The challenge to steam
Electricity was the first important substitute for steam power on railways both in the United States and in other countries.
The use of electric power in transportation had its beginning in 1887 when the first electric street railway was placed in operation in Richmond, Virginia. The success of this first electric line led to the adoption of the electric motor on street railways everywhere, and the somewhat slow and cumbersome horse cars, so long a familiar sight in every city, were seen no more. The new motive power not only gave a more rapid and convenient method of transportation on the surface of city streets, but it also made possible the construction of the great rapid transit subway lines in New York, Boston, Chicago, and Philadelphia, and in large foreign cities such as London, Paris, Berlin, and Moscow.
The introduction of the electric street railway for local urban service was soon followed by the contruction and operation of many electric interurban lines. These new railways were built primarily to give rapid and frequent passenger service between nearby cities, and in many parts of the United States they rivalled the steam railroads as passenger carriers.
In recent years many of the street railways in smaller cities and many of the electric interurban lines have been torn up because of the great improvement in highway transportation made possible by the motor vehicle. In the larger cities too. bus transportation has grown in favor, but the electric street railway, the subway, and the elevated street railroad are still
the most important agencies of local passenger transportation. When electric power was first introduced in transportation not many persons thought of its being used to take the place
of the steam locomotive on railroads, but it was not long until the new kind of motive power showed that under certain conditions it was greatly superior to steam, and as early as
1895 the electrification of portions of steam railroads was begun . Since that time the use of electricity in place of steam has steadily grown. In the United States more than 3,000 miles of steam railway lines, and more than twice that mileage of track, have been electrified. In some European countries electrification of steam railways has advanced even more
rapidly than in the United States. Nearly all the railroads of Switzerland are now operated by electric power. In Italy and Sweden a large portion of the steam railway mileage has been electrified, and in Germany, France, Great Britain, Norway, and Spain numerous projects of steam railway electrification have been successfully completed. In Brazil, Argentina and Chile the change from steam to electricity has been made on part of the railway lines, and in Mexico, Australia and Japan some progress in railroad electrification has been made. There are several reasons why electricity, under certain conditions, is greatly superior to steam as a motive power on railroads.
Perhaps the most apparent advantage of electric power over steam is its cleanliness. In long tunnels the smoke and gas of steam locomotives are a source of extreme discomfort and even of danger to passengers and to trainmen. In cities the operation of steam locomotives is disagreeable both on account of the unwholesome gas and smoke and because of their loud noise. It is in the cleanliness of electric power that we find in part the reason for the electrification of railroad tunnels and the electrification of steam railway lines in great metropolitan districts such as New York, Chicago, and Philadelphia. The use of electric power in cities makes it possible also to place railway tracks entirely underground if desired, something which can not be done if the trains are drawn by steam engines. The removal of railways from the surface of the earth to subways gives more space for streets and buildings. While the desirability of eliminating the smoke and gas of the steam locomotive is one of the outstanding reasons for electrifying steam railways, this is not the most important reason.
One of the greatest advantages of electric power over steam is that electric trains can be operated at a higher average speed than steam trains. This is not because they can run faster at full speed, but because they have a much greater acceleration, that is, they can attain full speed much more quickly after starting. This higher average speed of electric trains has led to the electrification of steam railroads in several urban districts, where the volume of passenger traffic is so large that steam trains can not handle it without a substantial increase in the number of railway tracks. An electrified railroad can operate a much larger number of trains than a steam railroad, and in nearly any large city electrification is less costly than the construction of additional tracks for steam trains. In some cities where the operation of a large number of trains has been made necessary because of the increase of passenger traffic, the construction of additional tracks and station facilities has been virtually impossible, because of lack of space, and electrification has offered the only solution of the congestion problem.
The greater train capacity of an electrified railway has also been a reason for the electrification of sections of steam railroads in mountainous regions where railway construction costs are very great. In some places it has been cheaper to electrify a single track road than to build the additional tracks necessary for steam operation.
Still another reason for steam railway electrification is that electric power is superior to steam power on the steep grades found in mountainous districts. When a steam locomotive, drawing a heavy freight or passenger train, ascends a long, difficult grade, its power may gradually diminish because it consumes steam faster than it can produce it. An electric locomotive, deriving its power from an outside source, can exert its maximum effort during the entire climb. Electric operation on mountain grades makes it possible to run heavier trains at greater speeds than is possible with steam operation. The electric locomotive has an advantage over the steam locomotive not only in ascending steep grades, but also on long down-hill movements. With steam operation the speed of a train on a descending grade must be controlled by the train brakes, and if long continued application of the brakes is necessary to prevent a train from going too fast, there is a great deal of wear on brake shoes and car wheels. When an electric locomotive goes down hill with a heavy train the engineer shuts off the electric current. The engine's motor continues to turn, but it is being turned by the movement of the train and acts as a brake, much as the engine of an automobile , in first or second speed, can be made to act as a brake when the automobile descends a steep hill. But the most interesting feature of using an electric motor as a brake is that when it is made to turn by the weight of the train it becomes an electric dynamo or generator, and generates electricity, which it feeds into the power line of the railroad. An electric locomotive going down a steep hill may actually help pull another electric train up the hill. This "regenerative braking" is one of the most interesting economies of railway electrification.
