H ILLINOI S UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN PRODUCTION NOTE University of Illinois at Urbana-Champaign Library Large-scale Digitization Project, 2007. ::r:: ·-·-·.;.~- ;; a:./1 ·, i ::1:~ .i i:: ~,:_~~N~U:E hI tfi -·;-~-4 ~ XI ;"' :`·tEnfared rssa8o~elsar-matt~:~P ,r + ·:-:_·r·I :a : ·i-~--. r; fi ·:~ \·-e · - :::c ;: 3:·-: -i:1 r- ·II_ ·;-' i ~1· :~rail~ ;x ::~: .~3:·~ := :5··_:- i~~~·~'::-· · ;r -·iW1--: , ·vi:a~t 1.1:.4. ,·-i:~~e 4;;' (, ~::: : "- ~,~~,~,- tt~r~~-~4 .~"-~ :rrr- :~~:: BULLETIN No. 74 NGINtEERING EXPERIMENT STATION D BY tHR UN asIst OF I.LINoM, TtIIBAXAý 'EUoAan AaIAr CA HA", LT, LoNDox ________________ '. A:.~ A: A:: i:~i A AA " LA- A A A A-: A A - A A-· A ~~-~· A Aa A-W ·EtC 'J A A A AO1ZN ifA . UNIVERSITY OF ILLINOIS BULLETIN 2 AA- ISStUE W.O.Lr Vol. X 1 1APRIL IS, 1914 No. 33 ['Enter*ed asgecond-clags matterJDeo. 11na, 19t1, o a o i t Ubana, . under the At of Aug. 12 THE TRACTIVE RESISTANCE OF A 28-TON ELECTRIC' CAR BY HAROLD H. DUNN "I-,-~" '· :-;· -;- .is ii:? ·-:."- :':l·S: · -··-: _:: : i- i;.-. ":: ;i· -;i;; i- :' -. ~: ~;::I: :::;--:::;j:: 1: -·~--:I:;; -. -; i - t·.~ -~---I i ,i: a .k :;.-I~?:-·.-1..·-·L· ~-: ·--· :;· i:z·~3 -T::-.d:·* -Yi ~a·I: In :~ ·--:-" ;d·-~ :"-" u, Ib·::"r"-~:"i- 3 '4 IHE 'gineering ExperiIment Station wa established by act of the Board of Trustees, December 8, 1903. It is the purpose of the Station to carry on investigations along various lines of engineer- itg ,and to study problems of importance to professional engineers and to the manufacturing, railway, miBing, constructional, and industrial iterests of the State. The control of the Engineering Experiment Statioi is ested in the heads of the several departments of the College of Engineering. These constitute the Station Stat and, with the Director, determine the char- ater of the investigations to be undertaken. The work is carried on ander the supervision of the Staff, sometimes by research ellows as graduate work, sometimes by members of the instructional sta of the College of Engineering, but more frequently by investigators belonging .to the Station corps. The results of these investigations are published in the form of bulletins, which record mostly the experiments of the Station's own sta of investigators There will also be issued from time to time in the form of circulars compilations ging the results of the experients of engineersu, industrial vorks, technical intitutio, an gvernmental testing departments. The volumi e and n-amb at the top of the title page-of the cover are merely arbitrary numbers abd refer to the general publications of the Univeraity ol Illinois; either abovethe title 'or below Ase seal is given e number of EngineeringEprimet. Station Wlti* ocircular, ^ which, sdd bi -wed in mferring to thee pplications. For eopie' of _belletinS, ercule4;, or rotbr information addrw the Vagineering Rxperiment Stations, Urban&, Ilinois. S 1- '3. 4,, 1; 4;^,.^ 'AyS 3i,3 4 4 "i'k- 4 4, 4' 4.^ ^*.e..^a ^t'v ^^i1-^'/ *'f^.,'?^^.^'--^-^ >1' -'1'' 4-, 4, As ~ UNIVERSITY OF ILLINOIS ENGINEERING EXPERIMENT STATION BULLETIN No. 74 APRIL, 1914 THE TRACTIVE RESISTANCE OF A 28-TON ELECTRIC CAR BY HAROLD H. DUNN, Assistant in Railway Engineering, Engineering Experiment Station CONTENTS PAGE I. Introduction ........................................... 3 1. P urpose ..................... .. . .............. 3 2. Definition of Terms ............................. 3 3. Acknowledgments ............................... 3 II. Summary................. .......... ............... 4 III. Means Employed in Conducting the Tests................ 5 4. The Electric Test Car ........................... 5 5. The Recording Apparatus ........................ 5 6. T he T rack ..................... ............... 5 IV. Test Conditions and Methods of Test ..................... 6 7. Test Conditions ................ ................ 6 8. Calibrations ...................... ............ 7 9. General Plan of the Tests........................ 8 10. Group A ................. ..................... 11 11. Group B .................................... 14 12. G roup C ...................................... 15 V. Results of the Tests ................ ..... ........... 17 13. Results of the Individual Tests ................... 17 14. Results of All the Tests .......................... 18 15. Discussion of the Final Results .................... 20 16. - Comparison with Other Experiments. .............. 22 Appendix I. The Electric Test Car......................... 23 Appendix II. Methods Employed in Calculating the Results .... 30 Appendix III. The Results of the Individual Tests. ............ 35 THE TRACTIVE RESISTANCE OF A 28-TON ELECTRIC CAR. I. INTRODUCTION. 1. Purpose.-Three series of tests have been conducted by the Railway Engineering Department of the University of Illinois to deter- mine the resistance offered to the motion of a 28-ton electric interurban car running on straight, level track, in still air at uniform speed; and to ascertain the relation existing between that resistance and the speed of the car. The first part of this bulletin describes the purpose, methods, and final results of the tests, but all details not essential to an under- standing of the general methods and results are excluded. In the three appendices details are given concerning the apparatus, the methods of calculation, the test data, and the intermediate results. 2. Definition of Terms.-By the terms "resistance," "train resistance," and "car resistance" used in this bulletin is meant the number of pounds of tractive effort required at the rims of the driving wheels for each ton of train or car weight, to keep it moving at uniform speed on straight level track in still air. Such resistance data is employed in determining railway motor capacity, power consumption, and possible schedule speeds of a car or train of cars. 3. Acknowledgments.-The interest and co-operation of the officials of the Illinois Traction System have made it possible to carry out these tests over the lines of that road, and members of the Railway Engineer- ing Department staff who have been concerned with this investigation thoroughly appreciate such interest and assistance. The tests were planned by Professor Edward C. Schmidt, in charge of the Department of Railway Engineering, and they have been carried out under his general direction and supervision. He has also directed the work of the final computations, and reviewed the manuscript of the report. The tests of groups A and B were made under the direct super- vision of Mr. Edgar I. Wenger, formerly Associate in the Department of Railway Engineering, and the preliminary calculations for these tests were made under his direction. The tests of group C and their prelim- inary calculations were made with the assistance of Mr. Daniel C. Faber, formerly a Research Fellow in the Engineering Experiment Station. ILLINOIS ENGINEERING EXPERIMENT STATION II. SUMMARY. Eighteen tests made on selected sections of tangent track are described. The track upon which the tests were made is of good con- struction, such as one would expect to find on the better grade of inter- urban electric railways. The weather during the tests was generally fair. The average temperature was not below 250 F., and the wind velocity did not exceed 26 miles per hour. The test car used is described in detail in Appendix I. The general plan was to run the test car backward and forward over the chosen track section at a variety of speeds, but maintaining approximately the same constant speed during each pair of opposing runs. The tests comprise in all 269 resistance determinations of which 131 have been calculated from runs during which the wind opposed the motion of the car, 130 from runs during which the wind helped the car, and 8 from runs made when no wind was blowing. During the two tests of group A, comprising 45 resistance determinations, opposing runs have been separated by a considerable time interval during which wind and weather conditions might change; but through changes made in the method of making the tests, opposing runs for the remaining tests have been separated by a small time interval. Each test, consisting of a number of "runs," resulted in a number of values of average net car resistance which have been plotted with the corresponding average speed, giving diagrams such as Fig. 3. Through the two groups of points representing the results of runs in opposing directions, curves have been drawn between which a final mean curve has been decided upon. By this method wind resistance has been elim- inated as nearly as may be from the results. The curves thus determined have been accepted as the results desired from the individual tests and have been grouped in Fig. 1. A final mean curve has been drawn there and repeated as Fig. 2, which represents the average relation between resistance and speed for all the tests. The results of the individual tests are shown in Figs. 10 to 19 and Tables 3 to 12, inclusive, in Appendix III. The final results of the investigation are presented in Fig. 1, Table 2, and in formulae 1 and 2, page 20. It is believed that Fig. 1, Table 2, and formulae 1 and 2 provide expressions for the mean relation between the speed and the resistance of the car to which these tests apply, when it runs on tangent level track of good construction, at uniform speed, and in still air. The DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR greatest variation from these mean values under these conditions was about 9 per cent. If application is made of these results to predict the resistance of any car of similar design and weight it should be borne in mind that the results apply to tests made with a car whose running-gear was in excellent condition, and that the tests were run in weather when the temperature was above 250 F. III. MEANS EMPLOYED IN CONDUCTING TTIE TESTS. 4. The Electric Test Car.-The data for this report have been obtained by means of the electric test car belonging to the Railway Engineering Department of the University of Illinois. It is a standard 45-foot interurban car of the double end type, weighing, complete with equipment, 55 150 pounds, subject to correction on account of changes in the equipment at different times. The cross sectional area of the car body and trucks is 90 square feet. The motor equipment consists of four 50-horsepower, axle mounted, number 101-D Westinghouse direct current motors, geared to the axle in the ratio of 22 to 62. The Westinghouse unit switch system of multiple control is used. The trucks, which are of the C-60 type of the Standard Motor Truck Company, are placed 23 ft. 3 in. between centers and have a wheel base of 6 ft. 4 in. The wheels are 33 in. in diameter and have the standard Master Car Builders' tread and flange, and the journals conform to the 41/4 in. x 8 in. standard of the same association. A more complete description of the car will be found in Appendix I. 5. The Recording Apparatus.-By means of the apparatus within the car a continuous graphical record of current, voltage, speed, time by 5 second intervals, distance traversed, brake cylinder pressure, and location on the road may be kept. These records are drawn upon a chart 40 inches wide which is made to pass under the recording pens at a rate proportional to time or distance. Other data taken during this investigation, but not recorded upon the chart, are described on page 11. Fig. 9 shows a copy of a portion of the chart from test 121. The transverse lines which mark one of the sections selected for calcu- lation and some of the explanatory lettering do not appear on the original record, and the records as shown in Fig. 9 are grouped more closely together than on the original chart. A more complete description of the recording apparatus is to be found in Appendix I. 6. The Track.