. Baltimore and Ohio employees magazine . example of the usualconstruction of second track in this case it is assumed that the oldballast is in such a state that it is uselessand it is decided to create the new sub-grade on level with the top of the oldballast. It is apparent that of the 22 THE BALTIMORE AND OHIO EMPLOYES MAGAZINE old ditches will become reservoirs forthe collection of water unless a systemof drainage as outlined is provided. Thenecessity is made more imperative whenthe subgrade is of clay or other materialwhich holds water. Figure 5 is an example of what mayhapp
. Baltimore and Ohio employees magazine . example of the usualconstruction of second track in this case it is assumed that the oldballast is in such a state that it is uselessand it is decided to create the new sub-grade on level with the top of the oldballast. It is apparent that of the 22 THE BALTIMORE AND OHIO EMPLOYES MAGAZINE old ditches will become reservoirs forthe collection of water unless a systemof drainage as outlined is provided. Thenecessity is made more imperative whenthe subgrade is of clay or other materialwhich holds water. Figure 5 is an example of what mayhappen when the construction of secondtrack is in a cut and upon a curve. The it the most undesirable material to use ifit is placed in such manner as to be higherthan the original subgrade. Such materialshould preferably be used to widen the fillbelow the original subgrade and materialsecured for top fill which will not damup water underneath the ballast. Slips often occur in material whichhas been placed on embankments to Ttone. ^otlla-^T. le Wtfli. Track- FIGURE 5 old ditches have become have worked on the trackraising and re-raising and in the mean-time the subgrade has assumed suchshape that the only permanent cure isdrainage as outlined. The necessity of raising the tops offills with additional material is onewhich cannot be avoided. Usually thematerial most easily available is used,this often being material taken from sideditches in cuts and which from the verynature of its existence in the ditch makes widen them out to a sufficient extent tohold ballast. These slips will occur eventhough care is taken to keep below sub-grade and use proper material. A prac-tice should be followed in constructionof new embankments, of providing extratop width and consequent extra fill,sufficient to make unnecessary any widen-ing of fill after settlement. The settle-ment can then easily be corrected by theapplication of a top fill of suitable mate-rial to av
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbaltimo, bookyear1912
