these problems that made his task herculean. Instead of having to calculate immense weights and masses, he found himself baffled by infinitesimal fractions.

50,000 Miles a Second

His real problem was to make his line “talk” — to send something 3,400 miles with a breath as the motive power. His task was more difficult than that of the telegraph engineer. On a telegraph line an isolated impulse of electricity, strong enough to make clicks at its journey’s end and so spell out a message, is sent over the wire. If the wire is so long that the impulse becomes weak, it is made to operate a relay, or electrical valve, which gives the impulse fresh life from a local battery, thus enabling it to continue on its course. When the transcontinental line was built such relays, which are in common use to-day, were almost unknown. What the telephone engineer had to deal with were feeble currents — currents that were controlled by the human voice. With little aid he had to carry them to the other end of the wire, where they had to be made to vibrate the diaphragm of the receiver audibly.

Experiments have shown that it takes but the fifteenth part of a second for the voice to travel all the way from New York to San Francisco. This is equal to a speed of over 50,000 miles a second. If it were possible for sound to carry as far, a word uttered in New York, and travelling through the air without the aid of wires and electricity, would not reach San Francisco until some four hours later, the speed at which sound travels being 1,126 feet a second. The telephone not only transmits speech, but also transmits it thousands of times faster than its own natural speed.

But, while the telephone is breaking speed records, it must also guarantee safe delivery to those millions of little passengers —sound waves — which it carries at an average rate of 2,100 a second. There must be no jostling or crowding. These tiny waves—thousands and thousands of varying shapes, made by the human voice, and each as irregular and as different from the other as the waves of the sea — must not tumble over one another or get into one another’s way, but must break upon the Pacific coast just as they started at the Atlantic, or the whole line fails and the millions of dollars spent upon it have been thrown away.

OVERHEAD TELEPHONE WIRES linked New York with San Francisco by January 1915In all those thousands of miles of line, if just one pin-point of construction is not as it should be, if there is one iota of imperfection, the great stretch of wire is useless, and the currents, waves, sounds and words do not reach the end as they should. It is such tremendous trifles, not the climbing of mountains and the bridging of chasms, that make this transcontinental line one of the wonders of the ages.

OVERHEAD TELEPHONE WIRES linked New York with San Francisco by January 1915. Only in cities were the lines laid underground. Some 130,000 poles were used, spaced at intervals generally of about 135 feet. The line consisted of 5,920,000 lb. of hard-drawn copper wire.

The engineer in telephony cannot change his motive power. A breath against a metal disk changes air waves into electrical currents, and these electrical currents, of which millions are required for a single conversation, must be carried across the continent and produce the same sound waves in San Francisco as were made in New York. Here is a task so fine as to be gigantic. Professor H. N. Casson, a telephone expert, has declared that the energy set free by cooling one spoonful of water just one degree would operate a telephone for ten thousand years. To nurse and coax this minute current of electricity 3,400 miles across the continent, under rivers and over mountains, through the blistering heat of the alkali plains and the cold of snowcapped peaks, occupied the time, thought and labour of the cleverest minds of the engineering and scientific world.

No patient ever had a more devoted or a more skilful band of nurses than this invalid of a current. Beginning with that first timid step in Boston in 1876, they led the weakling on, mile after mile, to city after city, till it reached the other coast. It took an army of thoughtful, conscientious, patient men, keen of brain and skilled of hand, striving day and night for the one great end — the perfection of a system and the conquering of time and space. In office, laboratory and shop, under the earth, high up in the air, they thought, experimented and toiled, always aiming at this ideal of universal service. There was no isolated problem. The fight was not a duel to be won by a single inventor struggling for the solution of some one big problem, but a battle, a campaign in which thousands helped to overcome a thousand hindrances, imperfections and difficulties.

The first telephone conversation between persons separated by any appreciable distance took place in 1876 between Boston and Cambridge, Mass., over about two miles of line. In 1881 Boston and Providence, Rhode Island, were linked together over a line forty-five miles long. In 1884 New York was able to talk with Boston for the first time over a 235-miles circuit. New York and Chicago were linked by telephone in 1892, over a distance of 900 miles, and in 1911 the line had been extended to Denver, Colorado, a distance of 2,100 miles. Two years later Salt Lake City, Utah, was reached, 2,600 miles away, and in January 1915 New York was in touch with San Francisco, 3,400 miles away.

