Results Of Experiments On Mechanical Motors For Tramways Made By The Jury On Railway Appliances At The Antwerp Exhibition
By Captain DOUGLAS GALTON, D.C.L., O.B., F.R.S.
An interesting feature of the International Exhibition at Antwerp was the competition which was invited between different forms of mechanical motors on tramways for use in towns, and between different forms of engines for use on light railways in country districts, or as these are termed, "Chemins de Fer Vicinaux."
These latter have obtained a considerable development in Belgium, Italy, and other Continental states; and are found to be most valuable as a means of cheapening the cost of transit in thinly peopled districts. But owing to the fact that the Board of Trade regulations in this country have not recognized a different standard of construction for this class of railway from that adopted on main lines, there has been no opportunity for the construction of such lines in England.
There has, however, been a great development of tramway lines in England, which in populous districts supply a want which railways never could fully respond to; and although hitherto mechanical traction has not attained any very considerable extension, it is quite evident that if tramways are to fullfil their object satisfactorily, it must be by means of mechanical traction.
It is also certain that the mechanical motor which shall be found to be most universally adaptable, that is to say, most pliant in accommodating itself to the various lines and to the varying work of the traffic, will be the form of motor which will eventually carry the day.
The competition between different forms of motors at the Antwerp Exhibition, which was carefully superintended, and which was arranged to be carried on for a reasonable time, so as to enable the qualities and defects of the different motors to be ascertained, affords a starting point from which it will be possible to carry on future investigations.
I have, therefore, thought it advantageous to the interests of the community in this country to bring the results arrived at before this Society; and as the "Chemins de Fer Vicinaux," to which one part of the competition was devoted, have no counterpart in this country, it is proposed to limit the present paper to an account of the experiments made on the motors for tramways.
Certain conditions were laid down in the programme published at the opening of the Exhibition, to regulate the competition, in order that the competitors might understand the points which would be taken into account by the judges in awarding the prizes.
The experiments were made upon a line of tramway laid down for the purpose in the city of Antwerp, carried along the boulevards from near the main entrance of the exhibition to the vicinity of the principal railway station, a distance of 2,292 meters.
The line ended in a triangle of 505 meters, in order that those motors which required to run always in the same direction should be enabled to do so.
Out of the whole length of the line, viz., 2,797 meters, 2,295 meters were in a straight line, 189 meters in curves of 1¾ chains radius, and 313 meters in curves of 1 chain radius. There were on the line four passing places, besides a passing place at the terminus; these were joined to the main line by curves of 1¾ chains radius.
The line was practically level, the steepest incline being 1 in 1,000; this circumstance is somewhat to be regretted, but the city of Antwerp afforded no convenient locality where a line with steep gradients could have been obtained. The motors were kept in sheds close to the commencement of the line of tramway near the exhibition, where all necessary cleaning and such minor repairs as were required could take place.
A regular service was established, according to a fixed time-table, to which each motor was required to conform. Each journey was reckoned as starting from the end near the exhibition, proceeding to the beginning of the triangle, and returning to the starting point. An hour was allowed between the commencement of each journey, fourteen minutes were allowed for a stoppage at the end near the exhibition, and eighteen minutes at the other end - thus allowing twenty-eight minutes for traveling 2 miles 1,500 yards, or a traveling speed of about 6 miles an hour. The motors were required to work four days out of six, and on one of the four days to draw a supplementary carriage.
An official, assisted by a storekeeper, was appointed to keep a detailed record -
1. Of the work done by each of the motors. 2. Of any delays occurring on the journey, and of the causes of delay. 3. Of the consumption of fuel, both for lighting the fires and for working. 4. Of the consumption of grease. 5. Of the consumption of water. 6. Of all repairs of whatever nature. 7. Of the frequency of cleaning and other necessary operations required for the efficient service of the motor.
The experiments lasted about four months. Five competitors offered themselves, which may be classed as follows: Three were propelled by the direct action of steam, and two were propelled by stored-up force supplied from fixed engines.
Propelled by the direct action of the steam. 1. The Krauss locomotive engine, separate from the carriage. 2. The Wilkinson locomotive engine (i.e., Black and Hawthorn), also separate from the carriage. 3. The Rowan engine and carriage combined. Propelled by stored-up force. 4. The Beaumont compressed-air engine. 5. The electric carriage.
It is somewhat to be regretted in the public interest that other forms of mechanical motors, such as the Mekarski compressed-air engine, or the engine worked with superheated water, or cable tramways, or electrical tramways, were not also presented for competition.
1. The Krauss locomotive is of the general type of a tramway locomotive, but with certain specialties of construction. It has coupled wheels. The weight is suspended on three points. The water-tanks form part of the framing on each side; a covering conceals all except the dome of the boiler. Above the roof is a surface condenser, consisting of 108 copper tubes placed transversely, each of which has an external diameter of 1.45 inches. The boiler is similar to that of an ordinary locomotive; its axis is 3 feet 10½ inches above the road. The body of the engine is 9 feet 11 inches long, and 7 feet 2½ inches wide. The axles are 4 feet 11 inches from center to center. The platform extends along each side of the boiler; the door of the fire-box is in the axis of the road. The engine driver stands on the right-hand side, in the middle of the motor, where he has command of all the appliances for regulating the movements of the engine as well as of the brake.