The first project of steam railroad electrification completed in the United States was undertaken in 1895 by the Baltimore and Ohio Railroad for the purpose of getting rid of the smoke of the steam locomotives in the tunnels or subways through which the railroad reaches its main passenger station in the city of Baltimore. Since that time many American railway tunnels have been electrified. In some cases tunnel electrification has been part of the electrification of railways in mountainous regions or in urban districts, but in a few instances the elimination of smoke and gas in the tunnels has been the only reason for the use of electric power. The long Hoosac
Tunnel of the Boston and Maine Railroad in Massachusetts was electrified in 1911. Two railroad tunnels between the United States and Canada, the Michigan Central tunnel under the Detroit River between Windsor and Detroit, and the Canadian National Railways tunnel under the St. Clair River between Port Huron and Sarnia, have also been electrified.
The steam railroads in and about the City of New York have been extensively electrified. The New York Central and the Pennsylvania railroads both found electrification necessary in order to reach their new passenger terminals on Manhattan Island by tunnels and subways. The main line of the New York, New Haven, and Hartford Railroad is electrified from New York to New Haven, a distance of 75 miles. The New Haven has also electrified some of its branches in New England. Altogether the New Haven has an electrified trackage of more than 500 miles. The New York Central has electrified its main line from the Grand Central Station in New York to Harmon, and it has also electrified its most important suburban lines extending from New York into Westchester County. The Long Island Railroad, whose trains enter the Pennsylvania Station in New York by means of a tunnel which passes beneath East River, has electrified nearly 300 miles of its main track lines serving the suburban districts of Long Island. The Delaware, Lackawanna and Western Railroad has electrified parts of its system in the vicinity of New York, in order to accommodate the increasing number of suburban passengers who travel on this road.
The Pennsylvania Railroad has taken the lead among eastern railroads in the electrification of main lines. From New York southward through Philadelphia and Baltimore to Washington , and from Philadelphia westward to Harrisburg, this important railroad is now completely electrified. It is probable that at some future time the electrification will be extended as far west as Pittsburgh. Both the Pennsylvania and the Reading have electrified their chief suburban lines in the Philadelphia district.
In Chicago, the Illinois Central Railroad's line to Richton, and several branches, have been electrified for the purpose of providing more train capacity and to eliminate smoke. While the electrification of steam railroads in the mountainous regions of the United States has not been carried out on an extensive scale, several projects of much importance have been completed during the present century. In Montana , Idaho and Washington the Chicago, Milwaukee, St. Paul and Pacific Railway has electrified sections of a total length of 700 miles. Another important electrification in the western part of the United States is that of the Great Northern Railroad between Skykomish and Wenatchee, Washington. This electric line, which is 73 miles long, includes the great tunnel, 7.8 miles in length, through which the Great Northern passes the Cascade mountain range. One of the advantages gained by the use of electric power on these railroads has been the lessened danger of forest fires caused by flying sparks from steam locomotives.
In the eastern part of the United States the outstanding examples of steam railway electrification in mountainous country have been on the Norfolk and Western and the Virginian railroads. Both these roads carry large quantities of coal to the seaboard from mines in Virginia and West Virginia , and their electrification was undertaken for the purpose of giving increased capacity and more economical operation. These are the only roads in the United States on which electrification was undertaken solely to facilitate the hauling of heavy freight trains. The electrified section of the Norfolk and Western, between Bluefield and Iaeger, West Virginia, is 64 miles long, while that of the Virginian between Mullens. West Virginia, and Roanoke, Virginia, is 134 miles in length. The mileage of electrified track is about the same on both roads.
In the operation of electric roads, trains may be drawn by electric locomotives, or they may be propelled by motors on individual cars. In the freight service all traction is supplied by electric locomotives. In the passenger service both electric locomotives and cars equipped with motors are used. On electrified suburban lines, since the cars do not leave the electrified tracks, it is the customary practice to employ multipleunit trains, each car, or every other car in the train having its own motor. The motors in the different cars are connected and all are controlled by a single motorman. Many through passenger trains, which for a part of their journey must be drawn by steam locomotives, are hauled over electrified divisions by electric locomotives.
Electric locomotives are not much like steam locomotives. They have no fireboxes and no boilers to provide power. They work best in cold weather, because the fast moving motors get overheated more easily on hot summer days. Steam locomotives, on the other hand, work best in hot weather , because cold weather cools off the boiler and cylinders and makes it hard for firemen to keep up steam pressure. Electric locomotives have no fires to clean, they do not have to carry a heavy load of fuel and water, and they can be used steadily for a longer time than steam locomotives because they do not have to be given so much daily care.
Electric locomotives get their power either through a wire above the center of the track or through a third rail running along the side of the track. When an overhead wire is used to carry the electric current the locomotive is brought into contact with the wire by means of a pantagraph. It consists of a framework of springs and levers, carrying a metal shoe, which slides along the electric wire. The pantagraph has the same use that the trolley pole has on an electric street railway car. The trolley pole carries a trolley wheel, however, instead of a sliding shoe. Where a third-rail carries the electric current for an electric locomotive, contact is made by a shoe which reaches out from the side of the locomotive and slides along the third rail.
