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All railcar movers are rated in pullng capacity, drawbar pull, or tractive effort with the maximum pulling capacity listed either in pounds, tons or kilo newtons. Many factors can and do affect rolling resistance. Grade, track curvature and road bed condition all have an effect on the actual rolling resistance. How to measure curves To find the degree of curve, stretch a line sixty-two (62) feet long with a mark at the mid-point (31 ft.) on the outside of the inner rail flange. Measure the distance from the mid-point mark vertically to the rail flange. Each one inch increment equals 1 degree of track curvature. Rise Radius Degree Rise Radius Degree 1 5766 1 18 321 18 2 2883 2 19 304 19 3 1922 3 20 289 20 4 1442 4 21 275 21 5 1153 5 22 263 22 6 961 6 23 252 23 7 824 7 24 241 24 8 721 8 25 232 25 9 641 9 26 223 26 10 577 10 27 215 27 11 525 11 28 207 28 12 481 12 29 200 29 13 444 13 30 193 30 14 412 14 31 187 31 15 385 15 32 182 32 16 361 16 33 176 33 17 340 17 34 171 34 Caution: on tracks with 20 degrees or more curve consultation with a factory representative is recommended. How to measure grade To find the percent of grade, stretch a 100" line as shown below. When the line is level, measure the number of inches above the rail ("A" below). Each inch represents one percent of grade. Grade and curve combined Total Resistance Track curve in degrees 0 1 2 4 6 8 10 12 14 16 18 20 22 24 26 0% 10 11 12 14 16 18 20 22 24 26 28 30 32 34 36 .5% 20 21 22 24 26 28 30 32 34 36 38 40 42 44 46 1.0% 30 31 32 34 36 38 40 42 44 46 48 50 52 54 56 1.5% 40 41 42 44 46 48 50 52 54 56 58 60 62 64 66 2.0% 50 51 52 54 56 58 60 62 64 66 68 70 72 74 76 2.5% 60 61 62 64 66 68 70 72 74 76 78 80 82 84 86 3.0% 70 71 72 74 76 78 80 82 84 86 88 90 92 94 96 Note: to determine Tractive Effort requirements, multiply gross railcar weight in tons x number of cars x curve/grade resistance selected from chart above. Example: 5 cars @ 131 tons each on 1% grade and 10 degree curve, 131 x 5 x 40 = 26,200 lbs. tractive effort. No. of cars x weight of each car x total resistance = Drawbar Pull Required   (Note: adverse weather conditions may affect track performance) Any reputable railcar mover manufacturer will arrange a demonstration and/or limited test. It is in your best interests to have them do so, to meet your requirements and for them to explain what kinds of training and after market support you can expect. © copyright 2003, railcarmover.com all rights reserved.