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Comparison of horsepower required and power savings for streamlined vs. conventional highway and rail vehicles.


Identifier  ExFiles\Box 161\1\  scan0018
Date  31th May 1936 guessed
  
3.

H.P. REQUIRED FOR OVERCOMING AIR RESISTANCE

TABLE 1 (Fig. 4)
| TYPE OF EQUIPMENT | | | A | K | Miles per Hour |
|---|---|---|---|---|---|---|---|---|---|
| | | | | | 60 | 50 | 40 | 30 | 20 |
| Highway Bus | 1 | StreamlineExperimental Streamline Bentley B.23.A.E | 64 | .0006 | 22 | 12.8 | 6.5 | 2.8 | 0.8 |
| | 2 | Conventional | 72 | .0015 | 63 | 36 | 18 | 7.8 | 2.3 |
| Highway Truck | 3 | StreamlineExperimental Streamline Bentley B.23.A.E | 86 | .001 | 50 | 29 | 15 | 6.3 | 1.8 |
| | 4 | Conventional | 92 | .0016 | 85 | 52 | 25 | 10.6 | 3.1 |

H.P.A = KAV^3 / 375
K = Air Resistance Coefficient
A = Sq. Ft. Frontal Area
V = Miles per Hour

Fig. 4.

The following table, Fig. 5, shows the cost of overcoming air resistance for a period of 1000 hours in four types of streamlineExperimental Streamline Bentley B.23.A.Ed and conventional railroad equipment, using a power cost figure of 1 cent per horsepower hour.

POWER SAVINGS BY STREAMLINING

RAIL EQUIPMENT
Per 1,000 Hours @ $0.01 Per H. {Arthur M. Hanbury - Head Complaints} P. H. {Arthur M. Hanbury - Head Complaints}

TABLE 2 (Fig. 5)
| TYPE OF EQUIPMENT | | | Average V | A | K or KT | H.P.H. | Dollars per 1000 Hrs | Saving per 1000 Hrs. |
|---|---|---|---|---|---|---|---|---|
| Rail Car | 1 | StreamlineExperimental Streamline Bentley B.23.A.E | 52 | 96.2 | .00059 | 29074 | 290.74 | 544.50 |
| | 2 | Conventional | 52 | 125 | .00134 | 83524 | 835.24 | |
| Three Car Train | 3 | StreamlineExperimental Streamline Bentley B.23.A.E | 52 | 108 | .00087 | 43225 | 432.25 | 2110.71 |
| | 4 | Conventional | 52 | 125 | .00408 | 254296 | 2542.96 | |
| Six Car Train | 5 | StreamlineExperimental Streamline Bentley B.23.A.E | 52 | 108 | .0019 | 102277 | 1022.77 | 2138.64 |
| | 6 | Conventional | 52 | 125 | .0051 | 316141 | 3161.41 | |
| Freight Container Car | 7 | StreamlineExperimental Streamline Bentley B.23.A.E | 45 | 103.5 | .0009 | 30058 | 300.58 | 175.56 |
| | 8 | Conventional | 45 | 125 | .0017 | 47614 | 476.14 | |

Fig. 5

Comparisons in the above tables are based on approximately existing operating speeds for highway service whereas the speeds shown in the rail service
  
  
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).


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