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).
Graph comparing the thrust and slip performance of various engine fan designs against engine speed.
| Identifier | ExFiles\Box 75\3\ scan0157 | |
| Date | 18th December 1924 | |
| PERCENTAGE SLIP THRUST IN LBS. WEIGHT THRUST SLIP 40/50 ENGINE SPEED (R.P.M.) CHASSIS M.P.H. 15/52 AXLE. 33.5" DIA TYRE. F.{Mr Friese} Fan tip dia. 1. Standard 40/50 six-bladed fan. 22" 2. Standard 40/50 six-bladed fan with three blades removed. 22" 3. E.A.C. four-bladed fan. 23" 4. Hispano fan. 17 1/4" 5. High speed 40/50 six-bladed fan. 22" 7. Goshawk fan. 18" 8. Fan made to recommendations of Prof. Watts. 22" 9. 2nd Fan made to recommendations of Prof. Watts, but with swept back blades. 22" 10. Exnl. EAC. fan- first modification. 23" 11. Ditto, second modification. 23" 12. Ditto, third modification. 23" H.E.W 18-12-24 E&C | ||