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).
Chassis springing instructions worksheet for calculating wheel loads and spring ratings.
| Identifier | ExFiles\Box 71\1\ scan0172 | |
| Date | 16th December 1924 | |
| RR 71 (20H) (DB{Donald Bastow - Suspensions} 491 16-12-24) MP 307678 ROLLS-ROYCE LTD. SERIES W. CHASSIS SPRINGING INSTRUCTIONS. CHASSIS BODY WEIGHTS | Wt. | Front | Rear | |-------|-------|------| | 5 cwt.| 84 | 196 | | 6 ,, | 101 | 235 | | 7 ,, | 118 | 274 | | 8 ,, | 134 | 314 | | 9 ,, | 151 | 353 | | 10 ,, | 168 | 392 | | 11 ,, | 185 | 431 | | 12 ,, | 202 | 470 | | 13 ,, | 218 | 510 | | 14 ,, | 235 | 549 | PASSENGER WEIGHTS | No. | Front | Rear | |-----|-------|------| | 2 | 46 | 108 | | 3 | 69 | 162 | | 4 | 92 | 216 | | 5 | 116 | 270 | | 6 | 139 | 323 | | 7 | 162 | 377 | NOTE. — In allowing for Passengers max. weights only are used. SPARE WHEELS. — For each Spare Wheel on STEP add 50 lbs. front and 25 lbs rear to that side. REAR, add 37½ lbs. to each rear wheel. BY THIS CHART, SPRINGS ARE FITTED SUITABLE FOR 75% OF MAX. LOAD IN ACCORDANCE WITH R’s INST. SPRINGS. FRONT. N.S. 1050 O.S. 1100 REAR. N.S. 1900+WIDE O.S. 2000 MAIN TABLE: | | FRONT | | REAR | | | | NEAR | OFF | NEAR | OFF | | 1. FIXED CHASSIS WEIGHTS, incl. 300 lbs. Spares, 1 cwt. Luggage on Grid | 850 | 900 | 725 | 775 | | 2. VARIABLE LOADS: | | | | | | (a) Body.....cwt..... 8½ | 142 | 142 | 334 | 334 | | (b) Passengers—No...... ... | 69 | 69 | 162 | 162 | | 3. ADDITIONAL LOADS: | | | | | | 2 .....Spare Wheel(s) on Step | 50 | 50 | 25 | 25 | | .....Spare Wheel(s) on Rear | | | | | | .....lbs. LUGGAGE IN BODY | — | — | 112 | 112 | | (subtotal) | 1111 | 1161 | | | | LESS 50LB EACH FRONT | 50 | 50 | | | | Effective Wheel Loads ... | 1061 | 1111 | | | | ADD 50% TO REAR...LESS 100LBS | | | 579 | 604 | | SPRING RATING ... | | | 1927 | 2012 | REMARKS: SIGNED DATE | ||