While electric locomotives have no boilers to provide their power, those used to draw passenger trains must carry small boilers to provide steam heat for the cars. On some locomotives these boilers use oil for fuel. The electric locomotive must also have motors to compress air for the air brakes, the locomotive whistle, and the train signal system.
The power for electric railways is generated in great power houses and carried to the railways on copper wires. In some power houses the dynamos and generators which produce the electric current are driven by steam engines. So even when an electric locomotive is pulling a train, it may be that steam is really doing the work. In some power houses, however, the dynamos are driven by water power. In the western part of the United States, where there is not much coal, there are many swift mountain streams, which can be used to run hydroelectric power stations. Though the cost of building hydroelectric power houses is large, once they are built, they can generate electricity very cheaply. In the eastern part of our country most of the power houses which generate electricity are operated by steam, though many hydro-electric plants have been built in recent years. The greatest hydro-electric power house in the United States is at Niagara Falls.
During recent years our Federal Government has completed some huge dams across various rivers of the country, and it has several others in the process of construction, and still others planned for the future. These dams are designed to control the flood water of the rivers and to improve navigation . All of those which have been completed are producers of large quantities of hydro-electric power, and nearly all of those planned for future construction will also provide a fall of water capable of generating electric current. The Wilson Dam and the Wheeler Dam in the Tennessee River and the Norris Dam in the Clinch River are now providing power for urban and rural commuities in the Tennessee Valley. In the Far West the huge Hoover Dam which crosses the Colorado River between Nevada and Arizona has a great hydro-electric power house. Dams across the Columbia River at Grand Coulee and Bonneville, and the huge dam across the Missouri River at Fort Peck, Montana, are some of the other important projects of the Federal Government which make available the powers of our rivers. It is hoped that Canada will cooperate with the United States in the development of the hydroelectric power which would be made available by building dams in the St. Lawrence River.
We are gradually using up the great stores of coal in the United States, and though there is still an enormous supply left, it will become more expensive as time goes on because of the greater cost of getting it from the mines. As coal be comes dearer, electric power will be used more and more, and especially electric power generated at hydro-electric stations. Some people believe that electricity will before long become so cheap in comparison with coal that all our leading railroads will be electrified. Perhaps the day will come when we shall not use steam locomotives at all and operate the trains on all our railroads with electric locomotives.
The electric locomotive is not the only substitute for the steam locomotive. On many short branch line railroads, passenger trains drawn by uneconomical steam locomotives are being replaced by single cars which secure their power from gasoline engines such as we have in automobiles. Some of these cars are little more than large motor buses built to
run on railroad tracks. Another type looks much like an ordinary passenger car, and has a powerful gasoline motor in a small compartment at the front end of the car. In most cars of this type the power of the gasoline engine is not applied directly to the axles of the cars. It is used to operate a dynamo, and the electricity generated by the dynamo runs a motor which propels the car.
In places where it can be used at all the gasoline car or the gasoline- electric car is much more economical than the steam engine and train. Though gasoline is much more expensive than coal, the weight of a single car is not nearly so great as the weight of a two or three car train and a locomotive. Also, fewer men are required to operate it. Moreover, the gasoline motor is more efficient than the steam engine, putting to useful work a much larger percentage of the energy stored in its fuel. While the gasoline engine is suitable for single cars, it can not be used to draw a heavy train of cars. Where there are large numbers of passengers and large quantities of freight to be transported, we must have long trains, and those trains must be pulled by locomotives. But even for pulling long trains on roads that are not electrified there has appeared a type of engine which is already a formidable rival of the steam locomotive.
This is the Diesel-electric locomotive. The engine of this locomotive, like the gasoline motor, is an internal combustion engine, deriving its power from the combustion of fuel in its cylinders. But instead of gasoline the Diesel motor uses a cheap grade of oil as fuel. It has no electric spark like that of the gasoline motor, the firing of the oil being brought about by the compression of air in the cylinders. When air is subjected to a pressure of 400 pounds or more per square inch, it becomes hot, so hot that it will ignite oil. In the Diesel engine a charge of oil is forced into the cylinder after the air is compressed. The oil burns, and the resulting gas acts upon the piston just as the exploding mixture of gasoline and air acts upon the pistons in the cylinders of an automobile. The Diesel engine is water-cooled, just as the engine in a motor car.
The internal combustion oil engine was first perfected by a German scientist, Dr. Rudolf Diesel, in the latter years of the nineteenth century. It has been greatly improved in recent years and is being used more and more in place of other kinds of engines. It is much more efficient in the consumption of fuel than either the steam engine or the gasoline motor. That is, it transforms a much greater part of the energy of its fuel into useful working energy. Diesel engines have been built which have an efficiency of more than forty per cent, double that of most gasoline motors, and six times as great as that of the ordinary steam locomotive.
In water transportation the Diesel engine is widely used. Before the Second World War began motorships were being built in larger numbers than steamships. Tugs, ferryboats, self-propelled barges and lighters, submarines, and various naval auxiliary craft, were equipped with Diesel engines. Not only are such engines more efficient on ships, but they permit the saving of the large amount of space taken up by furnaces, boilers and water tanks. Seme of our finest transatlantic passenger ships built during the decade before the war were motorships, though the largest vessels were driven by steam turbines.
