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).
Stiffness tests on a chassis frame without a cruciform member.
| Identifier | ExFiles\Box 113\5\ scan0091 | |
| Date | 12th May 1939 | |
| 1010 To By.{R.W. Bailey - Chief Engineer} from RM{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} c. Da.{Bernard Day - Chassis Design} c. Da{Bernard Day - Chassis Design}/DB.{Donald Bastow - Suspensions} c. Da{Bernard Day - Chassis Design}/JD.{J. Draper - Frames} RM{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}9/MH.{M. Huckerby}12.5.39. FRAME WITHOUT CRUCIFORM MEMBER. We have used a scrap frame as a rig to mock up what is, in effect, an approximation to the ideal frame consisting of side members rigid against vertical bending and braced by members rigid in torsion at front, centre and rear. The photograph attached shows the frame in its final form with the rear portion of the cruciform removed, leaving room for footwells. Measurements taken show that the final frame is as stiff as the B.V. frame and no heavier, and this is achieved by making extensive use of welding. The following table gives the stiffness of the frame in various conditions:- | | Front to Rear (axles). | Dash to Rear axle. | Dash to front axle. | Weight. lbs. | |---|---|---|---|---| | 1. | As received (old bump chassis). | 1115 | 1950 | 2605 | 280 | | 2. | Box member in centre, rear portion of cruciform removed. | 925 | 1450 | 2555 | 268 | | 3. | Box member in centre and petrol tank made solid with frame. | 1135 | 1900 | 2810 | 279 | | 4. | Box members in centre and at rear (see photo) and tank cut out. | 1010 | 1600 | 2740 | 274 | | 5. | Box members in centre and at rear, and side members braced (see photo). | 1225 | 2130 | 2880 | 282 | | ||