APRIL1900. 185 ROAD LOCOMOTION. BY PROFFSSORH. S. HELE-SHAW, LL.D., F.R.S., Menzher, OF LIVERPOOL. There are strong reasons for thinking that the subject of mechanical propulsion upon common roads has now reached a point when it deserves the very careful consideration of mechanical engineers. The idea of bringing the matter generally before the Institution for discussion is due to our President, whose far-reaching judgment will be admitted by all. The title of this Paper must be admitted to be very comprehensive, but it seems that what is ueeded at this time is a discussion of the general principles of the engineering features of the question, rather than a detailed description of any particular system. For many years the uses and importance of the traction engine have become more and more recognised, and its possibilities in connection with the present war have quite recently been brought very strongly before the public. This engine, the work of which covers only a portion of the field for mechanical propulsion on roads, has been very fully dealt with before this Institution and elsewhere, and it will be in the first place instructive to consider what has led to a general revival of a movement for lighter road-locomotives which about seventy years ago, in the days of Hancock and Gurney, reached a point that for a time appeared to be leading to permanent results of the most important kind, but which ended in complete failure. In one sense this revival is undoubtedly due to the passing of the Locomotives on Highways Act in 1896, previous to which, for more than twenty years, a law had existed, popularly known as the “Man with the Red Flag” Downloaded from pme.sagepub.com at The University of Auckland Library on June 4, 2016 186 ROAD LoaoMomoN. APRIL1900. Act, which made it impossible for any self-propelled vehicle to proceed at a rate of more than four miles an hour. The immediate cause of the passing of this Act was the attention aroused in this country by the successful introduction of the motor vehicle for purposes of pleasure in France, where the red flag was not at any rate used specially for obstruction on highways. This freedom from legal restriction enabled an enterprising paper, " Le Petit Journal,'' to organise in 1894 a trial of motor vehicles between Paris and Rouen, which was so successful as to 'lead to one on a larger scale between Paris and Bordeaux over a distance of more than seven hundred miles. These trials proved conclusively the grcat possibilities of motor vehicles, and attracted much attention in this country, where after the first exhibition and trial in England, which was originated by Sir David Salomons in 1895 in the grounds of the Local Agricultural Socicty at Tunbridge Wells, successful measures were taken to obtain a more enlightened legislative treatment. We must however look deeper for the real causes of the present movement, which can be traced to the gradual feeling amongst ell classes of the community that modes of transport both for purposes of pleasure and business on the roads had not kept pace, or indeed had made, little progress at all, compared with the great changes which had been effected in speed, comfort and convenience, in the direction of locomotion by rail. Mr. Samuel W. Johnson, speaking of the progress of railways in his Presidential Address" before this Institution, showed that in thirty years the annual train-mileage had increased from 200 millions to 350 millions, and remarked that " Our iron roads are the arteries and veins of the nation." Pursuing this very true and striking analogy farther, it may be said that the capillaries and smaller blood vessels are in their way just as important as the larger veins. Now while the railway arterial systems have developed enormously and satisfactorily, there is still much room in present modes of collecting and distributing goods for improvements, which would materially benefit the trade and commerce of the country. .* Pruceedings, 1898, page 119. Downloaded from pme.sagepub.com at The University of Auckland Library on June 4, 2016 APKIL1900. ROAD LOCOMOTION. 