. American engineer and railroad journal . 10of Table I, and is graphically shown by the accompanying dia-gram. A more detailed explanation of Table I is as follows: Column 4 gives the coefficient of friction as reported to theconvention of 1906. Column 5 is the weight of the shoe at thebeginning of the wearing test. Column 6 shows the number of ap-plications made. Column 7 gives the total loss of weight in 8 gives the loss of weight per application. This equalsthe total loss of weight divided by the number of 9 shows the number of million foot-pounds absorbed
. American engineer and railroad journal . 10of Table I, and is graphically shown by the accompanying dia-gram. A more detailed explanation of Table I is as follows: Column 4 gives the coefficient of friction as reported to theconvention of 1906. Column 5 is the weight of the shoe at thebeginning of the wearing test. Column 6 shows the number of ap-plications made. Column 7 gives the total loss of weight in 8 gives the loss of weight per application. This equalsthe total loss of weight divided by the number of 9 shows the number of million foot-pounds absorbed perapplication. This is found by multiplying the pressure contact(2,208 pounds) by the coefficient of friction (column 4), by thedistance in feet passed over by the surface of the wheel duringthe application (1,640), and by dividing by one million. Column10 shows the million foot-pounds of work which can be done byeach shoe under conditions of test for each pound of materiallost. It is obtained by dividing the values of column 9 by those. 1 175 BOS 17» 16) lefe E09 I S3 I7S 172 £13 163 200 158 2£0 194 Number op- 3hog of column 8. That the values in column 10 vary between widelimits is best shown by the diagram accompanying. As to the significance of results.—In carrying out the tests allshoes were subjected to the same exposure to wear. Whetherthe relative results would be the same had the conditions of testinvolved lighter pressure or higher speeds than those which wereactually employed, is a question which the committee has not yethad time to determine. It is not impossible that a shoe giving arelatively poor performance under the conditions of the testwould show relatively better under some other conditions. If,for example, shoes are designed for specified service, it wouldperhaps be unfair to expect all to show at their best under asingle condition of operation. The probability is, however, thata shoe which is good under one condition of running will notbe bad under o
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectrailroadengineering
