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).
Design and manufacturing changes for car bonnets, including materials, fittings, and construction methods.
| Identifier | ExFiles\Box 102\6\ scan0105 | |
| Date | 19th February 1931 | |
| HS.{Lord Ernest Hives - Chair} } FROM DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} SG.{Arthur F. Sidgreaves - MD} } C. to BY.{R.W. Bailey - Chief Engineer} WOR.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} re. BONNETS. X.7260. We are assuming that the following are accepted facts: (1) That nothing be done for 20/25 bonnet. (2) That it is not desired to change the appearance of the bonnet of either P. 2. or Japan 3. by - (a) Abolition of side or top hinges, (b) a bonnet to open as on the Humber, (c) a bonnet to open as on the Daimler. We assume therefore that 2 things are needed - (3) Abolition of all or nearly all the visible rivets. (4) The fitting of shutters. The carrying out of (1) appears to demand a steel bonnet. The shutter design is determined by the bonnet material. We therefore suggest that Derby should as soon as possible make a bonnet for P. 2. in steel - 22 SWG (.028") with plain sides, as follows: The hinges should be formed as now and be of .036" staybright attached to the bonnet plate be electric spot welding. The stiffeners should be as follows: (5) Horizontal ones in steel as now. (6) Transverse ones as for N.2. series in steel. (7) The bottom edge horizontal stiffener now of strip spring steel should be made thus - [handwritten drawing of a J-shaped profile] The experience gained in this experiment should answer for us (8) Can we have a steel bonnet .028" thick and so have little increase in weight. (9) Is such a bonnet more money. (10) Can such a thin bonnet have flat side plates. (11) Can we make it rustproof. (12) Can we electrically weld together the bonnet plate and double thickness of hinge material. (13) Can we remove the marks of the welding and prevent this shewing in the paint. We should be glad if SG.{Arthur F. Sidgreaves - MD} would confirm or correct our statements re. the appearance (items 1. 2. 3. and 4.) and if HS.{Lord Ernest Hives - Chair} would give us his views re items (2) - b. and c. DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} | ||