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).
Performance comparison of Marles steering against other steering systems, focusing on ratio and efficiency.
| Identifier | ExFiles\Box 28\2\ Scan009 | |
| Date | 2nd February 1926 guessed | |
| contd :- -2- the Marles steering is apparent when shunting. Under heavy loads on large locks, it does not appear to wind up and tend to stick as is the case with some Phantom steerings. On the whole, therefore, for the majority of work which a steering is called upon to do, the R-R is preferable. STEERING RATIO. The attached graph shews the velocity ratio of the two steerings. It will be observed that while the Marles is for all practical purposes constant on both locks, the R-R leverage decreases very slightly towards the extreme of each lock. In addition the Marles is geared some 12% lower than the E.A.C. STEERING EFFICIENCY. We have measured the raltive mechanical efficiency of the two steerings. The results shewthat the Marles steering is definitely less efficient than the best of our steerings to the extent of some 20%. EFFICIENCY OF MARLES STEERING. The following figures indicate the relative efficiency of the Marles steering - Load applied to steering wheel 18" radius. Effort required to raise 317 lbs. at pendulum lever radius or torque of 3000 ins.lbs. | Average EAC. Steering. | Good EAC. Steering. | Marles Steering. 12% lower gear. | |------------------------|---------------------|------------------------------------| | 22 lbs. | 18 lbs. | 22.5 lbs. | Readings mean of lubricated and un-lubricated. In no case do the results vary by more than 1 lb. between the two conditions. contd :- | ||