[Illustration: THE MAKING OF AN EMBANKMENT BY DUMP-TRAIN]
[Illustration: "SMALL TEMPORARY RAILROADS PEOPLED WITH HORDES OF RESTLESS ENGINES"]
Then the real survey-work begins. The engineers divide the line, if it is of any great length, and the several divisions prosecute their work simultaneously. Each surveying party consists of a front flag-man, who is a captain and commands a brigade of axe-men in their work of cutting away trees and bushes; the transit-man, who makes his record of distances and angles and commands his brigade of chain-men and flag-men; and the leveller, who studies contour all the while, and supervisors, rod-men and more axe-men. Topographers are carried, their big drawing boards being strapped with the camp equipment; and a good cook is a big detail not likely to be overlooked.
In soft and rolling country this is a form of camp life that turns back the scoffer: busy summer days and indolent summer nights around the camp-fire, pipes drawing well and plans being set for the morrow's work.
Another summer all this will be changed. The resistless path of the railroad will be stepped through here, the group of nodding pines will be gone, for a culvert will span the creek at this very point.
Sometimes the work of these parties becomes intense and dramatic. The chief, lowered into a deep and rocky river canon, is making rough notes and sketches, following the character of the rock formation, and dreaming the great dreams that all great engineers, great architects, great creators must dream perforce. He is dreaming of the day when, a year or two hence, the railroad's path shall have crowded itself into this _impasse_, and when the folk who dine luxuriously in the showy cars will fret because of the curve that spills their soup, and who never know of the man who was slipped down over a six-hundred-foot cliff in order that the railroad might find its way.
It is then that the surveying party begins to have its thrills. Perhaps to put that line through the canon the party will have to descend the river in canoes. If the river be too rough, then there is the alternative of being lowered over the cliffsides. Talk of your dangers of Alpine climbing! The engineers who plan and build railroads through any mountainous country miss not a single one of them. Everywhere the lines must find a foothold. This is the proposition that admits of but one answer--solution. Sometimes the men who follow the chief in the deep river canons, the men with heavy instruments to carry and to operate--transits, levels, and the like--must have lines of logs strung together for their precarious foothold as they work. Sometimes the foothold is lost; the rope that lowers the engineer down over the cliffside snaps, and the folk in the cheerful dining-room do not know of the graves that are dug beside the railroad's resistless path.
It is all new and wonderful, blazing this path for civilization; sometimes it is even accidental. An engineer, baffled to find a crossing over the Rockies for a transcontinental route saw an eagle disappear through a cleft in the hills that his eye had not before detected. He followed the course of the eagle; to-day the rails of the transcontinental reach through that cleft, and the time-table shows it as Eagle Pass.
Possibly there are still alternative routes when the surveyers return in the fall and begin to make their finished drawings. Final choices must now be made, and land-maps that show the property that the railroad will have to acquire, prepared. The details, of infinite number, are being worked out with infinite care.
The great problem of all is the problem of grades; in a mountainous stretch of line this is almost the entire problem. Obviously a perfect stretch of railroad would be straight and without grades. The railroad that comes nearest that practically impossible standard comes nearest to perfection. But as it comes near this perfection, the cost of construction multiplies many times. Most new lines must feel their way carefully at the outset. Moreover it is not an impossible thing to reconstruct it after years of affluence--of which more in another chapter.
A three-per-cent grade is almost the extreme limit for anything like a profitable operation; even a two-per-cent grade is one in which the operating people look forward to reconstruction and elimination. Yet there are short lengths of line up in the mining camps of Colorado, where grades of more than four per cent are operated; and it is a matter of railroad history that away back in 1852, when the Baltimore & Ohio Railroad was being pushed through toward Parkersburg, and the great Kingwood tunnel was being dug, B. H. Latrobe, the chief engineer of the company, built and successfully operated a temporary line over the divide at a grade of ten per cent--528 feet to the mile. A locomotive which weighed 28 tons on its driving-wheels carried a single passenger car, weighing 15 tons, in safety and in regular operation over this stupendous grade for more than six months. The ascent was made by means of zigzag tracks on the so-called switchback principle. That scheme succeeded earlier planes operated by endless chains; an instance of which is the quite famous road of Mauch Chunk, originally operated for coal, and now a side scenic trip for passengers. Other planes of this sort, you will remember, were in operation at Albany and Schenectady on the old Mohawk & Hudson route, now a part of the New York Central lines; but all of them involved a change of passengers and freight to and from their cars, and the zigzag switchback was considered quite an advance in its day. Two of these ancient switchbacks are still in regular use for passengers and freight--one at Honesdale, Pa., and the other at Ithaca, N. Y.
