You will run to Alton regardless of train No. 5.
or perhaps—
You will meet and pass train No. 5 at Alton.
The holding order is dispensed with by some, and with some it is the practice to issue orders to inferior trains while a superior is held by a holding order until its movements can be determined on, when it receives an order covering all that have been given to trains against it.
Under the "duplicate" system the holding order may be used, but such has not been the general practice, and it would not under this system be used in the manner above described. This system, as its name implies, requires that the order given to each train shall be a duplicate of that given to every other train concerned in the movement provided for in the order. For the simple movement above described an order is addressed to the conductor and engineman of each of the two trains, in the same words, as follows:
Trains No. 4 and No. 5 will meet at Alton.
This, being in the same words to each, may be transmitted over the wire to both at the same time. This is usually done, and offers one of the chief advantages of this form of order. The trains are stopped by signals, which are required either to be displayed when an order is sent, or to stand normally in position to stop trains, which are only permitted to pass on the signal being changed or on getting proper orders.
Objection has been made to the "duplicate" form that it does not distinctly order a train to proceed farther than its schedule rights permit, nor in definite terms direct the other not to go beyond the new meeting-point. The objection has no weight, as an order to meet can only be construed as authorizing each train to go to the station named, and not beyond it until both are there; and it is easy and proper to provide a rule which shall definitely settle the point for those who are unaccustomed to this form, if it should be deemed necessary.
The fatal defect in the "single order" system is that the orders to the two trains, written separately and differently expressed, are subject to the grave danger of inadvertently giving in one a meeting-place different from that given in the other. This liability is greater if an interval of time occurs between the preparation of the two. The risk is very much increased by the usage under this system of including several meeting-points in one order, and becomes still more serious if meeting-points are to be made for several trains moving in each direction. The schedule for these must be rapidly made up and written out in parts, giving to each train its part, differing in form from all the others. There is nothing but the care and skill of the Dispatcher to prevent the opposing orders from differing in some particular. When we consider the care necessary in preparing a time-table, to properly show the running time and meeting-places of the several trains, we must see that the risk, in the process described, of getting something wrong, must far outweigh any supposed convenience in a train having an order showing a continuous schedule of its meeting-points for several opposing trains. Those unacquainted with this work would be astonished at the extent to which the skill of some dispatchers in this direction has been developed. To the uninitiated the mental operations would be simply bewildering, which are required of a brain from which issue for hours, without apparent effort, the instructions under which the trains on a busy road are moved expeditiously and harmoniously. It is not to be denied that many men have moved traffic of huge dimensions safely and with entire satisfaction by the "single order," but this does not at all prove that the system possesses inherent principles of safety. Great personal ability and skill have, with it, achieved marked success where in less able hands its defects would have become apparent; but that some have developed this remarkable ability is no reason why we should depend upon this in a matter of such vital importance. The prevalence of methods which require exceptional skill has doubtless interfered with the more extended usefulness of the railroad telegraph which would probably have resulted under a system more readily operated by men of less experience and ability.
Men who have successfully worked under the "single order" method have stated that the mental strain is very great, augmented by anxiety born of the fact that a single error may be fatal to property or life. Now, a mode of constructing orders which may be operated with safety by men of moderate skill, which relieves them of the mental strain, and which in itself provides against the most serious chance of error must at once commend itself. The "duplicate" would appear to meet these requirements; and that such is the case is the abundant testimony of those who have used it.