Every Foot Electrically Tested

There were four wires on this transcontinental line, providing two physical circuits and one phantom. One physical circuit, or pair of wires, served as the sending conductor, and the other pair as the return of the phantom circuit.

The stringing of these wires across the continent, setting the poles and securing insulation, presented a task of the first order. Some 130,000 poles supported the line, which consisted of 5,920,000 lb. of hard-drawn copper wire, with a diameter of 0.165 in. In addition, each physical circuit called for 13,600 miles of fine hair-like insulated wire, with a diameter of 1/4,000 in., for its loading coils. These loading coils, which were spaced about eight miles apart, consisted of iron rings built up of fine iron wire, over which were wound many turns of insulated copper wire. The object of these coils was to prevent the distortion of the current which at that time was a great drawback to long-distance telephony.

BORING IN ONE OF THE SHALLOW LAKESNot only was the extension from Denver to San Francisco most carefully laid, but a thorough electrical survey was also made of the whole line from the Atlantic to the Pacific. Every foot of the line was electrically tested and measured. This made it possible for the loading coils to be placed in the most advantageous position to ensure a perfect balance throughout the line.

BORING IN ONE OF THE SHALLOW LAKES. This was done by a special drilling machine, here seen boring a hole for a telephone pole in Humboldt Lake, Nevada. A huge screw drilled the hole beneath water which varied in depth from a few inches to 4 feet.

From Denver the line runs almost due north to Cheyenne, in Wyoming, whence it strikes out in a westerly direction to Salt Lake City. This is because it was desired to tap new ground and open up communication with isolated cities. Hence the great trans-

continental railway routes were avoided. This meant that the surveying parties had to blaze a trail through virtually unknown and uninhabited territory, where they were cut off from civilization for months at a time. They were called upon to endure great hardships, suffering from the intense heat of the plains and from the severe cold of the mountains. Everything they needed — tents, bedding, provisions, instruments, and tools — had to be taken with them.

Twelve men, as a rule, in charge of an able engineer comprised a surveying party. Each man had his allotted task, from the one who worked the theodolite to the cook who prepared the meals. As they moved forward they drove in stakes, each bearing a number to indicate to the construction gangs that followed them where to set the poles, spread about 135 feet apart. In this way they mapped out the route of the first transcontinental telephone line. Progress varied considerably. Twelve miles a day was regarded as a rapid advance. Sometimes no more than two miles, or even less, was covered, because of the rough ground and the difficult character of the country traversed.

These pioneers dreaded the sand and dust storms encountered in the deserts. When the storms occurred, as they often did with dramatic suddenness, a hasty retreat had to be made to the tents a mile or more away to escape the flying particles of hot sand, which bit into the flesh because of the force of the wind. On such occasions the tents were buried in soft sand. These storms raged often for two days, during which the men were confined in their hot, stifling canvas homes, not daring to venture out. Blizzards, too, often drove them to seek similar shelter, and so severe were the storms that tents were frequently blown down and provisions and clothing drenched with rain.

In negotiating swamps to discover the best route for the poles, the engineers often sank up to their armpits and had to be dragged out of the mire by ropes. Then at night their slumbers were frequently disturbed by the growls of wild beasts that prowled round the camps. On the great plains bands of wild horses were seen. Sometimes the more daring of the party gave chase, because by the law of the land these horses are the property of anyone who can catch and tame them. In the higher altitudes of the Rocky Mountains snow and ice gave the surveyors trouble and made their work exceedingly arduous.

Traction Engine with Crawler Wheels

Every now and then their path would be blocked by rivers. These had to be forded and their depth ascertained, as well as the strength of the current and the nature of the bed.

The surveyors were followed by the construction gangs, who picked up the stakes, erected the poles and then strung them with wires. These men had to carry with them not only the heavy poles, cross-arms, miles of wire and other materials needed for the line, but also all their stores, provisions and even water. Prairie schooners, or covered-in wagons, were principally used, drawn by sure-footed mules. In the dry, salty air of the alkali plains of Nevada, horses quickly became exhausted, so a special traction engine was devised to haul the wagons. To enable it to travel more easily over the soft ground it was fitted with huge crawler wheels.


POLE SETTING IN A SALT SINK near Stone House, about sixty miles east of Winnemucca, Nevada. The pole was pushed into a vertical position, with its base in the hole previously excavated, by the men in the construction gangs. When the pole had been set, with cross-arms fixed and insulators attached, linemen fixed the wires. Sometimes the ground was so hard that it had to be blasted to take the pole.

