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).
Cost and manufacturing analysis for Bentley bonnet top plates and the introduction of a Widney Hinge.
| Identifier | ExFiles\Box 7\6\ X 605 Bonnet-page18 | |
| Date | 7th January 1938 | |
| -2- RBL/BB.1/MR.7.1.38.Cont'd.{John DeLooze - Company Secretary} Bentley cars after service would no doubt be also more pronounced in the thinner material, and in addition slight bonnet distortion adjacent to the hinge may occur due to the deflection caused if the bonnet is opened hard against the internal hinge stop. In order to accomodate the Widney Hinge it is necessary to provide a double bend in the top plate which cannot be done with existing equipment, and it would therefore be necessary to install a special press costing approximately £300. 0. 0d. before this hinge could be standardised. The bend in question has been produced by the Widney Hinge makers on the experimental bonnets, but this procedure would not be acceptable on a production basis. Quotations for comparative purposes are given below for Bentley bonnet Top Plates supplied complete in the assembled condition by the makers of the Widney Hinge, but it is very unlikely that outside suppliers would achieve the desired standard of finish, and it would therefore be necessary to manufacture these parts in our own factory. Cost of present standard Bentley Bonnet Top Plates, assembled complete with hinge (13.SWG) .092 Alum ........................... £2. 15. 4d. Cost of above if produced in 16.SWG. .064 Alum ........................... £2. 8. 0d. Cost of 16.SWG. alum top plates assembled at R.R. complete with Widney Hinge....... £2. 7. 0d. Cost of 16.SWG. alum top plates bought out complete including hinge from Widney Hinge manufacturers .................. £1. 18. 9d. The actual cost of the Widney Hinge is 5/- as compared with 10/10d. for the present standard part, but the assembly cost is slightly higher which practically negatives this saving. The Bonnet Top Plates for the first six Wraith Chassis are being produced in the 16.SWG. aluminium with Standard Hinges, which will provide experience of the manufacturing difficulties likely to be encountered should this material be proposed for standardisation. RBL/for Bannister. JEC | ||