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).
Bump test of a 20 HP 'India' chassis, detailing frame specifications and breakages.
| Identifier | WestWitteringFiles\M\2April1925-June1925\ Scan88 | |
| Date | 25th September 1924 | |
| B.R. 493a (50m) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}/LS/LG22.b.25. BUMP TEST OF 20 HP. 'INDIA' CHASSIS. Bumping rear axle. Drum r.p.m. 105. 2" lift cams, one on each drum and set at 180° to each other. Load on front of chassis = 600 lbs. approx. " " rear " " = 1000 " " . FRAME. Rear cross member with increased overhanging length outside frame to suit wider track of 56". Front anchorage brackets rear springs to also suit 56" track. Anchorage of front springs as standard. FRONT AXLE. Standard for 4-wheel brake chassis. SPRINGS (EQUAL) Front - Firths 650 lbs. (F.61906) Rear - Firths 900 lbs. (F.53172) BREAKAGES, EXCLUDING ROAD SPRINGS. After running 20 hrs. 5 mins. the dumb iron which screws rear cross member to off-side frame member sheared across where end of frame buts up to shoulder on the dumb iron. This fracture was absolutely flush with end of frame. Crack started in rear cross member after 98 hrs. This was just inside frame and against near side dumb iron. contd | ||