The term light railways is somewhat vague and indefinite, and therefore to give a precise definition of its significance isGreat Britain not an easy matter. No adequate definition is to be found even in the British statute-book; for although parliament has on different occasions passed acts dealing with such railways both in Great Britain and Ireland, it has not inserted in any of them a clear and sufficient statement of what it intends shall be understood by the term, as distinguished from an ordinary railway. Since the passing of the Light Railways Act of 1896, which did not apply to Ireland, it is possible to give a formal definition by saying that a light railway is one constructed under the provisions of that act; but it must be noted that the commissioners appointed under that act have authorized many lines which in their physical characteristics are indistinguishable from street tramways constructed under the Tramways Act, and to these the term light railways would certainly not be applied in ordinary parlance. Still, they do differ from ordinary tramways in the important fact that the procedure by which they have been authorized is simpler and cheaper than the methods by which special private acts of parliament have to be obtained for tramway projects. Economy in capital outlay and cheapness in construction is indeed the characteristic generally associated with light railways by the public, and implicitly attached to them by parliament in the act of 1896, and any simplifications of the engineering or mechanical features they may exhibit compared with the standard railways of the country are mainly, if not entirely, due to the desire to keep down their expenses.
The saving of cost is effected in two ways: (1) Instead of having to incur the expenses of a protracted inquiry before parliament, the promoters of a light railway under the act of 1896 make an application to the light railway commissioners, who then hold a local inquiry, to obtain evidence of the usefulness of the proposed railway, and to hear objections to it, and, if they are satisfied, settle the draft order and hand it over to the Board of Trade for confirmation. The Board may reject the order if it thinks the scheme to be of such magnitude or importance that it ought to come under the direct consideration of parliament, or it may modify it in certain respects, or it may remit it to the commissioners for further inquiry. But once the order is confirmed by the Board, with or without modifications, it has effect as if it had been enacted by parliament, and it cannot afterwards be upset on the ground of any alleged irregularity in the proceedings. (2) The second source of economy is to be sought in the reduced cost of actually making the line and of working it when made. Thus the gauge may be narrow, the line single, the rails lighter than those used in standard practice, while deep cuttings and high embankments may be avoided by permitting the curves to be sharper and the gradients steeper: such points conduce to cheapness of construction. Again, low speeds, light stock, less stringent requirements as to continuous brakes, signals, block-working and interlocking, road-crossings, stations, &c., tend to cheapness in working. On the lines actually authorized by the Board of Trade under the 1896 act the normal minimum radius of the curves has been fixed at about 600 ft.; when a still smaller radius has been necessary, the speed has been reduced to 10 m. an hour and a guard-rail insisted on inside the curve. Again, the speed has been restricted to 20 m. an hour on long inclines with gradients steeper than 1 in 50, and also on a line which had scarcely any straight portions and in which there were many curves of 600 ft. radius and gradients of 1 in 50. In the case of a line of 2½ ft. gauge, with a ruling gradient of 1 in 40, a maximum speed of 15 m. an hour and a minimum radius of curve of 300 ft. have been prescribed. Curves of still smaller radius have entailed a maximum speed of 10 m. an hour. It must be understood that a railway described as “light” is not necessarily built of narrower gauge than the standard. Many lines, indeed, have been designed on the normal 4 ft. 8½ in. gauge, and laid with rails weighing from 50 to 70 ℔ per yard; a flat—footed 60 ℔ rail, with the axle load limited to 14 tons, has the advantage for such lines that it permits the employment of a proportion of the locomotives used on main lines. The orders actually granted have allowed 50 ℔, 56 ℔, 60 ℔ and 70 ℔ rails, with corresponding axle loads of 10, 12, 14 and 16 tons. On a line of 2 ft. gauge, rails of 40 ℔ have been sanctioned. In regard to fencing and precautions at level-crossings, less rigid requirements may be enforced than with standard railways; and in some cases where trains are likely to be few, it has been provided that the normal position of the gates at crossings shall be across the line. Again, if the speed is low and the trains infrequent, the signalling arrangements may be of a very simple and inexpensive kind, or even dispensed with altogether. It should be mentioned that the act provided that the Treasury might advance a portion of the money required for a line in cases where the council of any county, borough or district had agreed to do the same, and might also make a special advance in aid of a light railway which was certified by the Board of Agriculture to be beneficial to agriculture in any cultivated district, or by the Board of Trade to furnish a means of communication between a fishing-harbour and a market in a district where it would not be constructed without special assistance from the state.
As a general classification the commissioners have divided the schemes that have come before them into three classes: (A) those which like ordinary railways take their own line across country; (B) those in connexion with which it is proposed to use the public roads conjointly with the ordinary road traffic; and (Neutral) which includes inclined railways worked with a rope, and lines which possess the conditions of A and B in about equal porportions.
The Light Railways Act 1896 was to remain in force only until the end of 1901 unless continued by parliament, but it was continued year by year under the Expiring Laws Continuance Act. In 1901 the president of the Board of Trade introduced a bill to continue the act until 1906, and to amend it so as to make it authorize the construction of a light railway on any highway, the object being to abolish the restriction that a light railway should run into the area of at least two local authorities; but it was not proceeded with. Towards the end of 1901 a departmental committee of the Board of Trade was formed to consider the Light Railways Act, and in 1902 the president of the Board of Trade (Mr Gerald Balfour) stated that as a result of the deliberations of this committee, a new bill had been drafted which he thought would go very far to meet all the reasonable objections that had been urged against the present powers of the local authorities. This bill, however, was not brought forward. In July 1903, Lord Wolverton, on behalf of the Board of Trade, introduced a bill to continue and amend the Light Railways Act. It provided that the powers of the light railway commissioners should continue until determined by parliament, and also provided, inter alia, that in cases Where the Board of Trade thought, under section (9) subsection (3) of the original act, that a proposal should be submitted to parliament, the Board of Trade itself might submit the proposals to parliament by bringing in a bill for the confirmation of the light railway order, with a special report upon it. Opposition on petition could be heard before a select committee or a joint committee as in the case of private bills. The bill was withdrawn on the 11th of August 1903, Lord Morley appealing to the Board of Trade to bring in a more comprehensive measure to amend the unsatisfactory state of legislation in relation to tramways and light railways. In 1904 the president of the Board of Trade brought in a bill on practically the same lines as the amending bill of 1903. It reached second reading but was not proceeded with. Similar amending bills were introduced in the 1905 and 1906 sessions, but were withdrawn. During the first ten years after the act came into force 545 applications for orders were received, 313 orders were made, and 282 orders were confirmed. The orders confirmed were for 1731 m., involving an estimated capital expenditure of £12,770,384. At the end of 1906 only 500 m. had been opened for traffic, and the mileage of lines