"Our method? That's a simple enough affair as a rule. We set up this spindly tower on rails, that we call the 'traveller' and it moves backwards and forwards over the trusses and the timber falsework that we build before the steel really begins to be set up. When the steel--the trusses--is up and riveted, then away with the falsework. Our bridge stands by itself. You can put up a 500-foot span in no time at all by using the falsework."
You make bold to ask what the engineer does when the river is too deep to admit of falsework. He is quick to answer.
"We generally fall back on a cantilever," he says, without hesitation.
Then he begins to tell you about one of the latest of American problems--the new bridge of the Idaho & Washington Northern Railroad, just now being built over the Pend Oreille River, Washington. They could span that narrow cleft only on the cantilever principle, and when they began to balance their cantilever, there was not enough room for the back arm. But the engineers only chewed off fresh cigars and began forcing their great span out mid-air. They made the balance by placing 600 tons of steel rails on the back-arm. For every foot the span reached out anew over a so-called "bottomless" they added a few more rails. You can generally trust an engineer in such a time as that.
Look closely now upon the workmen who are fabricating this giant bridge.
Look closely upon them. They are different from those whom we saw toiling in the caissons below. Scandinavians may and do toil as sand-hogs at the bottom of the stream; Lithuanians may mine the ore, and Hungarians roll it into steel; Americans build upon their toil and erect this bridge. These builders speak no unfamiliar tongue. They are the product of Ohio, the Middle West, the South, the Pacific Coast, New England; they rise immeasurably superior to every other class of labor employed upon the work. Some of them have been sailors, and their talk has the savor of the sea. All of them are men, clear-headed, cool-headed, true-headed men.
If you come upon them at the noon-hour, sprawled along the narrow ledge of a single plank you may be impressed by two things--their Americanism and their cosmopolitanism. The first of these is writ upon each man as you look at him; the second is evident in talk with him. This big fellow must have been a sheriff out in Montana, and he must have been a sheriff for bad men to dodge; his neighbor is talking about his last job, a sky-high cantilever down in Peru. The two side-partners over by the tool-box are just back from India. American bridge-building talent encircles the world.
Here is a boss who got his first training down on the Nile; his assistant has done some mighty big work on the Trans-Siberian.
These are the men who are building the bridge. In a little time there will be no advancing ends, finding their path from pier-top to pier-top. There will be, instead, a long and slender path for the railroad; the bridgemen will have done their work well; a great river will have once again been conquered.
The bridge problem is always different, it constantly has the fascination of variety. That variety will come into play at unexpected turns. Once, down in a deep Colorado canon, whose walls rose precipitously for a thousand-odd feet, and which was all but filled by a deep and rapid river, the engineers of the Rio Grande & Western found absolutely no ledge whatsoever upon which they might rest their rails. They puzzled upon the problem for a little while, and then they swung a girder bridge parallel with the river. The bridge was supported by braced girders, that fastened their feet in the walls of the canon, hardly wider there than a narrow city house. The railroad has been running over that construction for more than thirty years; it is one of the scenic wonders of the land, and a triumph for the engineer that built it. In constructing the expensive West Shore Railroad up the Hudson River, similar difficulties were experienced south of West Point, and truss bridges were built parallel with the steep river banks to carry the tracks from ledge to ledge. It is not an unusual matter for the construction engineer to spend a quarter of a million dollars to span some deep, waterless gully in the mountains, which could not be filled for more than twice that sum.
Many times, in these days of increasing weight of equipment, it becomes necessary to replace a bridge, without interrupting the traffic. The construction engineer never fails to meet the problem. Years ago, he took Roebling's famous suspension bridge at Niagara Falls, removed the stone towers and replaced them with towers of steel, without delaying a single train; and a little later he took that bridge itself, and substituted a heavy cantilever for it, while all the time a heavy traffic poured itself over the structure. The rebuilder of bridges works like the original builder--with plentiful falsework. He timbers in and around his structure, and then step by step and with exceeding caution removes the old and substitutes the new. An old girder is taken out between trains; before another train of cars shall roll over the structure a new one is ready, temporarily bolted until the riveters can make it fast. It sounds complicated, but it is remarkably simple, under the careful plans of a patient engineer, who has that infinite thing that we call genius.