As the gangs moved forward they pitched their tents and began to erect the poles. First came the digging of the necessary hole. This accomplished, the pole was dragged to the hole until the base overhung it. While one man poised his foot upon the overhanging end, holding it in position, others lifted the pole. One or two men armed with stout spiked lances fitted the barbs into the pole near its top. With pushing, lifting, prising and pressing, the pole was canted into an upright position. Then it dropped vertically into the hole until it rested firmly upon the bottom. The soil was rapidly filled in and the post was straightened before the final tamping was done. Pole setting was trying work. Sometimes the ground was found to be so hard that dynamite had to be used to obtain a hole of sufficient depth to sink the poles. In the desert the reverse was the general rule. To obtain the desired rigidity cement had to be used. Every now and then the line traversed great stretches of water, varying in depth from a few inches to four feet. To facilitate work here a special boring machine was used — virtually an immense drill. This machine, carried on a trolley, was dragged to the desired position, when the huge screw was driven deep down into the muddy water, excavating a hole of considerable depth. Into this the pole was set.

The salt sinks taxed the pole setters most of all. Instead of encircling them, the surveyors had run their line straight across them. The sinks are salt depressions invariably covered with water to a depth varying from 18 inches to 3 feet. The water is as brackish as the Dead Sea, murky in colour, and fringed with a dirty white ruff where evaporation has taken place.

Wearing gum-boots and thigh-boots, the men floundered in the sticky mass, with swollen tongues, burning mouths and eyes reddened into fiery orbs by the salt-impregnated atmosphere. Digging the necessary holes and erecting the poles in such conditions was a trying task, with the thermometer registering as much as 120 degrees Fahrenheit. One reason why the poles were carried across the salt sinks instead of round them was because once erected there would be no further cost of upkeep or renewal. The salt penetrating the fibres of the wood converts it into a petrified mass as hard as rock, so that there is no danger of decomposition below the ground line. Even the exposed sections of the posts are strengthened by the flying salt being driven into the wood, finally sheathing it in an armour of white mineral capable of defying all rotting influences.

Buried in Snow to the Cross-Arms

When the poles had been set, the cross-arms fixed and the insulators attached, the wire was trailed out in a continuous length as the coil was unwound. The wire was lifted over each arm as it was passed so that, by the time the lineman came along, the telephone link was drooping from post to post in festoons. Climbing irons enabled the lineman to gain the cross-arm with ease, the wire was stretched and attached to the insulator.

The gravest difficulties, strangely enough, were not encountered in the mountains. The ranges were traversed by more or less defined wagon roads capable of carrying a four-wheeled vehicle, although here and there the distance between the wheel and the cliff edge was only just enough to inspire confidence. Among the mountains it was the grades and the madly rushing creeks which harassed the builders. At times they were driven from their work by the fury of the storms which raged among the Rockies and Sierras. Now and again a length of line would go down, the poles collapsing before the onslaught of Nature, who appeared to rise in rebellion at this conquest of the continent.

The wild bears of the mountains gave the men some anxiety. Although they seldom attacked any of the men, they displayed much daring and cunning. They hung round the camps in the hope of getting at the provisions, and on one occasion a gang returned to camp for the evening meal, famished and tired, only to discover that the cook had been chased up a tree by two bears.

In the higher reaches of the mountains it was found desirable to place the line in the most sheltered positions, and here houses were built for the linemen, whose duty it was to maintain the telephone during the cold and storms of the winter months. Each house contained a couch, a small stove, cordwood, and canned provisions; the houses were used by the men as temporary shelters during blizzards. The poles here are often buried in snow to the cross-arms.

Such were the difficulties encountered in the building of the first transcontinental telephone line. After Bell had opened the line, connexion was made with Washington, and later the line was extended to Jekyl Island, off the coast of Georgia.


ACROSS THE SALT FLATS. The transcontinental telephone line was designedly built across Humboldt Lake and similar regions in Nevada, despite the difficulties involved in setting the poles. The reason for this was that the salt would penetrate the fibres of the wood and preserve the poles indefinitely, so that once set they need no further attention.

You can read more on “Central Telegraph Office”, “International Exchange” and “ModernTelephone Exchanges” on this website.

The First Transcontinental Telephone Line