In all the cases mentioned above, the oper ating results have proved satisfactory, and some remarkable records are made in regular service. On the Norfolk and.Western, for ex ample, the speed of freight trains up the heavy grades has been practically doubled, while two electric locomotives handle as much tonnage per train as three of the large Mallet steam locomotives formerly used.
The general electrification of steam railways is highly improbable for some time to come, not so much because of the difficulty in design ing suitable equipment as because of the enor mous cost involved. The electrification of a steam railway requires, not merely the re placing of steam locomotives by electric loco motives, but also the installation of power house and transmission equipment, of new shop and terminal facilities and various other items. Thus, while material savings in operation may, under favorable conditions, be effected by the use of electric locomotives, the first cost in the majority of cases is prohibitive. For some time to come, therefore, electrification will probably be confined to city terminals and large tunnels, to mountain grades and to congested districts where the amount of traffic moving is fairly constant during the greater part of the day.
No uniform method of developing, trans mitting and utilizing electric power in railway work has as yet been adopted. Direct and alternating current, the overhead wire and the third rail, and various different types of loco motives, are all in successful use. Each elec trification problem must be studied by itself, and that system used which is best fitted for the special conditions to be met.
The majority of electric locomotives are built on a co-operative plan, one company sup plying the mechanical parts and another the electrical equipment. The Baldwin Locomo tive Works and the Westinghouse Electric and Manufacturing Company have worked together in this way, as have also the American Loco motive Company and the General Electric Com pany. Thus the locomotives, in both their mechanical and electrical features, represent the work of designers and builders who are experts in their respective lines.
Before closing this review, mention should be made of the use of internal combustion motors in locomotive work The extremely variable conditions as to speed and load, under which locomotives operate; the weight and space limitations which are necessarily imposed, and various other considerations, have hin dered the introduction of this class of motor in general railway service. There is, however, a
growing field for the internal combustion loco motive in light switching, contractors' and industrial service; and the success of these machines in such work points to their increas ing use in the future.
The fact that the internal combustion loco motive consumes no fuel while standing idle makes it specially suitable for work in which the service requirements are intermittent. In plantation service, for example, when the mills are not grinding, it is desirable to have loco motives ready for immediate use, even though they may only occasionally be needed. Gasoline locomotives meet these conditions admirably, as they are dependent upon no external source of power, consume fuel only when operating and can be placed in service without previous preparation.
The Baldwin Locomotive Works has made a special study of the gasoline locomotive, and has developed a series of four standard designs weighing three and one-half, five, seven and nine tons, respectively. In many respects these machines follow steam locomotive practice. The entire construction, including the motor and transmission, is spring supported. The motor drives a transverse jack-shaft, from which power is transmitted to the wheels by means of side rods. No chains are used in the trans mission system, and there is a positive drive from motor to wheels. The minor fittings and equipment are arranged, in each case, to suit the special conditions under which the loco motives operate. The locomotives can be built for any practicable track gauge, and can, if desired, be arranged to use alcohol for fuel instead of gasoline.
The immediate future will probably witness a continued increase in the weight and capacity of steam locomotives, and a greater refinement in their design for the purpose of developing maximum power in proportion to the fuel and water consumed. Electrification will be ex tended in districts where its advantages can be fully realized. The internal combustion motor possesses many advantages for railway work, and its extensive use in large locomotives may be expected as soon as a suitable design is produced. The difficulties here are by no means insurmountable, and there are prospects that a type of internal combustion motor will be de veloped which will, in turn, revolutionize the present methods of railway operation.