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).
Specification tables for 9-leaf and 10-leaf springs, detailing space between leaves, thickness, and load data.
| Identifier | WestWitteringFiles\L\July1924-September1924\ Scan69 | |
| Date | 9th September 1924 guessed | |
| SPRING DRAW ON 9-LEAF SPRING No. F.2441. Table 1: Space between leaves. No. 1 and 2 .725" 2 " 3 .300" 3 " 4 .250" 4 " 5 .275" 5 " 6 .150" 6 " 7 .150" 7 " 8 Nil 8 " 9 Nil Thickness of spring with centre bolts complete - 3.250" When free - 5.100" Total nip - 1.850" Normal load 2000 lbs. SPRING No. F.2441 Table 2: Space between leaves. No. 1 and 2 1.400 2 " 3 .250 3 " 4 Nil 4 " 5 Nil 5 " 6 Nil 6 " 7 Nil 7 " 8 Nil 8 " 9 Nil 9 " 10 Nil Thickness of spring with centre bolt complete - 3.725 When free - 5.375 Total nip - 1.650 Normal load 2100 lbs. Rear springs off 46-PK. | ||