On land vehicles, too, the Diesel engine is being widely used. Many trucks and buses, and many tractors, are equipped with Diesel motors. In England nearly all the heavy-duty trucks are Dieselized . Within the past few years Diesel motors have been developed which can be used to propel ordinary passenger automobiles , and even airplanes. Many people think that it is only a question of time until all our motor cars will be run with Diesel engines.
The railroad was seemingly a little slow in trying out the Diesel engine as a source of power, but during the past twenty years it has made up for lost time. The first use which railroads made of the new type of engine was in switching locomotives , and the experiment was highly successful, so successful in fact, that hundreds of Diesel-electric switchers are now to be found in the yards of American railroads. These engines have several advantages over steam locomotives in switching. They do not require so much time for repairs; they do not have to stop so frequently for fuel, and do not have to take on boiler water at all; they are economical in fuel consumption, because they burn no fuel during the time they may be waiting for further work to be done; finally, at speeds up to six miles an hour, the speeds at which most switching movements are made, they accelerate more rapidly than steam locomotives. In some yards it has been found possible to do with three Diesel electric switchers work which formerly required four steam locomotives. One railroad reported that by the substitution in one of its freight yards of one Diesel electric switcher for two steam locomotives, the work of the yard was performed more speedily and more efficiently, with a saving of $1,900 a month, of which $1,500 represented savings in fuel costs alone.
The Diesel locomotive has been of much help in the conservation of steel, copper and other materials. This saving was of high importance during the war, when so many things indispensable to the nation's military effort were altogether too scarce. Another advantage of the Diesel locomotive is that it does not make as much noise as a steam locomotive, and is therefore more satisfactory for use in switching movements carried on near the residential sections of a city. Diesel-electric locomotives are being used in increasing numbers to pull passenger trains and freight trains, which were formerly drawn by steam locomotives. For a few years it was thought that however great the merits of the Dieselelectric locomotive, it could not be used extensively in road service, because, compared with a steam locomotive, its tractive power decreases more rapidly with increasing speed. But the Diesel locomotive has been vastly improved since the first ones were put in service on our railroads, and in road service, just as in switching service, it is now challenging the steam locomotive, which for so many years was the only source of motive power on our railroads.
In October, 1935, the Atchison, Topeka and Santa Fe Railroad made a test run of a new Diesel-electric locomotive, designed for use on their finest passenger trains running between Chicago and Los Angeles. The test run was better than either the builders of the locomotive or the railroad managers expected. Leaving Los Angeles at 5:00 A. M. Wednesday , October 16, drawing a nine car train of standard steel passenger cars, weighing 720 tons, the new locomotive and its load reached Chicago at 10:34 P. M. the next day, completing the run of 2,228 miles in 39 hours and 34 minutes. The train made eleven stops during its long journey. This was the fastest time ever made by a train with standard steel car equipment. The best previous run between Los Angeles and Chicago, made in 1905, was more than five hours slower than the time made by the new Diesel.
This Santa Fe locomotive did not look a bit like a steam locomotive. It looked more like a couple of passenger cars or like a multiple-unit electric train. It was a multiple-unit engine with two sections exactly alike. Each section contained two oil-electric engines, each having a rating of 900 horsepower. The entire engine developoped 3,600 horsepower. It easily attained a speed of 100 miles an hour. It could be operated in either direction, each end having an engineer's cab.
So successful were the experiments which the Santa Fe made with its Diesel passenger locomotive that it was placed in regular service early in 1936, pulling the railroad's crack passenger train, "The Super Chief," between Chicago and Los Angeles. Less than two years later a second "Super Chief," with a Diesel locomotive, began regular runs over the main line of the Santa Fe. These fine trains do not now have the heavy passenger cars, such as were in use a few years ago, but have cars of much lighter weight.
Many other railroads have adopted Diesel engines for passenger service. Between 1934 and the attack on Pearl Harbor in December 1941, about 120 new high-speed, light weight passenger trains were put into service in the United States, and of this number at least half used the Diesel motor as a source of power. A number of well-known trains once
powered by steam locomotives "went Diesel," among which was the Chicago and North Western's famous "400," operating between Chicago and the Twin Cities, St. Paul and Minneapolis , by way of Milwaukee. It adopted the Diesel in September, 1939.
Many of the American high-speed passenger trains, which were household names before 1942, were discontinued during the Second World War. The movement of troops and the transportation of the vast amount of materials needed in our war industries made it necessary to limit the civilian passenger service to which the country was once accustomed. After hostilities ended, though it took a long time to restore railroad service to its former state, the discontinued trains gradually returned, and many new, fast trains were scheduled throughout the country, trains more comfortable and luxurious than those of pre-war days. A striking feature of the improved post
war passenger service was the increased use of Diesel-electric locomotives. In a later chapter we shall have more to say about the fine passenger trains on American railroads, and you will see how extensively Diesel locomotives are used. It must be remembered, however, that at the present time, by far most of the passenger trains on our railroads are still drawn by steam locomotives. But the mileage of Diesel-powered trains is growing steadily. There is every reason to believe that this growth will continue for years to come, unless our scientists develop an entirely new type of motor, which will supersede both steam and electric locomotives.
