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 replacement of insulation materials on a ballast resistance unit and potential heat-related failure.
| Identifier | ExFiles\Box 39\3\ Scan154 | |
| Date | 9th September 1921 | |
| X3513 R.R. 235a (100 T) (S.H. 798. 10-12-30) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2948 EFC. from By.{R.W. Bailey - Chief Engineer} BY4-P6.9.21. X. 3531̂ - BALLAST RESISTANCE X. 3716. Referring to EFC2/T31821, I would like to remind you that when replacing the mica and micanite insulations on the above unit by Bakelite Dilecto, it will be necessary to leave the Ignition Switch on and the engine in such a position that the current will be passing through the ballast resistance all night, as this is a state of affairs which may easily occur by accident under service conditions. Bakelite Dilecto, if I remember aright, is not essentially a heat resisting insulation and may fail under the above conditions. BY.{R.W. Bailey - Chief Engineer} | ||