Sometimes a bold engineer strikes out into a new method, quicker and less expensive than these piecemeal efforts. Of such was the job at Steubenville, O., where a 205-foot double-track span was erected on heavy falsework alongside the old bridge. In a carefully chosen interval between a service of frequent trains, both the old and the new spans--together weighing 1,300 tons--were fastened together and drawn sideways a distance of twenty-five feet in one minute and forty seconds. The new span was then in place, and the old one--ready to be dismantled--stood on falsework at the side. The entire job had been accomplished in an interval of seventeen minutes between trains.
That is not unusual. The floating method is sometimes adopted with remarkable success--especially in the case of draw-bridge spans. There the problem complicates itself exceedingly, for both the water and the land highways must be kept open for traffic; yet it is a matter of record that the Pennsylvania Railroad, operating a fearfully heavy suburban service in and out of Jersey City, recently substituted one draw for another on its Hackensack River Bridge without delaying a single train.
But even in this high noon of the day of steel, the stone bridge holds its own. The big chiefs of railroad construction look upon it with favor.
Higher priced than a steel bridge of equal capacity it requires initial outlay. But forever after, it represents a saving--a saving chiefly in that very important figure, maintenance. A steel bridge requires constant attention and constant expense. A stone bridge requires little of either; and therein lies its strength in its old age. Engineers point to such structures as the Thomas Viaduct down at Relay, or to the wonderful stone bridges that have stood through the centuries in older lands; they bear in mind the constant battle that a steel bridge must make against the ravages of weather and against the sinister thefts of corrosion, and ofttimes they rule in favor of the oldest type of sizable bridge.
Two things are all-important in the choice between the steel bridge and the arch bridge of stone or concrete. The first is the accessibility of the quarries. If they are not very near the solid bridge will cost four times that of one of steel and the average American railroad is not able to spend money in that fashion, even in the hopes of future economies in maintenance. If the quarries are close at hand, as they were years ago when Kirkwood built the Starucca Viaduct for the Erie, the cost of a masonry bridge will hardly exceed that of steel trusses, and the concrete structure may cost a little less. Then there comes into play the second consideration. The stone or concrete bridge has tremendous weight, no ordinary foundation work will serve it. If the river bed and banks be of sand or poor earth, the engineer had best give up his hopes of the Roman form of structure. He can build steel towers and trusses on piles of caissons--hardly solid stone piers and abutments and aides.
All these things considered, the stone bridge is still more than holding its own in modern railroad construction. The Boston & Albany Railroad began building these splendidly permanent structures along its lines through the Berkshires more than twenty years ago. More recently both the Pennsylvania and the Baltimore & Ohio have been looking with favor upon this type of bridge. The Baltimore & Ohio has just finished building its massive Brandywine Viaduct, near Wilmington, a splendid double-track structure, 764 feet in length, and composed of two 80-foot, two 90-foot, and three 100-foot arches.
The three great stone bridges that the Pennsylvania has built upon its main line are all four-tracked. Two splendid examples of these span the Raritan River at New Brunswick, and the Delaware at Trenton, New Jersey.
The third, spanning the Susquehanna at Rockville, Pa., just north of Harrisburg, is the largest stone bridge in the world. It is over a mile in length, and is composed of 48 arches; 220,000 tons of masonry was employed in its construction.
Concrete viaducts were first employed in interurban electric railroad construction, and latterly they have been brought more to the service of the steam railroad. A splendid example of this very new form of construction exists in the extension of the Florida East Coast Railroad over the keys and shallow waters of Southern Florida, for seventy-five miles between Homestead and Key West. A considerable portion of the line is over the sea.
The Florida keys are like a series of stepping-stones, leading into the ocean from the tip of the peninsula to Key West. They lie in the form of a curve, the channels separating the islands varying from a few hundred feet to several miles in width. Nearly thirty of these islands were used in the construction of the new railroad. More than fifty miles of rock and earthen embankment have been built where the intervening waters are shallow, but where the water is deeper and the openings are exposed to storms by breaks in the outer reef, concrete arch viaducts have been used.
These viaducts consist of 50-foot reinforced concrete arch spans and piers, with here and there a 60-foot span.
