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 data for a Silver Ghost type nut and worm with 1.125 lead.
| Identifier | ExFiles\Box 38\1\ Scan175 | |
| Date | 13th March 1926 guessed | |
| SILVER GHOST TYPE NUT & WORM - 1.125 LEAD. The following table gives the loads and corresponding efforts required to give efficiencies the same as laid down for the new .720 lead nut and worm. Actually the efficiency with the increased lead should be higher but the high efficiency is not so essential with the more reversible steering. [DIAGRAM LABELS] P 20" RAD. W [TABLE DATA] Load W. lbs. | Effort P. | Efficiency % 1200 | 14.05 - 15.2 | 76.5 - 70.6 900 | 10.15 - 10.95 | 79.4 - 73.7 600 | 6.25 - 7.02 | 86.0 - 76.4 300 | 3.125 - 3.52 | 86.0 - 76.4 Hs{Lord Ernest Hives - Chair}/ACL. | ||