. The railroad and engineering journal . ct, the parenthesis marks () are translated by the wordpermits or frees, which means that there is no interlock-ing ; in our notation, on the other hand, the bar or colonhas the advantage of representing graphically a real rela-tion of interlocking, without obliging the operator to sup-pose that the movement is made in order to be able towrite it on paper. Thus the arrangement : If aN, bR : cN unless dNor fN, which means that we can reverse c, ist, if a is re-versed ; 2d, if a, b, and d are normal ; 3d, if a, b, and <?are normal, would be written : (
. The railroad and engineering journal . ct, the parenthesis marks () are translated by the wordpermits or frees, which means that there is no interlock-ing ; in our notation, on the other hand, the bar or colonhas the advantage of representing graphically a real rela-tion of interlocking, without obliging the operator to sup-pose that the movement is made in order to be able towrite it on paper. Thus the arrangement : If aN, bR : cN unless dNor fN, which means that we can reverse c, ist, if a is re-versed ; 2d, if a, b, and d are normal ; 3d, if a, b, and <?are normal, would be written : (^n — a -\- b -\- d — a ^ 6+ ,)c. It may be asked whether the first notation, which con-sists simply in writing the relation as it is presented to themind, as it would proceed in practice—only replacing theusual words by some abbreviations—is not more simplethan the other, in spite of the advantage, more apparentthan real, which the last has of expressing reciprocalactions clearly and rapidly. It is possible that we mayN 0 6. e?iid b normal r, rcrnia] come to the conclusion, already suggested by MM. Hubertiand Flamache, that it is best to use one or the other nota-tion according to the case presented. As examples of the application of compound interlockingsystems we give below several apparatus recently installedin different yards to solve particular problems presented. I. S/. Denis Yard. Signal Post No. I. The track, c/,fig. 4, is provided with a stop-signal <7, which protects thepoint of the switch b, but which had to be placed beforethe switch f, because there was not room for it betweenthe two switches. The object is to cover b safely without *56o THE RAILROAD AND [December, 1888. delaying movement in the direction c e—that is, when coccupies its normal position, shown in fig. 4 by the blackshading, the signal a can only be changed when the switchb is not turned toward </.• but this interlocking relationmust not continue when c is turned in the directi
Size: 1739px × 1437px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, bookidrailroadengi, bookyear1887
