TIPS FOR STEAM-WAGON DRIVERS.
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Information of Outstanding Interest to Those in Charge of Steam Vehicles.
-NTOST drivers of steam wagons will .111.readily understand that it is impossible to get lubricating oil into the steam cylinders by means of ordinary oil cups, as any such proceeding would be prevented by high-pressure steam within the cylinder pushing the oil out again. In order to overcome this difficulty, all steam wagons are equipped with some form ot mechanical lubricator embodying a pump, which is able to overcome the pressure of the steam and force the lubricant into the. cylinder. This oil is not delivered direct on to the parts which actually need it, such as the face of the slide valve or the surface of the piston and cylinder walls, but is caused to mingle with the steam, so that the latter is oily and effects the lubrication of these important parts itself.
This mechanical pump, states "E.J.," of Sandbach, does not often go wrong, and even if it does, the driver will find that, provision has been made by the manufacturers against such a contingency. An emergency lubricator is fitted on to the high-pressure side of the Foden wagon. Its exterior is familiar to most drivers: some no doubt have made them:. selves familiar with its interior anatomy, too.
Its operation is as follows :—When the valve on the top of the lubricator is opened steam enters the lubricator through a very fine jet, and, as it enters, is condensed, thus forming water which, being heavier than -the oil, sinks to the bottom of the lubricator and forms a layer of water there. As this layer of water increases in depth it forces the oil through the feed pipe, which makes its exit near the top of the lubricator and paves thence into the cylinder.
To fill this lubricator, begin by opening the bottom drain tap, which will allow any water which happens to be con tained therein to escape. Then close the bottom valve and pour in oil until the reservoir is about seven-eighths full. Be careful never completely to fill a lubricator of this type, but always leave room for the oil to expand, which it will do, of course, as it is heated.
If this precaution be not taken there
is *a grave risk of the container being burst by the expanding oil. After filling, regulate the flow of oil by screwing down the top valve until it is shut, and then turning the handle back again about one
eighth of a revOlution. If more than this be allowed the oil will feed too freely and be wasted.
When the engine is working in the ordinary way—that is to say, compounded—the oil passes first to the H.-P. cylinder and then, with the steam, reaches the L. .P. cylinder and lubricates its parts. When, however, the engine is not compounded—when it is working double high-pressure, for example—or when, owing to some mishap, the lowpressure cylinder only is in use, then there is no nieans.of lubricating the moving parts other than the special lubricator which is provided for the purpose and which must be set in operation whenever either of the two conditions named above exists. This emergency lubricator, on the L.-P side, works on the same principle as that on the top of the H.-P. cylinder, and must be filled and adjusted in the manner already 'described in connection with the smaller cylinder.
THE drawing of a traction engine, re produced frem a sketch which we have received from " G.H.P.," of Deptford, illustrates this correspondent's method of getting an engine of this type up a steep hill the surface of which does not afford the necessary grip for the driving wheels. Apparently he carries as part of his regular equipment all of the following items, which are of use whenever the wagon is in the predicament be describes, or ditched, or otherwise in trouble :—Tow chain, single-pulley block. strong C-hook made of 2-in. steel, a. baulk of hard timber 5 ft. long, and either 4 ins. by 8 ins. or 4 ins. by 12 ins.
• a pick and a spade.
The engine winding drum is that put in shape for use, 4nd all the wire rope but two or three coils is run off. The single block is fastened to the front coupling of the engine, as shown in the sketch, and the rope passed through it in such a way that it is kept from rubbing against the front wheel or the fore part of the engine. Pull the rope straight forward, and put the C-hook into the existing loop on the end of the
rope. Now calculate the proper location of the trench which is shown On the sketch by reckoning that the tow chain is to pass right round the baulk once and the two ends fastened to the C-hook.
Then, using the pick and spade, dig a trench long and wide enough to accommodate the baulk and just so deep as is judged necessary in order to ensure that the engine will be pulled right out of the bad place, or up the hill, without it being likely to lift the baulk out of its trench, The rest of the job will be easy, and the method of doing it can readily be ascertained by referring to the illustration which is reproduced.
, IN THE case of the Foden Wagon which came into the hands of " L.M.R.," of Grantham, the friction driving gear of the pump had worn so badly that it refused to work. The usual alternative is to fit a new wheel ; hut, as this involved rather a considerable loss of tine, as well as being expensive, this corre spondent thought he would try the effect of truing up the driving wheel in place. He accordingly examined it, and found that the V-projections in. the small wheel were bottoming in the corresponding grooves in the other, instead of the sides of the grooves bearing upon one another. He, therefore, hammered all round the top of the projection, thickening it up. Then he set the engine in motion slowly and trimmed the edges up with a scraper. This temporary repair has now been completed about six months, and our correspondent informs us that it is still giving every satisfaction and appears to be good for some little time to come.