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).
Blueprint graph showing the efficiency of a Marles Weller steering system for a Phantom II before and after a bumper test.
| Identifier | ExFiles\Box 28\2\ Scan122 | |
| Date | 31th January 1933 | |
| MARLES WELLER STEERING EFFICIENCY PHANTOM II TESTED NEW AND ALSO AFTER 43 HOURS ON BUMPER TEST. TESTED FOR EFFICIENCY AS WHEN STEERING AND AS WHEN SELF CENTREING (I.E. REVERSALS) STEERING: - 13/32 PITCH. BOX RATIO 16.55:1 IN CENTRE POSITION OF STEERING. TESTED ON BUMPER RIG WITH 10.5" PENDULUM LEVER AND SOLID SIDE STEERING TUBE ENDS. BEFORE BUMPING TEST AFTER NORMAL STEERING SELF CENTREING EFFICIENCY (%) LOAD AT PENDULUM LEVER (INS. LBS.) | ||