In the discharge of these duties the Directeur de l'Arrière is aided by a staff which comprises both the technical and the military elements; but he is not himself responsible for the actual working of either the rail or the road services.
Railway services in the Zone of the Armies are—subject to the supreme authority of the Directeur de l'Arrière—under the control of a Director of Railways who is assisted by (1) a combined military and technical staff; (2) a Line Commission for that section of the zone where the railways can still be worked by their ordinary staffs; and (3) one or more Field Line Commissions ("Commissions de chemins de fer de campagne"), together with Railway Troops, for the section where military operation is necessary.
In the interests of that co-ordination to which so much importance is rightly attached, the Director of Railways refers to the Directeur de l'Arrière all demands for transport that concern the railways of both the Zone of the Interior and the Zone of the Armies or involve conveyance by road as well as by rail. He also passes on to the Commissions in charge of either section of the railways included in the Zone of the Armies the orders he himself receives from the Directeur de l'Arrière in respect to such transport requirements as may concern them. Time-tables drawn up, and other arrangements made, by these Commissions are subject to his approval. He further decides as to the distribution, within the Zone of the Armies, of the rolling stock and the railway personnel placed at his disposal by the Commander-in-Chief.
The Field Line Commissions are the executive agents of the Director of Railways in the discharge of the various duties assigned to him. The number of these Commissions is decided by the Directeur de l'Arrière, and the date of their entering on their functions is fixed by the Director of Railways. Each Commission consists of a staff officer and a railway engineer. Of these the former is military president of the Commission and has the controlling voice. When he considers it necessary that he should accept, in addition to his own responsibility, that of the technical commissioner, the latter must defer to his views and to the orders he gives. The president has an assistant—also a staff officer—who can replace him when necessary, while the Commission has a staff of secretaries and orderlies as approved by the Minister of War. The personnel of the Commissions includes Railway Troops ("Sapeurs de chemins de fer" and "Sections de chemins de fer de campagne"); a telegraphy staff; Station Commissions; and "gendarmerie" to undertake police duties in the stations and on the trains.
In addition to making traffic arrangements and undertaking the operation of those lines at the theatre of war that may pass under full military control, the Field Line Commissions are required to carry out such construction, repair, maintenance or destruction work on the railways as should be found necessary.
On the Lines of Communication passing through the two zones and ensuring direct communication between the interior and such accessible points on the railway as may, from time to time, be nearest to the armies in the field, the leading stations en route are required to serve a variety of military purposes; though in each and every such instance the system of organisation is such that the duties to be discharged or the responsibilities to be fulfilled are undertaken by, or are under the control of, a Commission formed on the now established basis of representation thereon of both the military and the technical elements.
For the conveyance of troops, there are, in the first place, Mobilisation Stations and Junction Stations, whence the men within a certain district are sent to the Embarkation Stations, at which complete units for the front are made up. These are followed by Stations for Meals ("Stations haltes-repas"), for men and horses; though in this case the "stations" may really be goods or locomotive sheds, able to accommodate a large number of men. At the end of the railway line, so far as it is available for troops, come the Detraining Stations.
In regard to supplies and stores, the first link in the chain of organisation is constituted by the Base Supply Stations ("gares de rassemblement"). Here the supplies going from a certain district outside the theatre of operations to any one Army Corps must be delivered; and here they are checked, made up into full train loads, or otherwise dealt with in such a way as to simplify and facilitate their further transport.
In certain cases full train-loads arriving at these assembling stations pass through to destination, after being checked; but the general practice is for the consignments forwarded from base supply stations to go to the Supply Depôts ("Stations-magasins"), serving the purposes of storehouses from which supplies, whether received from the base or collected locally, can be despatched in just such quantities, and at just such intervals, as circumstances may require. These depôts are organised on a different basis according to the particular service or purpose for which they are designed,—Cavalry, Engineers, Artillery, Medical, Telegraph Corps; provisions, live stock, clothing, camp equipment, etc. Their number, character, and location are decided by the Minister of War in time of peace. On the outbreak of war those in the Zone of the Armies pass under the control of the Commander-in-Chief together with the railway lines within that zone. The situation of the depôts may be changed, or additional depôts may be opened, by the Directeur de l'Arrière, with the consent of the Commander-in-Chief.
Each station depôt is under the charge of the military member of the Station Commission. His special function it is to supply therefrom the wants of the Army in accordance with the demands he receives. These demands he distributes among the different departments of the depôt, giving instructions as to the time by which the railway wagons must be loaded. He also takes, with the stationmaster, all the necessary measures for ensuring the making up, the loading, and the departure of the trains; but he must not interfere with the internal administration of the station or with the technical direction and execution of the railway services.