Which of these four towns, or which particular point along the said 2,000 miles of coast-line, an invader would select for his main attack—apart from feints elsewhere—must needs be uncertain; but this very fact only adds to the imperative importance of those responsible for the defence of Australia being able to move troops freely, and within the shortest possible period, either from one State to another or from any place to another within one and the same State, as the defence conditions might require.
When we thus pass on to consider the question as to the use of existing lines of railway in Australia for strategical purposes, we find that the most noteworthy expression of opinion on this branch of the subject is contained in the following extract from the "Memorandum" which Lord Kitchener wrote in 1910, as the result of an investigation made by him, at the request of the Commonwealth Government, into the "Defence of Australia":—
Railway construction has, while developing the country, resulted in lines that would appear to be more favourable to an enemy invading Australia than to the defence of the country. Different gauges in most of the States isolate each system, and the want of systematic interior connection makes the present lines running inland of little use for defence, although possibly of considerable value to an enemy who would have temporary command of the sea.
The "different gauges" undoubtedly constitute one of the most serious shortcomings of the existing railways in Australia in regard to those military movements with which we are here alone concerned.
Strategical considerations as applied to rail transport require, not only that troops shall be readily conveyed, when necessary, from one part of a country or one part of a continent to another, but that a mobilisation of the forces shall be followed by a mobilisation of railway rolling stock. Locomotives, carriages and trucks on lines which are not themselves likely to be wanted for military transport should be available for use on the lines that will be so wanted, in order that all the rolling stock of all the railways in all parts of the country or of the States concerned can, at a time of possibly the gravest emergency, be concentrated or employed on whatever lines, or in whatever direction, additional transport facilities may be needed.
The importance of this principle was first recognised by von Moltke; but when the railways of Australia were originally planned, each State took a more or less parochial view of its own requirements, its own geographical conditions, or its own resources, and adopted the gauge which accorded best therewith, regardless of any future need for a co-ordinated system of rail-transport serving the requirements of the Australian continent as a whole.
So we find that the 3 ft. 6 in. gauge has been adopted in Queensland, South Australia (with a further 600 miles of 5 ft. 3 in. gauge), Western Australia, and the Northern Territory; the 4 ft. 8½ in. gauge (the standard gauge in Great Britain and, also, of over 65 per cent. of the world's railway mileage,) in New South Wales; and the 5 ft. 3 in. gauge in Victoria. This means, in most cases, that when the frontier of a State is reached, passengers, mails, baggage and merchandise must change or be transferred from the trains on the one system to those of the other.
Assuming that the west-to-east trans-continental railway (which is being built with the 4 ft. 8½ in. gauge) were now available for use, a traveller by it from Perth, Western Australia, through South Australia, Victoria, New South Wales, and Queensland would require, on account of the differences in gauge, to change trains at least five times. This may be regarded as an extreme case; but the evils of the existing conditions are presented to us in a concrete form by an estimate which the Defence Department of the Commonwealth recently made as to the time it would take to move a force of 30,000 mounted troops from Melbourne to Brisbane. It was shown that, with the present break of gauge, this operation would occupy no less a time than sixty-three days; whereas if there were no break of gauge twenty-three days would suffice. Thus the differences of gauge would mean a loss of forty days in effecting transfers at the frontier. In this time much might happen if the enemy had obtained temporary control of the sea. Under these conditions, in fact, he would be able to move his own forces by sea for the still longer distance from Adelaide to Brisbane in five days. Brisbane might thus be captured by the enemy while the reinforcements it wanted were still changing trains at the State boundaries.
It may be of interest here to recall the fact that at one time there were still greater differences of gauge on the railways in the United States; that in 1885 the American railway companies resolved upon establishing uniformity as a means of overcoming the great inconveniences due to these conditions; and that in 1886, after adequate preparation, the conversion of practically the entire system of railways in the United States to the 4 ft. 8½ in. gauge was effected in two days. Strategically, therefore, the United States Federal Government could now, not only send troops by rail from any one part of their vast territory to another, but utilise almost the whole of the available rolling stock for military purposes.[88]