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).
The bump test of an EAC.11 chassis.
| Identifier | ExFiles\Box 119\2\ scan0231 | |
| Date | 17th December 1924 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. Expl. No. REF: HS{Lord Ernest Hives - Chair}/CP/LG17.12.24. EXPERIMENTAL REPORT. BUMP TEST OF EAC.11. CHASSIS. SPECIFICATION OF CHASSIS. FRAME. EAC.11. short wheelbase. Fitted with additional cross member at front of chassis. Fitted with top half of crankcase weighted with 800 lbs. Rear of frame fitted with a ballast box weighing approx. 1000 lbs. FRONT AXLE. EAC.11. Radius rods attached to bottom of axle, and anchored a to pillar attached to frame so that they assume a position almost parallel to rear half of springs. FRONT SPRINGS. 45" symmetrical. Shackled at front, anchored at rear. RADIATOR. EAC.11. Fitted with integral vertical shutters. Filled with water. STEERING GEAR. EAC.11. straight side steering tube. CONDITIONS OF TEST. Bumping front axle. Drums make 105 r.p.m. Tyres = 65 lbs.sq.in. Cams = 2" lift. Cams set at 180º (one cam per wheel). SUMMARY OF IMPORTANT FAILURES(excluding road springs) BETWEEN FIRST 90 AND 138 HOURS. Running time. hrs.mins. | Piece No. | Position on Chassis. | DESCRIPTION. 55 - 50 | F.2888 | Near | Flange 3rd. cross member (from front of chassis) cracked. 55 - 50 | F.2725 | Off. | Flange 3rd. cross member (from front of chassis) cracked. 137 - 42 | F.70370 | --- | Outer tube of steering column broken at flange where it is attached to steering box. REMARKS ON BEHAVIOUR OF VARIOUS PARTS OF CHASSIS. Frame. No signs of failure other than the cracks in the cross member flanges tabulated above. Radius rods. No signs of failure. Engine suspension. No signs of failure. contd :- | ||