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The New Zealand Railways Magazine, Volume 2, Issue 2 (June 1, 1927)

Economy of Transport

Economy of Transport

It is a regrettable defect of the Departmental organisation favoured in some Railway systems that the functions of the civil and mechanical engineering and of the traffic departments are so strictly differentiated, that their community of interest in the important questions of economic train loads and train speeds is apt sometimes to be lost sight of, while real efficiency may be sacrificed on the altar of departmental statistics. Thus a traffic officer's want of appreciation of the influence of speed on locomotive efficiency on the one hand, or a locomotive engineer's neglect of the effects of slow, though heavy freight trains on wagon efficiency on the other, may lead to unreasonable demands in the effort to secure some fancied advantage in favour of one or other of the two departments.

From the sole point of view of locomotive results, slow freight speeds and full loads stand generally for a high freight ton mileage per engine and low fuel consumption per ton mile; but heavy loads mean also slow train movements all round, not only between, but at, stations, and perhaps also a certain amount of obstruction to other and more important traffic. This all tells against wagon efficiency, and upon the latter factor the profitable operation of a railway very largely depends. Thus, considering the matter purely from the point of view of locomotive economies, the best speed for freight trains on level sections is probably about 20 to 25 miles per hour. Thereafter the possible freight ton mileage per engine per annum diminishes with every increment of speed, as the loads hauled have to be correspondingly reduced, other conditions remaining constant. Speaking generally, however, experience indicates that in the case of long loads and level sections the maximum return is obtained from the locomotives and rolling stock—taken together as representing so much capital invested—when freight trains are timed for a mean speed of about 20 miles per hour, between stations, which implies an actual running speed of 22 to 25 miles per hour, or more on short runs.

A point to be borne in mind by the locomotive engineer is that although the fuel bill is usually the heaviest single item of locomotive working expenditure, it is not the only or the ultimate criterion of railway efficiency. The fuel question is one of the greatest importance; departmentally it is perhaps the most important question of all, because it is the most difficult to handle. But in the broader fields of railway policy and efficiency, the wagon question is not less important than fuel consumption, nor is it less difficult. For while, down to a certain point (which is determined mainly by the ruling grade), reduced speeds mean heavier engine loads, lower fuel consumption per unit hauled, and a greater vehicle and ton mileage per annum, they result directly in lowering the amount of freight that can be handled in the same period by a given number of wagons. For, whatever the train speed may be, the rated capacity of the wagon remains constant, so that the total amount of freight that a given number of wagons can deal with in a given period of time depends on the speed with which they can be passed over the section.

The very fact that traffic and loco. departmental interests are apparently conflicting in this connection renders the matter of wagon efficiency one in which there should be the closest co-operation and interchange of views and established data. Amongst the many factors by which the earning capacity of the stock is influenced, the following should be no less the concern of the locomotive than of the traffic officer: firstly, the maintenance of a high daily mileage per wagon; secondly, accurate engine loading; and thirdly, the securing of full engine loads all along the line.

After making all necessary allowance for these matters, wagon efficiency still depends on the use that is made of the available carrying capacity of the rolling stock by the staff entrusted with its loading. Experience does not provide any grounds for assuming that the employees whose business it is to deal with the loading of wagons can be left to carry out the work without an effective check on their actual performances. But without prompt and accurate returns to show the actual freight handled and the wagons dealt with, it was impossible in the past to gauge properly or control effectually the extent to which advantage was being taken of the carrying capacity of wagons. Statistics showing wagon ton miles will shortly be available, and much interesting light will then be thrown on this very important phase of railway operation.

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