After the data had been assembled it was sifted and refined to assess what proportions could, in the broad sense, be regarded as having a good rail potential. Bulky and awkward traffic, traffics needing wide dispersal by road, irregular streams—all these and others were deemed to be unsuitable.
In deciding what traffics should be regarded as favourable, loadability, regularity of flow, distance and terminal requirements were all taken into account. The outcome of this first analysis was the 93 m. tons already referred to and its composition by distance is shown in the second line of Table No. 23.
Then, as far as practicable, the consignment sizes and the terminal conditions, which could apply if the traffic passed by rail, were determined. It was particularly desired to establish the volume which could comprise full, or part, train loads and pass under the most favourable terminal conditions. The results are shown in Section 2 of Table No. 23.
It will be seen that the potential volume of traffic in the larger consignment sizes passing under the most favourable rail conditions, i.e., siding/siding, amounts to 13·4 m. tons. There is also 3·9 m. tons of potential full train-load traffic, with siding conditions at one end only, and blocks of traffic, amounting to 15·9 m. tons, with similar conditions. Distance grading may well be the final determining factor as to the rail value of these latter groups as it is only in the higher ranges, 150 miles and above, that a margin over direct costs can be expected.
All traffic embraced in the 93 m. tons, and moving more than 70 miles, was assessed as to its suitability for Liner Train conveyance. Estimates of the potential tonnage, in distance ranges, are shown in Section 3 of the table. Out of the 15·7 m. tons, two-thirds would be drawn from wagon-load traffic where there would not be a siding at either end. The balance is drawn from traffic which could have terminal conditions involving a siding.
Further studies of the potential will be made to determine whether there remains, within the 130 m. tons discarded originally, any more traffic of Liner Train potential. Some traffics, by reason of fragility or other characteristics, might have been judged unsuitable in the earlier stages.
Coal, Coke and Patent Fuels
A similar study carried out with the full co-operation of the National Coal Board, merchants, and traders, covered 209 m. tons of fuel of which 150 m. tons passed by rail. The balance—59 m. tons—was carried by private lines, sea, waterways, and road, or by a combination of some of these means.
Map No. 6 shows the volume and geographical distribution of fuel conveyed by road, canal and coastwise. A substantial proportion of the traffic passing coastwise is carried to the ports by rail, a combination of function which is probably the most suitable and economic.
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