MILITARY RAILROADS. The general subject of military railroads includes the loca tion, construction, operation and maintenance of railroads in the theatre of war under mili tary auspices and for military purposes; that is, with a personnel consisting of officers, enlisted men and civilian employees, and for the main purpose of facilitating the movements and sup ply of an army. The difference between war and peace conditions causes a wide departure of military from civil railroad practice. The more prominent conditions of military railroad service are: 1. Quick results for a short period.
2. A trained personnel for the full develop ment of the mechanical possibilities of the property.
3. Moderate and practically uniform speed requirements for all traffic.
4. A civil road is operated on the presump tion that the track is safe; a military road must be operated on the presumption that the track is unsafe.
5. The property is usually in fair but un equal condition, often hastily restored after partial demolition. The operation of the whole depends on the condition of the most inferior parts.
6. A military road is best operated with an ample supply of motive power and rolling stock, and a moderate speed: whereas on a civil road the tendency is to increase speed toecono mize motive power. The known ratios of equipment and mileage on civil roads cannot be taken as sufficient for military roads.
Railways constructed and operated for mili tary purposes vary from a rough, narrow-gauge road on which the motive power is man or mule, to a fully equipped modern, standard gauge road. The first would probably be used in the approaches of siegeworks or to supply an army in a winter camp or a fortified position of great extent, and the latter when an existing commercial line is taken over for military uses. Between these two extremes are numerous grades of railways, but each grade shades grad ually into the next above and below, and any considerable classification must be artificial and of very little use in discussing the general sub ject. The only classification that seems logical is to divide them into those that are built and operated within and beyond the field of the enemy's field of observation and fire. The former are called combat railways and the lat ter supply railways.
Within the field of observation and fire of a besieged place practically all movements must be made under artificial cover. The location of these lines of approach are dictated by military principles, and the line of the combat railway will therefore be determined, not by questions of economy, or ease of construction, but by the location of the siege approaches and paral lels. For the same reason, the grade of the line
is practically thrown out of the consideration, although a slight change in the direction of the approach might be made to keep the grade of the line below the limiting grade, if by such a change no military advantage were lost. This limiting grade should be kept as low as prac ticable, for the difficulty of moving cars under such adverse conditions is very great, and for any slope greater than six or eight feet in a hundred, the difficulties of ascent with loaded cars will be great, even for animal traction; and above that, the cars would have to be moved by cable.
The possibilities of combat railways for both offense and defense are very great and have never been fully realized. Guns up to six inches calibre and howitzers of larger calibre can easily be fired from cars. Some blocking up may be necessary. Such use of a railway increases greatly the amount of artillery avail able in any sector of the defense whence it can be as rapidly moved elsewhere. Owing to the light weight or narrow-gauge cars, an empty car can be easily lifted back on the track if it is derailed. With loaded cars, however, this is not always the case, and car replacers will be necessary to facilitate this replacing without unloading the cars. Whether a road is con structed or merely taken over for military pur poses makes no difference in the operation and maintenance of the line. The unit of organiza tion is the division, or a section of line from 150 to 300 miles in length which is self-con tained. The persons in charge of a military railway are divided into two classes — Military Controlling Staff and Civilian Officials. The former is chosen from engineer officers and others who have had railway experience, and their function is to make known the military desires and to see that the roads are operated so as to attain these ends. Having given their instructions, they allow the civilian officials and employees to work out the technical details in the manner dictated by their railway experi ence; the military staff only interferes in cases where they believe that the civil officials are not endeavoring to carry out the military plans, or are not succeeding in doing so. The organiza tion and line of responsibility and the relation of the military controlling officials are shown in the diagram.