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).
Letter from supplier Ferodo regarding a mix-up in the composition of servo disc fragments, confirming VG.91 was sent instead of VG.90.
| Identifier | ExFiles\Box 141\2\ scan0290 | |
| Date | 3rd June 1939 | |
| 1180 All Communications to be addressed to the Company. FERODO LIMITED BRAKE & CLUTCH LININGS CHAPEL-EN-LE-FRITH, STOCKPORT, ENGLAND. TELEPHONE: 250 CHAPEL-EN-LE-FRITH (8 LINES) TELEGRAMS: FRICTION, PHONE, CHAPEL-EN-LE-FRITH. CODES: WESTERN UNION FIVE LETTER EDITION, BENTLEYS COMPLETE & 2ND PHRASE, MARCONI INTERNATIONAL, LIEBER'S CODE, LIEBERS LATEST CODE, A.B.C. 5TH & 6TH EDITIONS. Depots:- LONDON 222, TOTTENHAM COURT RD W. 1. ABERDEEN 26, GUILD STREET. BELFAST 8, 10 & 12, MONTGOMERY ST BIRMINGHAM 108, CORPORATION ST BRISTOL 118, VICTORIA STREET. CARDIFF 60, CHARLES ST DUBLIN 120, UPPER ABBEY ST GLASGOW 70, WATERLOO ST LEEDS 25, HUNSLET RD LIVERPOOL 1-3, BERRY STREET. MANCHESTER 16, JACKSON'S ROW, DEANSGATE. NEWCASTLE-ON-TYNE 24, ELDON PLACE, BARRAS BRIDGE. 3rd June, 1939 YOUR REF. Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems}6/JH OUR REF. JNL/KM Messrs. Rolls Royce Ltd., Derby. For the attention of Mr. Dixon. Dear Sirs, We thank you for your letter of the 1st of June received this morning, enclosing fragments of servo disc reputed to be Ferodo VG.90, and which you suspect is VG.91. Our chemical examination confirms yours in that we, too, qualitatively determine the presence of tar acid derivatives. This means that your suspicions are correct and the material is indeed VG.91. We regret exceedingly this should have happened and are endeavouring to trace the reason for the unauthorized change, so that the same state shall not occur again. In the meantime, manufacture of VG.90 replacement discs has been going on and these replacement discs are now ready and will be posted to you under separate cover today. Replacement brake segments in VG.90, as demanded in your recent letter on this same subject, will follow in two or three days. You may rest assured that VG.90 is a stable and constant product and that in future supplies will in every way conform to the first standard. We should like to put on record to show that the mistake was not one just of carelessness:- a) That in our general output VG.91 has entirely superseded VG.90. b) That this is because VG.91 is very much easier to manufacture than VG.90 in that it is far stronger, particularly in thin sections and, further, that it does not require expensive moulds as does VG.90. c) That the change in composition is minute and results, on the showing of our tests, in an increase in coefficient of friction of .05 throughout the temperature range. - continued - | ||