NARROW GAUGE AS APPLIED TO BRANCH RAILWAYS IN N.S.W. XXV. 



which it takes up, and the two loaded tiers of the standard 

 gauge truck is impracticable on the 2ft., owing to that, also, 

 throwing the centre of gravity too high ; while to gain sufficient 

 height for cattle, the floor of the 2ft. cattle truck has to be 

 lowered between the bogies, the space over which is wasted. 

 Hence a greater proportion of dead weight is necessary than in 

 the larger 4ft. 8^in. vans. 



If we except coal and firewood, which are nearly all confined 

 to the main lines of New South Wales, which latter, being 

 already made, are necessarily excluded from our comparison, it 

 will be found from the Railway Commissioners' reports that the 

 bulk of the remaining up traffic, which we may fairly assume as 

 generally applicable, as an all round average, to extensions, is 

 divided, as to weight, in the following approximate propor- 

 tion, viz. : — 



Grain . . 42% This loading occupying about 50 cubic ft. of space per ton 



Hay, Straw, &e. 14 „ „ „ 300 



Wool ..17 „ „ „ 150 



Cattle ..14 „ „ „ 162 



Sheep, &c. . . 13 „ „ „ 406 



100 Average = 164 cubic feet per ton. 



The down traffic will be considered later. 



As goods occupying about 93 cubic feet to the ton, form the 

 load in which the loading space, 2,040 cubic feet, of the standard 

 gauge bogie goods waggon is fully utilized it is evident that 

 there is an unavoidable waste of weight carrying capacity for all 

 the above loading, except, in the case of grain, and still more 

 must this be the case as the gauge decreases, for the cubical 

 capacity is limited in both cases, but more frequently in the 

 narrow gauge, as regards some classes of loading, by the height 

 of the centre of gravity of the waggon and its load. This height 

 is taken, as a maximum, at about 6 feet over rail for the standard 

 gauge, and, proportionately, 2ft. 8in. for the 2ft. gauge, though 

 this unduly favours the latter, as, owing to the greater lateral 

 overhang, the danger of lateral displacement of the centre of 

 gravity, through careless loading, is greater. 



