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).
Report comparing the orthodox and Rover type bonnets for B.III & B.50 car models.
Identifier | ExFiles\Box 112\3\ scan0051 | |
Date | 21th September 1938 | |
805 also 1026+ 405. To Ry. from Rm{William Robotham - Chief Engineer}/Std. c. Da.{Bernard Day - Chassis Design} c. HPS.{Horace Percy Smith - Experimental Factory Mgr} c. Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork} Rm{William Robotham - Chief Engineer}/Std.1/MH.{M. Huckerby}21.9.38. REPORT ON BONNETS - B.III & B.50. In connection with the various discussions re bonnets for B.III and B.50, and regarding HPS.{Horace Percy Smith - Experimental Factory Mgr}2/VS.{J. Vickers}30.6.38, we wish to make it clear that we consider that the 'Rover' type of bonnet (i.e. side plates separate from top plates with the latter opening independently) should be used on future B.III and B.50 cars. The reasons for using the Rover type of bonnet (as opposed to the orthodox type which we use at present) are based on our experience with a steel bonnet of each type (the Rover and orthodox bonnets being fitted to 1.B.50 and S.B.V. respectively) and are as follows:- (1) With the present position of the spare wheel carrier on B.III and B.50 it is impossible to open and close the bonnet in service without sooner or later damaging the paint on the off side bonnet plate - this is due to the closeness of the spare wheel carrier to the bonnet. This trouble is also present to a smaller extent on Wraith, although the clearance is greater than on B.III and B.50. (2) For economy reasons it is desirable to make the bonnet in .040 steel instead of .092 aluminium - with the orthodox bonnet in steel (.040 - 19 S.W.G.) there is so much flexibility on the top plates that when opening and closing the bonnet the lower corners of the side plates persistently foul the scuttle and lamp supports, with resultant damage to both - this can readily be demonstrated on S.B.V. car. (3) With an orthodox bonnet and steel side plates it is extremely difficult to keep the side plates reasonably flat or make them follow the contour of the scuttle owing to necessary overhang of thin gauge metal from the rear fastener to the end of the bonnet - this trouble can easily be overcome on the Rover type of bonnet. | ||