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).
Particulars of front springs suitable for the Wraith II type levers on a Continental Phantom III (39-EX).
| Identifier | ExFiles\Box 92\6\ scan0066 | |
| Date | 16th December 1936 | |
| To BY.{R.W. Bailey - Chief Engineer} Copy to Ea. Rm.{William Robotham - Chief Engineer} EHC. HFS. Rm{William Robotham - Chief Engineer}/Les.{Ivan A. Leslie} 3006 LES - What is the position of you Continental lightened suspension. Rm{William Robotham - Chief Engineer} Continental Phantom III - 39-EX. We have been asked to instruct front springs suitable for the Wraith II type levers having a front wheel load of 1150 lbs. and 5" initial deflection. Below we give particulars of these springs:- | | Inner spring. | Outer spring. | | :--- | :--- | :--- | | Wire Diameter. | 0.393" | 0.782" | | Mean dia. of coils. | 2.618" | 3.993" | | No. of effective coils. | 10 1/2 | 5 1/2 | | Normal Load. | 633 lbs. | 2587 lbs. | | Normal Deflection. | 3.400" | 1.607" | | Free Length. | 9.475" | 8.057" | | Maximum Load. | 826 lbs. | 4264 lbs. | | Maximum Stress - uncorrected. | 90,400 lbs/in² | 90,400 lbs/in² | | Maximum Stress - corrected. | 112,000 lbs/in² | 117,000 lbs/in² | | Maximum Deflection. | 4.440" | 2.647" | | Rate/inch. | 186 lbs. | 1612 lbs. | | Rate/inch of combination. | 1798 lbs. | | | Rate/inch at wheel. | 229.5 lbs. | | EV.{Ivan Evernden - coachwork} By the wording in Rm{William Robotham - Chief Engineer}/Les.1/AP.11.12.36 ("a normal load of 1150 lbs"), we take it that you mean a normal sprung weight at the wheel of this amount. | ||