-This investigation was carried out on the tracks ILLINOIS ENGINEERING EXPERIMENT STATION of the Illinois Traction System between Danville, Urbana, Champaign, Decatur, and Springfield-a single track line of good construction over which an hourly service is maintained between the points named. That part of the line between Danville and Urbana, 32 miles in length, was laid during 1903 and 1904 with 70-pound A. S. C. E. section rails except for 9 miles near Urbana, where 60-pound A. S. C. E. 1901 section rails were in use at the time these tests were made. All rails were laid on oak cross-ties spaced about 24 inches between centers and ballasted with gravel and cinders. This track had between 2 and 3 years in which to become settled before the tests were started. The track between Champaign and Decatur was laid in 1906 and 1907 with 70-pound A. S. C. E. section rails laid on oak, elm, and chestnut cross- ties spaced about 24 inches between centers and ballasted with gravel. When tests were made over this track it was well settled and in first- class condition. The line between Decatur and Springfield was laid in 1905 and is in all respects similar to that between Champaign and Decatur, except that part of the track is ballasted with cinders. A survey of the Danville-Urbana line was made by the Railway Engineering Department of the University immediately preceding these tests and the results expressed in a profile drawn to a scale of 1/-inch to 100 feet. Elevations were taken on the north rail to 0.1 ft. at stations 300 feet apart, and turning points were taken at every fourth station where levels were read to 0.01 ft. The exact distances between all trolley line poles were recorded and incorporated in a table from which all distances, such as those between section limits, were determined. For the purpose of this investigation certain long sections of com- paratively level and well ballasted tangent track on the Champaign- Decatur-Springfield line were selected and surveyed by the Railway Engineering Department of the University. The results of these surveys were expressed in profiles, drawn to a scale of 1/-inch to 100 feet, which were used in making the calculations. IV. TEST CONDITIONS AND METHODS OF TEST. 7. Test Conditions.-The tests were all run during moderate weather. With four exceptions they were made on clear days only and on dry track. Data in regard to wind velocity and direction were obtained from United States Meteorological stations at Urbana, Springfield and Peoria, and during one group of tests, designated as group "C," these data were supplemented by wind determinations made by means of a portable wind vane and anemometer set up beside the test track. Tables 3 to 12 inclusive in Appendix III show that the approximate DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR average wind velocities prevailing during the tests varied from 0 to 26 miles per hour. The lowest average air temperature recorded during any test was 25° F., and the highest recorded temperature was 80° F. TABLE 1 A SUMMARY OF TEST CONDITIONS 1 2 3 4 5 6 7 Approximate Wind Data Approximate Teat No. Weight of Car Average Rail and Load Air Condition Average Average Veity Temperature Direction Velocity Parallel to Test Track Pounds Deg. F. M. P. H. M. P. H. 15-16 56 600 40 Dry S. of W. 7.2 7 23-24 56 250 70 Dry S. W. 15.1 11 73-74 56 650 40 Wet N. of W. 10.0 9 77-78 56 800 40 Dry N. W. 12.0 12 91-92 56 350 45 Dry S. W. 26.0 24 95-96 56 350 65 Dry N. W. 16.0 15 109-110 56 950 55 Wet S. W. 18.0 13 111-112 56 350 55 Wet S. W. 18.0 13 113-114 56 200 55 Dry S. W. 10.0 7 117-118 56 200 25 Wet .S. W. 12.0 9 119-120 56 750 45 Dry W. of S. 3.5 2 121-122 56 750 30 Dry E. of N. 3.0 2 123-124 56 750 30 Dry S. E. 4.0 3 125-126 57 350 35 Dry S.W. 15.0 10 127-128 57 500 25 Wet 0 0 129-130 57 350 65 Dry S. E. 15.0 10 141-142 57 800 40 Dry W. 3.8 3 153-154 57 900 60 Dry 0 0 The track sections selected for the tests are all straight and they vary in length from 250 to 10 000 feet. The majority of the tests were made on sections varying in length from 1000 to 1500 feet. Other requirements to be met by the sections were that the grade should be comparatively light and uniform, and that the track should be well ballasted and in good condition. While on the road the car was always in charge of a regular train crew provided by the Illinois Traction System. 8. Calibrations.-Preceding the commencement of the tests, all instruments were calibrated and at intervals during the investigation check readings were taken by means of indicating instruments in the same circuits as the recording instruments. Wherever possible, the results of these calibrations were expressed in the form of equations or tables as well as curves, and in making the calculations one of the two former was used in place of taking readings from curves. Owing to changes made in the apparatus during the tests, more than one calibration was necessary for several of the instruments. ILLINOIS ENGINEERING EXPERIMENT STATION 9. General Plan of the Tests.-The test car records give quantities from which the gross resistance offered to motion of the car over a given section of track must first be calculated. The result desired from each run is that element of gross resistance which is always operating to retard a moving car or train; namely, the net resistance on straight and level track, at uniform speed, in still air. The other elements, one or more or none of which may be acting with the net resistance to form gross resistance, are: Resistance due to grade, resistance due to acceleration, curve resistance, and wind resistance (as distinguished from still air resistance). The tractive effort consumed by grade and acceler- ation may readily be determined by calculation, and the tests herein reported were so planned as to eliminate the two remaining elements. Curve resistance has been eliminated by selecting for calculation only those sections of chart made while the car was running on straight track. It is thought that by the procedure explained below the effect of wind resistance upon the final result has been reduced to a minimum. The car was first run in one direction and then in the other over a given track section, at as nearly uniform speed as possible. A series of such runs, made at speeds varying through as wide a range as possible. constituted a test. Each run results in a value of average net car resistance which, when plotted with the corresponding average speed, becomes one point on a resistance-speed plot such as is shown in Fig. 3. By the to and fro motion of the car the wind alternately helps and opposes its motion and thereby decreases or increases its resistance. The resistance values from each test therefore fall into two groups, one of which represents values of resistance running with the wind, while the other represents values running against the wind. In the figures, those points applying to runs with the wind are shown as solid dots, while the points applying to runs against the wind are shown as open circles. By methods which are described on pages 13 and 14, a mean curve has been drawn in each figure which represents the values of resistance with the influence of wind eliminated. These mean curves have been accepted as the desired resistance curves for the individual tests and have been grouped together as Fig. 1. An average curve obtained from this group, by the method described on page 20, has been repeated as Fig. 2 and accepted as the final curve of resistance for this 28-ton electric car under the conditions described. As a result of slight variations in the methods of conducting the tests, they fall into three groups designated as A, B and C, which differ in the effect their conditions have on the assumptions regarding wind DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR (I t~ PR I-I • - : ::: i::::: - : ,== = ^"ES^ _______I V^3d --- --- _ ..3 . . ..__ _. . . . 1- -- ---- - _ _ _ _ _ _ _ _ _ - _ "S B- _--3:)N I.I- - -.- - _ - lll ILLINOIS ENGINEERING EXPERIMENT STATION - ----~---------- - -- - ------------------l - - - - - - - - - - - - - - - - - _ - - - 4 - -a: I f NO~L~dt9,~N 9s~~w~ _ _ \ I I]_ _ - ! - _I . . .._ _ , _ _ _ _ _ DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR resistance, in the methods of obtaining certain data, and in the speed range. 10. Group A.-Those tests comprised in group A were through runs from Urbana to Danville, 32 miles, and return. During any test of this group only one set of opposing runs was made on any given section and such opposing runs were separated by a considerable time interval, since it took over an hour to run from Urbana to Danville or to return. Test 23-24 is characteristic of this group. The results are shown in Table 4 and Fig. 11, which has here been repeated as Fig. 3. The recording apparatus was kept in operation throughout the trip and the following data recorded graphically upon the chart: a. Current used by the motors. b. Trolley line voltage. c. Speed of the car by electrical recorder. (See App. I.) . d. Time by 5 second intervals. e. Location upon the road. f. Distance by 50 ft. intervals. g. Brake cylinder pressure. The following data were taken but not recorded graphically.: h. Average wind velocity and direction. k. Air temperature. 1. Rail condition. m. Weight of car and load. Item e, the location of the car on the road, by means of which it is possible to correlate any position of the car with the profile of the road, was made by marking upon the chart the position of numbered trolley line poles, stations, or other markers as they were passed by a given point on the car. The brake cylinder pressure, item g, was recorded in order to make it possible to distinguish and to avoid those periods during the tests when the brakes were applied. Data regarding average wind velocity and direction, item h, were obtained from United States Weather Bureau Stations. Fig. 9, page 27, has been reproduced from a tracing of a portion of the chart for test No. 121. Sections of chart were selected for calculation by comparison of the profile and chart as described in Appendix II. In general, the requirements to be met by the chosen chart sections are that the car shall be running on straight track, that no brake applications be made, that there be no heavy grades between the section limits, and that there be no considerable voltage, current or speed variation. They were chosen ILLINOIS ENGINEERING EXPERIMENT STATION so that the speed range covered was as large as possible and so that the number of sections from an east bound trip (Urbana to Danville) would be balanced by the same or approximately the same number from the west bound trip. In this way the number of resistance determina- tions made from data taken during runs against the wind were balanced by an approximately equal number from runs with the wind. From test 23-24, for example, fourteen sections were chosen from the east bound and thirteen from the west bound trip. In all the tests reported in this bulletin the variations in speed in passing the track sections have exceeded 2 miles per hour in only 28 per cent of the total number of resistance determinations, and in only 24 cases out of 269 has this speed variation exceeded 5 miles per hour. The maximum variation over any section was 9.95 miles per hour. Each of the chosen chart sections has afforded, through calculations made with the data there recorded, a value of average net car resist- ance. The calculations are described in Appendix II. The steps in the process are here stated briefly. The average values of current and voltage were found for each section by determining the average ordinates of the curves. This data, with the time required for the car to pass the track section, and the efficiency of motors and gears at the above current and voltage, made it possible to calculate the energy in foot pounds delivered by the current to the driving wheels of the car. The energy thus determined was then corrected for grade and acceleration resistances, thereby giving the net energy absorbed by car resistance, from which the average net car resistance in pounds per ton was readily obtainable. In order to make the grade correction it was first necessary to determine the elevation of the center of gravity of the car as it entered and again as it left the track section. The correction for accel- eration was calculated from the speeds determined by the heights of the speed curve at the points of entrance and exit. For this purpose determinations were made of the force required to produce accelerations in the rotation of the revolving parts as well as of the force required to produce the acceleration in the motion of translation of the car as a whole. From each test a number of chart sections have been chosen and, as has been stated, each section has resulted in a value of average net car resistance which has been plotted with the corresponding average speed, thereby giving diagrams such as Fig. 3. Due to the method of selecting chart sections from opposing runs, the points on each such resistance-speed plot fall into two groups as previously explained. The DUNN-RESISTANCE OF A 28-TON ELECTRIC OAR numbers beside the points are the item numbers from the tables in Appendix III. In drawing the curve to represent the results of the individual tests the two