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).
Status report outlining seven different design options and their progress for the Spectre steering system.
| Identifier | ExFiles\Box 95\1\ scan0185 | |
| Date | 12th July 1935 | |
| Y35D 12.7.35. SpectreCodename for Phantom III Steering. (1) L.H. cam with zero crowning 6° 35' helix. Received from the Adamant Co. and about to be tried in a steering box. (2) L.H. cam with 0.002 crowning 6° 35' helix. Delivery expected from Adamants at any moment. (3) Cam with Timken bearings and crowning as determined from results of (1) & (2) 6° 35' helix, N.Sch.455 4. At present being detailed by BY's Dept. (4) Timken bearings on roller combined with best of (1), (2) & (3). N.Sch.4489. Not yet detailed. (5) Cam with reduced helix 5° 48', 8" pendulum, crowning as (3), ball bearing roller and present cam bearings, N.Sch.4549. Detail completed by BY.{R.W. Bailey - Chief Engineer} and sent to Adamants. (6) Same as (5), but with Timken bearings on cam. Detail not yet completed. (7) Dependent on results of (4). Timken bearings on roller for (6). No scheme. | ||