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).
Use of hard versus soft aluminium for louvred bonnets and the necessity of a stiffening frame.
| Identifier | ExFiles\Box 119\3\ scan0138 | |
| Date | 10th July 1931 | |
| COPY. X1085. Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork} c. Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} c. Hs.{Lord Ernest Hives - Chair} By/Cgh{W Clough}18/G.10.7.31. X.385. X.1085. RE. BONNETS. -------- With reference to Da{Bernard Day - Chassis Design}/Evl/M.7.7.31. although the Works did at one time use soft aluminium for making louvred bonnets they are now using a hard material. The 40/50 HP. side panel when louvred is too flabby without the stiffening frame, although we think the 20/25 HP. would be stiff enough without the frame, but the plates are generally distorted after the louvres have been pressed in and a lot of hard work would be required to straighten them again, whereas the stiffening frame corrects this fault immediately. Another reason for the stiffening frame being fitted is that the side plates developed cracks which started at the top and bottom corners of the end louvres. We do not quite see how the shape of the louvres could be altered to avoid the splitting of the material, but the present double form of louvre is very little worse if any than the single form. BY/Cgh.{W Clough} | ||