groups of points were first considered separately and a curve drawn for each. Thus, for example, curve A, Fig. 3, was drawn to represent the relation between resistance and speed for all the runs of test 23-24 during which the wind opposed the motion of the car, and curve B for the opposite condition. In order to draw these curves the plotted points were considered as being subdivided into a number of smaller groups, for each of which averages of speed and resistance were determined and plotted. Through the points representing these averages FIG. 3. THE RELATION OF RESISTANCE TO SPEED FOR TEST 23-24. the curves were drawn. The groups of points were chosen so that the resulting average points would be distributed at about equal intervals throughout the speed range. The next step was to draw a mean curve such as C, Fig. 3, which would represent the relation existing between resistance and speed in still air. Since investigations indicate that the resistance offered by wind varies with the square of the speed, an arith- metical mean would not satisfy the conditions. Accordingly, an equation taking account of this fact has been derived (see Appendix II, page 34) and by means of it the ordinates of points on the mean curve have been calculated from the ordinates of the A and B curves at the same speed. The mean curves drawn by this method agree much more closely ILLINOIS ENGINEERING EXPERIMENT STATION than do those curves drawn as arithmetical means between the A and B curves, and it has consequently been assumed that the method used has resulted in curves more accurately representing the resistance in still air than would have been obtained by using the arithmetical means. The six curves thus obtained from tests of groups A and B, and the four from group C which were drawn by another method, were then superimposed upon each other in order to determine the characteristic form, and the individual curves were then modified to conform to that general shape. The curves drawn in this manner have been accepted as the results desired from the individual tests. In group A there are two tests, namely 15-16 and 23-24, comprising together a total of 45 resistance determinations. The results are shown in Figs. 10 and 11 and Tables 3 and 4 in Appendix III. 11. Group B.-The tests belonging in group B differ from those in group A in the method of making the tests and in the effect this change in method has upon the assumptions regarding wind resistance. Whereas opposing runs from tests of group A were separated by a considerable time interval during which wind conditions might change, the tests of group B were planned so that the time interval between opposing runs would be as small as possible. A well kept section of track 1495 feet in length and located on the Urbana-Danville line was chosen for this purpose. The limits of this section, between which there was a difference in elevation of 0.56 feet, were defined by markers and offsets were made in the location record on the test chart as they were passed by the car. These points located the chart section to be calculated for each run. During any test the car was run back and forth over this section at a variety of speeds, each pair of opposing runs being made at approximately the same uniform speed. Data exactly similar to that obtained during the tests of group A were taken during each run. The reasons enumerated on pages 11 and 30 for the rejection of any chart section apply also to the runs of this group of tests. Through calculations made in the same way as has been described for the previous group, each run has resulted in an average value of net car resistance for the average speed at which the car passed the track section. These have been plotted and curves drawn by the method described for group A. There are four tests in group B, namely, 73-74, 77-78, 91-92 and 95-96. The results are given in Figs. 12 to 15 and Tables 5 to 8, inclusive, in Appendix III. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR 12. Group C.-The principal points of difference between the tests of this and of preceding groups lie in the method of obtaining certain data, in the plan of grouping the results from two or more tests made on the same track section, and in the method of drawing the final curves. Track sections, each comprising two or more tangents varying in length from 338 to 1320 feet, were chosen so as to meet the same requirements as those prescribed for the tests heretofore described. They have been designated by letters as follows: D: Approximately 2680 feet long, located near Urbana on the Danville-Urbana line. W: About 3700 feet in length, located near White Heath on the Champaign-Decatur line. S: About 4100 feet long, located near White Heath on the Champaign-Decatur line. R No. 1: Approximately 3000 feet long, located near Riverton on the Decatur-Springfield line. R No. 2: About 4500 feet in length, located near Bement on the Champaign-Decatur line. During each test the car was run back and forth over the chosen track section, as during the tests of group B, so that opposing runs were separated by a small time interval as in that group. Throughout each run the recording apparatus was kept in operation and data taken which were similar to those obtained during the tests that have been described, although the method of taking them was in some cases different. Changes made in the instrument equipment were as follows: For the tests of groups A and B line voltage was recorded; but during the tests of group C connections were changed so that the record was that of voltage across the terminals of one motor. This change was made to facilitate calculations. A Boyer mechanical speed recorder was installed in addition to the electric recorder described in Appendix I, and the record made by it has been used in the calculations. Both instruments were driven from the same shaft. A portable windvane and anemometer were used during these tests to determine wind direction and velocity. These instruments were set up beside the test track and readings were made at intervals during the tests. By this means much more accurate determinations were made than could be obtained from the Weather Bureau reports. It was found upon the completion of the tests of groups A and B ILLINOIS ENGINEERING EXPERIMENT STATION that a low enough speed range had not been obtained and steps were therefore taken to supply this deficiency on subsequent tests. Two water rheostats were connected in the trolley circuit for the control of the motor voltage and the speed was held as nearly as possible at a constant predetermined value by the operator, who had for his guidance an ammeter in series with the speed-recording ammeter. From the record of each run made over the test track, chart sections were chosen for calculation in accordance with the requirements stated on page 14 to conform to the characteristic shape. The resistance curves groups A and B. Each such chart section has resulted in one point on a resistance-speed plot such as Fig. 16, Appendix III. The results of all tests made on any given track section have been grouped together as, for example, track section D, on which tests 109-110, 111-112 and 113-114 were made. Inasmuch as the resistance-speed points in Fig. 16 have been derived from the results of tests made under some- what different weather and wind conditions, it was found impracticable to draw the final curve in the same manner as for groups A and B. Consequently, in place of following the method described on page 13, the points on each resistance-speed plot, irrespective of the wind effect, were assumed to be divided into a number of groups, for each of which arithmetical averages of the values of speed and resistance were deter- mined and plotted. These groups of points were chosen so that the resulting averages would be distributed at about equal intervals through- out the speed range. Through them the curve representing the relation between resistance and speed was drawn and later modified as described on page 14 to conform to the characteristic shape. The resistance curves thus derived, which are shown in Figs. 16 to 19 inclusive, have been accepted as the results desired from this group of tests. It is recognized that this method of drawing the resistance curves is a deviation from the general plan followed for the preceding tests, but Fig. 1 shows that this deviation has brought about no greater vari- ation of the individual curves from the mean curve MM than is found among those drawn as described on page 13. This may be accounted for by the fact that the wind velocities prevailing during the tests in question (see column 7, Table 1) were on the whole less than those prevailing during the preceding tests, and that consequently the resist- ance-speed points for runs with and against the wind were closely interwoven. Had the tests of group C lent themselves to the plan described on page 13, the curves with and against the wind would have DUNN-RESISTANCE OF A 28-TON ELECTRIC OAR been quite close together, and the mean curves determined by the two methods would not have differed greatly. It will be noted that the numbers of the tests here included are not consecutive. Some of the tests bearing the intervening numbers were made for other purposes, but a considerable number were made for the purpose of this investigation and were later discarded for various reasons. Of the latter the greater number were omitted because an insufficient number of runs were made over the track sections to accu- rately determine a curve. This was occasioned by the necessity of running the car on sidings to allow regular cars to pass. Others were discarded because it was impossible to choose a sufficient number of chart sections that would meet the requirements, and still others were in the nature of preliminary runs. V. RESULTS OF THE TESTS. 13. Results of the Individual Tests.-The results of the individual tests are shown in the form of resistance-speed curves in Figs. 10 to 19 and Tables 3 to 12, inclusive, in Appendix III. These tests, without exception, show a marked increase in resistance as the speed increases. The effect of wind resistance is clearly shown by a comparison of Figs. 10 to 15 inclusive, which have been derived from tests of groups A and B. For those tests during which a heavy wind alternately opposed and helped the motion of the car, the two curves, such as A and B (Fig. 3), drawn to represent the results of runs in opposite directions, are some distance apart, while for tests during which the wind was light these curves are quite close together. Figs. 15 and 10 illustrate this difference. Fig. 15 has been derived from test 95-96 during which the component of the average wind velocity parallel to the track was 15 miles per hour while Fig. 10 has been derived from test 15-16 during which that component was 7 miles per hour. Had the wind velocity and direction remained precisely alike during all runs of a test, then the components of the wind velocity parallel to the track would have been of like value and the process of drawing the mean curve for the test would be valid in so far as the fundamental assumption underlying this process is in itself valid. The wind velocity and direction did not remain precisely constant during all runs of a test, however, and the resulting mean curves are consequently slightly in error. lNo method of eliminating this error or of evaluating it has presented itself. ILLINOIS ENGINEERING EXPERIMENT STATION The component of the wind velocity which is perpendicular to the test track increases gross resistance, irrespective of the direction in which the car is running, by pressing the flanges of the car wheels against the head of the rail, thereby increasing the frictional resistance. No method has been found for evaluating its effect upon the final resist- ance values and it is therefore included in the accepted results. Obviously it is one cause for the variations among the resistance curves as well as for the variations among the individual resistance-speed points. Due in part to the reasons just mentioned, the points in any of the resistance-speed plots may vary considerably from the final mean curve for that test. The maximum variation of any point from the mean is approximately 90 per cent. Any comparison of variations from the mean made to determine the agreement of the results among them- selves should, however, be confined to the results obtained from runs in one direction only. Such a comparison among the resistance deter- minations for tests of groups A and B shows variations which, though large in some cases, are not unusual for this class of experimental work. The maximum variation from the mean for the first two groups of tests occurred during test 23-24 (Fig. 3). Point 9 varies 42.5 per cent from mean curve B. The next largest variation is 24 per cent, while the average is much less than that. A very small percentage of this variation may be due to accumulated errors in instruments or in the calculations, although all reasonable precautions have been taken to avoid such errors. Each step in the process of making the calculations and producing the tables and curves has been duplicated at a different time and usually by a different person, and in all cases where the cal- culated value of resistance differed greatly from the mean all calculations leading thereto were repeated. The influence of such variable and uncontrollable elements of net resistance as flange friction, journal fric- tion, instantaneous changes in velocity and direction of the wind, and changes in the lubrication of bearings and gears, is believed to be sufficient to account for the differences shown in the curves here presented. The variations of the points in Figs. 16 to 19, inclusive, are chargeable to the differences in the test conditions that are represented on those resist- ance-speed plots as well as to the above-mentioned causes. 