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).
Visit to Ferodo Works to test the bursting strength of new chevron wound facings.
| Identifier | ExFiles\Box 129\1\ scan0154 | |
| Date | 2nd June 1937 guessed | |
| Herewith a report of a visit to Ferodo works by M.R.S as requested wednesday June 3rd Noted HS{Lord Ernest Hives - Chair} File Took Vauxhall 25 HP car leaving 10-30. Saw Mr Jougley, He showed me the new chevron wound facings which they had just completed, sizes 13.5" - 11" - 10". Two 13.5 facings were spun to test for bursting strength. One commenced to fail at 5400 RPM and the other at 5000, in both cases it was pieces of the outer edge only which flew off, -ie- radially outside the outer row of holes. In both cases the plates were drilled with .375 holes, near the edge, to EX. 27309. It is considered that if these holes were arranged on a smaller diameter pitch circle, the bursting speed would be improved, and in addition to this, the two facings tested, were the first two made, and the outer edges were not pressed to the full radius of the mould, thus leaving them weaker than production facings would be. We then drilled one of the 13.5" Thermoid discs recently received from America, this failed at 6193 RPM, at which speed the stress would be 53 % higher than at 5000. | ||