There are four of these arch viaducts aggregating 5.78 miles in length.
The longest is between Long Key and Grassy Key, 2.7 miles, and is called the Long Key Viaduct; across Knight's Key Channel, 7,300 feet; across Moser's Channel, 7,800 feet, and across Bahia Honda Channel, 4,950 feet.
The material of these islands is coralline limestone. In many places the embankment for the roadway is 8 or 9 feet in height, and the roadbed is ballasted with the same material. The result is one of the finest and safest railway roadbeds in the world.
Across the Delaware River at Slateford, Pa., the Delaware, Lackawanna & Western Railroad is building the largest concrete bridge in the world, a few feet longer than the great structure by which the Illinois Central crosses the Big Muddy River and just 100 feet longer than the Connecticut Avenue Bridge, at Washington, D. C. The Lackawanna's bridge is 1,450 feet long, with five arches of 150-foot span, and a number of shorter arches.
The track is carried at an elevation of 75 feet above highwater; and to find living-rock as a solid foundation for a structure of so great a weight, the abutments and piers were carried about 61 feet below the surface of the ground.
With the bridge-builder at his elbow, the railroad constructing engineer hesitates at no river, no arm of the sea, no deep valley, no wild ravine, no cleft in the mountain-side. He calls to his aid the magic of the men who have made this branch of American practical science famous: a feathery trestle appears, as if by magic. Across its narrow edge the steel rails follow their resistless path.
CHAPTER VI
THE PASSENGER STATIONS
EARLY TRAINS FOR SUBURBANITES--IMPORTANCE OF THE TOWERMAN--AUTOMATIC SWITCH SYSTEMS--THE INTERLOCKING MACHINE--CAPACITIES OF THE LARGEST PASSENGER TERMINALS--ROOM FOR LOCOMOTIVES, CAR-STORAGE, ETC.--STORING AND CLEANING CARS--THE CONCOURSE--WAITING-ROOMS--BAGGAGE ACCOMMODATIONS--HEATING--GREAT DEVELOPMENT OF PASSENGER STATIONS--SOME NOTABLE STATIONS IN AMERICA.
The railroad terminal is the city gate. Without, it rises in the superior arrogance of white granite, as an architectural something. It has broad portals, and through these portals a host of folk both come and go.
Within, this city gate is a thing of stupendous apartments and monumental dimensions, a thing not to be grasped in a moment. In a single great apartment--a vaulted room so great as to have its dimensions run into distant vistas--are the steam caravans that come and go. It is a busy place, a place of an infinite variety of business.
In the early morning the train-shed gives the first sign of the new-born day. Before the dawn is well upon the city, the great arcs that run into those distant vistas in wonderful symmetry are hissing and alight, and the first of 500 incoming trains is finding its way into the gloom of the shed. Some few trains have started out with the early mails and the morning papers. The great rush into town is yet to begin.
Even before dawn, a thousand little homes without the city have been awake and fretful. The gray fogs of the night lie low, and lights begin to twinkle, lines of shuffling figures to find their way to the nearest suburban station. It is very early morning when these begin to pass through the city gate. The earliest suburban trains slip in from the yards and come to a slow, grinding stop beneath the shed. Before the wheels have ceased turning, the first of the workers is off the cars and running down the platform. In fifteen seconds, the platform is black with men.
There are many more of these trains, a great multiplication of men within a little time. Before seven o'clock, the trains begin to increase; to follow more and more closely upon one another's heels. After seven, they come still oftener; two or three of them may stop simultaneously on different tracks under the great vault of the shed; they are heavy with people. There is a constant clatter of engines, stamping and puffing, dragging their heavily laden trains and snapping them quickly out of the way of others to follow. The electric lights under the shed go out with a protesting sputter, and you realize that the day is at hand. This mighty army of those who live without the city walls is flocking in, in an unceasing current now. There is an endless procession from the track platforms; a stream of humans finding its way to the day's work.
Do you want figures so that you may see the might of this army?
Binghamton, N. Y., is a city; a little less than fifty thousand persons live there. If the whole population of Binghamton--every man, woman, and child--were poured through the portals of this terminal on any one of six mornings of the week, it would be about equal to this suburban traffic. In a single hour--from seven to eight--45 trains have arrived under the roof of this shed and discharged their human freight; in the following hour, 64 trains empty another great brigade of the army from without the city walls.
