This Special Committee met the same obstacle-the lack of information concerning earth pressures and pipe loading—and are now awaiting results of experiments at Iowa Agricultural College before reporting, which experiments will probably require another year to complete. Your Committee has confined its investigation to the application of reinforced concrete pipe and finds it of general use among railways. The majority of the roads prefer to purchase under approved specifications from reputable manufacturers rather than to attempt its manufacture. It is reported that the principal advantage is its cost, particularly under war conditions, when it could be obtained at a figure greatly under that quoted for cast iron. The greatest objection to its use is the excessive weight of the individual piece, chiefly in the large diameters, which often necessitate work train and derrick for placing, thus increasing the cost. Preference is expressed for the circular section rather than for oval section, as in many cases the oval section has been laid with flat side down, which resulted in failure. The circular section, properly designed and manufactured, eliminates this difficulty. Some favor pipe culverts only at unimportant openings and limit the maximum diameter to 36 in., as above that size a concrete box, affording a greater waterway, may be constructed at practically the same or less cost. Your Committee concludes that where cost and other essential items are equal, there is no particular advantage in using reinforced concrete pipe in preference to other approved forms of culverts. In view of the joint investigation of the subject now under way by a Special Committee of other societies, your Committee recommends the Masonry Committee be permitted to conclude the subject for this Association at such time as may be proper, and that your Committee be relieved of the subject. Appendix I (9) THE EXCESSIVE COST OF MAINTENANCE DURING THE EARLY PERIOD OF OPERATION C. C. CUNNINGHAM, Chairman; R. C. GOWDY, F. RINGER, W. M. JAEKLE, Sub-Committee. There has been considerable amount of thought spent on the part of the various engineers of the various railroads of the United States relative to the question of the increased cost of maintenance of roadway and track during the early periods of operation of newly-constructed lines. This question involves a good many factors and must be carefully studied as it is applied to railroads built in different localities. In order to develop information as to whether the cost of maintenance is greater during the early periods than it is during the later periods of operation one must necessarily compile cost data for two lines of railroad which the length and physical conditions are essentially similar. The new lines should be compared with a line which has been in operation under similar traffic for a period of several years and where the track and roadbed have become fairly stabilized. The physical and topographic conditions vary so greatly in different parts of the country that this is a subject which has to be approached with a great deal of care as in many places it would be difficult to find two lines of railroad which are closely comparable. When determining the difference in cost of maintenance during the early period of operation of one line with another, one should also take great pains to see that the methods and standards followed in construction are approximately identical. One should not attempt to compare a line built for Class A, main line traffic, and one built to handle secondary or branch line traffic. If the natural surface and the soil is of a stable nature one would be lead to expect that if the new roadbed were well built that the early cost of maintenance due to the solidification of the roadbed would not be excessive. However, a comparative study might introduce either elements which would make a change. A number of railroads have been compiling data in order to develop this information but their study has not as yet reached a concrete form. For the consideration of the members of the Association we are submitting Forms "A" and "B," which may prove of value in a study of the subject. The methods now in vogue on different railroads in compiling cost of maintenance in compliance with the instructions of the Interstate Commerce Commission are of sufficient extent to enable one to arrive at a correct result, provided these methods are followed intelligently. Form A STUDY OF EXCESS MAINTENANCE COSTS INCIDENT TO SOLIDIFICATION AND SEASONING OF ROADBED AND TRACK Roadway Miles on bottoms or overflow land. Average height of fills......: Maximum Grade....: Length of Maximum Grade.. Roadway Miles in cuts.... : Roadway Miles on fills. Topography of Country Traversed: Low Swampy, River Margin, Valley, Rolling, Prairie, Plains, Hills, Plateau, Desert or Mountains. Is line with or across drainage or on ridge? Supporting Power of Natural Surface as Foundation for Roadbed and Track: Soil: Solid or soft, stable or unstable? Have slides or subsidence occurred and if so to slight or heavy extent? Silt, Clay, or Loam? Sandy Silt, Clay or Loam? Sand, Gravel, Loose Rock, etc.? Ballast: Temperature range...... In cuts?.. Approximate average present depth of ballast on fills in inches under tie.. .... .... Approximate average annual rainfall in inches. In cuts in inches under tie. show the estimated quantities and reproduction costs Total cost. S. R. cu. Total cost. Where original yardage and costs can not be ascertained, reported by the Bureau of Valuation. Report quantities and costs for the full line under study, covered drains. Original or estimated reproduction cost.. Com. cu. yds... yds... Total cost.. Total cost. Remarks: Other Characteristics or Local Conditions Which May Have Influenced Maintenance. Characteristics of Line Used to Develop Normal Costs, if Separate Line was Used. Date opened for operation. : Other Tracks. |