From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparison of horsepower required to overcome air resistance for streamlined versus conventional trains at various speeds.
| Identifier | ExFiles\Box 161\1\ scan0019 | |
| Date | 31th May 1936 guessed | |
| 4. are stopped up to correspond with existing practice for streamlined trains. It is simpler to make the railroad comparisons at the same speeds for conventional and streamlined equipment than to go into the detail involved in showing the air resistance costs on the increased amount of conventional railroad equipment required to do the same work in the same time. The difference in the final figures between the two methods is negligible. The forms of streamlined rail car and freight container car are shown in Fig. 6 and 7. The other forms reported are all too well known to require illustration. In addition to the tests made by the writer at New York University, those made and reported by the following constitute the principal data used in determining all air resistance coefficients: Professor Alexander Klemin, New York University. Instituto Aerotechnique, St.{Capt. P. R. Strong} Cyr, France, by Maurain. The Westinghouse Company, by Tietjens and Ripley. Bureau of Standards, Washington, D.C. by R.H. Heald. Paul Jaray, Zeppelin Works, Friedrichschafen, Germany. Massachusetts Institute of Technology, by E.{Mr Elliott - Chief Engineer} J.{Mr Johnson W.M.} W. Ragsdale. The horsepower required to overcome air resistance in the four forms of railroad equipment is shown in the following table. H.P. REQUIRED FOR OVERCOMING AIR RESISTANCE TYPE OF EQUIPMENT | A | K or KT | Miles per Hour ---|---|---|--- | | | 100 | 80 | 70 | 60 | 50 | 40 | 30 | 20 Passenger Rail Car | 1 | Streamline | 96.2 | .00059 | 152 | 78 | 52 | 33 | 19 | 9.7 | 4.1 | 1.2 | 2 | Conventional | 125 | .00134 | 448 | 229 | 153 | 96 | 56 | 28 | 12.1 | 2.6 Three Car Train | 3 | Streamline | 108 | .00087 | 261 | 128 | 88 | 54 | 31 | 16 | 6.8 | 2.0 | 4 | Conventional | 125 | .00408 | 1360 | 696 | 466 | 294 | 170 | 87 | 37 | 11 Six Car Train | 5 | Streamline | 108 | .0019 | 547 | 280 | 188 | 117 | 68 | 35 | 15 | 4.4 | 6 | Conventional | 125 | .0051 | 1701 | 871 | 583 | 367 | 212 | 108 | 46 | 14 Freight Container Car | 7 | Streamline | 103.5 | .0009 | | 127 | 87 | 54 | 31 | 16 | 7.6 | 2 | 8 | Conventional | 125 | .0017 | | | 195 | 123 | 71 | 36 | 15 | 4.5 A = Sq.Ft. Frontal Area V = Speed - Miles per Hour Single Cars H.P. = KAV^3 / 375 Trains H.P. = K_L + K_1 + nK_2 + K_O K or K_T = Air Resistance Coefficient K_L = Air Resistance coefficient for Locomotive K_1 = " " " " First Car K_2 = " " " " Intermediate Cars K_O = " " " " Rear Car N = Number of Intermediate Cars Fig. 8. | ||