There are two ways to direct the movement of trains. The first is the one still most commonly in use upon the railroad of the United States, by the written instructions of the train-order; the other is by the indications of the fixed signal--upon the open line, generally the automatic block. For train-order instructions the moving train must either slow down or stop completely, but with signal indications it may keep moving ahead at a good pace. In the one case time is lost, in the other it is gained.
This may seem in itself a small matter, but much multiplied it comes to a real saving indeed. On a single important division of a single important freight-carrying railroad--the Susquehanna division of the Erie railroad, 140 miles of double-track--a careful test was made of the savings accomplished by the installation of electric block-signals within the first calendar twelvemonth after they had been put in service, supplanting old-fashioned manual block-signals. Over that division in a typical year there move the huge traffic of 2,322,070,451 ton-miles.
Under the manual block the year before, the Erie's train-despatching was by written train-orders sent by telegraph. The division was divided into two despatchers' districts, two men for each district, four men for the division, for each of the three eight-hour tricks, or twelve men for the twenty-four hours, in addition to two chief train-despatchers. Moreover the Susquehanna division had employed in the twelvemonth immediately preceding the installation of its automatic electric blocks 136 signalmen at forty-six intermediate stations who had been paid $94,752 on the eight-hour day basis. Even then it had sought to economize by closing down a number of its block stations at night to make a little saving on its pay-roll, even though the net result was to make its blocks excessively long in those hours and so slow up and greatly delay its train movement.
Contrast this with a despatchers' service of but six men--in addition, of course, to the two chief despatchers--for the entire division with no signalmen whatsoever (aside from the telegraph offices open at seventeen intermediate points instead of forty-six as of old, where the retention of an operator and the written train-order system was imperative), and we begin to see real savings. The Erie people took that first year of their automatic block operation and compared it with the twelve months immediately preceding when they had moved 2,137,868,274 ton miles of freight traffic over the Susquehanna division. With their new kink in scientific railroad operation they were able not only greatly to reduce their operating force but to increase their ton-miles per train from 254,054 to 274,217, a very considerable efficiency increase. In other words they not alone made the valuable saving in time from having fewer trains upon the line--the actual saving in that first year came to 697 trains--but an operating cost of $87,969. At the rate at which money was then worth, this was the interest on a capital investment of $1,759,380.