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).
Data table showing the power required to drive a Goshawk engine radiator fan under various conditions.
| Identifier | ExFiles\Box 75\3\ scan0222 | |
| Date | 6th January 1925 | |
| POWER REQUIRED TO DRIVE RADIATOR FAN IN VARIOUS CIRCUMSTANCES. No. 24 Goshawk Circumstances :- Date | Motor field current (amps.) | Motor speed. | Fan speed R.P.M. | Ratio. | Volts across motor brushes. | Motor armature current. | Volts across motor brushes light. | Motor armature current light. | Thrust (lbs). 6-1-25 | 1.493 | 438 | 1000 | 2.28 | 63.53 | 4.79 | 61.38 | 1.90 | 1.188 6-1-25 | 1.493 | 617 | 1400 | 2.27 | 88.08 | 5.69 | 86.75 | 1.99 | 2.375 6-1-25 | 1.492 | 792 | 1800 | 2.27 | 113.66 | 6.80 | 110.90 | 2.06 | 3.500 6-1-25 | 1.492 | 971 | 2200 | 2.27 | 137.29 | 7.95 | 135.24 | 2.04 | 5.250 6-1-25 | 1.482 | 1150 | 2600 | 2.26 | 162.86 | 9.60 | 159.59 | 2.09 | 7.500 | ||