14. Results of All the Tests.-The six resistance curves for the individual tests of groups A and B, and those representing the results obtained on the four track sections of group C, have all been brought together in Fig. 1.* In view of the number and character of the elements *Each curve has been marked with the test number or letter corresponding thereto. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR of net resistance that can not be controlled, the differences among the curves there shown are not greater than might be expected. For speeds up to 20 miles per hour the maximum variation among the resistance values from the different curves is about 13 per cent, between 20 and 30 miles per hour this variation is approximately 17 per cent, while above 30 miles per hour it approximates only 20 per cent. TABLE 2 VALUES OF RESISTANCE AT VARIOUS SPEEDS, DERIVED FROM THE FINAL CURVE AND THE CURVES FOR THE INDIVIDUAL TESTS. THIS TABLE PROVIDES THE CO-ORDINATES OF THE CURVES IN FIGURE 2. Final Mean Curve 5.25 5.52 5.81 6.12 6.48 6.80 7.12 7.50 7.87 8.25 8.62 9.05 9.48 9.87 10.32 10 75 11.22 11.66 12.13 12.62 13.03 13.62 14.12 14.65 15.22 15.75 16.36 16.90 17.50 18.12 18.75 19.37 20.04 20.75 21.44 22.13 22.87 23.66 24.45 25.26 26.12 Test 15-16 17.10 20.44 24.20 25.02 Test 23-24 13.84 17.15 21.00 25.56 Car Resistance-Pounds Per Ton Test 73-74 13.55 15.73 18.75 22.16 23.68 Test 77-78 6.62 8.48 10.50 12.75 15.34 18.22 21.45 25.25 Test 91-92 10.02 12.13 14.54 17.22 20.25 Test 95-96 9.75 10.18 12.37 14.85 17.62 20.75 22.12 Tests on Section D 5.65 6.87 8.62 10.55 12.65 15.00 15.50 Tests OD Section W 8.12 9.00 11.30 13.93 16.88 20.25 24.15 25.00 Tests on Section S 8.75 10.44 12.75 15.30 18.21 21.50 Tests on Section R 7.55 8.02 10.60 13.45 16.70 20.47 22.13 Speed Miles Per Hour 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 The mean curve MM shown in Fig. 1 and reproduced as Fig. 2 has been drawn to express the average relation between resistance and Car Resistance--Pounds Per Ton ILLINOIS ENGINEERING EXPERIMENT STATION speed for all the tests. To determine this curve, the resistances corre- sponding to a given speed, say 10 m.p.h., were taken from the individual curves of Fig. 2 and averaged. In this process each resistance value was given a weight corresponding to the total number of resistance deter- minations represented by the curve from which it was taken. These averages were calculated at speeds varying by steps of 5 miles per hour and plotted in Figs. 1 and 2. Through them the mean curve MM has been drawn. The curve thus determined represents the final results obtained from this investigation. The values of resistance at various speeds have been determined from all the curves shown in Fig. 1 and they are presented in Table 2. The data there given are sufficient to accurately reproduce all the final resistance-speed curves. The final results have also been expressed in the form of an equation which is given as formula 1. This equation makes it possible to calculate resistance values that do not vary more than one-half of one per cent from those obtained from the curve MM. In this formula B is the resistance expressed in pounds per ton and S is the speed in miles per hour. R = 4 + 0.222 S + 0.00582 82 ......... (1) This equation has been modified as shown in formula 2 to take more definite account of air resistance. In formula 2, A is the cross-sectional area of the car expressed in square feet and W is the car weight in tons. A R = 4 + 0.2'22 S + 0.00181 - S ....... (2) These formulae are the equations of a parabola which corresponds closely to the curve MM. In using these formulae care should be taken not to extend their use to speeds much beyond the limits of the curve MM. 15. Discussion of the Final Results.-The final results of this investigation are presented in Fig. 2, Table 2, and formulae 1 and 2, all of which express the mean relation between speed and resistance for the 28-ton car when running at uniform speed on tangent and level track of good construction, during weather when the temperature is not lower than 250 F., and when the wind velocity does not exceed about 26 miles per hour. The curve MM (Figs. 1 and 2) is an average of curves derived from ten individual tests that have been run under conditions which, though they differ somewhat, are not at all unusual. Notwithstanding this difference in test conditions, the maximum variation of the individual curves from the mean curve MM is only 12 per cent (see Fig. 1). With the exception of that portion of the curve for DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR test 23-24, which lies between 30 and 34 miles per hour, the maximum variation of the individual curves from the mean curve is only 9 per cent for all speeds above 30 miles per hour. At speeds below 30 miles per hour this variation is considerably less than 9 per cent. In other words, all curves from the individual tests lie within a narrow belt. All points within this belt may very properly be considered to represent a relation between car resistance and speed which is true under some usual conditions. FIG. 4. COMPARATIVE DIAGRAM OF RESISTANCE-SPEED CURVES CALCULATED BY MEANS OF SEVEN FORMULAE APPLICABLE TO ELECTRIC RAILWAY CONDITIONS. w = 28 TONS. A = 90 SQ. FT. N = 1. 1. DAVIS. 5. LUNDIE. 2. UNIVERSITY OF ILLINOIS. 6. ARMSTRONG. 3. SMITH. 7. MAILLOUX. 4. BLOOD. If it is desired to estimate the resistance of any car which in weight and general design is similar to the car used during these tests, it is believed that the curve MM offers a basis for the prediction of such resistance, the accuracy of which will lie within the limits just stated; that is, it is believed that by the use of the curve MM net resistance may be predicted within about 9 per cent. Obviously, in using the curve for such a purpose the conditions surrounding these tests must be fully appreciated. ILLINOIS ENGINEERING EXPERIMENT STATION In addition to the expression given for the resistance in still air, the tables and curves in Appendix III provide information as to the excess resistance due to wind. They show that during moderate weather and for wind velocities up to 24 miles per hour which directly oppose the motion of the car, the resistance may exceed that in still air by as much as 70 per cent at speeds below 30 miles per hour, and by 50 per cent at speeds above 30 miles per hour. 16. Comparison with Other Experiments.-For purposes of com- parison with the results of other investigations the following formulae are given, together with Fig. 4: 0.3 S2 Davis1 R= 5 + 0.13 S + --- [1 + 0.1 (N - 1)] University of R = 4 + 0.222 S + 0.00582 82. Illinois R = 4 + 0.222 S + 0.00181- 82. A Smith2 R = 3 + 0.167 S + 0.0025 -- S. Blood' R = 6 + 0.13 8 + (0.0014 + -- .) 8. Lundie4 R =4 + 0.24S+ 4 50 0.002AS2 Armstronga R== /W + 0.03S- W [1+ 0.1 (N-i1)] Mailloux R = 3.5 + 0.15 S + 0.02N+ 0252 NW Notation:-R== Car resistance in pounds per ton. 8= Speed of the car in miles per hour. W= Weight of the car in tons. N= Number of cars in the train. A= Effective cross-sectional area of the car body and trucks in sq. ft. 1. Street Railway Journal, 1904, v. 24, p. 1003. 2. Proc. Amer. Inst. Elec. Eng., 1904, v. 23, p. 696. 8. Proc. Amer. Soc. Mech. Eng., v. 24, p. 945. 4. Street Railway Journal, 1902, v. 19, p. 557. 5. Standard Handbook for Electrical Engineers, Section on Electric Traction, by A. H. Armstrong. 6. Proc. Amer. Inst. Elec. Eng., 1904, v. 23, p. 731. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR APPENDIX I. THE ELECTRIC TEST CAR. The electric test car, by means of which the tests reported in this bulletin were made, was built under the direction of the University of Illinois and placed in operation in 1906. The equipment, which is for 500-volt direct current operation, was placed so as to provide facilities for the instruction of students as well as for conducting investigations concerning various features of electric car operation. For this purpose the switch group, circuit breaker, limit switch and certain other parts of the equipment were placed within the car where their action under all conditions might readily be seen. The weight of the car with its equipment, subject to certain corrections, is 55 150 pounds. The cor- rections referred to are necessitated by additions to the equipment and changes made therein at different times. The general design of the. car is shown in Figs. 5, 6 and 7. Car Body.-The car body, which is of the double-end type commonly used in moderately heavy interurban service, was built by the Jewett Car Co., of Newark, Ohio. Its principal dimensions are given in Fig. 7. The cross-sectional area of the body and trucks is 90 square feet. The vestibules are of the round end type. Ball bearing center plates were installed between tests 29 and 30. Trucks.-The car body is mounted upon Standard Motor Truck Company C-60 type trucks whose main dimensions are:- Distance from center to center of trucks 23 ft. 3 in. Wheel base, 6 ft. 4 in. Lateral play of axle journals, 3/16 in. Axle journals, 41/4 in. X 8 in. Diameter of wheels, 33 in. Weight of truck exclusive of electrical equipment, 7824 pounds. On one truck there are four rolled steel wheels, while those on the other truck are chilled cast iron. Both sets have the standard M. C. B. tread and flange. Motors.-On each truck are two number 101-D Westinghouse 500- volt, direct current motors, each one having a commercial rating of 50 H. P. They are mounted on the axles and geared thereto in the ratio of 22:62. The characteristic curves are shown in Fig. 8. ILLINOIS ENGINEERING EXPERIMENT STATION FIG. 5. THE ELECTRIC RAILWAY TEST CAR. FIG. 6. INTERIOR OF ELECRIC RAILWAY TEST CA. DUNN-RESISTANCE OF A 28-TON ELECTRIO CAR FIG. 7. PLAN AND CROSS SECTION OF THE ELECTRIC RAILWAY TEST CAR. Control Equipment.-The motor control equipment is that known as the Westinghouse unit switch system of multiple control. In this type of control the switches which make the necessary connections and short circuit the starting resistances are operated by compressed air from the brake reservoir. The valves which control the air are operated from the master controller through the medium of magnets and a low voltage storage battery circuit. Acceleration is governed by a limit switch the armature of which is weighted to give the desired rate. ILLINOIS ENGINEERING EXPERIMENT STATION -00 0o F 30 0 WI- 45 30 z u IL (LI 0 0. Ljl 0 I 105 90 __ _ _ _ ^ ^ f/\^ "/5 ' " 45 30 15 0 --I- 2~ -I *1 -··· '/ 1 / j / 1 / 6 ,/ - - - / U0 R0 30 I-0O 150 I0 Z10 CURRENT- AMPEE RS . FIG. 8. THE CHARACTERISTIC CURVES OF THE TEST CAR MOTORS. WESTINGHOUSE NO. 101-D, 500 VOLT D. C. RAILWAY MOTOR. GEAR RATIO 22:62. 33 INCH WHEELS. CONTINUOUS CAPACITY 46 AMPERES AT 300 VOLTS. CONTINUOUS CAPACITY 42 AMPERES AT 400 VOLTS. 1. ELECTRICAL HORSE POWER. 2. BRAKE HORSE POWER WITH GEARS. 3. TRACTIVE EFFORT. 4. EFFICIENCY WITHOUT GEARS. 5. APPROXIMATE EFFICIENCY WITH GEARS. 6. SPEED. 7. TIME TO RISE 750 C. FROM 25° C. 8. SAFE TIME FOR LOAD IN SERVICE FOR 200 C. RISE FROM 750 C. THE RECORDING APPARATUS. Within the car there is apparatus by means of which a continuous graphical record may be kept of motor current, voltage, speed, time, distance, location, and brake cylinder pressure upon a chart 40 inches in width. The Chart.