The matter of grades being settled, and with it as a corrollary the question of minor curves, minor details next claim attention. Perhaps the water supply along the new line is defective. Then arrangements must be made for impounding, and perhaps suitable dams and waterworks will be built for this purpose. The water must be soft, to protect the locomotive boilers; if hard, an apparatus is erected for the softening process.
Grade crossings are to be avoided, highway crossings being built, wherever possible, over or under the railroad.
A railroad crossing another railroad at grade is an abomination not to be permitted nowadays. The universal use of the air-brake has permitted a reduction of the "head-room,"--the necessary clearance between the rail and overhead obstruction--from 20 feet to 14 feet. The old "head-room" was necessary to protect the brakeman who worked atop of the box-cars. This reduction of six feet in clearance was a matter of infinite relief to engineers, particularly in the bridging of one railroad over another.
The entire problem of bridges is so intricate a phase of American railroad construction as to demand attention in a subsequent chapter. In actual railroad practice it is apt to demand a separate branch of engineering skill, both in construction and in maintenance. We turn our attention back to the main problem of the building of our railroad.
When all plans are finished, contracts remain to be divided and sub-divided; for it would be a brave contractor, indeed, who in these days would consent to essay himself, any considerable length of railroad line.
In fact, in recent work of heavy nature, the price is almost invariably placed at an indefinite figure, a certain definite percentage of profit being allowed the contractor on each cubic yard of rock or soil. In such a case the contractor's business becomes far less a game of chance; he is, in effect, the railroad's agent supervising its construction at a certain set stipend.
Let us say that the construction on our railroad begins in the early spring. As a matter of real fact it would not be halted long because of adverse weather conditions. Even up in the frozen and uninhabitable wilds of the Canadian Northwest, work has been prosecuted on the new Grand Trunk Pacific throughout the entire twelve months. But in summer the construction gangs rejoice. The great proposition of bringing mile after mile of future railroad to sub-grade--the level upon which the cross-ties are to be set--fairly sweeps forward under the genial warmth of the sun.
The construction is under the supervision of competent engineers, who are, of course, under the direct supervision of the railroad's own organization. Every six to twelve or fifteen miles of new line is divided into sections, better known as residencies, for each is under the eye of its own resident engineer. He reports to the construction engineer, who in turn reports to the chief engineer of the railroad, an officer who reports to no less person than the president of the company.
This great force--for each engineer has gathered about him a competent staff of young men as expert with compass, with level, and with transit as were the men who first projected the line--is in the field as quickly as the contractor. They are to see him bring the line to sub-grade; to see him place bridges and culverts, bisect high hills with cuttings, bore tunnels through even higher hills and mountains, span deep valleys with great embankments. To facilitate quick construction the residencies are made numerous; work begins at as many initial points as possible. These points, of course, are situated, where possible, close to water communication or existing railroad lines, in order that material may be brought with the least possible delay and expense.
Of course, if the country has a sharp contour, the ordinary difficulties of line-construction multiply very rapidly. The great cuttings through the hills may have to be carved out of resisting rock, a work that is carried on through many levels, known to the engineers as ledges or as benches. If there are high hills to be notched there will probably be great hollows where the circumstances do not justify carrying the line on bridge or trestle. In these cases come the fills, or embankments. We have already shown how the locating engineer in the first instance has tried to plan his line so that the earth or rock from his cutting will be as nearly as possible sufficient to form the near-by embankments. Sometimes it is not, and then the resident engineers must locate borrow-pits, where the hungry demand of the railroad for dirt will cause a great hollow to show itself on the face of the earth. The borrow-pit must be carefully located--convenient of access, far enough from the track not to be a danger spot to it. This is one of the infinity of problems that come to the construction engineer.
For these big jobs laborers' camps will be established close to them; and small temporary railroads peopled with hordes of restless dummy-engines and forcing their narrow-gauged rails here and there and everywhere, will be busy for long weeks and months. There will not be much hand-cutting in the ledges. Steam shovels, mounted like locomotives upon the rails, and pushing forward all the while, will fairly eat out the hillside. One of these will catch up in a single dip of his giant arm more than a wagon load of soft earth or of rock that has been blasted apart for his coming.
