What could be done at Baltimore has been done under the Detroit River, twice. The Grand Trunk pierced underneath that stream in 1890, by a single-track tunnel 6,000 feet in length, in which for seventeen years both freight and passenger trains were hauled by special locomotives, fitted for the burning of anthracite coal. Although these engines rendered rather satisfactory service, it was found desirable to substitute electric locomotives for them in order to remove the limitations of haulage capacity in the tunnel; for it is a known fact that electric trains can be operated much more rapidly and also more closely together than steam. The change obviated the danger and inconvenience due to locomotive gases in the tunnel. The electric locomotives first went into service in February, 1908. The tunnel is now clean, well-lighted, and safe to work in; and trains of much greater length than before can be hauled, thus relieving the congestion in the freight-yards on both sides of the river.
Similarly, electric locomotives have become the tractive power in the great new tunnel which the Michigan Central has just completed across the Detroit River at Detroit, and upon the Cascade Tunnel where the Great Northern Railroad pierces one of the great ranges of the Western Divide. The Cascade Tunnel is interesting from the fact that it is entirely built upon a heavy grade of 1.7 per cent for its length of more than three miles. The steam locomotives are cut out from the service, while on the heavy up-grade of the tunnels an electric locomotive, of tremendous pulling power, will carry even the heaviest freights through the bore at an average speed of fifteen miles an hour. These Cascade Tunnel locomotives are the only ones in the country taking alternating current at triple phase and at the tremendous voltage of 6,600 directly from an overhead trolley wire. And that will bring us in a moment to another consideration of this question of the development and the delivery of power.
The most recent of tunnel installations has just been completed in the greatest of all American mountain bores—the Hoosac Tunnel. This famous tube, four and three-quarters miles in length, gave itself very readily to the skill of the electric engineer, with the result that the Boston & Maine system, its present owner, finds the greatest impediment to the operation of its main line from Boston to the west entirely removed.
The earlier installations were all what is known as direct current; that is, the power is brought directly from the dynamos in the power-houses and by means of third-rail or overhead trolley it is delivered to the motors of the locomotives of the cars. But some years ago the larger of the distinctively electric railroads found that for great current demands over a large distributing district, this system was expensive and impracticable; that, for the chief thing, it required copper cables for carrying long-distance current so large as to be of very great cost. So some of these, with the aid of the electrical manufacturers, experimented and developed the alternating current of high voltage and low amperage, which is capable of being carried to distant transforming or sub-stations and there reduced to low voltage and high amperage. This alternating current system, because of its great operating economies, is rapidly becoming the standard for the city railroad systems of metropolitan communities, as well as for the great trunk-line interurban electric roads that are beginning to gridiron the country. The New Haven Railroad, when it first began to electrify its extensive suburban service into New York City, was the first to bring it to the service of a standard steam road, and by a clever adaptation of its locomotives was able to bring a single-phase alternating-current directly to them at the enormously high voltage of 11,000, without the use of transforming stations or direct-current transmission. After some fearfully disappointing experiments at the outset, the New Haven system has finally proved the worth of its alternating-current, and the road is now engaged in erecting its overhead transmission construction all the way from Stamford (the present terminal of the electrical service) to New Haven, 72 miles distant from New York. Within ten years its heavy New York and Boston traffic will probably be entirely handled by electricity, and the run of 232 miles will be made without difficulty in four hours or even less.
At present the steam locomotives of these trains and the other trains that serve almost all of New England are detached from the inbound movement at Stamford, and the remaining 33 miles of the run into the Grand Central Station is made behind a powerful electric locomotive. The process is, of course, reversed on outbound trains. For the 12 miles from Woodlawn into the Grand Central the run is made over the tracks of the Harlem division of the New York Central Railroad which uses direct current at a voltage of 650, and third-rail instead of overhead transmission. The wonderful adaptability of the alternating current is shown, not in the fact that a change must be made from overhead trolley to third-rail alone, for that is merely a slight mechanical problem, but in the fact that a locomotive hauling a heavy train can, without a great slacking of speed, change from receiving an alternating current of 11,000 volts to a direct current of 650 volts. Outbound, it reverses the process.