-Fig. 9 has been reproduced from a tracing of a portion of the chart for test No. 121. The records there shown are grouped more closely together than in the original record, and the transverse lines which mark one of the sections selected for calculation and some of the explanatory lettering do not appear thereon. This chart is ~j2 / / / -0._ - , - -f.- - - - 7 I- -_ -I _ _ ^--z--- :=^^:: ^=1::: ^"^5~^ZZZ z^'^E~z I 0 \/1 DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR ILLINOIS ENGINEERING EXPERIMENT STATION caused to pass from a supply roll, over a series of tension and guide rolls and the recording table, and is then rewound upon a detachable record roll. As the paper travels over the table the instruments draw on it continuous records of the above mentioned data. The paper may be driven by a motor, thus making the records on a time base, or by a flexible shaft geared to the axle, thereby making them on a distance base. Current Record.-The current taken by the motors is recorded by a General Electric graphic recording ammeter which is excited from a storage battery. A rheostat is provided for the adjustment of the exciting current which should be kept at a constant predetermined value. Check readings may be made by means of an indicating ammeter in the same circuit as the recording meter. Voltage Record.-The voltage record is made by a General Electric graphic recording voltmeter which is likewise excited by a constant current from the storage battery. The same provision is made for making check readings as described for the current record. Prior to test 121-122 these instruments were connected so as to give a record of line voltage, but for that and all subsequent tests the connec- tions were changed so that the record is that of voltage across the terminals of one motor. Speed Record.-One speed record is made by a General Electric graphic recording ammeter connected in the armature circuit of a 1/2 kilowatt low voltage generator which is excited by a constant storage battery current and driven from the axle by a flexible shaft. The current generated is proportional to speed and therefore the recording ammeter when properly calibrated gives a record of speed. A Boyer mechanical speed recorder was installed just prior to test 103-104 and its record has been used on all subsequent tests. Instantaneous values of speed are obtained from an "Autometer," which also is driven from the flexible shaft. Time Record.-By means of a contacting device on a clock, elec- trical connections are made every 5 seconds so as to operate two magnets to the armatures of which the time recording pens are attached. Offsets are thus made in the two time lines every 5 seconds. Location Record.-An observer, by means of a telegrapher's key, battery circuit, and magnet to the armature of which a recording pen is attached, causes offsets to be made in the line giving a record of location as a given point on the test car passes numbered trolley line DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR 29 poles, stations, or other markers. This record enables one to correlate any position of the car with the profile. Distance Record.-A pen operated electrically from a contacting device on one of the car wheels makes an offset in a line for every 50 feet of track passed over by the car. This record is used merely as a check on the distances obtained from a table giving the exact distance between any two trolley line poles. Brake Cylinder Pressure.-A pressure gage connected to the brake cylinder has been modified so as to make a record upon the chart. This record is used merely to determine and to avoid those portions of tests during which the brakes were applied. Auxiliary Apparatus.-The power consumed by the motors may be obtained from an integrating wattmeter. A separate wattmeter indicates the power consumed by the pump motors. For a part of the tests herein reported two water rheostats were placed in the trolley circuit for the purpose of cutting down the voltage and thereby obtaining lower speeds than it was otherwise possible to maintain. ILLINOIS ENGINEERING EXPERIMENT STATION APPENDIX II. METHODS EMPLOYED IN CALCULATING THE RESULTS. The steps in the process by which the final results have been reached are here explained in some detail. The description of the general process which has been given in Section IV of the body of the report is to be considered as supplementary to this Appendix. The data taken and the methods by which they were obtained have been described there and in Appendix I. Fig. 9 has been reproduced from a portion of the chart made by the recording apparatus during test number 121. Selection of the Sections.-From the chart produced during each test, sections have been chosen for calculation by comparison of the profile and chart. As has been stated, only those sections were considered where the car was running on straight track, and over which no brake applications were made. They were selected so that the average speeds over the sections chosen from any particular test should cover as wide a range as possible, and so that the number of sections from east bound runs would be balanced by the same or approximately the same number from west bound runs. In this way the number of resistance deter- minations made from data obtained during runs against the wind were balanced by an approximately equal number for the opposite condition. In addition, the following were considered sufficient reasons for the rejection of any section of chart: a. Any considerable variation of the current or voltage from the average value. b. Heavy grades between the section limits. Level track or light uniform grades are of course the preferable con- ditions. c. A large difference in the speed of the car when entering and when leaving the track section or at any points be- tween the section limits. Aside from other considerations it is highly desirable to choose both track and chart sections so that the energy consumed by acceleration and grade shall be as small as possible, in order that errors in their calculation shall have slight effect on the accuracy of the values of average net car resistance. When the variation in speed is large the energy required to produce acceleration is alone frequently greater than that required to overcome all other resistances combined. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR Fig. 9 shows one of the chart sections selected from a run made over a track section lying between trolley line poles numbered 4 and 12. These limiting points are designated on Fig. 9 by numbered offsets in the location record. Parallel lines drawn through them and per- pendicular to the location record line intercept all but four of the records at the points occupied by the pens at the moment when the car entered and left the track section. The four records in question, namely, current, voltage, brake cylinder pressure, and speed by the electrical recorder, are made by pens which move along arcs of circles and which are adjusted so that in their zero position their recording points lie in the same straight line as the other pens. For any but the zero reading, however, these pens take positions ahead of the others and consequently allowance must be made for this fact in determining their positions at the moments when the car passed the points of entrance and exit. This matter has been cared for by means of tem- plates, as shown in Fig. 9. The Calculations.-The result desired from each such section of chart is a value of average net car resistance. The following explanation of the derivation of each column of data in the tables should make clear all the processes involved in the production of the final results. Table 1 gives a summary of test conditions. Tables 3 to 12 inclu- sive present original data, and intermediate and final results as follows: Column 1. (Item No.) is self explanatory. Column 2. (Test No.) is self explanatory. Column S. (Wind opposing or helping) is from original data. Column 4. (Section limits) defines the track section as well as the chart section by stating the limiting points which have .been desig- nated by trolley line pole numbers. The location of each line pole or other marker is shown accurately upon the profiles. Column 5. (Grade) is derived from column 4 and the profiles, and expresses the grade as the difference in elevation in feet between the entrance and exit points. A positive sign indicates that the car is going up grade. Column 6. (Length of section) is derived from column 4 and a table giving the exact distance between any two trolley line poles. Column 7. (Time) is derived from the time record on the chart by determining the number of whole and decimal parts of 5-second intervals included between the parallel lines drawn through the limiting points of the section. ILLINOIS ENGINEERING EXPERIMENT STATION Column 8. (Motor data) is from the original data. Column 9. (Efficiency) is derived from columns 8, 13 and 14, and a table of efficiencies. Tables 3 to 12 inclusive, in Appendix III, show that the voltage (column 13) varied from about 100 to 600 volts. The low voltages were due largely to the method of using rheostats on the car for the purpose of obtaining low speeds. It was thought that the efficiency curve for the motors at 500 volts was not accurate enough under such condi- tions and therefore one of the motors was removed from the truck and a series of efficiency tests made upon it at five different voltages, namely, 120, 200, 300, 400, and 500. From the results of these tests a set of efficiency curves for the test car motors with gears was constructed, the. Westinghouse Electric & Machine Company's standard gear losses being used. The 500-volt curve, thus determined, corresponds with the curve provided by the manufacturer. From these curves the above mentioned table was compiled. Column 10. (Item No.) is self explanatory. Column 11. (Speed at entrance to the section) The height of the speed curve above its base line at the point occupied by the recording pen at the moment the car entered the track section represents the speed of the car at that moment, to some scale determined by a calibration curve. Such a curve was made for each test by plotting average speeds calculated from columns 6 and 7 against the corresponding average heights of the speed curve in sufficient number to determine a curve. Straight lines were found to satisfy the conditions and for each one the equation was found and used in the calculations. Column 12. (Speed at exit from the section) is determined from the height of the speed curve at the point of exit, and the equation of the calibration curve as explained above. Column 13. (Average voltage) is determined by first obtaining the average height of the voltage curve between the section limits. From a calibration table the voltage corresponding to the average height may be found and it is recorded in column 13. Column 14. (Average current) is determined from the current curve in the same manner as column 13 from the voltage curve. Column 15. (Energy imparted to the car by the current) is cal- culated by means of the equation- BE= W X e X T X 2655. in which Ec = the energy in foot pounds imparted to the car by the current. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR W = Average watts, calculated from columns 13 and 14. e -- The efficiency of the motors and gears for the given current and voltage (Column 9). T = The time in hours for the car to traverse the section= column 7 3600 2655 = foot pounds in one watt hour. Column 16. (Energy imparted to the car by the change in kinetic energy between the entrance and exit points) is determined from the entrance and exit speeds (columns 11 and 12), and an equation express- ing the relation between kinetic energy and the speed of the car. This equation was derived from a series of determinations of the force re- quired to produce acceleration in the rotation of the revolving parts as well as of the force required to produce the acceleration in the motion of translation of the car as a whole. The equation follows: Ek = (1995 + 5 P) (12 - S'2) in which Ek = The energy in foot pounds imparted to the car by the change in kinetic energy between the entrance and exit points. S1 = The speed of the car in miles per hour at the moment of entering the track section (column 11). S2 = The speed of the car in miles per hour at the moment of leaving the track section (column 12). P = The number of additional 150 pounds above the weight of the car and its regular equipment, that is above 55 150 pounds. This item includes live load and special equipment. 