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 report on Firth front leaf springs, detailing fracture analysis.
| Identifier | ExFiles\Box 52\2\ Scan110 | |
| Date | 29th October 1924 guessed | |
| BUMP TEST. R. {Sir Henry Royce} 43a Front Springs TEST OF LATEST PATTERN FIRTH SPRINGS, F71980, 1, 1100LBS & 1150 LBS. CONDITIONS: 2" CAMS SET AT 180°. DRUMS MAKE 105 R.P.M. TYRES AT 65 LBS/SQ. IN. LOAD ON FRONT OF CHASSIS = 1000 LBS. TABLE DATA: COLUMN HEADERS: SPRING DETAILS, FRACTURE, POSITION OF LEAF, POSITION OF FRACTURE FROM CENTRE BOLT, APPROXIMATE RUNNING TIME, THICKNESS OF LEAF, BRINELL AT FRACTURE ROW 1: SPRING DETAILS: N°012. NEAR SIDE. F71980. 1100 LBS. FLEXION: COMPRESSION = 1.5"; REBOUND = 2.8" FRACTURE A: POSITION OF LEAF: BOTTOM, POSITION OF FRACTURE FROM CENTRE BOLT: 2" TO REAR., APPROXIMATE RUNNING TIME: 16 - 23, THICKNESS OF LEAF: .200", BRINELL AT FRACTURE: 363 FRACTURE B: POSITION OF LEAF: NEXT TO BOTTOM, POSITION OF FRACTURE FROM CENTRE BOLT: 2" TO REAR., APPROXIMATE RUNNING TIME: 18 - 23, THICKNESS OF LEAF: .204", BRINELL AT FRACTURE: 363 FRACTURE C: POSITION OF LEAF: TOP, POSITION OF FRACTURE FROM CENTRE BOLT: 2.5" TO REAR., APPROXIMATE RUNNING TIME: 22 - 33, THICKNESS OF LEAF: .298", BRINELL AT FRACTURE: 401 ROW 2: SPRING DETAILS: N°013. OFF SIDE. F71981. 1150 LBS. FLEXION: COMPRESSION = 1.8"; REBOUND: 2.5" FRACTURE D: POSITION OF LEAF: TOP, POSITION OF FRACTURE FROM CENTRE BOLT: 2" TO REAR., APPROXIMATE RUNNING TIME: 13 - 46, THICKNESS OF LEAF: .303", BRINELL AT FRACTURE: 375 ROW 3: SPRING DETAILS: N°014. OFF SIDE. F71981. 1150 LBS. FLEXION: COMPRESSION = 1.7"; REBOUND = 2.5" FRACTURE E: POSITION OF LEAF: 5TH (FROM TOP), POSITION OF FRACTURE FROM CENTRE BOLT: 1.5" TO REAR., APPROXIMATE RUNNING TIME: 46 - 10, THICKNESS OF LEAF: .236", BRINELL AT FRACTURE: 415 FRACTURE F: POSITION OF LEAF: 6TH - " -, POSITION OF FRACTURE FROM CENTRE BOLT: 1.5" TO REAR., APPROXIMATE RUNNING TIME: 46 - 10, THICKNESS OF LEAF: .228", BRINELL AT FRACTURE: 401 FRACTURE G: POSITION OF LEAF: 7TH - " -, POSITION OF FRACTURE FROM CENTRE BOLT: 1.25" TO REAR., APPROXIMATE RUNNING TIME: 46 - 10, THICKNESS OF LEAF: .217", BRINELL AT FRACTURE: 388 FRACTURE H: POSITION OF LEAF: 8TH - " -, POSITION OF FRACTURE FROM CENTRE BOLT: 1" TO REAR., APPROXIMATE RUNNING TIME: 46 - 10, THICKNESS OF LEAF: .213", BRINELL AT FRACTURE: 388 FRACTURE J: POSITION OF LEAF: BOTTOM, POSITION OF FRACTURE FROM CENTRE BOLT: 1.5" TO REAR., APPROXIMATE RUNNING TIME: 46 - 10, THICKNESS OF LEAF: .210", BRINELL AT FRACTURE: 401 FRACTURE M: POSITION OF LEAF: TOP, POSITION OF FRACTURE FROM CENTRE BOLT: 16.5" TO FRONT., APPROXIMATE RUNNING TIME: 35 - 2, THICKNESS OF LEAF: .284", BRINELL AT FRACTURE: 388 | ||