The city gate is indeed a busy place. Its concourse or head platform echoes all day long with the unending tread of shuffling feet; beyond the fence, with its bulletins and ticket-examiners, is the vault of the train-shed, a thing of great shadows, even in midday. Its echoes are also unending. There seems to be no end of pushing and shoving and hauling among the engines; there must be an infinite stock of trains somewhere without. The human stream flows all the while.
The marvel of all this is that the terminal, which seems so intricate, so baffling, is under the control of one man--a man to whom it is as simple as the ten fingers of his hands. This man is keeper of the city gate. His watch-house is situated just without the big and squatty train-shed. It is long and narrow, glass-lined and sun-filled. Through its windows he keeps track of those who come and go.
"There's Second Seventeen, with them school teachers coming back from the convention out at Kansas City. Put her in on Twenty-one so's to give the baggage folks a chance. Them women travel with lots of duds."
These are orders to his assistants and orders in that watch tower are rarely repeated. The assistants are in shirt-sleeves like their chief, for the sun-filled tower is broiling hot. They nod to one another, click small levers, and Second Seventeen--a long train of sleeping-cars coming into the city in the hot moisture of the early June morning--is sent easily and carefully in upon track Twenty-one in the train-shed of the terminal.
There you have the explanation of that order that was meaningless to you but a moment ago. Track Twenty-one is nearest the in-baggage room of the station. With two cars, piled roof-high with heavy trunks, the thoughtfulness of the towerman in sending the special upon track Twenty-one will be appreciated by the baggage handlers. A vast amount of manual labor will be saved; and that counts, even upon a cool day.
[Illustration: THE NORTHWESTERN'S MONUMENTAL NEW TERMINAL ON THE WEST SIDE OF CHICAGO]
[Illustration: THE UNION STATION AT WASHINGTON]
This keeper of the city gate represents the survival of the fittest, the very cream of his profession. The chances are that he began his railroading off in some lonely way station on a branch line, developed qualities that brought him to the quick and favorable attention of his chiefs, then advanced steadily along the rapid lines of promotion that railroading holds for some men. He is one of three men, who, for certain hours, hold the keeping of the complicated city gate within their own well-drilled minds. The tower is the mind, the brain centre, the ganglion, of that city gate; but the tower is only wondrously mechanical, after all; the mind of the careful towerman is the mind that controls all the mechanism.
To the average traveller, the city gate is a thing that impresses itself upon his mind by its exterior and interior beauty, or its convenience of arrangement. He notes the broad concourses, the ample entrances and exits, the compelling magnificence of the public rooms, the great sweep of the train-shed roof, but beyond that train-shed roof is a tangle of tracks and signals about which he does not worry his busy head. Those tracks and signals represent more truly the station than the mere architectural magnificence of its outer shell. They are a tangle and a maze, apparently, but a tangle and maze that must represent skill and ease in their tremendous operation. They are neither tangle nor maze to the shirt-sleeved men in the tower. They must know each track, each switch-point, each signal as intimately and familiarly as they know the fingers of their hands.
Every mechanical device is employed to simplify the tangle for the comfort of the busy minds that must constantly employ themselves in solving it. In the big watch-tower--the "control" of the terminal--there is a map that is more than map. It depicts in miniature all the tracks and switches and signals that lie without and roundabout the tower; but this map shows switches and signals changing as the switches and signals of the train-yard change. It brings the distant corners of the terminal in closer touch with the towermen. In fog or blinding storm, this track model is invaluable--a veritable compass set within the brain of the terminal.
This illuminated map sets upon the best piece of mechanism that has yet been devised for the operation of the terminal yard. It is a long boxed affair, not entirely unlike the box of the old-fashioned square piano, but in this case (the terminal we are watching being of unusual capacity) more than thirty feet in length. This box is the very brains of the terminal.
It represents the acme of mechanical condensation. Reduced to its earliest and simplest equivalent--the separate hand operation of a gigantic cluster of switches in a great terminal yard--it would cover a vast area and result in the employment of an army of switchmen. Carelessness on the part of any one member of this army might cause a serious accident. The margin of safety would be very low in such a case.