1995 and 5 are constants derived from the -inertia calculations re- ferred to above. A negative sign before the figures in column 16 indicates that the speed of the car had increased in passing over the track section and consequently that the kinetic energy possessed by the car at the moment it left the section was greater than when it entered it by the amount given. This energy had to be supplied by the current, by the grade, or by both current and grade. Column 17. (Energy imparted to the car by the grade) is the product of the weight of the car (column 2, Table 1) and the difference in elevation in feet between the points of entrance and exit. A nega- tive sign indicates that the car is going up grade and is consequently requiring additional energy for that purpose. Column 18. (Net car resistance in pounds per ton)-The net ILLINOIS ENGINEERING EXPERIMENT STATION energy used in overcoming car resistance alone while traversing the track section is first found from columns 15, 16 and 17 by correcting the energy delivered by the current, for changes in speed and grade. From the net energy the average value for the section is found by divid- ing by the length of that section in feet (column 6), and this in turn is reduced to net car resistance in pounds per ton of car weight by dividing by the weight of the car in tons. This is the result desired from each chart section. Column 19. (Average speed) is calculated from the length of the track section (column 6) and the time required to traverse that distance (column 7). Columns 18 and 19 provide the co-ordinates of the points plotted in Figs. 10 to 19. Method of Obtaining the Mean Curves of Car Resistance for Tests of Groups A and B.-As described on page 13, the ordinates of points on the mean curves for the individual tests of groups A and B have been calculated by means of an equation which is based on the assumption that wind resistance varies as the square of the speed. The derivation of the equation follows: Let R. = the resistance at speed s excluding air resistance R = the total resistance at speed s = R. + cs2 (1) in which c = some constant quantity Ra =the resistance for a run against the wind at speed s = , + c (s+ v )2 (2) in which v == the component of the wind velocity parallel to the track. Rw -= the resistance for a run at speed s with the wind =R,+c(s--v)2 (3) Subtracting equation (3) from (2) and solving for c R, - R, (4) c ==-- (4) 4 sv Substituting (4) in equation (2) and solving for R. R= -a R, (s +V)2 (5) 4 sv Substituting equation (5) in equation (1) R =Ra R 4 (2s+v) (6) Equation (6) is the one sought. The mean curves of groups A and B, calculated by means of this equation, and those of group C, determined as described on page 16, after being modified as described on page 14 to conform to the general shape, were accepted as the results desired from the individual tests. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR APPENDIX III. THE RESULTS OF THE INDIVIDUAL TESTS. Note.-In the figures solid dots are for runs with the wind, and open circles are for runs against the wind. ILLINOIS ENGINEERING EXPERIMENT STATION TABLE 3 TEST No. 15-16. 1 2 3 4 5 6 7 8 9 Grade. Motor Data Section Limits. - _____ Wind Rise or Fall Length Time Item Test Opposing Over of to Number i No. No. or Trolley Line Section. Track Run in Use of fi Helping Pole - Section Section ver and and Numbers. + Up Connection Gears - Down Ge O or H Feet Feet Sec'es. % 1 15 H 1 620-1 575 +13.20 4 009 77.21 4 M 85.1 2 " 1 470-1 440 + 4.17 2 991 72.14 78.4 3 " " 1 440-1 380 - 5.34 5 994 127.94 " 79.6 4 " 1 380-1 345 -10.15 3 503 63.14 " 77.5 5 " " 1 335-1 305 -3.45 2 986 53.30 " 81.0 6 " " 1 295-1 270 + 4.05 2 495 42.50 " 81.4 7 " 1 250-1 230 - 3.74 1 987 32.20 " 82.4 8 " 1 070- 970 - 9.92 9 987 173.99 " 81.2 9 16 0 970-1 000 + 4.23 2 958 61.88 " 82.0 10 " 1 000-1 035 + 3.53 3 480 69.21 " 82.2 11 " " 1 035-1 070 + 2.15 3 549 66.02 " 82.9 12 " " 1 115-1 135 - 1.19 1 988 38.47 " 85.4 13 " 1 270-1 295 - 4.05 2 495 42.82 " 82.4 14 " 1 305-1 330 + 3.41 2 488 43.66 " 81.8 15 " " 1 400-1 430 +- 1.57 2 998 67.76 " 80.7 16 " 1 455-1 480 + 0.42 2 492 52.40 " 81.0 17 " 1 480-1 535 +17.12 5 473 110.77 " 81.4 18 " 1 580-1 620 -14.74 3 576 67.54 " 81.4 *S=Serie&-multiple. M=Multiple. Sw=Switching. C=Coasting. FIG. 10. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR TABLE 3 (Continued) TEST No. 15-16. 10 11 12 13 14 15 16 17 18 19 Speed Energy Imparted to Car Aver- Net A Item At At age Average By the Change ar e No. Entrance Exit Volt- Current By the in Kinetic By the Grade the to From age Current Energy ance Section Section Section M. P. H. M. P. H. Volts Amp's. Ft. Lba. Ft. Lbs. Ft. Lbs. Lb. PerM.P.H. 1 33.46 38.32 510 171.7 4 243 500 - 720 400 -747 100 24.46 35.42 2 26.65 29.24 351 132.1 1 934 200 - 298 900 -236 000 16.51 28.27 3 29.24 35.08 394 128.4 3 800 000 - 775 700 +302 200 19.60 31.95 4 35.08 36.37 411 113.4 1 682 000 - 190 300 +574 500 20.84 37.83 5 37.99 38.64 469 129.9 1 940 000 - 102 860 +195 300 24.05 38.20 6 39.94 39.29 494 129.9 1 637 000 + 106 350 -229 200 21.44 40.04 7 37.99 40.58 534 133.3 1 392 800 - 420 200 +211 700 21.06 42.07 8 34.10 41.23 467 131.5 6 398 500 -1 109 100 +561 500 20.69 39.15 9 29.57 32.16 436 141.1 2 302 000 - 330 150 -239 400 20.69 32.59 10 32.16 35.40 452 141.1 2 676 000 - 452 000 -199 800 20.55 34.28 11 35.40 37.02 492 142.0 2 820 000 - 242 300 -121 700 24.45 36.64 12 29.89 36.37 554 170.1 2 283 000 - 886 600 + 67 350 26.01 35.24 13 36.70 38.96 523 135.1 1 839 000 - 353 100 +229 200 24.28 39.73 14 37.99 37.34 492 132.6 1 718 000 + 101 100 -193 000 23.09 38.85 15 27.62 31.19 388 138.8 2 172 000 - 433 550 - 88 860 19.44 30.18 16 28.60 31.19 422 134.6 1 778 000 - 319 800 - 23 770 20.34 32.43 17 31.19 32.16 436 136.6 3 961 000 - 126 900 -969 000 18.49 33.68 18 29.24 36.37 456 134.4 2 485 100 - 966 000 +834 300 23.25 36.10 FIG. 11. ILLINOIS ENGINEERING EXPERIMENT STATION TABLE 4 TEST No. 23-24. 1 2 3 4 5 6 7 8 9 Grade Motor Data Wind Section Limits. Rise or Fall Length of Time to Run Number Effici- Item Teat Opposing - Over Track Over in Use ency No. No. or Trolley Line Pole Section Section Section and of Helping Numbers. - Connee- Motors + Up tion and -Down * Gears 0 or H Feet Feet Sec's % 1 23 H 1 471 -1 462 +0.2 897 18.71 4 M 83.5 2 " 1 462 -1 453 +0.6 896 16.50 ." 82.6 3 " 1 402.7-1 396.7 -1.94 600 10.75 " " 76.6 4 1 394.2-1 388.2 -0.16 594 10.12 " " 80.8 5 " 1 361 -1 343 -1.49 1 804 27.91 . . 79.3 6 "1 291 -1 282 -0.06 901 14.42 . . 80.0 7 1 081 -1 075 +0.78 582 10.07 " " 84.5 8 1 012 - 970 --4.76 4 144 66.90 . " 81.8 9 917.2- 901.75 +1.02 1 529 28.33 . " 83.3 10 " 871.5- 853.4 +2.15 1 803 31.65 . . 79.9 11 780.4- 720.5 -6.74 5 970 90.30 . . 83.4 12 567.4- 540.5 +0.43 2 689 45.07 . " 82.9 13 489.3- 468.5 +0.50 2 083 36.89 . . 81.2 14 190.5- 150.5 -3.96 3 948 86.45 " " 80.0 15 24 0 168.8- 190.5 +3.19 2 090 40.56 . . 83.2 16 0 " 403.1- 420.2 +1.33 1 664 35.60 . a 83.1 17 " 459.5- 492.3 +0.53 3 276 66.55 " 80.5 18 " " 550.5- 570.3 ---0.62 1 977 33.94 " " 82.5 19 625.3- 687.5 +2.29 6 270 109.49 " . 84.3 20 " 726.3- 780.4 +5.57 5 392 92.98 " " 84.0 21 "1 039 -1 075 +2.53 3 678 74.00 . 6 83.3 22 1 111 -1 141 -0.98 2 982 50.94 " " 84.5 23 1 226.5-1 251.5 +5.48 2 483 43.86 " " 83.9 24 1 273 -1 297.5 -2.46 2 443 40.00 " 83.8 25 " 1 306.8-1 334 +2.99 2 707 44.56 " " 83.7 26 1 343 -1 373 +4.97 3 004 50.88 . " 82.2 27 1 406 -1 465 -5.11 5 889 100.11 " " 82.0 *8= Series-multiple. M=Multiple. Sw=Switching. C=Coasting. TABLE 5 TEST No. 73-74. 1 2 3 4 5 6 7 8 9 Motor Data Item Test Wind Section Limits Grade Lengthof Time No. and i No. No. 0 or H Section Connection Efficiency 1 73 H 1 470-1 455 +0.56 1 495 23.78 4 M 81.1 2 C 24.60 4 M 81.9 3 " " " 29.00 4 M 80.4 4 28.58 4 S 84.7 5 28.31 4 8 84.7 6 "37.80 C - 7 74 0 1 455-1 470 -0.56 26.91 4 M 82.7 8 28.40 4 M 83.3 9 C 30.35 4 8 85.5 10 " " " 31.94 4 8 85.8 11 * 38.58 C - *S=Series-multiple. M=Multiple. Sw=Switchiog. C=Coasting. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR TABLE 4 (Continued) TEST No. 23-24. 10 11 12 13 14 15 16 17 18 19 Speed Energy Imparted to Car Net Apverae Item At At Average Average By the Change Car Ser No. Entrance Exit Voltage Current By the Kineti By the Grade to from Current in Kinetic By the G ae ce Section Section Section Energy M. P.H. M.P. H. Volts Amp's. Ft. Lbs. Ft. Lbs. Ft. Lbs. . Per M.P. H 1 31.33 34.97 464 153.8 822 230 - 493 520 - 11 250 12.58 32.69 2 34.97 37.16 455 145.3 664 520 - 323 040 - 33 750 12.21 37.02 3 38.61 39.71 435 108.5 286 630 - 176 180 +109 120 13.01 38.05 4 39.52 40.07 482 127.0 369 150 - 89 520 + 9 000 17.28 40.02 5 43.53 44.62 477 118.5 922 650 - 196 490 + 83 810 15.96 44.05 6 46.99 46.81 503 120.3 514 820 + 34 530 + 3 380 21.81 42.60 7 39.34 40.98 528 159.4 528 160 - 269 380 - 43 870 13.13 39.40 8 41.71 44.62 529 129.5 2 764 800 - 513 750 +267 750 21.61 42.23 9 37.34 39.16 515 144.0 1 290 700 - 284 730 - 57 380 22.06 36.80 10 39.16 39.16 459 123.0 1 052 900 0 -120 900 18.38 38.84 11 42.26 47.90 605 132.6 4 455 700 -1 039 900 +379 120 22.60 45.08 12 37.16 40.98 536 137.5 2 030 800 - 610 420 - 24 190 18.46 40.68 13 35.15 37.34 465 131.5 1 350 900 - 324 650 - 28 130 17.07 38.50 14 29.14 37.34 422 127.2 2 737 900 -1 114 800 +222 700 16.62 31.14 15 34.24 36.97 464 149.6 1 727 500 - 397 550 -179 400 19.57 35.13 16 29.14 33.70 448 151.4 1 479 800 - 586 000 - 74 810 17.50 31.85 17 32.42 33.70 426 130.8 2 201 500 - 173 080 - 29 810 21.69 33.57 18 38.61 38.25 526 136.0 1 477 200 + 56 580 + 34 880 28.21 39.71 19 33.15 41.89 548 151.6 5 655 200 -1 341 200 -128 800 23.73 39.04 20 37.34 40.62 548 146.9 4 636 900 - 522 920 -313 310 25.06 39.50 21 30.05 37.16 476 150.0 3 245 900 - 977 230 -142 300 20.55 33.89 22 37.89 40.98 571 149.4 2 708 100 - 498 380 + 55 130 27.00 39.89 23 39.16 39.52 536 147.1 2 139 800 - 57 920 -308 300 25.40 38.61 24 41.53 42.99 560 142.0 1 965 800 - 252 350 +138 400 26.95 41.64 25 42.80 41.89 548 142.4 2 146 500 + 157 600 -168 200 28.05 41.41 26 42.26 40.44 517 133.3 2 125 700 + 307 800 -279 560 25-49 40.26 27 38.25 42.07 515 132.2 4 121 800 -' 627 450 +287 440 22.83 40.11 TABLE 5 (Continued) TEST No. 73-74. 10 11 12 13 14 15 16 17 18 19 Speed Energy Imparted to Car Item- Average Average Net Car Average No. Entrance Exit Voltage Current By Current By Kinetic By Grade sistanc Seed 1 41.35 42.21 516 125.8 923 200 -146 950 -31 720 17.58 42.87 2 40.83 41.52 520 130.5 1 008 000 -116 200 20.31 41.45 3 33.56 35.29 443 127.7 972 800 -243 600 16.47 35.13 4 36.16 36.85 528 80.9 762 700 -103 000 14.83 35.72 5 35.12 35.99 530 81.2 761 100 -126 500 14.23 36.00 6 30.10 24.09 - - - +666 000 14.98 26.96 7 36.68 37.20 507 138.6 1 153 000 - 78 560 +31 720 26.12 37.87 8 34.60 36.33 506 144.9 1 279 000 -250 950 25.02 35.89 9 32.52 33.39 530 92.1 934 100 -117 250 20.02 33.58 10 30.97 32.87 528 98.0 1 046 000 -248 050 19.59 31.91 11 30.10 24.05 - - --- +669 950 16.50 26.42 ILLINOIS ENGINEERING EXPERIMENT STATION TABLE 6 TEST NO. 77-78. 1 2 3 4 5 6 7 8 9 Grade Motor Data It Wind Section Limits. Rise or Fall Number in ite Test pOver Length of Time to Run Number in Item Over Track Over Efficiency o No. No. mg Trolley Line Pole Section Uticn Se n Use and Motorf or Section Section Motors Helping Numbers -- Connection and Gears - Down 0 or H Feet Feet Sec's. % 1 77 H 1 470-1 455 +0.56 1 495 23.03 4 M 78.5 2 78 0 1 455-1 470 --0.5 27.68 4 M 82.3 3 77 H 1 470-1 455 +0.56 32.87 2 M 85.0 4 78 0 1 455-1 470 -0.56 32.57 2 M 85.7 5 77 H 1 470-1 455 +0.56 35.48 2 M 81.6 6 78 0 1 455-1 470 --0.56 36.26 2 M 78.9 7 77 H 1 470-1 455 +0.56 38.01 2 M 79.3 8 77 H 1 470-1 455 +0.56 57.22 C 9 78 0 1 455-1 470 -0.56 95.00 C 10 77 H 1 470-1 455 +0.56 85.00 C 11 78 0 1 455-1 470 -0.56 79.45 C 12 77 H 1 470-1 455 +0.56 77.58 C 13 78 0 1 455-1 470 -0.56 80.06 C 14 78 0 1 455-1 470 -0.56 29.82 4 M 82.2 *S=Series-multiple. M= Multiple. Sw=Switching. C=Coasting. --30- 1 1 1 __ TEST NO 73-74 - 0 2 3- 5 I I I I I 1 1 - -1-5 - .... 12.- FIG. 1. FIG. '12. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR TABLE 6 (Continued) TEST No. 77-78. 