STEAM-WORKED TRAMWAYS.

Globe, Volume IX, Issue 1292, 10 May 1878, Page 3

STEAM-WORKED TRAMWAYS.

[“Engineering,” February 2.J The question of the use of steam power on tramways in towns and cities continues to receive merited attention and practical development in connection with foreign countries and the colonies. The most recent instance in this direction which has come under our notice, is that of the Wellington city tramways, New Z‘ aland, which will be worked by steam power. The engines for this line are being constructed by Messrs Merryweather and Sons, at their Light Locomotive Works, at Greenwich, where, a few days since, a number of gentlemen interested in the development of tramways in the colonics assembled to witness the formal trial of the first of those engines which has just been completed. The engine is similar in general character to those of which the firm have manufactured a large number —upwards of sixty we believe —for the tramways of Paris, Rouen, Cassel, Barcelona, Guernsey, and other places. It however, embodies several improvements in details, which have been suggested by the extended experience of the manufacturers. The boiler is of the locomotive type, and its capacity being large hut little attention to stoking is required, and the pressure of steam does not greatly fluctuate on the road. The cylinders aic placed between the frames with one common steam chest, and are 7in. in diameter by Him stroke. The engine is carried by four coupled wheels 2ft in diameter, and the wheel base being only 4ft. 6in., the engine is enabled to go round curves of very small radius.; The exhaust steam—that hete noir of all tramway locomotive —may be dealt with in two different w ays. A water condenser consisting of several nozzles as in an ejector or bilge pump is placed on the footplate, and its auction and delivery are connected by means of copper pipes to opposite ends of a tank which is carried on the roof of the engine. The exhaust steam is admitted into the centre cone of the condenser, and is condensed in its passage through, at the same time sending the heated water up the delivery pipe to the top of the tank and drawing colder water from the bottom of the tank down the suction pipe. The process is continued until the whole of the water in the tank is raised to a temperature of from ISOdeg. to 200Jeg., and so long as the water in the tank remains below this temperature the exhaust steam is effectually disposed of. The tank holds 300 gallons, sufficient to last for a run of about ten miles. In order to meet cases where it is inconvenient to obtain sufficient water, or when the weather is comparatively warm, and the absolute freedom from visible steam is not insisted upon, another arrangement is provided, and has been found very efficient. By means of a three-way valve the exhaust steam, instead of being turned into the condenser, is directed through a nozzle placed at the bottom of a series of cones in the smokebox, and the hot air coming through the boiler tubes is brought into intimate contact with it, and absorbs so much of it that, except in very cold damp weather, the mixture of air and steam passes invisibly out of the chimney. The driving level’s are placed in the centre of one side of the engine, and are so arranged that the driver has simply to turn himself round to use them for running in either direction. The engine is fitted with a powerful brake, which is worked by the foot, so that the driver has at all times perfect and simultaneous control of the regulator, reversing lever, and brake, a moat important consideration in crowded thoroughfares. Steel, Lowmoor iron, and phosper-bronze are freely used in these, as in all the tram engines constructed by Messrs Merryweather, the workmanship being of excellent finish. The trial of the engine in question proved perfectly satisfactory, a very sharp curve being traversed with case, and the engine running quietly and smoothly, and being started and stopped at smart speeds with great promptness. Messrs Merryweather deserves credit for their enterprise in starting their light locomotive works at Greenwich, for to that enterprise must be largely attributed the rapid progress which has been made duiing the last few years in the use of steam on tramways. We mav add shat the engines are going out to New Z> a land in charge of Mr Charles A. Fsirlie, who will take the management of the Wellington City Tramways. |"WWII mi n.iw— irnni—ll—w ..