To make the fills the engineers must often build rough wooden trestles out of the permanent level of the line. The dummy-engines, with their trails of dump-cars, coming from the back of the steam shovels in the cutting, or from the nearest borrow-pit, will hardly seem in a single day to make an appreciable effect upon the fill. But the days and weeks together count, and the dumping multiplies until the rough trestle has completely disappeared, and the railroad has a firm and permanent path across the edge of the dizzy embankment. And these embankments can be made truly dizzy. The passenger going west from Omaha on the new Lane cut-off of the Union Pacific finds his path for almost twenty miles through deep cuttings of the crests of the rolling Nebraska hills, across the edge of the long fills over wide valleys. The Lackawanna railroad building a great cut-off on its main line where it passes through New Jersey has just finished the largest railroad embankment ever built--an earthen structure for two tracks, three miles long and seventy-five to one hundred and ten feet in height.
[Illustration: CUTTING A PATH FOR THE RAILROAD THROUGH THE CREST OF THE HIGH HILLS]
[Illustration: A GIANT FILL--IN THE MAKING]
[Illustration: THE FINISHING TOUCHES TO THE TRACK]
[Illustration: THIS MACHINE CAN LAY A MILE OF TRACK A DAY]
As the line goes forward, the track follows. The new railroad has probably popularized itself from the outset by hiring the near-by farmers and their teams to grade the line through their localities, particularly where an almost level country makes the grading a slight matter. Sometimes in level country, grading machines, drawn by horses, or by traction engines, have been used to advantage. These machines are equipped with ploughs which loosen the soil and place it on conveyor belts. Material can be deposited twenty-two feet away from the line, and a four-foot excavation can be made by these machines with ease.
But the laying of the track--the line having been finished at sub-grade with a top width of from 14 to 20 feet for each standard gauge track to be laid--the line begins to assume the appearance of a real railroad. Upon the first stretches of completed track, locomotives and cars employed in construction service begin to operate. As the track grows, their field of operation increases. Then comes the day when the track sections begin to be joined; the railroad is beginning to be a real pathway of steel.
To build this pathway is comparatively a simple matter, once the sub-grade is finished. A mile a day is not too much for any confident contractor to expect of his construction gangs. There was that time, back in '69, when a world's record of ten miles of track laid in a single day was established on the Central Pacific. For that mile of standard track the contractor will need 3,168 ties--eight carloads; 352 rails--five carloads; and a carload of angle irons, bolts, and spikes, as fasteners.
The track-layers are as proud of their profession as any man might be of his. Their skill is a wondrous thing. Two men who follow the wake of a wagon roughly place the ties as fast as they are dropped upon the right-of-way. Another man aligns them with a line that has been strung by one of the young engineers, a fourth with a notched board, marks the location of one rail. That rail--the line side--follows close to the location marks. It is roughly banded and lightly fastened in place. The other rail--the gauge side--quickly follows. The wonderfully accurate gauge representing the 4 feet, 8-1/2 inches that is almost the standard of the work, and which is tested every morning by the engineers, is in constant use. The railroad track must be true; there is not room for even the variation of a fraction of an inch in the gauge of the two rails.
In fastening the two long lines of rails, the profession of track-laying rises to almost supreme heights. The men who fasten the rail with angle iron and a single roughly-adjusted bolt in each rail-end are head-strappers and past masters in their art. After them in due season come the back-strappers, finishing that fine work of solidly bolting the rail against the vast strain of a thousand-ton train being shot over it at lightning speed. And after the back-strappers and the men who have spiked the rail to the ties, comes the locomotive itself, bringing more ties, more rails, more angle-bars and bolts, and more spikes to the front. Then sometime later the road-bed is ballasted and the line made ready for heavy operation.
But track-laying is frequently machine systematized these days; and in this, as in so many smaller things, the mechanical device has supplanted the man. A real giant is the track-laying machine. It is mounted upon railroad tracks and is a form of overhead carrier with a tremendous overhang. The carrier is fed with the cross-ties from supply cars just back of the machine and the ties are dropped, each close to its appointed place, as a locomotive slowly pushes the entire apparatus forward. In a smaller way the heavy steel rails are delivered from under the overhang of the carrier. A gang of men make short work of the fastening of the rail to the cross-ties and the machine moves steadily forward. It has been known to make two miles a day at this work.
Culverts have been laid for each small run or kill or creek; the bridge-builders along the new line finish their work and cart off their kits; the day comes when there is an unbroken railroad from one end of the new line to the other. It links new rails and new towns; its localities produce for new markets, commerce from strange quarters pours down upon the land that has known it not. Passenger trains begin regular operation, the fresh-painted depots are brilliant in their newness, the shriek of the locomotive sounds where it has never before sounded.