10 11 12 13 14 15 16 17 18 19 Speed Energy Imparted to the Car Net Average Item At At Average Average Car Speed No. Entrance Exit Voltage Current By the B y th e hGradeesist Oeth to from Current Energ y ance Section Section Section En M. P. H. M. P. H. Volts Amp's. Ft. Lbs. Ft. Lbs. Ft. Lbs. Per M. P. H. 1 45.22 44.46 507 112.4 759 750 +139 720 -31 810 20.44 44.25 2 35.48 37.01 499 136.8 1 146 960 -227 360 +31 810 22.41 36.82 3 29.94 31.85 480 89.5 885 210 -241 940 -31 810 14.40 31.01 4 34.34 36.05 507 98.7 1 029 860 -246 750 +31 810 19.19 31.29 5 28.61 29.94 510 64.9 706 830 -159 640 -31 810 12.14 28.72 6 27.84 26.31 499 57.6 606 320 +169 840 +31 810 19.03 28.11 7 26.12 25.17 420 61.1 570 050 + 99 890 -31 810 15.03 26.82 8 19.06 12.37 +431 050 -31 810 9.40 17.81 9 14.85 6.64 +361 690 +31 810 9.27 10.73 10 15.43 10.46 +263 780 -31 810 5.46 11.99 11 17.15 8.55 +453 090 +31 810 11.42 12.83 12 15.04 9.89 +263 200 -31 810 5.45 13.14 13 17.72 8.93 +480 220 +31 810 12.06 12.73 14 31.66 34.72 412 146.0 1 086 840 -416 400 +31 810 16.54 34.18 I II I I I l TEST NO. 77-78 II oh H-His| | | 12og 2s - gson FIG. 13. I I I I 40oFH4-451 ''' '''' '''' SPEED----M.P.H. '~'' '''' ''''' ILLINOIS ENGINEERING EXPERIMENT STATION TABLE 7 TEST No. 91-92. 1 2 3 4 5 6 7 8 9 Grade. Motor Data Wind Section Limits. Rise or Fall Length of Time to Run Item Test p - Over Track Over use an Efficiency of No. No. ing Trolley Line Pole Section. tion Section e n Motors Helping Numbers Connection and Gears - Down Oor H Feet Feet See's. % 1 92 0 1 455-1 470 --0.56 1 495 31.50 4 M 81.5 2 91 H 1 470-1 455 +0.56 25.61 4 M 78.0 3 92 0 1 455-1 470 --0.56 29.80 4 M 82.0 4 91 H 1 470-1 455 +0.56 30.35 C 5 92 0 1 455-1 470 --0.56 43.89 C 6 91 H 1 470-1 455 +0.56 36.46 C 7 92 0 1 455-1 470 --0.56 37.86 C 8 91 H 1 470-1 455 +0.56 44.96 C 9 92 0 1 455-1 470 -0.56 45.94 C 10 91 H 1 470-1 455 +0.56 41.47 C 11 92 0 1 455-1 470 --0.56 " 63.71 C *8=Series-multiple. M=Multiple. Sw= Switching. C=Coasting. TABLE 8 TEST No. 95-96. 1 2 3 4 5 6 7 8 9 Motor Data Item Test Wind Section Limits Grade Length of Time No. and-- No. No. 0 orH Section Connection Efficiency 1 95 H 1 470-1 455 +0.56 1 495 21.97 4 M 79.6 2 96 0 1 455-1 470 --0.56 27.55 " 82.6 3 95 H 1 470-1 455 +0.56 23.90 " 81.2 4 96 0 1 455-1 470 -0.56 27.42 " 82.0 5 95 H 1 470-1 455 +0.56 24.70 " 81.2 6 96 0 1 455-1 470 -0.56 28.40 " 82.6 7 95 H 1 470-1 455 +0.56 43.37 4 S 72.9 8 96 0 1 455-1 470 -0.56 58.10 4 8 73.6 9 95 H 1 470-1 455 +0.56 32.00 4 M 83.0 10 96 0 1 455-1 470 --0.56 33.10 " 83.1 11 95 H 1 470-1 455 +0.56 27.50 " 80.5 12 96 0 1 455-1 470 -0.56 30.20 " 82.7 13 95 H 1 470-1 455 +0.56 38.05 C 14 96 0 1 455-1 470 -0.56 33.30 C 15 95 H 1 470-1 455 +0.56 37.25 C 16 96 0 1 455-1 470 -0.56 35.20 C 17 95 H 1 470-1 455 +0.56 48.05 C 18 96 0 1 455-1 470 -0.56 39.75 C *S=Series-multiple. M=Multiple. Sw=Switching. C=Coasting. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR TABLE 7 (Continued) TEST No. 91-92. 10 11 12 13 14 15 16 17 18 19 Speed Energy Imparted to the Car Net Average Item At At Average Average B the Change Car Speed to from Current in Kinetic ance Section Section Section Energy M. P. H. M. P. H. Volts Amp's. Ft. Lbs. Ft. Lbs. Ft. Lbs. Lb. Per M. P. H. 1 32.71 33.24 454 134.7 1 157 860 - 71 130 --31 560 25.05 32.36 2 40.52 41.41 472 112.5 782 280 -148 390 +31 560 15.80 39.82 3 34.13 34.48 472 137.1 1 166 190 - 48 870 -31 560 25.78 34.21 4 35.01 32.00 +410 460 +31 560 10.50 33.59 5 27.56 20.10 +723 530 -31 560 16.43 23.22 6 28.80 25.78 +335 430 +31 560 8.71 27.96 7 30.93 22.76 +892 650 -31 560 20.44 26.92 8 22.76 18.85 +331 080 +31 560 8.61 22.67 9 27.38 17.43 +907 320 -31 560 20.79 22.19 10 26.67 22.23 +441 830 +31 560 11.24 24.58 11 20.63 12.10 +568 150 -31 560 12.74 16.00 TABLE 8 (Continued) TEST No. 95-96. 10 11 12 13 14 15 16 17 18 19 Speed Energy Imparted to Car Net Car Item Average Average -Resist- Avera e No. Entrance Exit Voltage Current By Current ByEKinetic By Grade ance 1 46.44 46.13 518 117.5 785 010 + 58 398 -31 556 19.27 46.40 2 37.87 37.24 499 138.7 1 161 600 + 96 295 +31 556 30.61 37.00 3 41.21 43.11 516 126.6 934 980 -326 020 -31 556 13.71 42.65 4 37.24 37.24 482 135.4 1 082 200 0 +31 556 26.44 37.17 5 39.94 42.00 510 127.0 958 050 -343 500 -31 556 13.84 41.27 6 35.34 36.76 488 140.0 1 182 000 -208 350 +31 556 23.87 35.89 7 22.96 25.18 539 45.6 573 090 -217 480 -31 556 7.69 23.50 8 17.40 18.20 522 46.8 770 440 - 57 957 +31 556 17.66 17.54 9 27.72 33.75 450 150.4 1 325 700 -754 300 -31 556 12.82 31.85 10 29.62 33.27 452 151.2 1 386 400 -467 130 +31 556 22.57 30.80 11 35.97 37.56 477 125.4 976 580 -237 920 -31 556 16.79 37.07 12 32.16 33.75 477 142.7 1 253 800 -213 260 +31 556 25.45 33.75 13 30.26 26.45 +439 690 -31 556 9.69 26.79 14 34.54 26.61 +986 810 +31 556 24.18 30.61 15 29.31 25.02 +474 310 -31 556 10.51 27.36 16 32.32 25.34 +819 020 +31 556 20.19 28.96 17 22.96 18.83 +351 230 -31 556 7.59 21.21 18 28.35 20.89 +747 520 +31 556 18.50 25.64 ILLINOIS ENGINEERING EXPERIMENT STATION Fl. 14. FIG. 15. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR FIG. 16. FIG. 17. ILLINOIS ENGINEERING EXPERIMENT STATION TABLE 9 TESTS ON TRACK SECTION D. 1 2 3 4 5 6 7 8 9 Grade Motor Data Item Test O s Section Limits. Rise or Fall Length of Time to Run Efliciency of o ppv- - Over Trar Number iO No. No. Trolley Line Pole Section Section Section Use and Motors Helping Numbers Up Connection and Gears - Down 0 or H Feet Feet Sec's. % 1 109 H 1 571-1 566 +0.37 445 11.8 4 S 70.1 2 110 0 1 575-1 581 +2.54 522 19.3 4 S 81.4 3 109 H 1 571-1 563 +0.42 714 20.9 4 S 71.6 4 110 0 1 575-1 581 +2.54 522 17.3 4 S 82.5 5 110 0 1 575-1 581 +2.54 522 12.5 4 M 84.5 6 109 H 1 571-1 563 +0.42 714 15.9 4 M 79.9 7 109 H 1 571-1 563 +0.42 714 16.9 4 M 74.5 8 110 0 1 575-1 583 +4.60 700 19.4 4 M 80.9 9 110 0 1 575-1 583 +4.60 700 20.2 1 86.0 10 109 H 1 571-1 566 +0.37 445 16.8 C - 11 111 H 1 581-1 575 -2.54 522 17.6 C 12 111 H 1 581-1 575 -2.54 522 22.3 C - 13 111 H 1 571-1 563 +0.42 714 20.6 4 S 73.9 14 112 0 1 575-1 581 +2.54 522 20.0 4 S 79.4 15 111 H 1 571-1 566 +0.37 445 12.4 4 S 70.5 16 112 0 1 575-1 581 +2.54 522 19.4 4 8S 76.6 17 111 H 1 571-1 566 +0.37 445 12.5 4 S 68.7 18 112 0 1 575-1 583 +4.60 700 26.7 4 S 80.8 19 112 0 1 575-1 583 +4.60 700 25.9 4 S 79.5 20 111 H 1 571-1 566 +0.37 445 12.5 4 S 61.5 21 112 0 1 575-1 583 +4.60 700 26.3 4 S 79.6 22 111 H 1 571-1 566 +0.37 445 12.7 4 S 66.0 23 112 0 1 575-1 583 +4.60 700 26.9 4 S 78.5 24 111 H 1 571-1 566 +0.37 445 10.5 4 M 72.6 25 112 0 1 575-1 581 +2.54 522 14.8 4 M 82.1 26 111 H 1 571-1 566 +0.37 445 10.5 4 M 67.8 27 111 H 1 571-1 566 +0.37 445 10.2 4 M 73.8 28 112 0 1 575-1 583 +4.60 700 20.0 4 M 74.5 29 111 H 1 571-1 566 +0.37 445 10.1 4 M 73.6 30 112 0 1 525-1 583 +4.60 700 18.5 4 M 80.8 31 111 H 1 571-1 566 +0.37 445 9.9 4 M 73.8 32 112 0 1 575-1 583 +4.60 700 18.5 4 M 81.5 33 114 0 1 575-1 578 +0.48 256 26.3 2 M 71.0 34 114 0 1 566-1 571 -0.37 445 20.7 2 M 65.0 35 113 H 1 571-1 566 +0.37 445 25.5 2 M 66.7 36 114 0 1 566-1 571 -0.37 445 26.7 2 M 70.5 *S=Seriec-multiplo. M=Multiple. Sw=Switching. C=Coasting. DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR TABLE 9 (Continued) TESTS ON TRACK SECTION D. 10 11 12 13 14 15 16 17 18 19 Speed Energy Imparted to Car Item At At Average Average Net Avee No. Entrance Exit Voltage Current By the in KinetingeBy the Grade Resistance Over the to the from the Current Section Section Section Energy M. P. H. M. P H. Volts Amp's. Ft. Lbs. Ft. Lbs. Ft. Lbs. TonPer M P. H. 1 24.30 23.94 492 42.9 128 600 + 35 700 - 21 070 11.30 25.72 2 16.74 17.64 496 65.0 373 400 - 63 580 -144 700 11.11 18.44 3 22.50 21.60 472 45.5 237 200 + 81 560 - 23 920 14.50 23.23 4 19.80 20.34 565 64.8 385 300 - 44 530 -144 700 13.19 20.57 5 27.36 28.98 460 174.0 622 000 -187 600 -144 700 19.49 28.56 6 31.50 32.76 449 124.0 521 600 -166 400 - 23 920 16.29 30.60 7 27.90 27.90 344 107.5 343 200 0 - 23 920 15.71 28.80 8 23.94 24.30 368 148.0 630 300 - 35 700 -262 000 16.68 24.59 9 22.86 22.86 484 77.2 478 600 0 -262 000 10.86 23.61 10 19.80 18.00 +139 800 - 21 070 9.36 18.03 11 19.62 19.08 + 42 510 +143 100 12.62 20.22 12 15.30 15.30 0 +143 100 9.72 15.95 13 23.04 22.50 496 47.8 266 100 + 50 040 - 23 670 14.54 23.62 14 17.64 18.00 475 59.9 333 000 - 26 110 -143 100 11.13 17.78 15 24.12 24.12 467 43.9 132 100 0 - 20 850 8.88 24.46 16 18.00 18.00 443 54.0 262 000 0 -143 100 8.09 18.33 17 24.12 23.40 460 42.2 122 800 + 69 620 - 20 850 13.68 24.26 18 17.64 18.00 477 63.6 482 400 - 26 110 -259 200 10.00 17.87 19 18.36 18.36 475 59.9 431 900 0 -259 200 8.76 18.42 20 23.22 22.68 417 38.8 91 680 + 50 450 - 20 850 9.67 24.27 21 18.00 17.64 467 60.6 436 800 + 26 110 -259 200 10.32 18.13 22 23.94 23.76 463 39.8 113 800 + 17 460 - 20 850 8.81 23.88 23 18.36 17.46 454 58.1 410 500 + 65 600 -259 200 11.00 17.74 24 28.44 28.26 337 105.5 200 000 + 20 800 - 20 850 15.94 28.88 25 22.14 24.66 372 160.4 535 000 -240 000 -143 100 10.32 24.03 26 27.72 27.72 306 96.2 154 400 0 - 20 850 10.65 28.88 27 30.06 30.24 365 104.0 210 800 - 22 100 - 20 850 13.38 29.72 28 23.22 24.30 358 149.0 586 400 -104 400 -259 200 11.30 23.85 29 29.34 29.52 352 106.0 204 600 - 21 550 - 20 850 12.93 30.02 30 25.20 25.38 381 141.5 594 500 - 18 520 -259 200 16.06 25.79 31 30.78 30.96 365 105.0 206 500 - 22 600 - 20 850 13.00 30.63 32 24.66 25.74 387 145.0 624 000 -110 800 -259 200 12.88 25.80 33 5.76 6.66 113 62.3 97 020 - 22 700 - 26 980 6.58 6.64 34 13.32 13.68 160 45.1 71 640 - 19 730 + 20 790 5.81 14.64 35 11.34 10.08 142 48.9 87 180 + 54 810 - 20 790 9.69 11.89 36 8.64 10.44 149 55.4 114 300 - 69 710 + 20 790 5.23 11.35 ILLINOIS ENGINEERING EXPERIMENT STATION TABLE 10 TESTS ON TRACK SECTION W. 1 2 3 67 1 2 3 4 5 6 7 8 9 Motor Data Item Test Wind Section Grade Length of Time Number and I No. No. 0 or H Limits Section Connection Efficiency 1 118 0 7-16 +1.37 1 189 24.1 4 M 78.4 2 118 0 21-30 -0.40 1 154 23.4 4 M 81.0 3 117 H 30-21 +0.40 1 154 35.1 4 S 63.1 4 118 0 7-16 +1.37 1 189 43.4 4 S 70.0 5 117 H 16- 7 -1.37 1 189 22.1 4 M 83.5 6 118 0 21-30 -0.40 1 154 22.3 4 M 80.1 7 117 H 16- 7 -1.37 1 189 20.5 4 M 78.2 8 117 H 16- 7 -1.37 1 189 20.1 4 M 79.2 9 118 0 21-30 -0.40 1 154 19.8 4 M 83.0 10 117 H 16- 7 -1.37 1 189 20.4 4 M 78.3 11 118 0 21-30 -0.40 1 154 32.7 4 S 73.7 12 117 H 30-21 +0.40 1 154 29.4 4 S 70.0 13 123 0 30-21 +0.40 1 154 33.2 4 S 70.6 14 124 H 21-30 -0.40 1 154 33.4 4 S 65.4 15 124 H 7-16 +1.37 1 189 35.9 4 S 66.8 16 124 H 21-30 -0.40 1 154 22.8 4 M 81.9 17 123 0 30-21 +0.40 1 154 36.6 4 M 82.9 18 124 H 21-30 -0.40 1 154 36.0 4 S 67.4 19 123 0 16- 7 -1.37 1 189 34.5 4 S 72.0 20 123 0 30-21 +0.40 1 154 33.8 4 8 74.7 21 124 H 21-30 -0.40 1 154 36.2 4 S 66.9 22 123 0 16- 7 -1.37 1 189 64.1 4 Sw 61.3 23 124 H 21-30 -0.40 1 154 32.3 4 M 77.9 24 123 0 30-21 +0.40 1 154 22.5 4 M 78.5 25 124 H 21-30 -0.40 1 154 25.5 4 M 74.3 26 124 H 21-30 -0.40 1 154 23.7 4 M 74.9 27 123 0 16- 7 -1.37 1 189 34.2 4 S 70.7 *S=Series-multiple. M=Multiple. Sw=Switching. C=Coasting. iL TESTS ON I I I TRACK SECTION S. II H s 10 15S 20 EE25 3LM.P.H. r SPEED--M.P.H. FIG. 18. I I 140H-IH451 I I I I I I i i I I i i I I 1 177111 i I I I i I I I 1 lrrTll 1 I I I I I LI I II I'B DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR TABLE 10 (Continued) TESTS ON TRACK SECTION W. 10 11 12 13 14 15 16 17 18 19 Speed Energy Imparted to the Car Item Average Average Net Car Average No. Entrance Exit Voltage Current By Current By Kinetic By Grade Resistance Speed Energy 1 35.28 34.02 407 119.0 674 850 +177 260 -76 990 23.20 33.61 2 33.48 34.56 449 131.7 826 550 -149 170 +22 480 21.58 33.60 3 23.76 21.24 415 42.5 288 140 +230 200 -22 480 15.22 22.41 4 19.44 18.54 399 52.0 464 910 + 69 390 -76 990 14.10 18.66 5 36.18 38.34 537 153.5 1 121 800 -326 750 +76 990 26.10 36.65 6 36.00 36.00 454 125.8 752 340 0 +22 480 23.89 35.27 7 40.68 40.50 467 113.5 626 610 + 29 660 +76 990 21.95 39.51 8 42.12 42.30 492 116.8 674 720 - 30 850 +76 990 21.58 40.31 9 40.32 41.04 555 142.5 958 580 -118 920 +22 480 26.59 39.70 10 40.32 41.04 473 114.5 638 020 -118 920 +76 990 17.84 39.72 11 23.76 24.30 555 59.0 582 090 - 52 680 +22 480 17.01 24.05 12 27.18 26.64 592 50.3 451 990 + 59 000 -22 480 15.06 26.75 13 23.40 23.58 256 52.3 462 930 - 17 340 -22 700 12.92 23.69 14 23.04 22.50 225 44.7 324 130 + 42 510 +22 700 11.89 23.54 15 20.70 20.34 220 46.6 362 570 + 30 290 -77 750 9.34 22.56 16 34.20 35.28 460 136.7 865 940 -153 830 +22 700 22.44 34.47 17 25.74 29.88 427 152.5 1 059 000 -472 050 -22 700 17.23 29.55 18 20.70 21.06 222 47.5 377 400 - 30 820 +22 700 11.28 21.83 19 22.50 23.40 268 54.8 538 040 - 84 690 +77 750 15.74 23.47 20 20.34 23.40 290 60.9 657 690 -274 380 -22 700 11.01 23.25 21 20.52 20.88 220 46.8 367 750 - 30 550 +22 700 10.99 21.72 22 11.34 11.70 119 42.5 293 270 - 17 000 +77 750 10.49 12.63 23 32.76 32.76 397 116.0 616 430 0 +22 700 19.52 33.74 24 33.30 33.66 417 118.8 645 310 - 49 420 -22 700 17.50 34.95 25 30.96 30.60 346 109.6 529 860 + 45 430 +22 700 18.26 30.83 26 32.04 32.40 372 108.6 528 900 - 47 560 +22 700 15.39 33.17 27 22.68 23.40 254 52.7 477 370 - 68 010 +77 750 14.43 23.69 TESTS ON TRACK SECTION "R I I ±H 5 H-+=10 H-15L jio lia3^H FIG. 19. Note.