G.— ENniNEERING. 137 



This conference emphasised the need of an early solution of the 

 problem by drawing attention to the fact that, while the cost of con- 

 verting the New South Wales 4 ft. 8^ in. lines to 5 ft. 3 in. had been 

 estimated in 1897 at about 4,250,000l, the conference now estimated 

 that this work would cost 19,250,000i. ; and, similarly, tlae cost of 

 converting the Victorian and South Australian 5 ft. 3 in. lines to 



4 ft. 8^ in. had been estimated in 1897 at 2,250,0001, and the new 

 estimate was 7,'25O,0O0L To account for this greatly increased cost it 

 was pointed out that in the sixteen years which had elapsed between 

 these two estimates being prepared the railway mileage in New South 

 Wales had nearly doubled, traffic and rolling-stock had gi-eatly increased, 

 and the cost of wages and materials had gone up from between 50 per 

 cent, to 150 per cent. 



The decision of the Commonwealth Government to adopt the 4 ft. 

 8i in. gauge for the East-West transcontinental line, and the construc- 

 tion of that line on that gauge, ought to have settled definitely the choice 

 of the standard railway gauge for Australia, but the question was re- 

 opened, and a Eoyal Commission was appointed on February 8, 19'21, 

 to report on the whole question of the standard gauge which should be 

 adopted for Australian railways, and to submit estimates of the cost 

 of conversion and recommendations as to how the work should be 

 carried out. This Eoyal Commission unanimously recommended that 

 the previous decisions as to the adoption of the 4 ft. 8^ in. gauge should 

 be adhered to ; they were of opinion that no important gain in the carry- 

 ing capacity of the railways would be secured by using the wider 



5 ft. 3 in. gauge, while the reduction in the cost of conversion would 

 be considerable if the 4 ft. 8i in. gauge were adhered to. 



Much confusion has arisen in discussing the gauge question by the 

 failure on the part of many of those who took part in the controversy 

 to appreciate the diffei-ence^ between ' track gauge ' and ' load or struc- 

 ture gauge.' At the present time locomotives are in use on 4 ft. Si in. 

 gauge lines giving a static pressure of 35,000 lb. between the rail head 

 and the wJieel tread, and such a pressure produces probably the maximum 

 permissible deformation in the metal of the rail head and the wheel 

 tread, hence it is the quality of the metal used in the rails and in the 

 tyres which determines ultimately the carrying capacity of the 4 ft. 

 8| in. or any other gauge. On the other hand, the structure gauge 

 determines the density the load must have in order to load the wheels 

 to their maximum capacity; and it is, therefore, to structural gauge 

 changes that attention should in the first place be given. The Aus- 

 tralian 1905 unifoiTTi structure gauge, when outside cylinder locomotives 

 are used, permits, as a matter of fact, the use of bigger diameter engine 

 cylinders on a 4 ft. 6J in. gauge track than on a 5 ft. 3 in. gauge line, 

 as shown in the lantei'n plate. On the other hand, the 5 ft. 3 in. 

 gauge permits a higher centre of gravity with the same stability and 

 ease of riding, but this higher centre of gravity is unobtainable with 

 the usual goods traffic on Australian lines. Undoubtedly it would 

 cost less to change from the wider to the narrower gauge than to 

 carry out the converse operation, since in the former the same 

 sleepers can be used, and no changes in banks, cuttings, and ballast 

 are required, and in the conversion of the rolling-stock the change 



