. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . of a piston backward-, andforwards in a cylinder. By this meansit is readily shown that the heat inthe furnace can be transformed intoenergy that is sufficiently strong tomove the piston against the resistanceincident to the weight of the locomo-tive and the load to which it may beattached. of 120 stro per minute. I hat is, the piston movesfrom the 11 of the cylinder to tck end of the cylinder and returnsgain, thus travelingIgh 40 inches of space, for one rev-olution of the driving wheels. Th
. Railway and locomotive engineering : a practical journal of railway motive power and rolling stock . of a piston backward-, andforwards in a cylinder. By this meansit is readily shown that the heat inthe furnace can be transformed intoenergy that is sufficiently strong tomove the piston against the resistanceincident to the weight of the locomo-tive and the load to which it may beattached. of 120 stro per minute. I hat is, the piston movesfrom the 11 of the cylinder to tck end of the cylinder and returnsgain, thus travelingIgh 40 inches of space, for one rev-olution of the driving wheels. The cal-culation for the Inn-, power is as fol-[1 80 per cent, effective pressure of 180His. is equal to 144 lbs. acting on theface of the piston. Area of piston 24 X24 X 7854 = 452 square inches X 144lbs. pressure taken as the average forthe full stroke = 65,088 lbs. X 4° 3 1/3 feet = 216,960 X 120 numberof strokes per minute = 26,035,200 foot-pounds per minute, divided by 33,000= 789 horse power. A locomotive con-sisting of two engines would on thiscalculation equal to twice this, or A 4-6-2 ON THE PARIS-ORLEANS RAILWAY. In calculating the horse power ofsteam engines it must be rememberedthat the pressure of steam is not equalduring the entire length of the strokeof the piston. Not only is the initialpressure in the cylinder lower than theboiler pressure, but the tendency is toa further decrease on account of therapid cooling of the metal of the steamchest and cylinder. Furthermore asthe slide valve closes some distancebefore the piston has completed itsstroke, a considerable allowance mustbe made for this decrease from theboiler pressure, even when the valve isin full travel. The ratio of loss usuallyallowed is equal to twenty per cent.,so that eighty per cent, of the pressureof steam in the boiler is reasonableallowance in calculations of this the case of a locomotive wherethe pressure in the boiler may beat 180 lbs. per square inch, the cylindersmeasur
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectrailroa, bookyear1901
