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).
The forces in pounds required to operate the Wraith reverse gear.
| Identifier | ExFiles\Box 99\4\ scan0174 | |
| Date | 12th January 1939 | |
| #28 To Da{Bernard Day - Chassis Design}/Hdy.{William Hardy} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}9/MH.{M. Huckerby}12.1.39. RE HELICAL REVERSE ON B.V. The figures you asked us to obtain to find out with what force the Wraith reverse worked into mesh are as follows:- Full Throttle. To pull lever out of mesh 24 lbs. To prevent lever working in 8 lbs. Over-run. To pull lever out of mesh 8 lbs. To prevent lever working in 2 lbs. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||