Cyclopedia of locomotive engineering, with examination questions and answers; a practical manual on the construction care and management of modern locomotives . , gives 44*6 lbs. asthe uncorrected rate. The distance D to A, where*the compression curve intersects the consumption line,!/is in., and the total length of the diagram C to Efis in. Then 44-6 x + 3-375 = 35 lbs- as th^corrected rate. Theoretical Clearance. The expansion and compresision curves of a diagram are created by the expansioiand compression of all the steam admitted during th|stroke. This includes the steam
Cyclopedia of locomotive engineering, with examination questions and answers; a practical manual on the construction care and management of modern locomotives . , gives 44*6 lbs. asthe uncorrected rate. The distance D to A, where*the compression curve intersects the consumption line,!/is in., and the total length of the diagram C to Efis in. Then 44-6 x + 3-375 = 35 lbs- as th^corrected rate. Theoretical Clearance. The expansion and compresision curves of a diagram are created by the expansioiand compression of all the steam admitted during th|stroke. This includes the steam in the clearand THE INDICATOR 239 space as well as in the cylinder proper. It is evident,therefore, that the volume of the clearance is one ofthe factors controlling the form of these curves, andwhen the clearance is known a correct expansion orisothermal curve maybe theoretically constructed, aswill be explained later on. Also, if the actual curves,either expansion or compression, of a diagram assumean approximately correct form, the clearance, if notalready k*iown, may be determined theoretically fromthem; although too much confidence should not be put. Figure 111 in the results, as they are liable to show either too littleor too much clearance, generally the latter, especiallyif figured from the compression curve. For the benefit of those who may desire to test thismethod of ascertaining the percentage of clearance oftheir engines, several illustrations will be given of itsapplication to actual diagrams taken from engines inwhich the clearance was known. Fig. hi is from an engine in which the clearancewas known to be 5 per cent. As compression cuts but 240 LOCOMOTIVE ENGINEERING a very small figure in this diagram, the expansioncurve alone will be utilized for obtaining the theoreticalclearance, and the process is as follows: Select two points, C and R, in the curve as far apartas possible, but be sure that they are each within thelimits of the true curve. Thus C is located
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectlocomot, bookyear1916
