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).
Modifications to the Wraith III Spring Drive units, specifically the drilling of holes in the friction disc for lubrication.
| Identifier | ExFiles\Box 6\6\ 06-page415 | |
| Date | 7th January 1938 | |
| To By, from Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} c. By/CS. c. Ds/Ros. c. HPS{Horace Percy Smith - Experimental Factory Mgr}/RH.{R. Hollingworth} 600 WRAITH III UNITS (SPRING DRIVE.) Further to our memo Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}2/WH.8.12.37 we have now found that by drilling 3 holes in the root of the friction disc in accordance with the attached drawing Rm.{William Robotham - Chief Engineer}483, the lubrication of the front "cotton duck" friction washer is satisfactory and stays so. This is confirmed both on the test bench and the road in conjunction with the filing holes in the rim of the damper wheel being blanked, the latter already being included on the LOP in accordance with our previous memo. If possible will you include the drilling of the holes to Rm.{William Robotham - Chief Engineer}483 on the 6 Wraith units which HRC. is building. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||