As might have been expected, the Diesel locomotive did not long remain confined to switching and passenger train service. As the Diesel gained in power and efficiency it was inevitable that it should be introduced into road freight service , as a rival to the steam and electric locomotives. On many railroads Diesels are now used regularly to draw freight trains. A few railroads have given up steam locomotives entirely, and have nothing but Diesel power on their tracks. One reason why the Diesel is so widely preferred is that it comes more nearly being an all-purpose locomotive, suitable for passenger or freight service. On the New Haven Railroad there is a 4,000 horsepower Diesel capable of a speed of 80 miles an hour, which draws an express passenger train from Boston to New Haven, and goes back to Boston pulling a 4,500 ton freight train. No reciprocating steam locomotive can be economically employed in such dual service.
Since the Atchison, Topeka and Santa Fe Railroad was the first American road to make use of a Diesel locomotive to haul an ordinary passenger train, it is interesting to record the fact that it was the first to employ Diesel-electric power in extended line haul freight train operation. On February 4, 1941, it placed in service two Diesel-electric freight locomotives of 5,400 horsepower each. On the first trial run of one of these locomotives between Argentine, Kansas, and Los Angeles, California , it pulled a load varying from 2,262 tons to 3,150 tons, for a total distance of 1,716 miles, over plain, mountain and desert, at an average running speed of 32.3 miles an hour. Its performance was in every respect so satisfactory that other railroads have since put into their line-haul freight service a considerable number of Diesel-electric locomotives. In the mountainous districts of the West the Diesel locomotive was a welcome addition to railroad power for moving the heavy war traffic bound for the Pacific coast. Steam locomotives of equal serviceability would have had to be so much heavier than those currently in use that it would have been necessary to strengthen many bridges and other track structures. Use of Diesels saved running time as they do not have to stop for fuel and water over long distances in desert and mountain terrain.
The development of the Diesel locomotive is reminiscent of the development of the steam locomotive. The Diesels of today are more powerful and more economical in fuel consumption than the first ones, and doubtless they will be greatly improved in the near future. One interesting feature of many of the newer Diesels is "dynamic braking." Going down hill, the Diesel, just like an electric locomotive, is permitted to turn the motor, instead of having the motor turn the wheels of the locomotive. The motor in the Diesel becomes a generator , but unlike the electric locomotive, it can not turn the power generated in the downhill movement into a wire or third rail, to help in the movement of other trains. The power is converted into heat, which is given off to the atmosphere through special cooling devices. But even if the power is not utilized, the dynamic braking saves the wear and tear of brake shoes, and makes for economy in the use of the train's compressed air. It "saves the brakes" just as an automobile driver does when he goes down steep hills in first or second gear.
The Diesel locomotive did its part in helping to win the Second World War in Europe. American manufacturers supplied not only planes and tanks and guns for our European allies but locomotives and cars for their railroads. Diesel locomotives helped carry supplies to the fighting Russian armies jn the days when the struggle was most violent. Several American Diesel-electrics were shipped to Bandar-Shahpur, on the Persian Gulf, to operate on the long, twisting railroad leading through Iran and Iraq to Russia. The supplies which moved over this route were an important part of the lend-lease goods sent from the United States, which enabled Russia first to withstand the savage assault of German forces, and later to turn upon them and drive them back to Berlin and surrender.
You may have noticed that the word, Diesel, has been capitalized in this chapter, and wherever it has been used throughout the book. In many newspapers, magazines, and other publications, the word is no longer capitalized. Originally , as the name of a person, the word always began with a capital letter. But the motor has come into such general use that what was once a proper name is now becoming a common name, and is spelled without the capital. There are not many uncapitalized nouns and adjectives in our language, which were once the names of scientists and inventors, but you may be familiar with a few, such as watt, joule, ohm, ampere, faraday and volt, all connected with electricity. One often finds the expression, pullman car, the name of the inventor not being capitalized, as was formerly the universal custom. When this book will be revised again, it is highly probably that the "Diesel" motor will be a "diesel" motor.
If we imagine the steam locomotive to have a mind, we might say that the Diesel locomotive is giving it something to think about. Electrification caused a substantial reduction in the number of steam locomotives, but the number of places in which the electrification of steam railroads would be an economical undertaking is so small, that the steam locomotive has had no reason to fear that the electric engine would put it entirely out of business. The Diesel is a much more powerful and aggressive rival. It can be used anywhere the steam locomotive can be used. Many engineers believe that it is so greatly superior to the steam locomotive that the latter does not have a chance in the race for supremacy. Certainly a large number of American railroad managers are giving convincing evidence of their confidence in this new kind of motive power. But the steam locomotive is not beaten yet. Some of our leading mechanical engineers still have faith in it, and believe that in the long run it will come out on top. It must be remembered that there is much room for improvement in the steam locomotive, because of its low thermal efficiency. So many improvements have been made in recent years that its efficiency has been almost doubled. It may well be that even greater improvements are on the way.
It may be that the steam locomotive will be retained, but an entirely different kind of steam locomotive from that to which we have so long been accustomed. Most of us are familiar only with the reciprocating steam locomotive, the one in which the expansive power of steam drives a piston back and forth in a cylinder, the backward and forward movement being converted into rotary movement by rods and cranks. Many years ago a type of steam engine was invented which proved to be ever so much more efficient than the reciprocating type. This was the turbine. The steam turbine has no piston to be driven back and forth. Its original motion is one of rotation. The turbine consists of a rotor equipped with a series of disks or vanes, mounted on a shaft, enclosed in a cylinder lined with vanes, between which the vanes of the shaft move. Jets of steam, under high pressure, strike the disks and cause the rotor to turn. The effect is something like what one sees when a pin-wheel is held out of the window of a rapidly moving automobile.
