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 showing the mechanical efficiency of a Marles Type L.T steering gear after a 7-hour test run.
| Identifier | ExFiles\Box 28\3\ Scan124 | |
| Date | 13th November 1934 | |
| HS{Lord Ernest Hives - Chair} 1605 MECHANICAL EFFICIENCY OF MARLES TYPE L.T STEERING GEAR FIGURES TAKEN AFTER GEAR HAD BEEN RUN FOR 7 HOURS ON RIG MID POSITION RATIO = 7:1 PEND LEVER = 10.15 3 1/4 TURN CAM. HELIX ANGLE 9.97° STATIC EFFICIENCY IN MID POSITION LOAD AT END OF PENDULUM LEVER. LBS. MOBILOIL D MARLES OIL Z. / 13/11/34 | ||