187 Railways are undoubtedly the cheapest system of land carriage for long distances, but there is a minimum distance below which the disproportion between haulage and terminal charges operates to their detriment. This feature of railway transport and the serious consequences of " breaking bulk " are exhaustively dealt with in an interesting and important report published in 1898, by the Special Light Railways Committee of the Liverpool Incorporated Chamber of Commerce, in which report it is made evident that Liverpool in particular suffers from these causes, and what is true of Liverpool is probably true of other great commercial cities. Cartages and terminals exceed the haulage charges over short distances by rail, whilst they become only a very small percentage of the whole when the distances are considerable. It must be obvious that a motor vehicle, which can travel from any one point to any other, which absorbs the short cartages into one straightforward journey, and which absolutely eliminates railway terminal charges, has a wide and promising scope for application. Mr. Alfred Holt, one of the leading shipowners of the country, has for many years urged the necessity of obviating these terminal charges, concerning which he states that the matter of handling is a " giant, and the transport a dwarf, and the giant is daily growing larger, and the dwarf smaller." The relation between these two charges may be shown in a very striking manner by plotting the terminal and conveyance charges, worked out in pence per net ton-mile taken from the Government Blue Book of 1892, dealing with the rates and charges, and is given in Fig. 1 (page 188). This curve shows clearly that up to 40 miles there is a field for a system of conveyance in the working of which terminals are not incurred, and it will be at once appreciated by engineers. Apart from these considerations, there cau be no doubt that with the rapid means for communication of ideas by telegraph and telephone, and of passengers and goods by means of the railway, the general want is felt of a more speedy means of transport by road. The great improvements which are needed in our road traffic hare been set forth by Major R. E. B. Crompton, R.E., at present in South Africa, and one of our old Members, in a Paper read by Downloaded from pme.sagepub.com at The University of Auckland Library on June 4, 2016 188 11OAD LOUOMOTION. APRIL1000. him before the Automobile Club, in which he clearly shows tho vast and beneficial changes that the general introduction of the motor vehicle would effect in the relief and expedition of traffic in our cities, and especially in the metropolis. Nor must the hygienic considerations be overlooked. This subject has been ably dealt with by Mr. E. Shrapnel1 Smith, Honorary Secretary of the Liverpool Self-Propelled Traffic Association, to whom the author is indebted for valuable assistance in many points dealt with in this Paper and particularly in connection with the final section. In his Paper, read before the Congress of the FIQ.1. Relation between Terminal and Contycince Charges on Railways. (Claeses 1 and 4.) Lrn-qth of Jrwr.n<, in MiCes Snnitary Institute at Birmingham in 1898, he points out that with riiotor vehicles, not only will our streets be less offensive, especially in summer weather, but exposed food stuffs will less frequently nford a nidus for organisms conveyed by disseminated particles from the roads ; and further, that the disintegrating effect of the horses' hoofs, which accounts for most of the dust of summer and the pasty slime of winter, will be to a great extent obviated. The sanitary advantages of the motor vehicIe have also been recognised and strongly urged by many medical officers of health and surveyors to municipal and urban councils. This shows, then, what forces are at work urging us, both for light and heavy traffic, in the Downloaded from pme.sagepub.com at The University of Auckland Library on June 4, 2016 APRIL1900. ROAD LOCOJIOTION. 189 direction of utilizing more efficiently and with mechanical power the 100,000 miles of road which we possess ia this country. From this side of the question we naturally turn to consider the difficulties of the problem, and it must at once be admitted that these difficulties are very great. The author has frequently seen the subject referred to as a question of mere mechanical detail, and the progress of the railway locomotive mentioned as a proof that these mechanical difficulties will be easily and rapidly overcome. Moreover, the whole blame for small progress made, and for previous failure, is often thrown upon restrictive Acts of Parliament. The truth is that the argument of the railway locomotive, so far from giving any grounds for the hope of an easy solution of the problem of road locomotion, really tends in the opposite direction. In the fist place, railways are one of the most striking examples of the nature of mechanical progress first pointed out by Reuleaux, that machines became more and more perfect as their restraint by what he called ‘‘ pairing ” was more completely effected, Le., as the mechaniml boundaries compelled the parts to move with more certainty under required conditions. The provision of a suitable track, upon which the train moves and by which its motion is guided, is the real secret of railway development. Hence it is that with a steel wheel rolling upon a hard smooth track, a continuous increase of weight, and of tractive force, together with increase of speed is enabled to be obtained.