The steam turbine with a condenser has a much higher thermal efficiency than the reciprocating steam engine. It needs no cranks and levers for transforming reciprocating movements into rotating movement. It has proved its superiority over the reciprocating engine in many places where the power of steam is employed. In nearly all great power plants where electric power is derived from steam power we find steam turbines turning the electric generators. In transportation the steam turbine has found its greatest use on steamships . Virtually all the great liners that sail the seas, our largest war vessels, and many smaller vessels of war and of commerce , which still use steam as their source of power, are equipped with steam turbines rather than with reciprocating engines.
The problem of adapting the steam turbine for use on railroad locomotives has presented many difficulties, so many, in fact that progress seems to have been somewhat slow. Nevertheless , there have been some interesting experiments with the turbine, and just now it may be that we are on the eve of success.
Railway mechanical engineers in Sweden, Germany and England have built several steam turbine locomotives, but the results they accomplished were not such as to lead to any duplication of the engines they produced. The London Midland and Scottish Railway has been operating a turbine locomotive between London and Edinburgh since 1933, but it has shown no marked superiority over the reciprocating locomotives in use on that road.
The first American railroad turbine appeared in 1938, when the General Electric Company, in cooperation with the Union Pacific Railroad, built a turbo-electric locomotive, which received a great deal of publicity during the time of its initial tests. It had a steam turbine, but like many of the Diesel engines, it employed an electric drive, the power of the turbine being converted into electric power before its application to the locomotive wheels. For some reasons, which have never been publicly disclosed, its performance was not entirely satisfactory, and it was not put into road service. It was a condensing engine. That is, the steam, after being exhausted from the turbine, was condensed into water and returned to the boiler. The condenser was air cooled, and it may be that the condensation resulted in a loss of power. Theoretically, the design of the locomotive was such that its builders were confident that it would be much more efficient than the old-fashioned reciprocating locomotive, and superior in some respects to the Diesel-electric. This now seems to have been another of those many instances in which theory, for some reason, did not justify itself in practice.
The disappointing results of the first efforts to use the turbine in land transportation by no means discouraged the engineers; it only spurred them to further experiment and research. In 1937 the engineers of the Pennsylvania Railroad, the Baldwin Locomotive Works and the Westinghouse Electric Company began working on designs for a steam turbine locomotive. Three years of planning, three years for construction—there was a war going on, and engineers had much to do—and in September, 1944, a new turbine locomotive, new in design, new in structural features, was delivered to the railroad , and immediately subjected to test—first on branch line tracks, and later in main line passenger and freight service.
This new monarch of the rails employed a direct drive; there were no intervening generator and electric motor. It was a non-condensing engine, the exhaust steam being used to create a firebox draft, just as in an old-fashioned reciprocating locomotive. The shaft of the turbine was connected with the axles of the driving wheels through reduction gears. It had two turbines, one for forward movement of the locomotive, and a less powerful one for reverse movement. When the engine moved forward, the reversing turbine became disconnected ; when a backward movement of the locomotive took place, the reversing turbine became engaged to the axles by means of a clutch. The forward-moving turbine had no clutch, and was at no time disengaged, being permitted to idle when steam was admitted to the reversing turbine. The locomotive had eight driving wheels, two pairs of which were connected with the driving mechanism, and connected with the other pairs by side rods. There were six leading truck wheels and the same number of trailing truck wheels, making the locomotive , according to Whyte's classification, a 6-8-6. The engine had a total weight of 560,000 pounds, of which 260,000 pounds rested on the driving wheels. The tender, fully loaded, weighed 449,400 pounds. The engine and tender together had a length of 108 feet; the boiler steam pressure was 310 pounds per square inch.
The early reports concerning this locomotive's performance were highly favorable. It was said to develop twenty per cent more power than a reciprocating locomotive with the same boiler capacity. At a speed of seventy miles an hour it developed 6,550 horsepower. With no reciprocating parts or unbalanced forces, it was said to run as smoothly as a Diesel. Though the locomotive was used regularly in road service on various parts
of the Pennsylvania system, it has not been duplicated. The builders have not seen fit to disclose if it showed some unlooked -for imperfections which indicate that it must be redesigned in certain respects before it can become a successful competitor of the reiprocating locomotive or the Diesel. It may be that like many new models of automobiles and other mechanical contrivances, it revealed the presence of "bugs" which the engineers must somehow get rid of.
