THE GAS MOTOR FOR STREET TRAMWAYS.

Evening Star, Issue 9774, 2 August 1895, Page 1

THE GAS MOTOR FOR STREET TRAMWAYS.

Mr Carroll, U.S. Consul-General for Germany, reports to his Government: — ... About one year ago I witnessed a trial trip of a gas-motor cir in Dresden, and since that time I have watched the progress and improvements that have been made, and am now able, with the aid of information obtained from Mr John Young, superintendent of the Gas Traction Company, Loudon and Dresden, to report that the motor during the first trial trip worked fairly well, but showed some deficiencies, apparently in its mechanical construction, and that siuce that time those deficiencies ’ have been remedied, and during later trial trips the motor car has proved entirely satisfactory. At the first trial the car always started with a noticeable jerk, and did not run smoothly, and when not in motion a considerable quantity of gas was used to keep the motor running, causing the car to sway and tremble ; the dutch coupling did not work regularly and broke easily; the car was clumsy and unsightly. All these objections have apparently been overcome, and an easy, manageable, economical motor for public-traffic is the result. The car "weighs five and a half German tons (about 12,127 English pounds). The distance between the wheels is 1.55 metres (about sft 2in), and the length of the car frame is 3 5 metres (about lift sin). There are fourteen inside seats, ten on both platforms, and twelve on top of the car, making a total capacity of thirty-six seats. The ear has a gauge of 1.435 metres (about 4ft Tin), and has the appearance of an ordinary street car, excepting the two folding doors in the centre of one side of the car, which cover the driving wheel. The motor has tea horse-power, with two cylinders, which are placed in line under one of the rows of seats, one on each side of the shaft. The gas in the machine is ignited by electricity without any noise. Two cylindrical gas tanks, are fixed parallel with the axles of the wheels under the floor of the car; a third gas tank is placed lengthways under the row of seats opposite the machinery, and serves as a proper balance to the car. These three gas tanks hold about 0.95 cubic metre (33.55 cubic feet I of gas, and weigh about 250 kilograms (5511b). The water used in cooling the cylinders circulates automatically through copper tubes eighttenths of a millimetre (0.0315iu) thick, which run from the top to the bottom of the car in a spiral shape. The water, when heated, rises to the top of these tubes, where it cools and then Hows hack into the gas cylinders. The tubes are concealed under the seats. The gas tanks are covered by plates. No part of the machinery is visible inside of the car. It is only accessible from the outside by opening the two large doors above mentioned and a number of smaller doors. The ear while in motion is noiseless, and there is no odor from the gas. The driving gear consists of four shafts. The motor shaft is driven directly by the gas motor, and transmits the motion by means of cogged wheels on the shaft. On this shaft there is a peculiar friction coupling. The friction coupling regulates the speed of the car bv means of a reversing lever, connecting a larger or smaller spur wheel, as may be desired, with the other parts of the machinery. Both wheel axles are driven by chains and chain wheels which rim in oil, so as to use the entire adhesive weight of the car for the development of the tractive power. To diminish the friction the bolts at the joints of these chains are encased in steel, which can revolve, and thus prevent any noise while the machine is working. During short stops the machine remains in motion. By means of a lever the machinery is thrown out of gear to stop the car. While out of gear the motor uses very little gas, because the number of revolutions is diminished, and only after every eight or ten rotations a new ignition of the gas occurs, which is sufficient to keep the motor in motion. One of these levers is connected with the “friction coupling,” and serves to diminish or increase the speed of the car from 150 to 240 rotations per minute ; the other lever is directly connected with the motor, and controls the movement of the car forward or backward. The levers are easily controlled by the conductor. This system of motor power is attracting wide attention, and many German cities are adopting it for street cars. The wheels of the car are peculiarly fastened to their axles. One wheel is secured to the axle, while the other can slip iu hub iu the proportion of 80 per cent, of the circumference of the axle towards the neighboring wheel until it is necessarily taken along by the rotation of the axle. Thus both wheels can revolve differently when the car takes a curve, and the friction or resistance caused by the curve is greatly diminished. The speed obtained at the trial trip was at the rate of 8.7 miles per hour. All curves were overcome with ease, and without any swaying or jerking motion, the smallest radius being 49.2 ft. The speed was diminished while passing over curves. The consumption of gas amounted to about one-third of one cubicmetre (11.74 cubic feet) per kilometre. The gas used for the motor is under a pressure of six atmospheres, and the manometer shows at all times the quantity of gas consumed. The compressed gas enters at first into a regulator for gas pressure (Pintsch system), where the pressure is reduced from 30 to 40 millimetres (1.18 to 1.57 inches) water pressure. The gas contained in the three gas tanks is sufficient to run the car 10.03 miles. The gas supply station consists of an 8 h.p. gas motor, which runs a force pump with a capacity to compress about C» cubic metres (2,118 cubic feet) of gas to 8 or 10 atmospheres per hour. The gas is taken from the city gas pipes in the street, and the tanks in the ears are filled by using rubber tyres or hoses ; they can he filled in about thirty seconds. It is estimated that one of these cars can be built and fully equipped for about 3,570d0l (£700), this estimate being based on the price of labor and materials in Germany, and on the theory of manufacturing on a large scale.