-Solid dots are for runs with the wind, open circles are for runs against the wind, and circles with the lower half black are for runs in no wind. 40H--45 Sil l ! | !r """"""' ILLINOIS ENGINEERING EXPERIMENT STATION TABLE 11 TESTS ON TRACK SECTION S. 3 Wind Oppos- ing or Helping 0 or H 4 Section Limits. Trolley Line Pole Numbers 37-29 12- 4 29-37 4-12 29-36 37-29 12- 4 29-37 12- 4 29-37 4-12 12- 4 29-37 12- 4 12- 4 37-29 29-37 4-12 12- 4 37-29 4-12 12- 4 12- 4 29-37 12- 4 29-37 4-12 12- 4 4-12 12--4 4-12 29-37 4-12 29-37 12- 4 29-37 12- 4 29-37 37-29 12- 4 29-37 12- 4 4-12 12- 4 37-29 5 Grade Rise or Fall Over Section + Up - Down Feet +0.76 -3.40 -0.76 +3.40 -0.54 +0.76 -3.40 -0.76 -3.40 -0.76 +3.40 -3.40 -0.76 -3.40 -3.40 +0.76 -0.76 +3.40 -3.40 +0.76 +3.40 -3.40 -3.40 -0.76 -3.40 -0.76 +3.40 -3.40 +3.40 -3.40 +3.40 -0.76 +3.40 -0.76 -3.40 -0.76 -3.40 -0.76 +0.76 -3.40 -0.76 -3.40 +3.40 -3.40 +0.76 6 Length of Section Feet S= Series-multi g. 7 Time to Run Over Section See's. Number in Use and Connection 4M 2 M 4 S 4 M 2,M 4 S 4 M 4 Sw 4 S 4 M 2 Test No. Item No. 8 9 Motor Data Efficiency of Motors and Gears % :-`~"' ~ """ " " *0"-- = S it hi 0= Coa n DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR TABLE 11 (Continued) TESTS ON TRACK SECTION S. 13 Average Voltage Volts 11 12 Speed 15 16 17 Energy Imparted to the Car By te By the Change Crent in Kinetic 10 Item No. I I 14 Average Current Amps. 95.7 79.2 131.5 77.0 115.0 170.0 86.6 102.0 82.0 102.0 94.0 52.2 94.1 57.9 45.1 53.6 50.7 46.9 41.7 58.5 53.3 43.3 81.6 125.0 90.0 78.6 94.4 66.3 95.0 39.0 45.8 49.7 53.1 52.5 104.0 116.0 81.2 50.0 57.8 37.0 50.8 128.0 143.0 85.4 136.0 At Entrance to the Section M. P. H. 28.05 32.20 31.47 34.36 29.12 31.48 37.40 26.08 33.10 27.88 28.22 31.11 24.62 25.89 25.52 22.82 19.76 20.68 24.99 20.30 22.82 26.08 33.81 29.11 36.33 26.25 24.44 32.38 24.62 26.61 22.63 20.48 23.19 18.50 33.09 26.98 32.55 17.78 19.22 19.94 15.62 36.50 34.00 38.68 38.31 At Exit rom the Section A. P. H. 26.98 32.01 33.10 31.11 30.40 35.97 37.04 26.98 33.28 28.77 26.80 30.40 27.32 26.25 26.61 23.55 21.73 19.76 25.52 22.11 21.91 26.80 33.45 30.75 36.33 26.80 24.99 32.55 25.18 26.80 21.39 20.48 20.83 19.40 32.91 28.05 31.66 18.50 19.76 19.04 17.24 37.95 34.35 37.78 38.31 19 Average Speed Over the Section M. P. H. Ft. Lbs. 349 380 217 740 705 910 211 130 482 080 1 180 600 289 940 422 600 256 530 422 170 346 860 226 290 657 240 270 080 312 270 482 400 426 170 352 740 265 660 580 900 468 620 280 810 246 270 642 430 316 350 503 150 689 070 371 790 689 940 220 150 344 890 348 960 405 450 387 050 406 300 473 860 222 730 331 000 507 570 173 390 381 270 675 280 848 320 281 280 796 440 Energy Ft. Lbs. +120 710 + 25 000 -215 760 +436 200 -156 180 -620 840 + 54 940 - 97 900 - 24 490 -103 360 +160 160 + 89 530 -287 490 - 38 480 -116 480 - 69 390 -167 560 + 76 270 - 54 880 -157 360 + 83 440 - 78 050 + 49 640 -201 250 0 - 59 810 - 55 730 - 22 630 - 57 170 - 20 800 +111 900 0 +212 970 - 69 930 + 24 350 -120 710 +117 150 - 53 550 - 43 150 + 71 920 -109 130 -221 300 - 49 040 +141 070 0 18 Net Car Resistance Lbs. Per Ton 14.23 14.57 17.78 15.19 13.55 17.23 17.98 12.26 14.21 12.07 10.50 17.01 13.77 14.20 13.00 12.33 10.06 7.89 13.50 12.68 12.01 13.23 16.35 16.15 17.03 16.22 14.72 18.13 14.71 13.12 8.82 13.07 14.23 12.01 20.85 13.21 17.81 10.69 14.05 14.65 10.51 21.63 20.27 20.57 25.12 By the Grade Ft. Lbs. - 43 130 +192 900 + 43 130 -192 900 + 30 650 - 43 130 +192 900 + 43 130 +192 900 + 43 130 -192 900 +192 900 + 43 130 +192 900 +192 900 - 43 130 + 43 130 -192 900 +192 900 - 43 130 -192 900 +192 900 +192 900 + 43 130 +192 900 + 43 130 -192 900 +192 900 -192 900 +192 900 -192 900 + 43 130 -192 900 + 43 130 +192 900 + 43 130 +192 900 + 43 130 - 43 130 +192 900 + 43 130 +192 900 -192 900 +192 900 - 43 130 ILLINOIS ENGINEERING EXPERIMENT STATION TABLE 12 TESTS ON TRACK SECTION R. 4 5 6 Section Limits Grade Length of Section 13 Item No. 2 Test No. 125 126 125 125 125 126 126 126 126 125 126 126 126 126 126 126 128 127 129 129 130 130 129 130 130 129 130 130 130 130 129 129 130 129 129 130 129 142 141 141 142 141 141 142 141 141 141 141 141 142 141 142 141 141 142 141 153 153 153 153 153 153 7 8 9 Motor Data Time No. and Ef Con ct ion s- 3 Wind 0 or H 0 H 0 0 0 H H H H 0 H H H H H H H H 0 0 H 0 0 H 0 0 0 0 H H 0 H H 0 H H 0 0 H 0 0 H 0 0 0 0 0 H 0 H 0 0 H 0 14 - 4 4 - 14 45 - 38 14 - 4 45 - 38 38 - 45 4 - 14 38 - 45 4 - 14 45 - 38 38 - 45 4 - 14 38 - 45 4 - 14 4 - 14 38 - 45 4 - 14 14 - 4 14 - 4 45 - 38 4 - 14 38 - 45 14 - 4 4 - 14 38 - 45 14 - 4 4 - 14 38 - 45 38 - 45 4 - 14 45 - 38 14 - 4 4 - 14 45 - 38 14 - 4 4 - 14 27 - 24 1 725 -1 730 1 741 -1 737.5 1 730 -1 725 1 737.5-1 741 1 730 -1 725 1 730 -1 725 1 737.5-1 741 1 741 -1 737.5 1 730 -1 725 1 741 -1 737.5 1 730 -1 725 1 730 -1 725 1 737.5-1 741 1 730 -1 725 1 737.5-1 741 1 730 -1 725 1 730 -1 725 1 737.5-1 741 1 730 -1 725 1 730 -1 725 1 730 -1 725 1 741 -1 737.5 1 730 -1 725 1 730 -1 725 1 741 -1 737.5 ' 8= Berice-multiple. M= Multiple. Sw= ing. -2.62 +2.62 -2.93 -2.62 -2.93 +2.93 +2.62 +2.93 +2.62 -2.93 +2.93 +2.62- +2.93 +2.62 +2.62 +2.93 +2.62 -2.62 -2.62 -2.93 +2.62 +2.93 -2.62 +2.62 +2.93 -2.62 +2.62 +2.93 +2.93 +2.62 -2.93 -2.62 +2.62 -2.93 -2.62 +2.62 -0.26 +1.63 -1.90 -1.63 +1.90 -1.63 -1.63 +1.90 -1.90 -1.63 -1.90 -1.63 -1.63 4-1.90 -1.63 +1.90 -1.63 -1.63 +1.90 -1.63 -1.63 -1.63 -1.90 -1.63 -1.63 -1.90 I 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 S 4 S 4 S 4 S 4 8 4 M 4 8 4 S 48 4 S 4 S 4 8 48 4 S 4 8 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 M 4 S 4 S 4 S 4 S 4 S 4 M 4 M 4 M 4 8 4 S 4 S 4 8 4 S 4 M 4 S 4 M 4S 4S 4 4M 4 M 4S 4S 4 8 4 S 4 S 4S ciency 80.3 78.9 84.3 73.7 80.5 83.8 75.9 85.1 77.4 83.8 85.0 80.2 77.3 71.4 75.3 76.3 72.4 62.4 66.6 73.5 72.0 63.3 38.0 72.5 70.7 76.0 82.5 82.9 83.2 84.0 72.7 46.7 82.7 45.8 65.4 83.4 49.5 74.0 55.0 65.4 71.4 44.0 43.0 69.4 69.3 53.6 66.5 43.0 60.3 77.7 49.6 63.1 55.1 58.4 73.2 47.8 41.0 31.0 42.1 33.5 43.4 37.5 DUNN-RESISTANCE OF A 28-TON ELECTRIC CAR TABLE 12 (Continued) TESTS ON TRACK SECTION R. 10 11 12 Speed Item No. Entrance Exit __ i ______ 35.29 36.52 34.73 33.11 29.16 33.67 29.68 30.96 26.80 30.60 32.02 30.78 32.58 30.22 32.58 34.01 35.47 32.75 32.76 36.52 34.38 35.28 36.19 33.82 20.32 21.41 21.22 19.61 21.78 22.31 20.88 21.41 15.42 16.31 27.48 25.51 23.78 25.58 22.13 26.29 21.22 19.97 20.52 18.54 18.54 18.54 15.29 16.02 18.17 18.00 37.98 38.18 29.70 30.08 30.79 32.07 31.51 31.51 31.32 33.49 28,07 30.25 29.71 27.57 32.78 32.95 29.52 28.81 27.72 28.28 33.68 34.02 14.76 14.76 19.32 19.86 20.95 21.67 20.58 21.85 15.36 14.64 25.62 25.28 29.05 28.32 26.52 25.28 18.60 19.87 15.18 15.36 13.92 16.08 15.90 15.54 20.78 21.83 26.35 26.35 22.02 22.38 21.12 20.04 13.02 14.28 21.12 20.58 22.57 21.49 23.47 23.47 21.57 21.92 19.94 19.03 14.71 16.16 22.11 21.39 19.94 19.94 16.16 16.70 13 14 15 16 17 18 19 Energy Imparted to the Car Net Car Average Average I ---h- - Resist- Average Voltage Current B t errt By theMo By the Grade ance Speed I ic Energy 431 128.4 809 490 -182 840 +150 260 380 127.7 739 860 +227 500 -150 260 441 168.7 920 480 -586 560 +168 040 321 112.2 569 730 -160 670 +150 260 365 145.2 657 630 -451 510 +168 040 387 139.7 648 150 +161 200 -168 040 340 119.2 642 040 +306 800 -150 260 490 178.8 1 028 200 -197 110 -168 040 361 122.6 684 670 +384 110 -150 260 480 156.2 815 570 -539 220 +168 040 496 173.2 964 010 -129 780 -168 040 397 132.1 809 540 +343 460 -150 260 264 70.3 620 020 - 94 160 -168 040 205 55.1 542 410 +136 070 -150 260 262 64.8 771 350 - 48 370 -150 260 266 68.1 566 770 - 46 400 -168 040 182 59.8 663 740 - 58 600 -150 650 193 84.0 267 060 +216 610 +150 650 214 46.4 359 960 -183 920 +150 260 265 59.0 418 670 -417 000 +168 040 214 55.6 551 010 +106 580 -150 260 175 43.4 216 130 +160 100 -168 040 112 29.4 85 830 0 +150 260 185 59.8 643 660 - 47 310 -150 260 180 55.1 380 700 + 12 730 -168 040 376 112.2 569 890 - 31 740 +150 260 387 156.4 1 082 800 - 47 020 -150 260 413 154.5 768 540 -166 550 -168 040 413 156.2 783 740 0 -168 040 445 164.7 1 239 500 -291 120 -150 260 298 111.7 362 330 -263 180 --168 040 162 54.2 90 420 +253 740 +150 260 432 149.3 1 089 700 - 23 130 -150 260 158 152.3 59 450 + 85 730 +168 040 232 89.3 305 820 - 64 920 +150 260 434 157.2 1 137 300 - 47 650 -150 260 99 34.4 41 520 0 + 14 910 248 61.3 285 450 - 44 110 - 94 210 173 36.6 54 430 - 63 980 +109 820 202 45.1 138 850 -112 350 + 94 210 149 59.4 142 600 + 45 040 -109 820 139 50.2 30 570 + 36 080 + 94 210 176 59.1 39 910 + 87 320 + 94 210 246 100.0 109 540 +133 920 -109 820 202 50.6 117 300 -101 820 +109 820 109 36.5 69 830 - 11 460 + 94 210 129 49.2 89 620 -135 110 +109 820 84 24.8 30 390 + 23 890 + 94 210 170 40.7 99 090 - 93 280 + 94 210 298 143.0 229 520 0 -109 820 155 33.6 60 990 - 33 330 + 94 210 191 85.6 83 700 + 92 680 -109 820 117 37.5 87 010 - 71 720 + 94 210 169 39.1 93 950 + 46 950 + 94 210 236 118.0 157 860 + 99 210 -109 820 159 65.1 54 160 0 + 94 210 223 27.4 57 270 - 31 740 + 94 380 94 20.5 15 330 + 73 940 + 94 380 113 30.8 31 120 - 93 330 +110 010 115 22.5 20 070 + 65 300 + 94 380 131 31.0 45 490 0 + 94 380 74 24.1 13 850 - 37 000 +110 010 20.53 36.43 21.59 34.35 19.03 31.50 14.78 30.92 14.18 30.00 24.31 32.31 21.10 31.81 25.13 33.51 24.27 33.21 16.84 35.61 25.25 35.02 26.49 34.50 13.56 21.39 13.96 19.74 15.13 22.00 13.36 22.55 11.98 15.77 16.71 25.12 8.62 24.39 6.43 25.38 13.40 20.63 7.89 20,62 6.24 19.35 11.78 16.54 8.54 17.04 18.19 37.35 23.39 30.61 16.45 31.82 23.34 31.66 21.08 32.97 10.13 30.90 13.06 30.10 24.21 32.50 11.87 29.45 10.33 29.41 24.81 33.21 5.29 16.18 9.81 20.58 10.27 21.72 8.05 22.40 7.97 15.05 10.72 26.20 14.77 29.22 13.68 26.49 12.83 20.58 10.17 15.94 6.58 16.00 9.90 15.37 6.66 21.98 12.25 24.51 8.12 22.10 6.81 20.96 7.30 14.50 15.67 21.42 15.08 21.92 9.89 23.90 7.98 22.82 12.22 20.34 4.88 16.00 11.96 17.12 9.31 20.22 8.88 16.33 -- i .... I PUBLICATIONS OF THE ENGINEERING EXPERIMENT STATION Bulletin No. I. Tests of Reinforced Concrete Beams, by Arthur N. Talbot. 1904. None available. Circular No. I. High Speed Tool Steels, by L. P. Breckenridge. 1905. None available. Bulletin No. 2. Tests of High-Speed Tool Steels on Cast Iron, by L. P. Breckenridge and Henry B. Dirks. 1905. None available. Circular No. 2. Drainage of Earth Roads, by Ira 0. Baker. 1906. None available. Circular No. 3. Fuel Tests with Illinois Coal (Compiled from tests made by the Tech- nologic Branch of the U. S. G. S., at the St. Louis, Mo., Fuel Testing Plant, 1904-1907), by L. P. Breckenridge and Paul Diserens. 1909. Thirty cents. Bulletin No. 3. The Engineering Experiment Station of the University of Illinois, by L. P. Breckenridge. 1906. None available. Bulletin No. 4. Tests of Reinforced Concrete Beams, Series of 1905, by Arthur N. Talbot. 1906. Forty-five cents. Bulletin No. 5. Resistance of Tubes to Collapse, by Albert P. Carman and M. L. 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THE REGIRAR^ 1 ' ; '^ 4 Uba-,Mes .s *5,. 2- *. .-ist1--;^ ^ '^ ^1-; ^ ^^^ ^-^ '^ 1 5^^ ^^ *^. . ^ ^ ^. 'I-A I U^¥ ;:y!S '% ^ ^ - S > 54. ,: - /: " : • * U r " ' . ...bana' 1 EDMUND J. JAMES, Ph. D., L.L. D., President The University includes the following de.partments: - - The College of Liberal Arts and Sciences (Ancient and Modern Lan- 'guages and Literatures; History, Economics and Accountancy," ' Political Science, Sociology; Philosophy, Psychology, Educationl; - ' Mathematics; Astronomy; Geology; Physics; Chemistry; B tany, S* r'Zoology, Entomology; Physiology; Art and Design; Cermic) S trical, Mechanical, Mining, Municipal and Sanitary, and Railway * Engineering), The College of Agricultre (Agronomy; Animal Husbandry; Dairy; S:Husbandry; Hortiiculture and Landscape Gardening; Veter-inary- Science; Agricultural Extension, Teachers'. -Course; Household :: The ollege of Law (three years' course) ,, . The School of Education The Courses in Busiess (General Business; Banking; Accountancy;. The School of Railway Engineering and Administration . The School of Music (four years' course) , .- The College of Dentistry (in, Chicago) - ^ /^ ^-~h^ ^'f~'i^ <'-^li'111 54 54. II i * 12 4'-. '~ .4.'- 4 ,2 C 4 4' --'.4 '4' '-4' '-'4 "7 4" C' '4' A '4 "4 'A"" -Q 'A) 4. A .4 4. 4 '- '-: '." "'A 4'S ' '4 -4' '4 .4'- 4 - .4' 2' / ' ''4 4' ' ' ' 12 '- 4" -'' / '7 "5;- 4'~~4' -'. 4' 4 4 V'S '2 .4 ' '~ A 4"'>' '4' - .4 -SQ *' 44444 .2 ~ "4"' " >,~ ~ 4?i~ A 4"... 4 44 44 #4 - ' .4 A 4 '4 -. . ''V ~' .4' A r'< ' ,~44'- ~ '~<' A .S'4'-'K4~ ' ' 4-' - AC . 4 - -k 744. . - ~'4" 4 ~"'A s( ~-r 4' ~< tr.'4't, 4~ 4 4.4 .4' 44,' 4 4..4'.4.4' ½ A ~ 4"t~c~.- 44~L