Is the turbine locomotive the answer of steam to the Diesel? We shall have to wait and see. There is one thing about a turbine locomotive, which marks a very great change from the old-fashioned railroad engine. It is not a "choo-choo." The exhaust steam flows from the turbine in a continuous stream, without any puffing sound. Even if the turbine does on trace the Diesel and save the day for steam, it will not seem to be a steam locomotive, the sound of which nearly every American child learned to imitate, as one of his earliest accomplishments. The Pennsylvania's turbine was not the only steam turbine designed to respond to the challenge cf the Diesel. The Chesapeake and Ohio Railroad has three turbine locomotives built by the Baldwin Locomotive Works and the Westinghouse Electric Company. They are in many respects different in design from the Pennsylvania engine. In the first place they have an electric drive, though the turbine is non-condensing. The wheel arrangement, 4-8-4-8-4, indicates that they are cf duplex construction, similar to the Pennsylvania's 6-4-4-6 mentioned in the preceding chapter. They are capable of speeding along at a hundred miles an hour, under the 6,000 horsepower each engine delivers, and are, like some Diesels, used to draw either freight or passenger trains.
Several other railroads have announced plans for the construction of steam turbine locomotives, seme with direct and some with electric drive. The Norfolk and Western Railroad has reported that nine eastern railroads, in co-operation with the Babcock and Wilcox Company and the General Electric Company, are planning to build a non-condensing, turboelectric giant of the rails. It will use pulverized coal for fuel, and with a high boiler pressure of 650 pounds per square inch, will yield 6,900 horsepower.
You may have noticed that the railroads which se^m most anxious to develop a steam locomotive that will rival the Diesel are the eastern railroads which have coal as one of the most important parts of their freight traffic. You may have noticed, too, that the Diesel first came into use on western railroads, in regions where there is little coal and where oil is plentiful. The larger eastern railroads appeared reluctant for several years to adopt the Diesel locomotive for road service. The Pennsylvania and the New York Central were the very last of the major railroads to put Diesel locomotives on their crack passenger trains.
It is easy to understand why so many of the eastern railroads desire to retain, if possible, the steam locomotive, or at least some type of locomotive that uses coal for fuel. If oil should entirely displace steam, the eastern roads would lose a large amount of profitable freight traffic. It is to their financial interest , and to the interest of their good customers who own coal mines, to maintain the use of coal as a source of power, if it is possible to do so.
It may be that the steam engine and the Diesel will not engage in a prolonged conflict to determine which is superior. They may both be outmoded before the contest can be ended with victory for one or the other. For a new type of motor has come into use. It is being predicted that within a few years it will be our leading mechanism for converting heat produced by combustion into mechanical energy.
This new motor is the gas turbine, an internal combustion motor which works on the principle of the steam turbine. Though the first experimental gas turbines were built some years before the Second World War, its development was greatly accelerated by that long conflict. The most common form of internal combustion motor, such as the gasoline motor of our automobiles or the Diesel motor, is a reciprocating motor, with pistons which move to and fro, as do the pistons of the reciprocating steam engine. The gas turbine has a rotor, driven by the expansion of the gas driven off by its burning fuel. The power developed by the rapidly whirling rotor can be transmitted to wheels or to propellers, just as power is transmitted from a steam turbine. But the most interesting way in which the power of the gas turbine is employed just now is by what is called "jet propulsion." It is the principle of the rocket, and of the whirling nozzle which scatters water over lawns. It harks back to the law framed long ago by the great English mathematician, Sir Isaac Newton, the law which declares that to all action there is an opposite and equal reaction. The fastest airplanes in the world are driven by jet propulsion , by the expulsion of gas from the nozzles of a gas turbine. The Air Force of the United States now has jet planes which develop speeds approaching a thousand miles an hour, speed greater than the speed of sound. They are the fastest moving vehicles that man has ever built.
One feature of the gas turbine which commends it to engineers is that it is fairly simple in construction. It has only a small number of moving parts, which makes it easy to maintain . Multi-motored jet planes are now being built, and soon we shall have large passenger planes whose turbines will drive them through the stratosphere by a combination of propellers and jets. Long journeys will be made at fantastic rates of speed. The trip from New York to London and back will be like a walk to the grocery or the post office.
As was to be expected, the builders of railroad locomotives were quick to investigate the possibilities of the gas turbine. As early as 1941, while the war in Europe was in progress but before the United States was drawn into the conflict, the firm of Brown, Boveri and Company built a gas turbine locomotive of 2,200 horsepower for the Federal Railways of Switzerland. Subsequently this locomotive was loaned to the French National Railways and operated daily on a run between Basle and Chaumont. This first gas turbine locomotive uses oil as fuel. Though experimental in character, and developing a number of faults which required correction, its performance was satisfactory enough to stimulate wide interest, and encourage engineers to plan more locomotives with gas turbine power plants.
The General Electric Company and the American Locomotive Company recently built such a locomotive for the Union Pacific Railroad. The motor had its first factory operating tests in September, 1947, and in March, 1948, it was exhibited to a highly interested group of railroad executives and engineers. The completed locomotive was delivered to the Union Pacific in June, 1949. As may be imagined, American railroad engineers are eagerly watching the performance of this latest type of motive power.
The gas turbines designed thus far for railroad locomotives do not rely upon jet propulsion, but transmit their power in a manner similar to the method employed by a steam turbine. The time may come, however, when jet propulsion will be common not only on locomotives, but on many other vehicles operated both on land and on water. Whatever the method of propulsion, the next few years are sure to see a growing use of this newest kind of motor. Its thermal efficiency is higher than that of any other motor ever known, and there seems to be no theoretical limit to the size to which it can be built.