The necessity of clearing out the smoke-filled Park Avenue Tunnel approach to the Grand Central Station brought both the New York Central, its owner, and the New Haven, its tenant, to electric traction for terminal and suburban service at New York. The New York Central’s system, as has already been stated, is direct-current and it is supplied from two great power-houses in the suburban district. Through trains are hauled in and out of the station by electric locomotives, while suburban trains, which make their round-trip runs entirely within the 25 or 30 miles of electric zone, are run without locomotives, the steel suburban coaches having motors set within their trucks, after the ordinary fashion of electric cars across the land. The change from steam to electricity at the Grand Central Station did more, however, than merely clear the long-approach tunnel of smoke and foul gases, so that nowadays a man can ride on the observation-platform over its entire length. The traffic in that wonderfully busy station has for many years had sharp limitations because of the four tracks in that tunnel, two tracks being used for the train movement in each direction. The limited station-yard capacity at the terminal has necessitated many trains being stored at Mott Haven yards; and the drilling of these empty trains in and out of the station, combined with the normally heavy movement of regular and special trains, has only added to the great congestion. The minimum three-minute headway between trains operated by steam through the tunnel, and its four-tracked viaduct approach, fixed the maximum traffic at 40 trains an hour in each direction. The capacity of the terminal with this limitation of service was taxed to its utmost, and some relief for the constantly increasing traffic was imperative. Now, owing to the improved conditions of electric operation, trains may be run on a two-minute headway, or less—this one measure thus increasing the station capacity by 50 per cent at the least.
The New Haven road has also adopted the practice of running some of its suburban trains without locomotives, but by means of motors underneath each coach—the multiple-unit system, as electrical engineers have come to know it. This is the system, with some slight variations, upon which the elevated and subway lines of New York, Brooklyn, Boston, Philadelphia, and Chicago are operated; and it is quickly applicable, as we have just seen, to some phases of terminal operation for the standard steam railroads. But the steam locomotive is to hold its own for many years, in many, many phases of railroad operation; electric traction is practical and economical only when there are fairly congested traffic conditions. The coaches that are standard for it, and which it must haul for many miles across the land, must be handled in the electrically equipped terminals by electric locomotives of one type or another. These locomotives are generally equipped with coal-heaters for maintaining the steam in the heating-pipes of the through equipment; and in these days, when the electric lighting of through trains is all but universal, they may supply current for this purpose also.
Electric locomotives have been completely successful where they have been used, both alone and in connection with multiple-unit suburban trains, in the Grand Central Station and the Pennsylvania Station in New York City as the first complete installations. But what has been so successfully done in New York will soon be repeated in other big cities in the land; Boston is already insisting that the network of suburban lines that spreads over her environs be electrified; Philadelphia is preparing for the electrification of the Pennsylvania’s fan-work of lines into Broad Street Station; Baltimore is demanding that what has been done in one great tunnel underneath her foundation hills be repeated in two others. Chicago will see great installations of this service within the next few years.
Nor is the use of electricity upon the standard steam railroad to stop bluntly with these terminal changes and improvements; many and many a decaying branch is yet to be fanned into new life, new strength, new activity, through a skilful transformation of its tractive powers. What has been done at the Detroit River and the Cascade tunnels is to be done elsewhere across the land—through the dozens of points where railroads pierce the mountains and go under the rivers by tunnels. Electric tunnels are yet to bring the Pennsylvania at lower grade at Gallitzin and the Southern Pacific through the high crest of the Sierras. Electric traction for the big steam roads is still in its infancy. Only 1,000 miles out of a total of 220,000 miles of steam railroad in the land are as yet operated by electricity. The other day a big traffic-man sat in his Chicago office and said:
“The first railroad that electrifies for the thousand or less miles between this town and New York is going to get all the rich passenger business. Not a big portion of it, mind you, but every single blessed bit of it!”