Life is awakened. The railroad, which is life, has reached forth a new arm, and creation is begun.
CHAPTER IV
TUNNELS
THEIR USE IN REDUCING GRADES--THE HOOSAC TUNNEL--THE USE OF SHAFTS-- TUNNELLING UNDER WATER--THE DETROIT RIVER TUNNEL.
Sometimes the construction engineer of the railroad brings his new line face to face with a mountain too steep to be easily mounted. Then he may prepare to pierce it. Tunnels are not pleasant things through which to ride. They are, moreover, expensive to construct, and when once constructed are an unending care, necessitating expensive and constant inspection. But--and that "but" in this case is a very large one--they reduce grades and distances in a wholesale fashion; and when you reduce grades you are pretty sure to be reducing operating expenses. A railroad man will think twice in his opposition to a smoky bore of a tunnel that will cost some three to five million dollars, when his expert advisers tell him that that same smoky bore will save him a hundred thousand tons of coal in the course of a year.
From almost its very beginnings the American railroad has been dependent upon tunnels, and thus has closely followed European precedent. The Alleghany Portage Railroad, to which reference has already been made, passed through what is said to have been the first railroad tunnel in the United States. It pierced a spur in the Alleghany Mountains, and it was 901 feet in length, 20 feet wide, and 19 feet high within the arch, 150 feet at each end being arched with cut stone. The old tunnel, built in 1832, which has not echoed with the panting of the locomotive for more than half a century, is still to be found not far from Johnstown, Pa. It simply serves the purpose to-day of calling attention to the durable fashion in which the earliest of our railroad-builders worked.
Of the building of the Baltimore & Ohio, tunnel-construction formed an early part, several paths being found across the steep profiles of the Alleghanies. The Kingwood Tunnel, which B. H. Latrobe drove, was nearly a mile long and the chief of these bores. But when the Hoosac Tunnel was first proposed--piercing the rocky heart of one of the greatest of the Berkshires--the country stood aghast. Four miles and a half of tunnel!
That seemed ridiculous away back in 1854, when the plan was first broached and folk were not slow to say what they thought of such an absurd plan.
For twenty years it looked as though these scoffers were in the right--the work of digging that monumental tunnel was a fearful drain on the treasury of the commonwealth of Massachusetts, which was lending its aid to the project. But the tunnel-diggers finally conquered--they almost always do--and the Hoosac remains to-day the greatest of all mountain tunnels in America. The system of continuous tunnels, by which the Pennsylvania Railroad recently reached its terminal in New York, stretches from Bergen Hill in New Jersey to Sunnyside, Long Island, a distance of some ten miles. In fact the largest feature of recent tunnel-work in this country has been in connection with terminal and rapid-transit development in the larger cities. For a good many years New York and Baltimore, in particular, have been pierced with these sub-surface railroads; it is a construction feature that increases as our great cities themselves increase. No river is to-day too formidable to be conquered by these underground traffic routes. A river such as the Hudson or the Detroit may sometimes halt the bridge-builders; it has but slight terror for the tunnel engineers.
The tunnel-work is apt to be a separate part of the work of building a railroad. It calls for its own talent, and that of an exceedingly expert sort. If the tunnel is more than a half or three-quarters of a mile long it will probably be dug from a shaft or shafts as well as from its portals. In this way the work will not only be greatly hastened but the shafts will continue in use after the work is completed as vents for the discharge of engine smoke and gases from the tube. The work must be under the constant and close supervision of resident engineers. The survey lines must be corrected daily, for the tunnel must not go astray. It must drive a true course from heading to heading. In the shafts plumb lines, with heavy bobs, to lessen vibration, will be hung. Sometimes these bobs are immersed in water or in molasses.
From the portals and from the bottoms of the shafts the headings are driven. If the tunnel is to accommodate no more than a single track it will be built from 15 to 16-1/2 feet wide, and from 21 to 22 feet high, inside of its lining; so the general method is first to drive a top heading of about 10 feet in height up under the roof of the bore. The rest of the material is taken out in its own good season on two following benches or levels.
Piercing a granite mountain is no rapid work. When the Pennsylvania Railroad built its second Gallitzin Tunnel in 1903, 13 men, working 4 drills in the top heading, were able to drill 16 holes, each 10 feet deep, in a single day. The engineers there figured that each blast removed twenty-three cubic yards of the rock. At night, when the "hard-rock men"
were sleeping and their drills silent, a gang of fourteen "muckers"
removed the loosened material.