One reason why a number of leading railroad executives are deeply interested in the gas turbine is that, unlike other internal combustion motors, it will not have to depend primarily upon oil for fuel. Gas turbines have been built which burn finely pulverized coal with entirely satisfactory results. Railroad managers who have been somewhat dismayed by the intrusion of the oil-burning Diesel motor are now pinning hopes upon the development of powerful gas turbine engines which will consume coal as readily as the old-fashioned steam locomotive, but with much greater thermal efficiency.
Anyhow, it is obvious that the last word in locomotive building has not yet been spoken. In fact it never will be. Just now the whole world is asking if all the varieties of moving power employed in transportation and in all other kinds cf industry will not soon be discarded—if the steam engine , the internal combustion motor, and even the electric motor, will not soon become obsolete. On July 16, 1945, on a lonely desert in New Mexico, a group of scientists and military leaders witnessed an awesome demonstration of the fact that mankind had a new source of power at its disposal, a demonstration that was repeated a few weeks later, with frightfully hideous results, at Hiroshima and Nagasaki. Science had discovered how to split the nucleus of the atom, had developed "chain reaction," and in tearing atoms asunder, they liberated energy in quantities which made the energy with which the world had hitherto been familiar—the energy of muscle, of the wind, of the steam engine, of internal combustion motorsseem puny and insignificant.
A new age had been born—the atomic age—to succeed the age of steam and the age of electricity. It has been pointed out previously that the industrial revolution which began late in the eighteenth century was really a power revolution, because at long last man had found how to convert the liberated energy of coal, oil and other fuels into mechanical energy through the medium of the steam engine. Now we know how to unlock a store of energy vastly greater than that which is freed by the process of combustion or by the chemical reactions of various metals and acids. We have not yet developed a medium through which this atomic energy can be converted readily into mechanical energy, to do the world's work, but few doubt that the problem of doing so will be satisfactorily solved. The process which we have used since the industrial revolution for freeing energy from matter, by combustion or by other chemical change, left the atom undisturbed. Combustion broke up the molecules of matter and rearranged the constituent atoms in different combinations, but the number and the character of the atoms remained the same. The mass and weight of the products of combustion—the water vapor, the gases, the ashes, left after burning took place—were precisely the same as the mass and weight of the fuel and oxygen which were consumed. Loosing the binding forces which held the atoms together in one kind of molecule and permitting them to reassemble to form other kinds of molecules liberated large amounts of energy, but it did not tap the vastly greater store of energy contained in the mysterious forces which held the particles of atoms themselves together.
Scientists finally discovered how to break up the atom. So far they have been able to deal successfully with the atoms of but a few elements, uranium being the most important. Moreover , they have been able to free only a tiny part of the energy locked in a single atom, but even this small part is so enormous in quantity as almost to defy comparison with the energy derived by the process of combustion. A tablespoonful of oil burned under a steam boiler or in an internal combustion motor would not release enough energy to produce an appreciable movement. But if the atoms of that much oil could be disintegrated, enough energy would be freed to drive a transatlantic liner from New York to Havre or to move a heavy freight train from New York to San Francisco.
So far the unlocked energy of the atom has been used chiefly for purposes of destruction, though some of the by-products of atomic disintegration have been of great value in determining the nature and causes of various human diseases, and in pursuing many kinds of scientific inquiry and experiment. Hundreds of laboratories are engaged in atomic research, aided and encouraged by our government, which also maintains great laboratories and plants of its own for making atomic weapons and developing means and methods of employing atomic energy in industries devoted to the welfare and peaceful progress of mankind. The time is not far distant when atomic energy will find its first use in industry. In the beginning it will probably be converted into electrical energy before it turns the wheels of mills and factories, but it may be that some day we shall have motors, both large and small, making direct use of atomic power.
In no other industry will the effect of the revolution of the atomic age be more pronounced than in the industry we call transportation. Transportation has long consumed the lion's share of the power set free by chemical changes in matter. It will continue to do so, but the use of this strange new source of energy may produce such changes in our facilities for transportation that there will be more difference between the locomotive of today and the locomotive of tomorrow than there now is between a giant Mallet and the humble wheelbarrow. We should not leave the subject without mentioning a few other kinds of locomotives which are to be seen occasionally in railroad yards and in industrial plants. One of these is the "fireless" steam locomotive. It has no fire-box and no boiler. Instead it has a huge tank into which steam is turned from a stationary boiler. This steam is used in cylinders just as in a locomotive that makes its own steam. Some tireless
locomotives hold enough steam to keep them going for several hours. There are other fireless locomotives, one kind driven by stored-up compressed air, and another by electric storage batteries . Some railroads make use of caterpillar tractors for shifting cars. It has already been told how tractors are employed in the construction and maintenance of railroads. One thing to be remembered in any discussion of new developments in railroad motive power is that a complete change to a different type of engine, even if it occurs, will take a great deal of time. There must still be much experimentation and research, and a study of the records of performance and of costs, before a final decision can be reached as to what type of locomotive will give the most efficient and most economical service. Then it must be remembered too that our present locomotives can not be scrapped and replaced in
a few days. We shall have our puffing, snorting, clanking iron horse for many years to come. Even if it has been a wasteful creature, and even if many people do think that it is being outmoded, it has been one of the most wonderful machines the world has ever known, and it has done an enormous amount of work which could not have been done without it.